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Articles 661 - 690 of 2268
Full-Text Articles in Physical Sciences and Mathematics
Definable Modules Over Definable Rings Without Zero Divisors In O-Minimal Structures, Jaruwat Rodbanjong
Definable Modules Over Definable Rings Without Zero Divisors In O-Minimal Structures, Jaruwat Rodbanjong
Chulalongkorn University Theses and Dissertations (Chula ETD)
In an o-minimal structure, every definable group admits a definable group manifold. Moreover, one can also show an analogue of this statement for definable rings. In this work, we prove that every definable module over definable ring without zero divisors admits a definable module manifold. In addition, we also give the classification of definable modules over definable rings without zero divisors in o-minimal structures
Direct Synthesys Of Lpg From Co2 By Using Czza And Hy Zeolite Hybrid Catalyst, Jaru Natakaranakul
Direct Synthesys Of Lpg From Co2 By Using Czza And Hy Zeolite Hybrid Catalyst, Jaru Natakaranakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
CO2 conversion to lower hydrocarbons (HCs) is a high-potential method that can significantly reduce and manage this greenhouse gas in the long term. Liquefied petroleum gas (LPG) is widely utilized in transportation. Furthermore, biomass appears to be more attractive for decreasing CO2 emissions through conversion to liquid transportation fuels, as it is a renewable and sustainable energy source. The objectives of this work were to examine the direct synthesis of LPG from CO2 hydrogenation using a mixed metal catalyst composed of copper, zinc oxide, zirconium, and alumina (CZZA), and an HY zeolite as a hybrid catalyst. The study tested four …
Tuning Of Metal Ion Selectivity By Varying Number Of Coordinating Atoms In Quinoline-Derived Fluorescent Sensors, Jutawat Hojitsiriyanont
Tuning Of Metal Ion Selectivity By Varying Number Of Coordinating Atoms In Quinoline-Derived Fluorescent Sensors, Jutawat Hojitsiriyanont
Chulalongkorn University Theses and Dissertations (Chula ETD)
Both Cd2+ and Zn2+ are metal ions in group 12 elements with very different toxicities but similar binding properties to most organic and biological ligands. In this work, a series of quinoline derivatives were synthesized and studied with an aim for Cd2+ selective turn-on fluorescent sensors. The structures of the compounds were designed to systematically evaluate the effects of amino protons, number of N-coordinating atoms, quinoline/picoline moieties and substituents on the sensing properties. The association constants of all synthesized ligands were studied by UV-vis absorption titration in aqueous solution. The results revealed that the ligands having 6- and 4- donor …
Strict Stability Of Fixed Points And Iteration Schemes, Kittisak Tontan
Strict Stability Of Fixed Points And Iteration Schemes, Kittisak Tontan
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, we introduce the concept of a strictly stable fixed point of a selfmap and investigate the relationship among various types of fixed point stability. We prove that all fixed point of a quasi-nonexpansive map is strictly stable and extend the concept of a strictly stable fixed point of a selfmap to an iteration scheme. We introduce the concept of convexly strictly stable fixed points of selfmaps and apply it to obtain virtual stability of some well-known iteration schemes in a convex subset of a Banach space.
Greybody Factors For Perfect Fluid Black Hole, Kunlapat Sansuk
Greybody Factors For Perfect Fluid Black Hole, Kunlapat Sansuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
The Einstein equation is a field equation which describes gravity in terms of the curvature of spacetime. It states how matter curves spacetime. The solutions of the Einstein field equation are the metrics of spacetime from which the curvature of spacetime can be found. The field equations are non-linear, which are complicated to solve. Therefore, some assumptions are needed to reduce the complexity of the Einstein equation. One of these assumptions is a perfect fluid sphere. Perfect fluid sphere satisfies the following: no viscosity, no heat conduction, and isotropy. Perfect fluid black holes are black hole solutions of the Einstein …
Thai Traffic Sign Classification System, Nattapol Namyang
Thai Traffic Sign Classification System, Nattapol Namyang
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, driving assistance technology is continuously developed to serve a comfortable and safe driving experience for the driver. The traffic sign is an important feature to improve the ability of this technology. However, in general, the traffic sign has various structures and details in each specific country for a clearly understanding purpose. Thus, this thesis aims to propose the classification and recognition system for the Thai traffic sign. In this study, the classification process provides the ability to categorize the Thai traffic sign into four classes by using a Support Vector Machine (SVM) and Random Forest (RF) classifier with the …
A Two-Stage Model For Balancing Instructor Workload And Teaching Preference In University Course Timetabling, Nipitta Burana
A Two-Stage Model For Balancing Instructor Workload And Teaching Preference In University Course Timetabling, Nipitta Burana
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis focuses on balancing instructor workload and maximizing preferences by using the data in the first semester of 2019 from Department of Mathematics and Computer Science,Faculty of Science, Chulalongkorn University as a case study. Since there are many instructors with over-workload in the department which directly affect their research qualities, balancing teaching workload is the main objective of this study. The proposed approach to balance workload is to split some basic courses into two parts: before midterm and after midterm and then assign each course to two instructors. Moreover, the preferences or the requests of teaching a course are …
Bacterial Cellulose Composites For Target Analyte Preconcentration In Analytical Applications, Panlop Lormaneenopparat
Bacterial Cellulose Composites For Target Analyte Preconcentration In Analytical Applications, Panlop Lormaneenopparat
Chulalongkorn University Theses and Dissertations (Chula ETD)
Bacterial cellulose (BC) is a well-known natural material with desirable properties including biocompatibility, biodegradability, hydrophilicity, high mechanical strength, high porosity, and broad chemically modifiable capacity. Herein, we incorporate carboxymethyl cellulose (CMC) in BC hydrogel to improve the swelling property and prevent collapsing of 3D bacterial cellulose network upon drying. In addition, gold nanoparticles (AuNPs) were successfully embedded within the BC/CMC composite using in situ chemical reduction. Moreover, AuNPs were uniformly distributed in BC/CMC matrix with a diameter of approximately 13 nm. The freeze-dried BC/CMC/AuNPs composite was subsequently used for adsorption of targeted analytes for laser desorption/ionization mass spectrometry. In particular, …
Development Of Novel Comprehensive Multidimensional Gas Chromatography For Improving Separation And Analysis Of Propylene Oxide Sample, Pannipa Janta
Development Of Novel Comprehensive Multidimensional Gas Chromatography For Improving Separation And Analysis Of Propylene Oxide Sample, Pannipa Janta
Chulalongkorn University Theses and Dissertations (Chula ETD)
New experimental and data analysis approaches in multidimensional gas chromatography (MDGC) comprising 1) comprehensive two dimensional GC (GC×GC) and 2) comprehensive multiple heart-cut were developed with an example application illustrated for analysis of propylene oxide sample. GC×GC system employed column set of long first dimensional (1D) nonpolar (60 m) and short second dimensional (2D) polar (5 m) columns with a flow modulator and a Deans switch (DS) as a splitter; whilst, the comprehensive heart-cut system applied solely a DS located between long 1D nonpolar (60 m) and 2D polar (60 m) columns without use of cryogenic trapping devices. Under the …
Fabrication And Characterization Of Triple-Cation Perovskite Solar Cells, Passakorn Phiromruk
Fabrication And Characterization Of Triple-Cation Perovskite Solar Cells, Passakorn Phiromruk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Presently, triple-cation perovskite solar cells have been appealing due to the outstanding power conversion efficiency (PCE). In this work, the Cs0.03(FAxMA1-x)0.97Pb(IyBr1-y)3 triple-cation perovskite solar cells fabricated by two-step deposition method were studied by varying the content of halide ions (Br and I) and the cation ratios of FA and MA. The results showed that the insertion of Br improved open-circuit voltage due to broader band gap. In case of MAPbI3-based devices, the PCE was also increased with the addition of Br. However, the FAPbI3-based devices were inferior to MAPbI3-based devices resulting from poor quality perovskite layer and the non-photoactive structure …
Generalized Factorizability Of Certain Implicit Dependence Copulas, Peerapong Panyasakulwong
Generalized Factorizability Of Certain Implicit Dependence Copulas, Peerapong Panyasakulwong
Chulalongkorn University Theses and Dissertations (Chula ETD)
The copula CX,Y of random variables X and Y that are uniformly distributed on [0,1] is called an implicit dependence copula if f(X)=g(Y) almost surely for some Borel functions f and g on [0,1]. Via a generalized Markov product, we give a one-to-one correspondence between the implicit dependence copulas and the parametric classes of subcopulas on a corresponding domain for the cases that f=g=Λθ, the tent function whose top is at (θ,1). We also show in the case f=g=α, a simple measure-preserving function, that implicit dependence copulas are generalized factorizable.
Effect Of Pyridoxal Phosphate And Tetrahydrofolate Bound On Human Serine Hydroxymethyltransferase By Molecular Dynamic Simulation, Peerapong Wongpituk
Effect Of Pyridoxal Phosphate And Tetrahydrofolate Bound On Human Serine Hydroxymethyltransferase By Molecular Dynamic Simulation, Peerapong Wongpituk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Serine hydroxymethyltransferase (SHMT), a pyridoxal phosphate (PLP)-dependent enzyme, is involved in one-carbon metabolism in multiple biochemical pathways, including the biosynthesis of purine and thymidine. SHMT1 is the enzyme to be studied clinically as a target for cancer chemotherapy. Therefore, the binding mechanism of this enzyme would be investigated. In this study, molecular dynamics simulations for 500 ns was applied on SHMT1 tetramer in six systems with different ligand cofactors (PLP-Lys, L-ser, PLS, PLG, THF, and MTHF) in order to understand its structural dynamics properties. The key residues Y'73, S53, H231, K257, R263 and R402 were found in all ligand cofactor/SHMT1 …
Classification Of Main Components In Airports From Remote Sensing Images By Efficient Network, Pimpisa Charoenchittang
Classification Of Main Components In Airports From Remote Sensing Images By Efficient Network, Pimpisa Charoenchittang
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, we classify the type of main components in airports from the remote sensing images. This datasets is considered as an interesting information since the same type of component may have different shape, size, and color. EfficientNet architecture is the deep learning architecture to use in this research due to the small number of parameters and computational time compared to the other architectures with similar accuracy. In our experiment, we apply the EfficientNet in versions B0, B1, B2, B3, and B4 to classify four types of components in the airport; the passenger terminal, the radio tower, the runway, …
Cops And Robbers On Hypergraphs, Pinkaew Siriwong
Cops And Robbers On Hypergraphs, Pinkaew Siriwong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Cops and robbers game is a game usually played on a finite connected graphwith two players, cop and robber. Recently, cops and robbers game played on hypergraphs was introduced. To give a better chance to a cop by allowing morethan one cop and at least one cop has to move, the cop-number, the least numberof cops to guarantee that they win the game, on graphs and hypergraphs is studied.This thesis provides (i) a characterization of a cop-win hypergraph (ii) some results on the products of hypergraphs and (iii) the cop-number of complete k-partite hypergraphs and n-prisms over a hypergraph. Moreover, …
Design And Synthesis Of Modified Chitosan/Collagen Coated-Gold Nanoparticles As A Carrier For Anticancer And Antiinflammatory Agents, Naruthai Hongsa
Design And Synthesis Of Modified Chitosan/Collagen Coated-Gold Nanoparticles As A Carrier For Anticancer And Antiinflammatory Agents, Naruthai Hongsa
Chulalongkorn University Theses and Dissertations (Chula ETD)
The proposes of this research are to improve the delivery efficiency of AuNPs. One of the problems with drug loading and drug degradation, the drug was loaded onto the surface of the gold particles, adheres to the outer of the surface, which was easy to decompose in the body. In this work, we have developed the coated AuNPs by modified chitosan (Bi-QCS), which the Biotin-Quat188-AuNPs@collagen (Bi-QCS-AuNPS@collagen) was designed as follow: (i) collagen was used as a reducing agent and a stabilizing agent in the AuNPs@collagen, while (ii) modified chitosan (positive charge polymer) was coated on the outer layer, which modified …
Graph And Number Theoretic Properties Of Certain Maps Over Finite Field, Pratchayaporn Doemlim
Graph And Number Theoretic Properties Of Certain Maps Over Finite Field, Pratchayaporn Doemlim
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, we study the graph over a finite field $\mathbb{F}_q$, where $q$ is a prime power, obtained by iterations of the map $g(x)=x^p$, where $p$ is a prime number. Some properties of the graphs such as a characterization of their vertices and the number of cycles with specific length are showed. Moreover, some statistical estimates about the tail and cycle lengths of the related graphs are established.
Fabrication Of Sno2 Layer As Electron Transport Layers For Perovskite Solar Cells, Rattanaphon Thanimkan
Fabrication Of Sno2 Layer As Electron Transport Layers For Perovskite Solar Cells, Rattanaphon Thanimkan
Chulalongkorn University Theses and Dissertations (Chula ETD)
A SnO2 has attracted more attention as electron transport layer (ETL) for perovskite solar cells (PSCs) because it has diverse advantages, e.g., wide bandgap energy, excellent optical and chemical stability, high transparency, high electron mobility, and easy preparation. In this work, SnO2 layer was fabricated by spin-coating and RF magnetron sputtering techniques with various conditions. The SnO2 layer was integrated into the planar structure of PSCs consisting of FTO/SnO2/MAPbI3/spiro-OMeTAD/Au. For spin-coating, SnO2 films can fully cover the FTO, but it has some particulates from recrystallization of SnO2 precursor as observed in the FESEM images. For RF sputtering technique, morphology of …
Anti-Oxidant And Anti-Inflammatory Compounds From Magnolia Liliifera (L.) Baill. Flower And Dendrobium Signatum Rchb.F., Prajak Khumploy
Anti-Oxidant And Anti-Inflammatory Compounds From Magnolia Liliifera (L.) Baill. Flower And Dendrobium Signatum Rchb.F., Prajak Khumploy
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this study, a purification of the EtOAc crude extract of Dendrobium signatum Rchb.f. aerial parts was performed fifteen compounds (1-15) and the hexane crude extracts of Magnolia liliiferra (L.) Baill. were further isolated to accomplish three compounds (16-18). They yielded one new picrotoxane sesquiterpene, 7-hydroxydendroterpene B (2) and a new a-pyrone, (-)-6R-signatone (4), along with sixteen known compounds. These included dendroxine (1), crystallinin (3), dendrocandin B (5), dendrocandin I (6), 6''-de-O-methyldendrofindlaphenol A (7), p-hydroxyphenylethyl-p-coumarate (8), 3,4-dihydroxy-5,4'-dimethoxybibenzyl (9), 3-methoxy-5-[2-(4-methoxyphenyl) ethyl]phenol (10), 4,4'-dihydroxy-3,5-dimethoxybibenzyl (11), naringenin (12), (2S)-homoeridodictyol (13), (2S)-homohesperetin (14), (-)-syringaresinol (15), (+) sesamin (16), (+) fargesin (17) and (-) kobusin …
Geology And Petrochemistry Of Volcanic Rocks In The Lam Sonthi Area, Lop Buri Province, Saowaphap Uthairat
Geology And Petrochemistry Of Volcanic Rocks In The Lam Sonthi Area, Lop Buri Province, Saowaphap Uthairat
Chulalongkorn University Theses and Dissertations (Chula ETD)
Lam Sonthi area is in Lop Buri province, central Thailand. Stratigraphically, the geology of the area consists of five rocks units; Unit I: Khao Ruak siltstone which is correlated to Khao Luak Formation (Early Permian), Unit II: Khao Phaeng Ma conglomerate, Unit III: Khao Ruak volcanics, Unit IV: Lam Sonthi polymictic conglomerate, and Unit V: Kuttaphet sandstone which is correlated to Phu Kradung Formation (Early Jurassic). In addition, the volcanic rocks, which are named as Kuttaphet volcanics and Khok Khli volcanics, could be found in the top of Unit IV as the polymictic intermediate breccia. Petrographic classification identifies the volcanic …
Graph Grabbing Games And Toucher-Isolator Games, Sopon Boriboon
Graph Grabbing Games And Toucher-Isolator Games, Sopon Boriboon
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this research, we study the graph grabbing game and the Toucher-Isolator game. In the graph grabbing game, we partially confirm a conjecture of Seacrest and Seacrest which states that Alice wins the game on every weighted connected bipartite even graph. In the Toucher-Isolator game, we give a simple alternative proof of a result of Räty that determines the most suitable tree on n vertices for Toucher which answers a question of Dowden, Kang, Mikalački and Stojaković.
Synthesis Of 5-Phenoxyprimaquine Derivatives And Their Tetraoxane Conjugates As Anti-Malarial Agents, Somruedee Jansongsaeng
Synthesis Of 5-Phenoxyprimaquine Derivatives And Their Tetraoxane Conjugates As Anti-Malarial Agents, Somruedee Jansongsaeng
Chulalongkorn University Theses and Dissertations (Chula ETD)
Currently, the development of the new anti-malarial drug for the treatment of the increasing drug-resistant strains of malaria was necessary. Therefore, this research was performed by synthesis and evaluation of their antimalarial activity for the development of primaquine which currently was used for anti-malarial drug. The substituents group on 5-phenoxyprimaquine derivatives which had the highest therapeutic index and less toxicity than primaquine were emphasized. The effect of substituted group at para position was studied. Three new derivatives with CN (7e), CF3 (7g), CONH2 (7h) substituents, and five known derivatives with OMe (7b), Br (7c), Cl (7d), F (7f) substituents and …
Fusulinacean Biostratigraphy And Carbonate Petrography Of Khao Khwang And Khao Khad Formations, Saraburi Province, Sutharat Sirot
Fusulinacean Biostratigraphy And Carbonate Petrography Of Khao Khwang And Khao Khad Formations, Saraburi Province, Sutharat Sirot
Chulalongkorn University Theses and Dissertations (Chula ETD)
These research purposes are to study petrography, fusulinids assemblage and age and study biostratigraphy correlation of Khao Khwang and Khao Khad Formations, Saraburi province. The fusulinids from the study area belong to 5 families, 11 subfamilies, 15 genera and 15 species including Robustoschwagerina, Yangchienia, Parafusulina loeyensis, Parafusulina gigantea, Laosella edoensis, Pseudofusulina, Chusenella chihsiaensis, Chusenella (Chusenella) shengi, Verbeekina verbeeki, Misellina, Pseudodoliolina, Thailandina buravasi, Neoschwagerina megasphaerica, Colania douvillei, Lepidolina shiraiwensis, Presumatrina ciryi, Sumatrina annae and Sumatrina cf. longissima. These fusulinids indicated that Khao Khad Formation was deposited oldest in Sakmarian to Yakhtashian and youngest in Midian age and Khao Khwang Formation was …
The Wormholes In The Modification Of General Relativity Theory, Takol Tangphati
The Wormholes In The Modification Of General Relativity Theory, Takol Tangphati
Chulalongkorn University Theses and Dissertations (Chula ETD)
A traversable wormhole, which is a class of wormholes in general relativity (GR), was proposed by Morris and Thorne in 1988. However, its existence requires the exotic matter violating the energy conditions. This thesis examines the wormhole solutions in the theory of massive gravity, focusing only on the de Rham, Gabadadze and Tolley (dRGT) theory of massive gravity which is the nonlinear massive gravity without ghost and quantify the wormhole solutions. We construct the wormhole solutions in context of the modified GR, investigate their stability, and examine the conditions of the exotic matter. Two methods for wormhole constructions are applied …
Electrochemical Reaction For Direct Synthesis Of Amides From Aldehydes, Tanawat Rerkrachaneekorn
Electrochemical Reaction For Direct Synthesis Of Amides From Aldehydes, Tanawat Rerkrachaneekorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Conventional synthesis of amide involves the use of harsh condition, strong oxidizing agents, high value metal catalysts or multiple step synthesis of starting materials. To overcome these problems, in this research, we develop a mild electrochemical oxidative amidation directly from commercially available benzyl alcohols and aldehydes with amines. Optimization studies indicate that this electrochemical oxidative amidation can be proceeded via the use of sodium iodide as both electrolyte and mediator in aqueous solution performing in undivided cell at room temperature without additional additive. Under the optimized condition, we are able to perform electrochemical oxidative amidation of various benzyl alcohols and …
Stochastic Differential Equation Models On Sphere For Animal Migration, Viput Puttanugool
Stochastic Differential Equation Models On Sphere For Animal Migration, Viput Puttanugool
Chulalongkorn University Theses and Dissertations (Chula ETD)
Animal migration is a seasonal movement of a bundle of animals from place to place. A migration cycle is often annually and closely linked with the cyclic pattern of seasons. A short-distance migration can be modeled on a planar surface, but most animals have long-distance migrations, e.g., Arctic terns migrate from the North Pole to the South Pole; thus, their migration should be modeled on a spherical surface. In addition, the Brownian motion term is included in a model to represent noises and randomness of movements. This work aims to simulate their migration routes using stochastic differential equations (SDEs) on …
Effect Of Dealumination And Desilication Of Beta Zeolite On Performance Of Nickel Catalysts In Hydroisomerization For Bio-Jet Fuel Production, Warodom Hunsiri
Effect Of Dealumination And Desilication Of Beta Zeolite On Performance Of Nickel Catalysts In Hydroisomerization For Bio-Jet Fuel Production, Warodom Hunsiri
Chulalongkorn University Theses and Dissertations (Chula ETD)
-The Global aviation fuel consumption tends to increase. In recent years, the European Union has announced that fossil fuels jet fuel must be mixed with 10% biofuels in 2020. bio-jet fuel production has many processes such as biomass pyrolysis. or hydro-p
Improved Adaptive Fractional Order Differential Method For Medical Image Enhancement, Wasin Tranghiranyathorn
Improved Adaptive Fractional Order Differential Method For Medical Image Enhancement, Wasin Tranghiranyathorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this work, we propose a construction of a new 5x5 fractional order differential mask that uses sixteen directions of gradient operator and weights each pixel in the mask by the Euclidean distance from the center of the mask. Then, we apply this new mask to the Adaptive Fractional Differential Algorithm (AFDA). The AFDA allows the optimal fractional order of each pixel to be obtained using an adaptive function constructed based on the area feature of image. Experimental results for medical images, show that the AFDA with the new mask gives better image enhancement than the original AFDA. It makes …
Mineral Inclusions In Sapphire From Basalt - Related Deposit In Southern Vietnam, Vu Doan Thi Anh
Mineral Inclusions In Sapphire From Basalt - Related Deposit In Southern Vietnam, Vu Doan Thi Anh
Chulalongkorn University Theses and Dissertations (Chula ETD)
Sapphires in Southern Vietnam have been discovered in alluvial deposit derived from Cenozoic basalts. Sample collections for this study were taken from the most significant gem fields including Pleiku, Dak Nong, Di Linh, Binh Thuan, and Krong Nang. Several syngenetic mineral inclusions in these sapphires were classified as alkali feldspar, zircon, ferrocolumbite, pyrochlore, and iron oxides. Mineral chemical characteristics of these inclusions appearred to have evolved from alkaline felsic suite. Oxide mineral inclusions occurred in sapphire included hercynite, wüstite, and ilmenite. Ilmenite ranged in composition between Il49-54He34-40Mt7-10 and Il24-30He36-38Mt35-40 falling in ilmenite-hematite series. Wüstite with nonstoichiometry, (Fe2+0.3-0.9)(Ti3+<0.179Al3+≤0.6Cr3+<0.1 Fe3+≤0.46)£≤0.23O, was usually associated with hercynite inclusion clearly indicating cogenetic sapphire formation. Wüstite and sapphire appeared to have formed from the breakdown reaction of hercynite (hercynite = sapphire+wüstite). Titanohematite series and titanomagnetite series might have crystallized during iron-titanium reequilibration via subsolidus exsolution. U-Pb geochronology of zircon inclusion in these sapphires yielded between 35.5 ± 1.6 Ma (~35 Ma) and 14.73 ± 0.29 Ma (~15 Ma) for Krong Nang sapphire, 5.94 ± 0.13 Ma (~6 Ma) for Binh Thuan and Dak Nong sapphire, and 5.491 ± 0.077 Ma (~5.5 Ma) for Di Linh sapphire. These age constraints relate to the main Cenozoic basaltic eruptions in this region. Crystallization temperature of sapphire formation was estimated at about 561- 7810C using Ti-in-zircon thermometry.
Knight's Tours On Ringboards, Deficient 4 X N Chessboards And Some L-Boards, Wasupol Srichote
Knight's Tours On Ringboards, Deficient 4 X N Chessboards And Some L-Boards, Wasupol Srichote
Chulalongkorn University Theses and Dissertations (Chula ETD)
A (legal) knight's move is the result of moving the knight two squares horizontally or vertically on the board and then turning and moving one square in a perpendicular direction. A closed knight's tour is a sequence of knight's moves that visits every square on a given chessboard exactly once and returns to its start square. A closed knight's tour and its variations are studied widely over the rectangular chessboard or a three-dimensional rectangular box. For m,n > 2r, an (m,n,r)-ringboard or RB(m,n,r) is defined to be an m x n chessboard, denoted by CB(m x n), with the middle part …
Intermodulation Distortions From A Chain Of Coupled Nonlinear Oscillators Near A Hopf Bifurcation, Yanathip Thipmaungprom
Intermodulation Distortions From A Chain Of Coupled Nonlinear Oscillators Near A Hopf Bifurcation, Yanathip Thipmaungprom
Chulalongkorn University Theses and Dissertations (Chula ETD)
The inner ear can produce sounds whose frequencies correspond to linear combinations of the stimulus frequencies, f1 and f2. These sounds, called Distortion Product Otoacoustic Emissions (DPOAEs), can be measured by inserting a microphone into the ear canal. In human, the intensity level of DPOAEs at frequency 2f1-f2 varies significantly with a stimulus frequency and can exhibit a quasi-periodic pattern, a feature termed a DPOAE fine structure. This distinctive characteristic has been generally accepted as a consequence of the interference between two DPOAE signals produced by two spatially separated groups of sensory hair cells, whose characteristic frequencies correspond to the …