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2022

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Articles 9121 - 9150 of 9306

Full-Text Articles in Engineering

Genetic Algorithm Based Deep Multi-Route Self-Attention For Single Image Super-Resolution, Nisawan Ngambenjavichaikul Jan 2022

Genetic Algorithm Based Deep Multi-Route Self-Attention For Single Image Super-Resolution, Nisawan Ngambenjavichaikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Image restoration, such as single image super-resolution (SISR), is a long-established low-level vision issue that intends to regenerate high-resolution (HR) images from low-resolution (LR) input counterparts. While state-of-the-art image super-resolution models are based on the well-known convolutional neural network (CNN), many self-attention-based or transformer-based experiment attempts have been conducted. They have shown promising performance on vision problems. A powerful baseline model based on the swin transformer adopts the shifted window approach. It enhances the capability by restricting the model to compute the self-attention function only on non-superimpose local windows while enabling cross-window relations. However, the architecture design is manually fixed. …

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A Linear Matrix Inequality Approach To Design State Feedback Control For Non-Polynomial Nonlinear Systems, Phing Lim Jan 2022

A Linear Matrix Inequality Approach To Design State Feedback Control For Non-Polynomial Nonlinear Systems, Phing Lim

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis aims to design a state feedback controller for non-polynomial systems with bounded control inputs. The problem formulation begins by transforming the non-polynomial systems into polynomial systems. This can be done by defining non-polynomial terms as new state variables with algebraic constraints satisfying the non-polynomial properties. This method avoids the approximation of the recast polynomial systems. Then we design the state feedback control based on the extended Lyapunov stability theorem and the quadratic performance criterion. Two state feedback control laws are proposed: Theorem 1 for static Lyapunov matrix variables and Theorem 2 for polynomial ones. For Theorem 1, the …

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Effect Of Drop-Out Layers Inside Recurrent Neural Networks In Household Load Forecast Application, Sanaullah Soomro Jan 2022

Effect Of Drop-Out Layers Inside Recurrent Neural Networks In Household Load Forecast Application, Sanaullah Soomro

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ensuring precise power load forecasting is highly important in planning the secure, steady, and cost-effective functioning of the power system. Grid planning and decision-making can be based on accurate long- and short-term power load forecasting. Recently, machine learning techniques have gained widespread adoption for both long- and short-term power load forecasting. Specifically, the Long Short-Term Memory (LSTM) is customized for time series data analysis. This research proposes an LSTM model for forecasting the power load of a single house containing electrical appliances over the next 20 days. We conducted a comparative analysis of the impact of dropout layers in load …

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Performance Analysis Of Jpeg Xr With Deep Learning-Based Image Super-Resolution, Taingliv Min Jan 2022

Performance Analysis Of Jpeg Xr With Deep Learning-Based Image Super-Resolution, Taingliv Min

Chulalongkorn University Theses and Dissertations (Chula ETD)

The demand for efficient high-level image and video codec compression has widely increased. Conventional image compression methods such as JPEG XR use a high quantization parameter (QP) to produce a highly compressed file for any given image. However, higher QP has unpleasing artifacts that lead to perceptual quality degradation. A feasible solution to tackle this limitation is to reduce the high-resolution image size by downsampling it before encoding it with JPEG XR. Then, the super-resolution algorithm is applied to the resultant low-resolution image to reconstruct the high-resolution result. In this research, we downsample the input image before JPEG XR. Then, …

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Deep Consecutive Attention Network For Video Super-Resolution, Talha Saleem Jan 2022

Deep Consecutive Attention Network For Video Super-Resolution, Talha Saleem

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the video application, slow motion is visually attractive and gets more attention in video super resolution. To generate the high-resolution (HR) slow motion video frames from the low-resolution (LR) frames, two sub-tasks are required, including video super-resolution (VSR) and video frame interpolation (VFI). However, the interpolation approach is not successful to extract low level feature attention to get the maximum advantage from the property of space-time relation. To this extent, we propose a deep consecutive attention network-based method. The multi-head attention and an attentive temporal feature module are designed to achieve better prediction of interpolation feature frame. Bi-directional deformable …

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Applications Of Deep Learning Framework And Localization To Intelligent Radio Spectrum Monitoring, Truong Thanh Le Jan 2022

Applications Of Deep Learning Framework And Localization To Intelligent Radio Spectrum Monitoring, Truong Thanh Le

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this thesis, the author proposed an intelligent radio spectrum monitoring system with implemented deep learning framework. Deep learning is a powerful method to handle hard tasks automatically. The system uses the RTL-SDR USB dongle as the sensor to collect the spectrum data. This dongle is a low-cost device that can measure the signal from 500kHz to 1700MHz. The maximum bandwidth of measurement is 2MHz. The main functions of this system are to collect the spectrum data and then detect the representation signals and extract their characteristics, such as bandwidth, center frequency, modulation type, and capacity. The modulation classification task …

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Functional Split In 5g Cloud Radio Access Network Using Particle Swarm Optimization, Wai Phyo Jan 2022

Functional Split In 5g Cloud Radio Access Network Using Particle Swarm Optimization, Wai Phyo

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Cloud Radio Access Network (C-RAN) is an innovative approach that has the potential to significantly reduce the expenses of setting up and operating wireless networks. C-RAN's placement of RAN functions, which strives to reduce bandwidth utilization and computation costs, is a critical component. In this study, our main goal is to reduce the costs associated with functionally placing the RAN while accounting for the computational expense and the front-haul bandwidth usage among various users. To achieve this, we propose to apply Particle Swarm Optimization (PSO) to achieve effective allocation of computational resources and the front-haul bandwidth, ensuring an efficient …

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Online Self-Learning System For Prediabetes Patients, Ye Moe Myint Jan 2022

Online Self-Learning System For Prediabetes Patients, Ye Moe Myint

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis implements a web-based application that combines a 3D learning center and educational game to facilitate the monitoring, management, and treatment of patients with prediabetes mellitus, by providing exercise plans and controlled diets. The application utilizes advanced web technologies, 3D modeling, and gamification principles to create an engaging learning experience. User-centered design ensures usability, and testing demonstrates positive outcomes, including increased knowledge, motivation, and engagement. This research contributes to digital health interventions by empowering prediabetes patients with informed decision-making and healthy habits. Future directions include expanding the application, refining the user interface, and evaluating long-term impact on prediabetes management.

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Green Supplier Evaluation And Selection For A Furniture Sales Company, Jiahao Li Jan 2022

Green Supplier Evaluation And Selection For A Furniture Sales Company, Jiahao Li

Chulalongkorn University Theses and Dissertations (Chula ETD)

This paper proposes a supplier evaluation method for a furniture sales company in China that focuses on the evaluation process and sustainability of business operation. Firstly, we have arranged a meeting with experts from various fields to gather information concerning evaluation problems and choices of evaluation indicators. We then go through the literature in the field of supplier evaluations to create a new green supplier evaluation indicator system comprising of 5 first-level and 19 second-level evaluation indicators. Once selected, the Fuzzy-entropy-TOPSIS approach has been adopted for the evaluation of 13 suppliers via MATLAB. We find that, among these suppliers, S1 …

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Critical Success Factors For Data Warehouse Implementation In An Industrial Associations Organization, Phatnarin Khantayana Jan 2022

Critical Success Factors For Data Warehouse Implementation In An Industrial Associations Organization, Phatnarin Khantayana

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this research is to delve into the key success factors (CSFs) associated with data warehouse (DW) implementation from the perspectives of various stakeholders within an organization. A data warehouse provides a unified and structured view of an organization's data for analysis and reporting, and successfully implementing such a system can have a significant impact on overall organizational performance. It enables better data management, facilitates improved decision-making, and enhances strategic planning. The scope of this research encompasses an in-depth examination of the core CSFs that are instrumental in achieving success during data warehouse deployments. It focuses on understanding …

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Demand Forecasting And Inventory Management For An Automotive Tire Distributor In Northeast Thailand, Vasinee Chantaraponpun Jan 2022

Demand Forecasting And Inventory Management For An Automotive Tire Distributor In Northeast Thailand, Vasinee Chantaraponpun

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this research is to improve the inventory management for an automotive tire distributor company in Northeast Thailand to mainly reduce the excessive unnecessary stock. According to the initial investigations, the main causes of overstock are unstable customer demands and a lack of an inventory control system based on theory. In order to better address the issues and scope down the research area, three suitable products and sub-dealers with different demand patterns are selected to find the best-fit forecasting model for each of them and be customized the inventory policy based on the demand patterns. The methodology is …

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Optimization Of Blast Design For Better Fragmentation & Reduction Of Ground Vibration At Khao Mai Nuan Pyrophyllite Mine, Saraburi Province, Thailand, Arif Khan Jan 2022

Optimization Of Blast Design For Better Fragmentation & Reduction Of Ground Vibration At Khao Mai Nuan Pyrophyllite Mine, Saraburi Province, Thailand, Arif Khan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Control blasting with better fragmentation is very important to decrease the environmental impacts of blasting and the cost of downstream mining operations such as loading, transportation, crushing, and milling. Proper blasting designs with optimized parameters such as burden, spacing, stemming, sub-drilling, and amount of explosive ensure the required fragmentation with ground vibration within the standards set by different monitoring agencies. This study dealt with the blasting design parameters, fragmentation, and ground vibration at the Khao Mai Nuan Pyrophyllite quarry Saraburi province, Thailand. First, grab samples were collected from the quarry's active benches and tested in a lab for strength, compositions …

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Effect Of Salinity Contrast Between Formation Water And Injected Low Salinity Water On Low Salinty Water Flooding In Dolostone Formation, Nuttapol Junput Jan 2022

Effect Of Salinity Contrast Between Formation Water And Injected Low Salinity Water On Low Salinty Water Flooding In Dolostone Formation, Nuttapol Junput

Chulalongkorn University Theses and Dissertations (Chula ETD)

Low Salinity Waterflooding (LSWF) has gained substantial prominence in current scientific method for oil recovery improvement, owing to its simplicity, cost-effectiveness, and environmental friendliness as an Enhanced Oil Recovery (EOR) technique. Various studies have highlighted the crucial role of injected brine salinity and the concentration of Potential Determining Ions (PDI) in stimulate oil recovery mechanisms. However, the majority of these studies have predominantly concentrated on sandstone reservoirs. In light of the fact that over 50% of hydrocarbon reserves are situated in carbonate reservoirs, this research focuses specifically on dolomite reservoirs to examine the applicability and feasibility of implementing LSWF in …

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Simulation Study On Co2 Enhanced Oil Recovery For Offshore Area In Thailand, Pariwat Wongsriraksa Jan 2022

Simulation Study On Co2 Enhanced Oil Recovery For Offshore Area In Thailand, Pariwat Wongsriraksa

Chulalongkorn University Theses and Dissertations (Chula ETD)

Fossil fuels are widely used all over the world. It generates carbon dioxide (CO2) which is one of the main causes for climate change and global warming. One practical technology to reduce CO2 emission is carbon capture, utilization, and storage (CCUS) which includes the use of CO2 for enhanced oil recovery (CO2EOR) and storage in the geological reservoir. In Thailand, there are some potential geological reservoirs for CO2EOR due to crude properties, depth of the reservoir and oil saturation, especially in the Gulf of Thailand. However, the high temperatures gradient in the Gulf of Thailand can lead to higher minimum …

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Physical Property Measurement Of Surfactant Coupled With Nanoparticles For Enhanced Oil Recovery, Phoo Pwint Nandar Jan 2022

Physical Property Measurement Of Surfactant Coupled With Nanoparticles For Enhanced Oil Recovery, Phoo Pwint Nandar

Chulalongkorn University Theses and Dissertations (Chula ETD)

The residual oil remained in the reservoir after the primary recovery and water flooding can either be produced by increasing the mobility of the oil or by altering the reservoir rock wetting behavior and diminishing the oil water interfacial tension. The surfactant flooding is one of the chemical enhanced oil recovery methods. At the optimal concentration, the surfactant flooding can provide the low interfacial tension favoring to the enhanced oil recovery. In contrast, the loss of the surfactant at the solid-liquid interface due to an adsorption lessens the amount of the surfactant required for oil displacement during the flooding. Therefore, …

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Effect Of Salinity Contrast Between Formation Water And Injected Low Salinity Water On Low Salinity Waterflooding In Shaly-Sandstone Formation, Sarun Phuenghansaporn Jan 2022

Effect Of Salinity Contrast Between Formation Water And Injected Low Salinity Water On Low Salinity Waterflooding In Shaly-Sandstone Formation, Sarun Phuenghansaporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Low salinity waterflooding is an improving oil recovery technique that is highly mentioned nowadays as it is cost-efficient and environmentally friendly. The technique involves injecting water with lower salinity compared to formation salinity to shift the surface equilibrium toward the liberation of oil from the rock surface. Nevertheless, successful of this technique depends on many parameters especially the presence of clays. Several types of clays can be found in oil reservoirs, and they may react to different cations in inject low salinity in different ways, resulting in different magnitudes of oil recovery. Moreover, the contrast of salinity between formation water …

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Pore Pressure Prediction Using Combination Drilling Efficiency And Hydro-Mechanical Specific Energy Methods, Munawir Arge Pratama Otolomo Jan 2022

Pore Pressure Prediction Using Combination Drilling Efficiency And Hydro-Mechanical Specific Energy Methods, Munawir Arge Pratama Otolomo

Chulalongkorn University Theses and Dissertations (Chula ETD)

Several methods of pore pressure prediction using drilling parameters were introduced and improved to meet the challenges of accurate prediction at a relatively low cost. Knowledge of pore pressure is essential for safe well planning, cost-effective drilling, and operational decision-making. Conventional methods in pore pressure prediction using drilling parameters have limitations on its application of making the normal compaction trendline that is only applicable in clean shale intervals. In this work, the concept of drilling efficiency (DE) and hydro-mechanical specific energy (HMSE) for predicting formation pore pressure is proposed. This method, termed DE-HMSE, is based on the theory that the …

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Optimizing Energy Efficiency Projects In Bangkok Large Commercial Buildings, Angelica Arisa Morgan Jan 2022

Optimizing Energy Efficiency Projects In Bangkok Large Commercial Buildings, Angelica Arisa Morgan

Chulalongkorn University Theses and Dissertations (Chula ETD)

As a significant contributor to greenhouse gas emissions in the Asia Pacific region, Thailand has pledged to lower its GHG emissions by 555 million tCO2e by the year 2030. In Bangkok, energy efficiency projects in the large commercial buildings sector are an integral method by which to reduce emissions and to support a lower carbon future. Besides carbon dioxide emissions, energy efficiency projects also have the potential for other benefits including electricity and cost savings. This study develops a methodology to quantify the emissions reduction, electricity savings, and cost savings potential of various energy efficiency methods in this sector, and …

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Analyzing Impact Of Economic Indicators On Vietnam Stock Market With Machine Learning Techniques, Nuttawan Sangsawai Jan 2022

Analyzing Impact Of Economic Indicators On Vietnam Stock Market With Machine Learning Techniques, Nuttawan Sangsawai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The study provides an analysis of the Vietnamese stock market using statistical and machine learning models. The dataset shows that all features have a positive linear relationship with the VN Index, but exhibit different scales and degrees of skewness. The Augmented Dickey-Fuller (ADF) unit root test was conducted to identify whether the variables were stationary or non-stationary, and most variables were transformed into stationary data through first differencing. The OLS method was used to construct a short run model, and the results indicated that only three variables, namely CPI, exchange rate, and S&P500 index, exhibited statistical significance. The ARDL Bound …

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Multi-Objective Vehicle Loading And Routing Problem For Fresh Fruit And Vegetable Transportation, Supisara Krairiksh Jan 2022

Multi-Objective Vehicle Loading And Routing Problem For Fresh Fruit And Vegetable Transportation, Supisara Krairiksh

Chulalongkorn University Theses and Dissertations (Chula ETD)

Multi-compartment refrigerated vehicles are recently utilized in the cold chain industry, due largely to their flexibility in storage capacities with different temperature settings. To better comprehend the costs and benefits of this vehicle type in fresh fruits and vegetable transportation, a multi-compartment vehicle routing and loading problem (MCVRLP) with three different objectives – namely (i) minimizing total transportation cost, (ii) minimizing CO2 emissions, and (iii) minimizing weight loss of fresh fruits and vegetable – is herein explored and solved by mathematical formulation and genetic-based evolutionary algorithm approaches. Based on our computational results, we find that large and complicated MCVRLP instances …

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Forecasting Cane Sugar Production Under Climate Change And Human-Ecotoxicological Impact, Arisara Tachabunya Jan 2022

Forecasting Cane Sugar Production Under Climate Change And Human-Ecotoxicological Impact, Arisara Tachabunya

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study forecasted sugar cane yield and cane sugar production using stepwise multiple linear regression (MLR) and autoregressive integrated moving average (ARIMA). Then, impacts on human health and ecosystems at the endpoint level were evaluated using openLCA software version 1.10.3 and the ReCiPe 2016 method. The functional units were the production of 1 kg raw sugar, 1 kg granulated sugar, and 1 kg refined sugar at Tamaka Sugar Industry Co., Ltd., Kanchanaburi province, Thailand. The result revealed that relative humidity at the Thong Pha Phum meteorological station, maximum temperature at the Kanchanaburi meteorological station, and oceanic Niño Index (ONI) were …

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Influence Of Tidal Current On Microplastic Dynamics In Chao Phraya River Estuarine Ecosystem, Jiradet Tang-Siri Jan 2022

Influence Of Tidal Current On Microplastic Dynamics In Chao Phraya River Estuarine Ecosystem, Jiradet Tang-Siri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Microplastics (MPs) can be found almost everywhere in marine ecosystems. That is one of the issues of concern around the world, including in Thailand. Estuary ecosystems are also among the most disturbed. By the estuary ecosystem affected by both rivers and oceans, such as the mouth of the Chao Phraya River in Thailand. Due to the change in tide, it is necessary to study the effects of tidal currents on the depth of MPs. Water samples were collected at approximately 60 water levels in 24 hours. Samples and three water quality indicators were collected at Pak Nam Chao Phraya. The …

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Bitcoin Candlestick Price Prediction With Recurrent Neural Network, Sutiwat Simtharakao Jan 2022

Bitcoin Candlestick Price Prediction With Recurrent Neural Network, Sutiwat Simtharakao

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bitcoin is a high-risk asset with a potentially high return. Predicting Bitcoin candlestick, i.e., open, high, low, and close (OHLC) prices, can help investors make trading decisions. The objective of this study is to develop a neural network model to predict the candlestick prices of Bitcoin for the next period. Additionally, this study investigates methods to enhance the model's forecasting performance by feature transformations, specifically data normalization. This study employs two neural network algorithms, Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU), to forecast daily Bitcoin OHLC prices. To enhance the model's performance, we compare sliding window normalization with …

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Wastewater-Based Epidemiology And Quantitative Microbial Risk Assessment Associated With Wastewater Contact Of Norovirus In Bangkok, Thailand, Nonnarit Sriporatana Jan 2022

Wastewater-Based Epidemiology And Quantitative Microbial Risk Assessment Associated With Wastewater Contact Of Norovirus In Bangkok, Thailand, Nonnarit Sriporatana

Chulalongkorn University Theses and Dissertations (Chula ETD)

Norovirus is one of the leading causes of acute gastroenteritis worldwide. Wastewater surveillance offer significant benefits such as enhancing our understanding of the disease occurrence in the population, evaluating the effectiveness of pathogen reduction in the treatment process, and tracking the spread of pathogens in the environment which pose a health risk to humans. Hence, wastewater surveillance is crucial. In this study, the influent and effluent samples were collected bi-monthly from March 2020 to March 2021 from three distinct wastewater treatment plants in Bangkok. Wastewater samples were concentrated and subjected to quantitative polymerase chain reaction (qPCR) to assess norovirus concentrations. …

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Development Of Stiffness Sensing And Adaptive Grasping With Soft Pneumatic Grippers, Chaiwuth Sithiwichankit Jan 2022

Development Of Stiffness Sensing And Adaptive Grasping With Soft Pneumatic Grippers, Chaiwuth Sithiwichankit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study presents a framework for stiffness sensing and adaptive grasping using soft pneumatic grippers (SPGs). The motivation was to imitate the capabilities of human hands. The challenge was the compliance of soft pneumatic actuators (SPAs). The study associated the behaviors of grasped objects with those on SPAs, introduced a new concept of SPA modeling, and proposed a method for stiffness sensing through SPG pincer grasping. Compression testing was conducted for validation. A technique for forecasting deformation and force on grasped objects based on their stiffness was established, and a control law was elaborated. The presented technique and control architecture …

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Simulation And Prototyping Of A Knee Assistive Device For Improved Gait Function, Khemwutta Pornpipatsakul Jan 2022

Simulation And Prototyping Of A Knee Assistive Device For Improved Gait Function, Khemwutta Pornpipatsakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to develop a knee-assistive device while walking. The research was separated into two sections: the gait support simulation in MATLAB and the prototype of the device. Data on body part positions and ground reaction force were collected from three adult Thai participants walking at a speed of 1.5 m/s to calculate knee moment. The simulation section provides support moments during walking using machine learning and artificial stiffness control strategy (MLASCS), composed of the kNN model and the instantaneous artificial stiffness per body mass (IASPB) equations. The MLASCS was used to determine the proper amount of support moment …

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High-Pressure Study Of Hybrid Organic-Inorganic Perovskites And Double Perovskites, Ardimas - Jan 2022

High-Pressure Study Of Hybrid Organic-Inorganic Perovskites And Double Perovskites, Ardimas -

Chulalongkorn University Theses and Dissertations (Chula ETD)

Hybrid and double perovskite have been of great attraction for optoelectronic devices. However, exploring a feasible method to enhance their optical abilities remains a considerable challenge. Here, the researcher reports the pressure-induced phase transition as an effective way to modify optoelectronic properties. The researcher successfully synthesized the hybrid perovskite (MAPbI3) and the double perovskite (Cs2TiBr6) by the inverse temperature crystallization (ITC) and solution method, respectively. the researcher studied the pressure dependence phase transition and photoluminescence (PL) by placing the sample into diamond anvil cells (DACs) through Raman spectroscopy. The first principles method was used to support the idea. The researcher …

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Improving Quality Of Cvd Graphene Grown On The Copper Foil By Physical Polishing Electropolishing And Thermal Annealing Pretreatment Processes, Methawut Sirisom Jan 2022

Improving Quality Of Cvd Graphene Grown On The Copper Foil By Physical Polishing Electropolishing And Thermal Annealing Pretreatment Processes, Methawut Sirisom

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study optimized the pretreatment processes (physical polishing (PP), electropolishing (EP), and thermal annealing) for high-quality graphene growth on thin copper (Cu) foils. PP using Brasso solvent was applied to smoothen the substrate surface, followed by EP with H3PO4 to reduce rolling lines and surface contamination. The EP process involved different H3PO4 concentrations (30-60%) and etching times (60-120 seconds). After thermal annealing at 860-940 ºC, graphene growth was performed using direct-liquid-injection chemical-vapor deposition with cyclohexane (C6H12) as the carbon precursor and nitrogen as the carrier gas. The optimized conditions involved PP and EP with 45% H3PO4 concentration and 90 seconds …

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Biopolymer Nanocomposites For Food And Healthcare Applications, Tatiya Siripongpreda Jan 2022

Biopolymer Nanocomposites For Food And Healthcare Applications, Tatiya Siripongpreda

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation focuses on development of biopolymers by integrating nanomaterials to improve the properties of pristine polymers for enhancing the performances of chemical sensors and laser desorption/ionization mass spectroscopy (LDI-MS) applied for food quality control health monitoring and biomedical applications. The dissertation is divided into 4 parts: the first part, polylactic acid and cellulose were used for dual detection platform of biogenic amines for food spoilage indication. Highly porous PLA film is fabricated by adding nanosized calcium carbonate resulted in high sensing element entrapment. On another side of platform, pristine cellulose is modified with graphene oxide and exploited a substrate …

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The Study Of Oxygenated Compounds For Oil Fingerprinting Application, Khairunisa Betariani Jan 2022

The Study Of Oxygenated Compounds For Oil Fingerprinting Application, Khairunisa Betariani

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oil spills have a large impact on the marine and coastal environments. The characterization of petroleum or its products spilled in the environment to its source rocks is an important tool to assist in the resolution of issues of environmental impact and legal responsibility. The composition and physical properties of spilled oils have changed during the weathering process. Petroleum biomarkers is a tool for defining the origin of each oil, which is unique for each type of oil. In general, petroleum biomarkers (i.e., hopane group) are widely used for oil fingerprinting by following the NORDTEST methodology. Besides the hopane group, …

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