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Quaternion Algebras Over Some Extensions Of Function Fields, Silipong Thongmeepun

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this thesis, we study quaternion algebras over rational function fields over finite fields of odd order. [It is known that a quaternion algebra is either the algebra of 2x2- matrices or a division algebra.] We determine conditions for quaternion algebras of the form(symbol) to be division algebras and conditions for quaternion algebras to split after the constant quadratic field extension.

Conversion Of N-Pentane To Light Olefins Over Modified Zr/Hzsm-5-Based Catalysts, Bharanabha Makkaroon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ethylene and propylene are important raw materials for producing several types of chemicals and polymers. According to the increase of propylene demand in recent year, the P/E ratio was increased to 0.85. In order to meet the propylene demand, the development of hybrid HZSM-5 catalyst for catalytic cracking becomes more interesting owing to the cracking activity from HZSM-5 zeolite acid site and loaded metal on HZSM-5 that expected to promote the dehydrogenation activity to the catalyst which could possibly enhanced the P/E ratio. The alternative feedstock for this process is n-pentane which is the low-value product from distillation process. The …

Influence Of Mixed Anionic-Nonionic Surfactants On Methane Hydrate Formation : Suppression Of Foam Formation, Chakorn Viriyakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Solidified natural gas (SNG) via clathrate hydrate is a new technology for natural gas storage with high energy content per unit volume, extremely safe, and ease to recover. Although SNG has several advantages, its limitation is low rate of hydrate formation. Sodium dodecyl sulfate (SDS) is well known as a kinetic promoter used to increase the hydrate formation rate. However, using SDS resulted in a large amount of foam during gas recovery. In order to alleviate this problem, mixtures of SDS with nonionic surfactants were investigated. Polyoxyethylene (n) lauryl ether (EO₃ and EO₅) and alkyl poly glycol (APG) were mixed …

Layer-By-Layer Surface Modification Of Polymer Filament For Catalytic 3d Printed Parts, Pornnutcha Thadasri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Catalyst was constructed in form of microreactor by fused deposition modeling (FDM) or 3D printing method that allow micro scale customization in order to achieve high detail construction. Poly (lactic acid) (PLA) and Poly (acrylonitrile-butadiene-styrene) (ABS) filaments were used as a built-up material. The surface modification was introduced to improve filaments surface adhesion by using alkaline treatment and Polyethyleneimine with variation of time and concentration and then deposited with polyelectrolyte multilayers by layer-bylayer technique before catalyst loading. Catalyst were synthesized by reduction reaction of Silver nitrate (AgNO₃) and sodium borohydride (NaBH4) with using poly (4-styrenesulfonic acid-co-maleic acid) as a capping …

Pyrrolidine As A Promoter For Methane Hydrate Formation: Comparative Study On The Thermodynamics, Kinetics, And Morphology With Tetrahydrofuran, Siravich Junthong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Solidified natural gas (SNG) via clathrate hydrates has been proposed as an alternative approach for natural gas storage and transportation due to its numerous advantages. However, a slow hydrate formation rate and a requirement of operating conditions are the major limitations, which need to be improved to make SNG competitive in a large scale deployment. In this work, the roles of 5.56 mol% pyrrolidine were investigated for the methane hydrate formation in terms of thermodynamics and kinetics along with morphology. The results showed that pyrrolidine generally improved the thermodynamic stability of mixed methane hydrates, enhancing the formation at milder conditions …

Solid-Liquid-Polymer Mixed Matrix Membranes For Gas Separation: Silicone Rubber Membranes Filled With Nax And Ky Zeolites Adsorbed Peg, Sitthikiat Boonchoo

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbon dioxide (CO₂) is one of the major constituents of natural gas and biogas. The presence of high CO₂ content causes some serious problems including reduction of heating value and corrosion of equipment's surface. Additionally, CO₂ emission is the main issue of the greenhouse effect. In consequence of these problems, membrane technologies have drawn much attention as potential techniques for gas separation. mixed matrix membranes (MMMs) have been studied and developed to provide the synergistic effect of inorganic and organic materials on membranes. In this study, PEG/NaX:KY/SR mixed matrix membranes (PZS MMMs) were prepared by the solution casting method using …

Identification Of Crude Palm Oils By The Analyses Of Fatty Acids, Volatile Organic Compounds, And Carotenoids, Somluk Sanorkham

Chulalongkorn University Theses and Dissertations (Chula ETD)

An in-depth analysis of crude palm oil is important to differentiate crude palm oil (CPO) from different geographic provenance for administrative control purposes to prevent and solve the problem of smuggling CPO from abroad to Thailand. In this study, eleven CPO samples from five provinces in Thailand were studied for their composition. The compositions of fatty acids, volatile organic compounds (VOCs), and carotenoids were characterized by GC-FID, GC-MS, and HPLC-DAD techniques, respectively. The chromatograms of fatty acids distribution were similar for all samples. The main components of fatty acids are palmitic acid, oleic acid, linoleic acid, and stearic acid. In …

Silver Surface Enrichment On Zsm-5 Zeolites For The Catalytic Cracking Of N-Pentane To Produce Light Olefins, Warisara Angguravanich

Chulalongkorn University Theses and Dissertations (Chula ETD)

The effects of Ag-incorporation on the catalytic performance of ZSM-5 zeolites have been investigated. Since Ag-incorporation can promote the formation of light olefins and significantly enhance catalytic performance in n-pentane catalytic cracking. However, the Ag-incorporated ZSM-5 zeolite was rapidly deactivated in npentane catalytic cracking. Thus, CLD and sulfation methods were introduced to improve catalytic activity and stability of Ag-incorporated ZSM-5 zeolites. The Agincorporated ZSM-5 zeolites have been prepared by the incipient wetness impregnation and CLD methods. Moreover, the sulfated catalyst was prepared by the sequential CLD and sulfation of commercial HZSM-5 zeolite. The catalytic activity and stability of Ag-incorporated ZSM-5 …

Comparison Of Area Under The Curves For Vancomycin From One- And Two-Compartment Models Using Sparse Data, Nyein Hsu Maung

Chulalongkorn University Theses and Dissertations (Chula ETD)

Vancomycin pharmacokinetics has been described by 1- and 2-compartment models. One-compartment models built from routine monitoring data, which were mainly trough samples, are commonly used to predict area under the curves (AUC), the useful indicator for vancomycin efficacy. The question stands whether AUCs from 1-compartment models with sparse data can sufficiently represent the true AUC. This study aimed to compare AUCs from 1- and 2-compartment models using sparse data. A previously published model was used to simulate full individual profiles for 100 patients. From these data, the reference AUC (AUCref) was calculated and two depleted datasets (trough-only and peak-trough) were …

กลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์จากคอปเปอร์ออกไซด์/รีดิวซ์กราฟีนออกไซด์นาโนคอมพอสิต, นพรัตน์ จันทร์มี

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในงานวิจัยนี้กลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์ถูกพัฒนาขึ้นโดยใช้นาโนคอมพอสิตของโลหะออกไซด์และรีดิวซ์กราฟีนออกไซด์ ขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนถูกดัดแปรด้วยรีดิวซ์ กราฟีนออกไซด์เพื่อเพิ่มการนำไฟฟ้าและดัดแปรด้วยโลหะออกไซด์ที่มีขนาดในระดับนาโนสองชนิด ได้แก่ คอปเปอร์ออกไซด์ และซิงค์ออกไซด์เพื่อเป็นตัวเร่งทางเคมีไฟฟ้าสำหรับการเกิดออกซิเดชันโดยตรงของกลูโคส โดยศึกษาความเข้มข้นของสารดัดแปรที่เหมาะสมด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องกราด จากนั้นเปรียบเทียบประสิทธิภาพการเร่งปฏิกิริยาของขั้วไฟฟ้าดัดแปรด้วยโลหะออกไซด์ด้วยเทคนิคไซคลิกโวล แทมเมทรีพบว่าขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนที่ถูกดัดแปรด้วยรีดิวซ์กราฟีนออกไซด์และคอปเปอร์ออกไซด์ให้กระแสสูงสุด จึงเลือกมาใช้เป็นขั้วไฟฟ้าสำหรับกลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์ สำหรับการตรวจวัดกลูโคสในตัวอย่างจริง อุปกรณ์รูปแบบใหม่ถูกสร้างขึ้นโดยติดกระดาษพิมพ์แวกซ์ที่เคลือบด้วยโซเดียมไฮดรอกไซด์เพื่อเป็นส่วนป้อนสารตัวอย่างลงบนขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนที่ถูกดัดแปรด้วย รีดิวซ์กราฟีนออกไซด์และคอปเปอร์ออกไซด์ อุปกรณ์นี้ถูกใช้ตรวจวัดกลูโคสในฟอสเฟตบับเฟอร์ซาลีนแสดงช่วงความเป็นเส้นตรงที่ 0.125 ถึง 7.0 มิลลิโมลาร์ และ 0.031 ถึง 7.0 มิลลิโมลาร์ โดยมีค่าสัมประสิทธิ์สหสัมพันธ์ที่ 0.9940 และ 0.9911 สำหรับการตรวจวัดด้วยเทคนิคไซคลิกโวลแทมเมทรีและเทคนิคแอมเพอโรเมทรี ตามลำดับ นอกจากนี้ขั้วไฟฟ้าคาร์บอนพิมพ์สกรีนที่ถูกดัดแปรด้วยรีดิวซ์กราฟีนออกไซด์และคอปเปอร์ออกไซด์สามารถคงประสิทธิภาพการตรวจวัดได้ถึง 6 วันภายหลังการเตรียมอุปกรณ์ กลูโคสไบโอเซ็นเซอร์แบบไม่ใช้เอนไซม์ที่พัฒนาขึ้นนี้จึงสามารถประยุกต์เป็นอุปกรณ์ทางเลือกสำหรับติดตามผู้ป่วยโรคเบาหวานอย่างง่ายโดยไม่ต้องเตรียมตัวอย่าง

The Effect Of Wildlife Wellbeing On Environmental Concern, Laura Casne

Department of Environmental Studies: Undergraduate Student Theses

Environmental campaigns have used animal imagery to push their initiatives for years, shocking viewers with images of human caused damage to change environmental behavior. The Royal Society for the Prevention of Cruelty to Animals (RSPCA), a nonprofit located in Britain released a statement that they responded to 5000 calls annually regarding litter and that the main victims were wildlife species (Litter and Animals | Rubbish and Animals - RSPCA, 2017). A previous study done by Schultz (2000) showed animals in different conditions (animals in nature and animals harmed in nature), with results indicated that those who viewed an image of …

Ecological Perspectives Of The Eastern Saline Wetlands Differ Between Visitors And Non-Visitors, Peter Janda

Department of Environmental Studies: Undergraduate Student Theses

The Eastern Saline Wetlands of Nebraska can be found in both Lancaster and Saunders counties in Eastern Nebraska. Due to the wetlands’ important services in the areas of recreation, wildlife habitat, and flood control, it is necessary to know the extent to which these services are valued and used by residents of Lincoln . Past research completed in 2015 by the Lower Platte South NRD observed public opinions toward wetland restoration and preservation, finding that 46% of the public strongly support it, 35% mildly support it and 16% do not support it (Saline Wetlands Conservation Partnership, 2006). This past study …

The Changing Habitat And Decline Of Ring-Necked Pheasant Populations In Otoe County, Nebraska, Jacob T. Herman

Department of Environmental Studies: Undergraduate Student Theses

Since the early 20th century, wildlife conservation in Untied States has walked a fine line of growth and decline. The implementation of the Ring-Necked Pheasant in Nebraska has brought a wealth of tradition and revenue to the state across multiple generations. This thesis analyzes how habitat changes in Otoe County, Nebraska have affected the Ring-Necked Pheasant population, and what programs are in place to counteract the issue. To answer this question, the study compared five different aerial photos taken from Google Earth Pro and the county archives located in Hardin Hall at the University of Nebraska- Lincoln. The results of …

Incorporating Tallgrass Prairie Into Urban Environments, Daniel Hauschild

Department of Environmental Studies: Undergraduate Student Theses

As an agricultural state with a population poised to shift to primarily urban based, Nebraska is in the unique position of being able to decide how people live in modern cities. While the benefits of including green spaces in urban areas are well documented, evidence also suggests that increased biodiversity in these areas compounds those benefits. As such, incorporating elements of functioning natural ecosystems within urban areas can potentially create pockets of sustainable landscapes. Nebraska’s two largest population centers are located on land that was historically tallgrass prairie, an iconic landscape in American history and now almost entirely absent from …

Growth And Feeding Response In Python Regius In Ambient Temperature Vs. Hot-Spot, Mckenzie Martinez

Department of Environmental Studies: Undergraduate Student Theses

Python regius, also known as the ball python or the royal python, is one of the most popular reptiles in the pet trade and has been heavily imported, kept, and bred in captivity since 1976 (Toudonou 1). This species has adapted to life in captivity extremely well making it one of the most popular reptiles in the reptile trade. It is one of the first reptiles many reptile enthusiasts own. It is a frequently used species for educating the public in zoos and other facilities. Some of the main reasons that Python regius has maintained its popularity in the reptile …

The Effects Of Street Tree Site Planting Width On Canopy Width And Ability To Provide Ecosystem Services, Ryan Kendall

Department of Environmental Studies: Undergraduate Student Theses

In a time where pests such as emerald ash borer are reducing urban forests, it is important to gain a return on investment for new trees planted. Since trees cost money, the value of the ecosystem services that they provide over the course of their lives should outweigh their costs. Due to the need for a return on investment, it is important to know whether newly planted street trees are being planted in a space that does not inhibit their growth or ability to provide benefits. This study, in Lincoln, NE looks to determine the relationship between a street tree’s …

The Effect Of Pictorial Signs On Recycling Rates, Christopher A. Sukstorf

Department of Environmental Studies: Undergraduate Student Theses

Recycling is a core way that college students can act altruistically. Many studies have been conducted to study how to increase the participation of recycling on college campuses, office buildings, and the like. This study focuses on the University Lutheran Chapel, a Christian church adjacent to the University of Nebraska – Lincoln. While the University of Nebraska – Lincoln has drastically improved recycling participation in recent years, the University Lutheran Chapel lags behind. Pictorial signs were used in an experiment to determine whether they improved recycling rates at The Chapel. Recycling rates at the University Lutheran Chapel were measured by …

Planning Urban Forests In A Changing Climate, Ethan Dudden

Department of Environmental Studies: Undergraduate Student Theses

As the effects of negative effects of climate change are realized, urban forests a means to reduce the potential damage and adverse conditions in urban areas (Wolf, et al., 2020) (Livesley, McPherson, & Calfapietra, 2016) (Xiao & McPherson, 2002). Preserving these resources is becoming more difficult however, as the trees that make up urban landscapes become less adapted to current conditions with every passing year (Aitken, Yeaman, Holliday, Wang, & Sierra, 2008). Changes in climate and world systems also point to invasive pests becoming greater threats to urban forest resources with time (Tubby & Webber, 2010) (Amberger et al., 2017). …

Future Implications Of Extreme Heat On Public Health For Those Living In Lincoln, Nebraska, Mandy Koehler

Department of Environmental Studies: Undergraduate Student Theses

Increasing temperatures are expected as the climate crisis progresses. This crisis is fueled by the increasing amount of greenhouse gas emissions being released into the atmosphere, which trap heat in the environment. With rising temperatures, more extreme heat events threaten multiple sectors of society including public health. To gain insight into future climate issues related to warming temperatures and public health for people living in Lincoln, Nebraska, this research will evaluate the predicted extent of extreme heat for this area and consider what other relevant regions do to deal with these problems. This study identifies the scope of future extreme …

To What Extent Has The Relationship Between Humans And Red Foxes (Vulpes Vulpes) Evolved Throughout History?, Abigail Misfeldt

Department of Environmental Studies: Undergraduate Student Theses

Red foxes are one of the few creatures able to adapt to living alongside humans as we have evolved. All humans and wildlife have some id of relationship, be it a friendly one or one of mutual hatred, or simply a neutral one. Through a systematic research review of legends, books, and journal articles, I mapped how humans and foxes have evolved together. First, the relationship between humans and foxes in a geographical manner by starting in Asia, moving to Australia and Tasmania, then Europe, Africa, finishing with North and South America. I will be analyzing all the information through …

On Geometric Design Rules And In-Process Build Quality Monitoring Of Thin-Wall Features Made Using Laser Powder Bed Fusion Additive Manufacturing Process, Aniruddha Gaikwad

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The goal of this thesis is to quantify the link between the design features (geometry), in-process signatures, and build quality of parts made using the laser powder bed fusion (LPBF) additive manufacturing (AM) process. This knowledge is the foundational basis for proposing design rules in AM, as well as for detecting the impending build failures using in-process sensor data.

As a step towards this goal, the objectives of this work are two-fold:

1) Quantify the effect of the geometry and orientation on the build quality of thin-wall features. To explain further, the geometry related factor is the ratio of the …

Artificial Neural Network For Pulmonary Rifampicin Resistant Tuberculosis Screening Indonesia : A Study In Accuracy And Cost-Effectiveness Analysis Of The Model, Bumi Zulheri Herman

Chulalongkorn University Theses and Dissertations (Chula ETD)

Background: Diagnosis of Pulmonary Rifampicin Resistant Tuberculosis (RR-TB) with the Drug-Susceptibility Test (DST) is costly and time-consuming, and the GeneXpert for rapid diagnosis is not widely available in Indonesia. This study aims to develop an Artificial Neural Network model and evaluate the deployed model performance for RR-TB screening. Methods: A cross-sectional study involved suspected RR-TB patients with complete sputum Lowenstein Jensen DST (reference) and 19 clinical, laboratory, and radiology parameter results, retrieved from medical records in hospitals under the Faculty of Medicine, Hasanuddin University Indonesia, from January 2015-December 2019. The Artificial Neural Network (ANN) models were built along with other …

Unit Cost Analysis Of Acute Respiratory Infection (Ari) Clinic For Covid-19 Screening At Bangbuathong Hospital, Nonthaburi, Thailand, Tharit Mongkol

Chulalongkorn University Theses and Dissertations (Chula ETD)

The COVID-19 outbreak has affected the services of all hospitals in Thailand, especially making their financial position at risk of bankruptcy. Although managing the cost of health care services for COVID-19 effectively can help reduce that risk, but very few researches has been done and analyzed on these issues. This study aimed to identify the unit cost and cost recovery of Acute Respiratory Infection (ARI) clinic for COVID-19 screening at Bangbuathong Hospital. This research was a descriptive study by retrospective data collection from hospital recorded and database of costs of ARI clinic between March to May 2021, which was the …

Biomimicry: Function And Aesthetic Of Vacation Home, Chonburi, Suparuek Techaborikiti

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis entitled 'BIOMIMICRY : FUNCTION AND AESTHETIC OF VACATION HOME IN CHONBURI' is an attempt to add an architectural element named fah lai (ฝาไหล literally translated as "flowing wall" popularly translated as "breathing wall") of Thai traditional house to the category of 'biomimicry'. This attempt is problematic because the term 'biomimicry' in architecture was invented in the 1990's much later than the Thai traditional houses. These two words, fa lai and biomimicry, belong to different cultures and different times. Moreover, the term 'biomimicry' itself has various interpretations. In this thesis, I will classify the uses of this word 'biomimicry' …

Technical And Scale Efficiency Of Public Hospitals In Papua New Guinea, James Noah

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of the study was to estimate the relative technical efficiency of public hospitals in PNG and estimate the magnitudes of output increases and/or input reductions that would have been required to make relatively inefficient hospitals more efficient using Data Envelopment Analysis for 20 hospitals in PNG using the data for 2017. The study is further extended using the Tobit regression analysis to investigate the institutional and contextual factors on hospital efficiencies. The results of the output-oriented DEA BCC Model indicated that the average constant returns to scale technical efficiency score was 79%; the average variable returns to scale …

A Model Of Willingness To Communicate In English In Iranian Efl Classroom Context, Azadeh Amirzadi

Chulalongkorn University Theses and Dissertations (Chula ETD)

The present study aimed to investigate the relationships between WTC in English in classroom context and four trait-like variables: L2 confidence, L2 motivation, L2 anxiety and grit, to propose a WTC model in EFL classroom setting in Iran, and to identify the best predicting variable of WTC in English. The participants were 488 non-English majored university students in two public and two private universities in Iran. The research instrument used in this study was an online questionnaire. The structural equation modeling (SEM) using Amos was conducted to analyze the data. The key findings are as follows. First, positive relationships were …

Effects Of Interleaved Form-Focused English Instruction On Thai Lower Secondary School Students' Grammatical Knowledge And Perception Towards The Instruction, Narongchai Rungwichitsin

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigated the effects of interleaved form-focused instruction (FFI) on Thai lower secondary students' grammatical knowledge, long-term retention, and their perception towards the instruction. Students took a pre-test, an immediate post-test, and a one-week delayed post-test, and were also interviewed at the end of the implementation. The test scores were to investigate the improvement of grammatical knowledge as well as the long-term retention, and the data from the semi-structured interview were analyzed to figure out the perceptions towards the overall instruction. The results showed significant improvement of grammatical knowledge in all areas of form, meaning, and use and also …

Development Of Phonics Teaching Guideline For Thai Elementary School Students: Lesson Learned From Best Practice Teachers, Wanida Roatchanaphaphong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purposes of this research were to 1) develop the phonics teaching guideline to teach phonics and 2) evaluate the quality of the developed phonics teaching guideline to teach phonics. The questionnaires, observations and interviews were used as main collecting procedures. The research instruments consisted of 1) Phonics teaching questionnaire, 2) fieldnotes and interview questions, and 3) Phonic teaching guideline quality evaluation questionnaire. The participants were 5 best practice phonics teachers who were currently working in a school context at the time which were selected by the research instrument Phonics teaching questionnaire. The data were analysed by statistical percentage, qualitative …

Power Loss Minimization With Second Order Cone Programming Relaxation, Akira Chuppawa

Chulalongkorn University Theses and Dissertations (Chula ETD)

The minimization of power loss in distribution systems is very important to increase the reliability and performance of the system. Therefore, this thesis determines power loss minimization in a power system. The active power loss can be minimized by the alternating current optimal power flow (ACOPF) under the limits of power generations, bus voltages, and distribution lines. The general ACOPF problem is computationally intractable in practice owing to the nonlinear objective function and nonlinear constraints. Accordingly, the conventional ACOPF is a nonconvex and NP-hard optimization problem. To address this difficulty, this work develops the computation of the ACOPF by applying …

Electrode Improvement And Neural Network-Based Dynamic Optimization Of Vanadium Redox Flow Battery, Apisada Chutimasakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The performance improvement of a vanadium redox flow battery (VRFB) was focused on this study. The two objectives of this study were (1) to investigate the effect of the operating temperatures of the Atmospheric Pressure Plasma jets (APPJs) process on the energy efficiency of the VRFB and (2) to determine the optimal electrolyte flow rate of the VRFB by solving a dynamic optimization based on a neural network model of the VRFB. The APPJs graphite felt electrode treatment temperature providing the highest energy efficiency of the VRFB was 550°C, explained by the Energy Dispersive X-ray Spectrometry (EDX) and X-ray photoelectron …