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Articles 1111 - 1140 of 2268
Full-Text Articles in Physical Sciences and Mathematics
A Scalable Shapelet Discovery For Time Series Classification, Nattakit Vichit
A Scalable Shapelet Discovery For Time Series Classification, Nattakit Vichit
Chulalongkorn University Theses and Dissertations (Chula ETD)
As time series data become more complex and users expect more sophisticated information, numerous algorithms have been proposed to solve these challenges. Among those algorithms to classify time series data, shapelet – a discriminative subsequence of time series data – is considered a practical approach due to its accurate and insightful classification. However, previously proposed shapelet algorithms still suffer from exceedingly high computational complexity, as a result, limiting its scalability to larger datasets. Therefore, in this work propose a novel algorithm that speeds up shapelet discovery process. The algorithm so called "Dual Increment Shapelets (DIS)" is a combination of two-layered …
Classification Of Risk Attitudes From Customer Behavior With Machine Learning, Teeranai Sriparkdee
Classification Of Risk Attitudes From Customer Behavior With Machine Learning, Teeranai Sriparkdee
Chulalongkorn University Theses and Dissertations (Chula ETD)
Every product and service in the market has its characteristic which has an impact on a consumer's decision to buy or use them. The risk is a special characteristic of financial products, so in financial product and service design must use risk as a critical factor. On the other hand, the consumer has different attitudes to the risk which can distinguish in 3 categories viz risk aversion, risk neutral and risk seeking. Therefore, knowing risk attitudes of consumer who is the target market is an important key to define marketing strategy such as designing service and product, campaign, and promotion …
Lightly-Supervised Learning Methods For One-Class Text Classification, Yiping Jin
Lightly-Supervised Learning Methods For One-Class Text Classification, Yiping Jin
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis introduces a lightly-supervised learning method to train text classifiers with very little manual labelling effort. We adapt two previous state-of-theart lightly-supervised models, generalized expectation (GE) criteria (Druck et al. (2008)) and multinomial naïve Bayes (MNB) with priors (Settles (2011)) to oneclass classification problem. Users just need to label a handful of keywords for the target category. We also combine the two aforementioned models by letting MNB automatically augment the list of GE constraints. In addition, we ensemble two families of classifiers to improve the accuracy further. We successfully applied our model to a real-world problem of online advertising. …
A Hotel Hybrid Recommendation Method Based On Context-Driven Using Latent Dirichlet Allocation, Weraphat Nimchaiyanan
A Hotel Hybrid Recommendation Method Based On Context-Driven Using Latent Dirichlet Allocation, Weraphat Nimchaiyanan
Chulalongkorn University Theses and Dissertations (Chula ETD)
Recommender systems play an important role in helping users find items that they want. Normally, ratings are used in content-based filtering (CBF) and collaborative filtering (CF) for recommendation. However, only ratings are not enough for recommendation. Thus, contextual information, context driven and Latent Dirichlet Allocation (LDA) are used to improve recommendation. Also, the context of individual user has changed in the timeline (context-driven). In this work, a hotel hybrid recommendation method (CF+CBF) based on context-driven using LDA is proposed. Firstly, we find missing user ratings of user-hotel rating matrix by applying LDA on user ratings in order to get predicted …
Lithological Classification By Deep Learning Algorithm, Worapop Thongsame
Lithological Classification By Deep Learning Algorithm, Worapop Thongsame
Chulalongkorn University Theses and Dissertations (Chula ETD)
Six machine learning algorithms are used to classify subsurface rocks based on fifteen well logging features from four geothermal wells in the Snake River Plain, Idaho, USA. Two experimental designs, single- and multiple-well tests, are developed to determine the most optimal model and hyperparameters. The single-well test randomly assigns the data in each well into 70% for training set, 10% for validation set, and 20% for test set. The multiple-well test combines data from three wells and splits the data in the fourth well into 70% for training set, 10% for validation set, and 20% for test set. Results show …
Rethinking Inclusive And Sustainable Educational Development For Moken Children, Jason Sanglir
Rethinking Inclusive And Sustainable Educational Development For Moken Children, Jason Sanglir
Chulalongkorn University Theses and Dissertations (Chula ETD)
Despite numerous education readjustments, efforts for equal opportunity in education, and an increase in present enrollment, many indigenous children in Thailand continue to fall behind in the formal education system. This study focuses on the Moken Chao Lay (sea people) communities in southern Thailand and looks to analyze and understand situations and shortcomings of Moken children's education and why they are still underperforming in the formal education system. Traditional ways of knowing, especially knowing through nature, are used as a platform to rethink the way we look at indigenous children's education in Thailand. Interview data was collected from school teachers, …
Selected Appropriate Decision Support Tool For Sustainable Rain-Fed Agriculture Referenced To The New Theory Of His Majesty King Bhumibol Adulyadej The Great: A Case Study Of Khao Wong District, Kalasin Province Of Thailand, Anutra Wannaviroj
Chulalongkorn University Theses and Dissertations (Chula ETD)
Thailand is an agricultural country of which almost 80% of the total agricultural land is rain-fed. An on-farm pond, which is a self-reliant small-scale water source for harvesting the rainwater to be used for the whole year, becomes radical for farmers in this area. These farmers need to select the agricultural water management scheme which uses limited rainwater harvested in the on-farm pond efficiently and productively to fulfill their household needs, which will lead to sustainable rain-fed agriculture. Therefore, the study aimed to select an appropriate decision support tool for sustainable rain-fed agriculture referenced to the New Theory of His …
Management Guidelines For Urban Public Parks: A Case Study Of Lumpini Park, Bangkok, Thailand, Napat Suwannapuk
Management Guidelines For Urban Public Parks: A Case Study Of Lumpini Park, Bangkok, Thailand, Napat Suwannapuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Bangkok is the capital city of Thailand. It is one of the most primate cities in the world. Bangkok also the center of the country in all areas, being a major source of work and attracts people from across the country, which resulted as population overgrowth, mental illness, pollution, rapid urbanization, and the like. Even though the government succeeds to increase public parks area to be recreation and a lung for the urban dweller's life, but the inconsistency between rules and practices in park management is one of the key factors that hinder Bangkok's sustainable development. In order to explore …
Factors Associated With Attitude Towards Purchasing Intention On Inverter Air Conditioner Among Thai Consumers, Reika Yasunaga
Factors Associated With Attitude Towards Purchasing Intention On Inverter Air Conditioner Among Thai Consumers, Reika Yasunaga
Chulalongkorn University Theses and Dissertations (Chula ETD)
Factors associated with Thai Consumers' attitude towards purchasing intention on higher efficiency Air conditioner (AC) was investigated in this study. Consumers' current preference factors on AC purchasing as well as characteristics of consumers who bought AC during the recent 5 years were firstly investigated by descriptive analysis. Relationship between consumers' purchasing attitude towards higher efficiency AC and their concern on three issues (inverter, information on energy label, and payback period) as well as their knowledge on two issues (inverter and information on energy label) was then analyzed by structural equation modeling (SEM) using data collected from 202 Thai consumers having …
Policy Guideline On Disaster Risk Reduction For Climate Change Adaptation : A Case Of Klong Yan Watershed Resourse Conservation And Rehabilitation Network, Suratthani, Siwaporn Promdaen
Policy Guideline On Disaster Risk Reduction For Climate Change Adaptation : A Case Of Klong Yan Watershed Resourse Conservation And Rehabilitation Network, Suratthani, Siwaporn Promdaen
Chulalongkorn University Theses and Dissertations (Chula ETD)
Thailand is one of South-east Asian countries that have been suffered from extreme events resulting from the impacts of climate change. One consequence of changes is the severity and frequency of extreme events leading to disasters in all regions of Thailand. These effects provided losses and damages at all levels. To solve such problems, water resource management under climate change adaptation has been set up under policy guidelines to reducing the disaster risk from the climate change. The objective of this study is to study the policy guidelines on disaster risk reduction for climate change adaptation on water resource management …
Traditional Ecological Knowledge Of Indigenous Peoples On Climate Change Adaptation : A Case Study Of Sea Nomads “Orang Suku Laut”, Lingga Regency, Riau Islands Province, Indonesia, Wengki Ariando
Chulalongkorn University Theses and Dissertations (Chula ETD)
At the international community, Traditional Ecological Knowledge (TEKs) have been recognized and acknowledged the important roles of indigenous peoples to tackle climate change. The cultural practice, cultural belief and adaptive capacity in managing nature by the Orang Suku Laut (OSL), Indonesian indigenous group who are living as nomads in the sea, would be considered as the key drivers to achieve the effectiveness of climate change adaptation (CCA). This research aimed to study the TEKs of indigenous peoples on CCA of the OSL, Lingga Regency, Riau Islands Province, Indonesia, for appropriate CCA policy implemented at their communities. Data collection was obtained …
Health Risk Assessment Of Inhalation And Dermal Exposure To Particle-Bound Polycyclic Aromatic Hydrocarbons Of E-Waste Dismantling Workers In Buriram Province, Thailand, Sarasanant Bungadaeng
Health Risk Assessment Of Inhalation And Dermal Exposure To Particle-Bound Polycyclic Aromatic Hydrocarbons Of E-Waste Dismantling Workers In Buriram Province, Thailand, Sarasanant Bungadaeng
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research mainly studied on the inhalation and dermal exposure concentrations of particle-bound polycyclic aromatic hydrocarbon (PAHs) that e-waste burning workers probably received during their work and further estimated the health risk assessment in both route of exposure. According to the obtained results, the total concentrations of PAHs on PM₂.₅-₁₀ ranged from 0.0703 to 20.9800 μg/m³. For PM₂.₅, the total concentrations of PAHs varied from 0.2669 to 89.9645 μg/m³. In the dermal dust samples, the total concentrations of PAHs on the particles before burning work ranged from 8.1072 to 253.6118 mg/kg with the average concentration at 95.3894 mg/kg. For the …
Plastic Waste Utilization As Macro Fiber In Concrete, Artid Poonyakan
Plastic Waste Utilization As Macro Fiber In Concrete, Artid Poonyakan
Chulalongkorn University Theses and Dissertations (Chula ETD)
The use of plastics has increased over the years, thus resulting in a large volume of plastic waste being generated and accumulated in the environment. Due to its non-biodegradability and persistence, recycling processes have become one of the sustainable solutions for preventing environmental deterioration. Plastic wastes, including high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), and polyethylene terephthalate (PET), were collected from industrial sector and used as additional ingredients (macro fiber) to improve mortar properties. Prior to mortar processing, an increase in wettability of plastic fibers using nonionic surfactant, Dehydol LS-12, was investigated. At the optimal concentration of …
Ecological Impacts Of Fishing Gears In Ko Chang, Trat Province, Thailand, Wichin Suebpala
Ecological Impacts Of Fishing Gears In Ko Chang, Trat Province, Thailand, Wichin Suebpala
Chulalongkorn University Theses and Dissertations (Chula ETD)
Knowledge of ecological impacts of fishing, especially in small-scale sector, is not always readily available, making it difficult to employ an ecosystem-based approach to fisheries management and to achieve sustainability. The topic of this dissertation was formulated with the aim to enhance this knowledge through conducting researches in Mu Ko Chang, Trat Province, the Eastern Gulf of Thailand. This study focuses on two main types of impacts, i.e. bycatch and habitat damages, consisting of three research modules: 1) assessing existing knowledge and analyzing the knowledge gap regarding bycatch and habitat impacts of fishing methods in Thai waters; 2) investigating fishing …
Seismic Characteristics Of Paleo-Pockmarks At Great South Basin, New Zealand, Arunee Karaket
Seismic Characteristics Of Paleo-Pockmarks At Great South Basin, New Zealand, Arunee Karaket
Chulalongkorn University Theses and Dissertations (Chula ETD)
Paleo-pockmarks and present-day pockmarks are founded in several varieties both onshore and offshore worldwide. These features can be used as an indicator of fluid flow process which expulses through an unconsolidated sediment within the basin. The Great South Basin, New Zealand is one of the basins that paleo-pockmarks are observed covering the southeast offshore of South Island at around 1.5 s (TWT) depth beneath the surface. This study aims to identify seismic characteristics of paleo-pockmarks in the Great South Basin and predict the possible fluid origins and their mechanism. The numerous paleo-pockmarks are identified and imaged by using 3D seismic …
The Influence Of Geological Structure On Stratigraphic Development During Multiphase Rifting In The Songkhla Basin, Gulf Of Thailand, Jidapa Phoosongsee
The Influence Of Geological Structure On Stratigraphic Development During Multiphase Rifting In The Songkhla Basin, Gulf Of Thailand, Jidapa Phoosongsee
Chulalongkorn University Theses and Dissertations (Chula ETD)
The Cenozoic N-S trending Songkhla rift basin, located in the southwest Gulf of Thailand, was developed as a predominantly orthogonal extended half graben structure. The half graben is controlled by a boundary fault zone on the western side of the basin, which forms a series of N-S to NNE-SSW, east-dipping normal faults. The rift spans two phases of rifting; the Eocene-Oligocene and the Oligocene-Miocene phases, the late syn-rift to post-rift transition occurred from the late Early Miocene to Middle Miocene. The main clastic hydrocarbon reservoirs in the basin are located in the Early Miocene to Middle Miocene section. These reservoirs …
Influences Of Geologic Conditions And Anthropogenic Activities On Changes Of Geomorphology And Sediment Load Characteristics Of The Ping And Chao Phraya Rivers, Nikhom Chaiwongsaen
Influences Of Geologic Conditions And Anthropogenic Activities On Changes Of Geomorphology And Sediment Load Characteristics Of The Ping And Chao Phraya Rivers, Nikhom Chaiwongsaen
Chulalongkorn University Theses and Dissertations (Chula ETD)
The Chao Phraya River flows into the largest river basin of Thailand. The Ping River is one of its the major upstream branches flowing down slope southwardly, joining the Chao Phraya River in the central plain and ends at the Gulf of Thailand. The sand-choked is extensively observed and the flood overflow occurs frequently and rapidly at the Lower Ping River. In contrary, the Chao Phraya River, the erosion of river bank and shoreline around the river mouth has been spatially increasing in place. The Landsat imageries taken in 1987, 1997, 2007 and 2017 were used to analyze geomorphological changes …
Crude Oil Removal By Sphingobium Sp. Mo2-4 And Bacillus Megaterium Tl01-2 Immobilized On Aquaporous Gel, Adisan Rungsihiranrut
Crude Oil Removal By Sphingobium Sp. Mo2-4 And Bacillus Megaterium Tl01-2 Immobilized On Aquaporous Gel, Adisan Rungsihiranrut
Chulalongkorn University Theses and Dissertations (Chula ETD)
Petroleum products are the major energy sources that drive global economy. The exploration and exploitation of crude petroleum oil increase the potential risk for oil spills in marine ecosystem. In this work, two non-pathogenic sponge-associated bacteria were developed as immobilized bacterial co-culture for crude oil removal from seawater. Two bacteria were Spingobium sp. MO2-4 that could degrade crude oil, diesel oil, and fuel oil, and Bacillus megaterium TL01-2 that could degrade crude oil, possessed high cell surface hydrophobicity, could tolerate heavy metal, and was able to form biofilm.. The modified polyurethane foam, aquaporous gel (AQ), was used as carrier for …
Formulation Of Oil Dispersants By Mixing Lipopeptide Biosurfactant And Non-Ionic Surfactants, Parisarin Nawavimarn
Formulation Of Oil Dispersants By Mixing Lipopeptide Biosurfactant And Non-Ionic Surfactants, Parisarin Nawavimarn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Marine oil spill can cause various harmful impacts to the environment. To solve this problem, dispersant is usually applied to enhance petroleum remediation in seawater. The commercial dispersants mostly contain surfactant and solvent that can be toxic to marine lives. This study aimed to formulate solvent-free biosurfactant-based dispersants by mixing lipopeptides from Bacillus subtilis GY19 with fatty alcohol ethoxylate (Dehydol LS7TH), a low toxicity nonionic surfactant. Hydrophilic-lipophilic deviation (HLD) concept was applied. The fractions of lipopeptide and dehydol LS7TH were determined based on the equivalent alkane carbon number (EACN) of hydrocarbons under seawater salinity (34ppt). The molar fractions of lipoppeptide …
Pm10 And Pm2.5 Concentrations In Bangkok Over 10 Years And Implications For Air Quality, Tin Thongthammachart
Pm10 And Pm2.5 Concentrations In Bangkok Over 10 Years And Implications For Air Quality, Tin Thongthammachart
Chulalongkorn University Theses and Dissertations (Chula ETD)
Atmospheric particulate matter particles with a diameter less than 10 micron (PM10) and less than 2.5 micron (PM2.5) have been adverse human health effect. Ambient air pollution data in Central Business District (CBD) of Bangkok monitored by Pollution Control Department and Bangkok Metropolitan Administration were collected over ten years in Bangkok from 2008 to 2017. Trend of the particulate matter concentrations data were investigated over ten year for implications of activities related to air pollution. Daily average air pollution data between year 2015 and year 2017 were used as the dependent variables to develop mathematic models with multiple linear regression …
Cyclic Clique Decompositions Of Powerof Cycles, Apiwat Peereeyaphat
Cyclic Clique Decompositions Of Powerof Cycles, Apiwat Peereeyaphat
Chulalongkorn University Theses and Dissertations (Chula ETD)
A clique decomposition P of a graph G is a collection of cliques of G such that each edge of G belongs to exactly one clique in the collection. We say that P is cyclic if there is an isomorphism : V (G)→ V (G) such that Kk{α (v₁), α (v₂), α (v₃), ... , α (vk)g is a clique in P whenever Kk{v₁; v₂; v₃; :::; vk} is. The k-power of an n-cycle, Ck n, is the graph having the same vertex set as Cn and uv is an edge in Ck n if and only if dCn(u; v) …
Defective Colorings On Complete Bipartite And Multipartite K-Uniform Hypergraphs, Artchariya Muaengwaeng
Defective Colorings On Complete Bipartite And Multipartite K-Uniform Hypergraphs, Artchariya Muaengwaeng
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, we modify the definition of a defective coloring and a defective chromatic number on graphs to a defective coloring and a defective chromatic number on hypergraphs. First, we find the defective chromatic number on a complete bipartite k-uniform hypergraph and the defective chromatic number on a complete bipartite k-uniform hypergraph of which each color class is acyclic. Second, we determine the defective chromatic number and the defective chromatic number of which each color class is acyclic on a complete k-partite k-uniform hypergraph whose each edge has k vertices from k different partite sets. Finally, we determine the …
Critical Exponent For Nonlinear Nonlocal Equations, Auttawich Manui
Critical Exponent For Nonlinear Nonlocal Equations, Auttawich Manui
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, we study the nonlinear nonlocal equation ∂t u=J*u-u+u¹+p where p>0 and J is nonnegative, bounded, and radially symmetric with unit integral. The Fourier transform of J satisfies J ̂(ξ)=1-A|ξ|^β (ln1/|ξ| 〗 )^μ+o(〖|ξ|〗^β (ln〖1/(|ξ|)〗 )^μ ) as ξ→0, for 0<β≤2, μ∈R, and A>0. In this study, we establish the local existence, uniqueness, and the comparison principle of solutions. Furthermore, we show that the Fujita critical exponent for this equation is β/n when μ<0. For the case μ>1, we discover that the critical exponent is β/n , and the solutions belong to the global to the small initial data regime.
Streaming Data Classification Method Using Scalable Hyper-Ellipsoids With Linear Discriminant Projection Distance Ratio, Perasut Rungcharassang
Streaming Data Classification Method Using Scalable Hyper-Ellipsoids With Linear Discriminant Projection Distance Ratio, Perasut Rungcharassang
Chulalongkorn University Theses and Dissertations (Chula ETD)
Learning streaming data with limited size of memory storage becomes an interesting problem. Although there have been several learning methods recently proposed, based on the interesting concept of discard-after-learn, the performance of these issues: the learning speed, number of redundant neurons, and classification accuracy of these methods can be further improved in terms of faster speed, less number of neurons, and higher accuracy. The following new four concepts and approaches were proposed in this dissertation: (1) a more generic structure of hyper-ellipsoidal function called Scalable Hyper-Ellipsoidal Function (SHEF) capable of handling the problem of curse of dimensionality by introducing a …
Generalized Symplectic Graphs And Generalized Orthogonal Graphs Over Finite Commutative Rings, Siripong Sirisuk
Generalized Symplectic Graphs And Generalized Orthogonal Graphs Over Finite Commutative Rings, Siripong Sirisuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Let R be a finite commutative ring with identity, n ∈ N and β a bilinear form on Rⁿ. In this dissertation, we count the numbers of free submodules and totally isotropic free submodules of Rⁿ of rank s by using the lifting idea. We define the generalized bilinear form graph whose vertex set is the set of totally isotropic free submodules of Rⁿ of rank s and the adjacency condition is given by some rank conditions. We study this graph when (Rⁿ, β) is a symplectic space and an orthogonal space. We can determine the degree of each vertex …
Variant Of D'Alembert Functional Equation On Compact Homogeneous Space, Sorawit Viwanthananut
Variant Of D'Alembert Functional Equation On Compact Homogeneous Space, Sorawit Viwanthananut
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, we introduce a new functional equation on compact homogeneous spaces based on the d'Alembert functional equation on compact groups. We solve the functional equation by using tools from harmonic analysis.
Closed-Form Formula For Pricing Discretely-Sampled Moment Swaps On One-Dimensional Ito Process, Kittisak Chumpong
Closed-Form Formula For Pricing Discretely-Sampled Moment Swaps On One-Dimensional Ito Process, Kittisak Chumpong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Moment swaps are essentially forward contracts on realized higher moments of log-returns of a specified underlying asset, which play an important role in protection against different kinds of market shocks. Variance, skewness, and kurtosis swaps are examples of moment swaps currently traded in markets. To facilitate market practitioners, this work provides a simple and easy-to-use pricing formula of moment swaps on discrete sampling under the Ito process, extended Black-Scholes model for stock prices and Schwartz model for commodity prices. Furthermore, the interesting topics of the fair prices are also investigated. Finally, Monte Carlo simulations are performed to support the accuracy …
Sustained Release Of Antibiotics From Bone Spacer, Miranda Oungeun
Sustained Release Of Antibiotics From Bone Spacer, Miranda Oungeun
Chulalongkorn University Theses and Dissertations (Chula ETD)
Bone spacer is a device developed to temporarily insert into the body to treat infected tissue caused by bone replacement. Burst release and short-time release of antibiotics from bone spacer not only limits their ability to clear infection but also causes tissue inflammation. Therefore, here we have fabricated bone spacers containing antibiotic-loaded particles, studied their antibiotic release character, and measured the compressive strength of PMMA cements. Four biocompatible particles were investigated. Vancomycin and erythromycin were used as hydrophilic and hydrophobic model drugs, respectively. Rice granules and calcium citrate particles were loaded with vancomycin and gave the percent loading of 84.9 …
Preparation Of Alginate Capsule Using Two Coaxial Glass-Tube, Panida Watchanung
Preparation Of Alginate Capsule Using Two Coaxial Glass-Tube, Panida Watchanung
Chulalongkorn University Theses and Dissertations (Chula ETD)
TEMPO-Oxidized bacterial cellulose (TOBC) were obtained using TEMPO-mediated oxidation (TOBC) to produce carboxylate groups on bacterial cellulose surfaces. TOBC had lower crystallinity but better aqueous dispersion than bacterial cellulose. TOBC was used as a reinforcement agent for production alginate capsules. The alginate capsules for entrapping rice bran oil were made via a coaxial-glass tube. The factors that influenced on the shape and production efficiency of capsules were the gap between tube tip and the Ca2+ ions bath and the viscosity of shell solution. However, these factors had no effect on the size and shell thickness of capsules. Increasing of TOBC …
Surface-Enhanced Raman Scattering Technique For Polycyclic Aromatic Hydrocarbons Detection Using Thiol-Functionalized Silver Nanoparticle Films, Sathita Taksadej
Surface-Enhanced Raman Scattering Technique For Polycyclic Aromatic Hydrocarbons Detection Using Thiol-Functionalized Silver Nanoparticle Films, Sathita Taksadej
Chulalongkorn University Theses and Dissertations (Chula ETD)
The detection of polycyclic aromatic hydrocarbons (PAHs) is developed based on surface-enhanced Raman scattering (SERS) using silver nanoparticle films as SERS substrates. The films are fabricated by a Langmuir Blodgett (LB) method and the surface of AgNP films are functionalized with various types of aromatic and aliphatic thiols, i.e., naphthalenethiol, phenylethanethiol, pentanethiol, octanethiol, and dodecanethiol, to create a hydrophobic layer for PAHs to attach on and stay in hot spot. The results indicate that nine kinds of PAHs with different structures, i.e., anthracene, chrysene, naphthacene, naphthalene, phenanthrene, pentacene, perylene, pyrene, and triphenylene, can attach on the surfaces of thiol-modified AgNP …