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2022

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Structural, Electrical And Optical Properties Of Copper Oxide Phase Mixture: An Active Layer Of Solar Cell, Rifat Ara Shams Jan 2022

Structural, Electrical And Optical Properties Of Copper Oxide Phase Mixture: An Active Layer Of Solar Cell, Rifat Ara Shams

Graduate Theses/Dissertations

Both CuO and Cu2O have been well studied and implemented individually as an active layer of a solar cell from early age of manufacturing. A mixture of these two-phase contents at different ratios can bring variance in absorbance which can present new and diverse aspect in solar cell fabrication with added efficiency. Previous works were successful to vary the phase mixture, and the nanostructures provided very high absorption co-efficient but poor optical response on electrical conductivity. The goal of this research is to find out the optimum parameter for the phase mixture of copper oxide with high absorption coefficient as …

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Stress And Its Interventions In Undergraduate College Students During Covid-19, Katie A. Jones Jan 2022

Stress And Its Interventions In Undergraduate College Students During Covid-19, Katie A. Jones

Graduate Theses/Dissertations

Though stress in postsecondary education is a highly researched topic, the emergence of the COVID-19 pandemic has created many new questions that require answers. It is important to connect total perceived stress in undergraduate students with academic, COVID-19, and distance-learning factors and examine the effectiveness of interventions on stress and anxiety during the pandemic. This research determines the efficacy of mindfulness stress interventions (cognitive-behavioral, guided meditation, and music) for individual differences in stress, self- efficacy, and anxiety and links these variables to performance. This study measures levels of different types of stress (total perceived, distance-learning, academic, and COVID-19) for undergraduate …

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Development Of Peg-B-Pla Based Micelles For Neutralization Of A Toxic Peptide, Giselle Campos Jan 2022

Development Of Peg-B-Pla Based Micelles For Neutralization Of A Toxic Peptide, Giselle Campos

Graduate Theses/Dissertations

I herein report the preparation and characterization of PEG-b-PLA block copolymer micelles and PEG-b-PLA/PLA mixed micelles as potential “plastic antidotes” for a toxic peptide, melittin. PEG-b-PLA micelles have been used in a number of biomedical applications for their biodegradability and biocompatibility. Along these lines, I investigated the colloidal stability and the peptide absorption properties of PEG-b-PLA/PLA mixed micelles. A series of PEG-b-PLA block copolymer micelles and PEG-b-PLA/PLA mixed micelles were prepared, and their colloidal stability was studied. The hydrodynamic diameters of stable micelles were determined by using Dynamic …

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Spatial And Temporal Heterogeneity Of Hyporheic Invertebrates In An Ozark Stream, David Fleshman Jan 2022

Spatial And Temporal Heterogeneity Of Hyporheic Invertebrates In An Ozark Stream, David Fleshman

Graduate Theses/Dissertations

The hyporheic zone (HZ), an ecotone between surface water and groundwater in streams, provides extensive but underappreciated habitat for invertebrates in alluvial systems like the gravel-bed streams common in the Ozark highlands. Relative to its importance as a habitat, little is known about spatial distribution and response to disturbance by invertebrates in the HZ. In riffle-pool systems, surface water typically enters the HZ at the head of riffles (downwelling) and returns to the surface at the tail of riffles (upwelling). Previous research has found differences in invertebrate communities and environmental variables between upwelling and downwelling zones, but results have been …

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Effects Of Sex And Reproductive Condition On Behavior Of Southern Red-Backed Salamanders: Activity, Agonistic Behavior And Escape Velocity, Megan N. Mosier Jan 2022

Effects Of Sex And Reproductive Condition On Behavior Of Southern Red-Backed Salamanders: Activity, Agonistic Behavior And Escape Velocity, Megan N. Mosier

Graduate Theses/Dissertations

Producing and carrying eggs is energetically costly and therefore can affect behavior. Female Southern Red-backed Salamanders (Plethodon serratus) in the Ozarks reproduce biennially, and so during the reproductive season some females are gravid and some are non-gravid. In this study, we compared the exploratory and aggressive behaviors of gravid females, non-gravid females, and males, as well as the escape velocities of each sex class. In exploratory trials, sex did not affect distance travelled, but gravid females and males showed shorter latencies to move than non-gravid females during the winter. During the aggression trials, individuals were subjected to a …

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Decomposition And Macroinvertebrate Shredder Colonization Of Autumnal Shed Sycamore Leaves In Mining-Contaminated Streams, Leslie Marie Hatch Jan 2022

Decomposition And Macroinvertebrate Shredder Colonization Of Autumnal Shed Sycamore Leaves In Mining-Contaminated Streams, Leslie Marie Hatch

Graduate Theses/Dissertations

Leaf decomposition in streams is an important ecological function facilitated by bacteria, fungi, and macroinvertebrates. Metal contamination can decrease leaf decomposition rates and reduce macroinvertebrate abundance and diversity. In the current study, I focused on mining-contamination in well-buffered streams in two different Missouri mining districts with varying extents of mining contamination, Big River and Pierson Creek. I measured decomposition rates of sycamore leaves, and abundance and diversity of macroinvertebrate shredders in leaf pack experiments with a full-factorial design to determine the effects of metal contamination of leaves and stream substrates. Comparisons were made between leaf packs upstream and downstream of …

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Synthesis Of Novel Nio/Comn2o4 Heterostructured Nanoparticles And The Effects Of Variable Size And Metal Concentrations On Their Magnetic And Surface Chemical Properties, Farhan Ishrak Jan 2022

Synthesis Of Novel Nio/Comn2o4 Heterostructured Nanoparticles And The Effects Of Variable Size And Metal Concentrations On Their Magnetic And Surface Chemical Properties, Farhan Ishrak

Graduate Theses/Dissertations

I studied the effect of core size and metal concentration on the structural, morphological, and magnetic properties of NiO-based magnetic heterostructured nanocrystals (HNCs) generated hydrothermally. The NiO nanocrystals were created by a thermal decomposition technique, while the surrounding Mn and Co-based phases were created through a hydrothermal procedure, with core diameters ranging from 9.31 nm to 24.51 nm and total metal concentrations of 0.05 M and 0.08 M. The resulting inverted AFM-FiM NiO/CoMn2O4 bimagnetic systems make up the heterostructured nanocrystals. The magnetic HNCs were thoroughly characterized using XRD, SEM-EDX, TEM, PPMS magnetometry, and XPS analysis. Investigations into the structure of …

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Public Perceptions Of Human Physical Interactions, Exhibition, And Conservation Of Tigers And Cheetahs, Abbie Knudsen Jan 2022

Public Perceptions Of Human Physical Interactions, Exhibition, And Conservation Of Tigers And Cheetahs, Abbie Knudsen

Graduate Theses/Dissertations

Tigers and cheetahs are common in the pet trade, public exhibits, and hands-on encounters with the public. Poor regulation of these experiences has resulted in numerous incidents worldwide in which a person was seriously injured or killed by captive big cats. Additionally, concerns for animal welfare have been raised by industry professionals. Prior research on primates has demonstrated exposing people to photographs of cats in different backgrounds can influence their attitudes about animals in captivity, but no study has addressed whether visual images affect human attitudes toward big cats. I used a survey that asked a series of questions about …

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Us Strategic Culture, Homeland Ballistic Missile Defense, And Mutual Vulnerability, Jacob T. Blank Jan 2022

Us Strategic Culture, Homeland Ballistic Missile Defense, And Mutual Vulnerability, Jacob T. Blank

Graduate Theses/Dissertations

Strategic scholars have long understood the indispensable linkage between culture and security policymaking. By shaping the perceptions through which decision-makers formulate security policy, strategic culture analysis adds vital context to the perilously difficult science of understanding and predicting state security outputs. One area where this analytical framework fails to generate the expected result is American missile defense policy. Salient themes of US strategic culture, including an optimistic and problem-solving mindset, positive role of machines, and ahistorical exceptionalism, are reflected in the American way of war – a technologically driven, leadership casualty averse, moralistic, apolitical, and firepower focused enterprise. These factors …

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ผลของนาโนแคลเซียมคาร์บอเนตต่อสมบัติของคอมพอสิตยางธรรมชาติที่พลาสติไซส์ด้วยน้ำมันพืช, กนกภรณ์ เลิศกาญจนาพร Jan 2022

ผลของนาโนแคลเซียมคาร์บอเนตต่อสมบัติของคอมพอสิตยางธรรมชาติที่พลาสติไซส์ด้วยน้ำมันพืช, กนกภรณ์ เลิศกาญจนาพร

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อปรับปรุงสมบัติของยางธรรมชาติเพื่อนำไปใช้ในผลิตภัณฑ์ที่ไม่ต้องการสีดำ โดยการเสริมแรงด้วยตัวเติมเสริมแรงทดแทนผงเขม่าดำ ได้แก่ แคลเซียมคาร์บอเนตแบบดั้งเดิม (PCC) และ นาโนแคลเซียมคาร์บอเนต (NCC) ที่มีการควบคุมขนาดและรูปร่างอนุภาค นอกจากนี้ยังต้องการทดแทนพลาสติไซเซอร์จากน้ำมันแร่ (MO) ด้วยน้ำมันรำข้าว (RBO) เริ่มจากผสมยางคอมพาวนด์ที่มีการแปรสัดส่วนของ PCC ที่ 0 10 20 30 40 และ 50 phr เปรียบเทียบพลาสติไซเซอร์น้ำมัน MO กับ น้ำมัน RBO ที่สัดส่วนคงที่ 5 phr ร่วมกับสารเคมีอื่นที่จำเป็นสำหรับการคงรูป ขึ้นรูปเป็นชิ้นงานด้วยการคงรูปที่อุณหภูมิ 160 องศาเซลเซียส จากผลการทดลองพบว่าPCC ที่พลาสติไซส์ด้วยน้ำมัน RBO ให้สมบัติทางกายภาพ สมบัติเชิงกล รวมถึงสัณฐานวิทยาที่ใกล้เคียงกับน้ำมัน MO ดังนั้นน้ำมัน RBO สามารถเป็นพลาสติไซเซอร์แทนน้ำมัน MO ได้ จากนั้นผสมยางคอมพาวนด์ที่มีการแปรสัดส่วนของ NCC ที่ 0 20 40 50 60 และ 80 phr และน้ำมัน RBO ที่สัดส่วนคงที่ 5 phr ร่วมกับสารเคมีอื่นที่จำเป็นสำหรับการคงรูป ขึ้นรูปเป็นชิ้นงานด้วยการคงรูปที่อุณหภูมิ 160 องศาเซลเซียส จากผลการทดลองพบว่าเมื่อเพิ่มปริมาณ NCC ส่งผลให้ปฏิกิริยาการวัลคาไนเซชันของคอมพอสิตยางธรรมชาติเกิดได้เร็วขึ้น เวลายางสกอร์ช (Ts2) และ เวลายางสุก (Tc90) มีแนวโน้มลดลง เนื่องจาก NCC มีอนุภาคขนาดเล็ก พื้นที่ผิวมาก นำความร้อนได้ดี และสามารถกระจายตัวในยางได้สม่ำเสมอ สำหรับสมบัติเชิงกลในด้านแรงดึงพบว่าสัดส่วน NCC ที่เหมาะสมคือ 50 phr มีค่าความทนแรงดึง 27.0 MPa อย่างไรก็ตามเมื่อสัดส่วนของตัวเติมเพิ่มเป็น 60 phr ขึ้นไป ตัวเติมเสริมแรงเริ่มเกาะกลุ่มกันเป็นก้อนส่งผลให้ความทนแรงดึงเริ่มลดลง จากภาพสัณฐานวิทยาพบว่า NCC มีการกระจายตัวในเนื้อยางสม่ำเสมอ ไม่เกิดช่องว่างระหว่างสารตัวเติมกับเนื้อยาง …

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Development Of Screen-Printed Electrochemical Sensor For Determination Of Uric And Oxalic Acids, Anurak Weingkum Jan 2022

Development Of Screen-Printed Electrochemical Sensor For Determination Of Uric And Oxalic Acids, Anurak Weingkum

Chulalongkorn University Theses and Dissertations (Chula ETD)

Uric acid (UA) and oxalic acid (OA) are biomarkers for various biochemical processes and are associated with an increased risk of diseases such as gout, cardiovascular disease, and renal stones. Therefore, the development of sensitive and reliable sensors to monitor the levels of UA and OA is crucial. In this study, we have developed portable and cost-effective electrochemical sensors by utilizing a screen-printed graphene electrode (SPGE). To enhance sensitivity and selectivity, the sensors were modified with bimetallic copper-palladium (Cu-Pd) nanoparticles and monometallic copper (Cu) nanoparticles, along with a molecularly imprinted polymer (MIP). The SPGE modified with Cu-Pd was fabricated through …

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Non-Invasive Wearable Chemical Sensor For Detection Of Sweat Biomarker, Thidarut Laochai Jan 2022

Non-Invasive Wearable Chemical Sensor For Detection Of Sweat Biomarker, Thidarut Laochai

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation focuses on the development of a non-invasive wearable chemical sensor for the detection of sweat biomarkers using electrochemical techniques. This dissertation can be divided into two parts. In the first part, a thread-based electrochemical immunosensor was developed for the detection of cortisol to identify adrenal disorder. The conductive threads were modified with MXene, gold nanoparticles and L-cysteine to increase conductivity and specific surface area for antibody immobilization leading to enhanced sensitivity. To create the cortisol immunosensor, anti-cortisol is immobilized on the modified electrode by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide coupling agents. The sensing mechanism is based on the …

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3d Printing And Shape Memory Of Silicone Acrylate Polymers, Aphiwat Pongwisuthiruchte Jan 2022

3d Printing And Shape Memory Of Silicone Acrylate Polymers, Aphiwat Pongwisuthiruchte

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this research is to develop a novel UV curable resin as a 3D printing material which possesses shape memory properties. The first part of the study focuses on formulating acrylate-based resins by combining low-cost polypropylene glycol (PPG) with a commercial acrylate-based resin. The effects of PPG content on the printability, thermal, mechanical, and thermomechanical properties of the formulated resins were studied. The results show that the mechanical properties of the printed parts were successfully enhanced at a small loading of 5%vol. However, a higher PPG content leads to printing failure and reduced mechanical properties. The degree of …

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Qualitative Analysis Of Agarwood Oil By Two-Dimensional Thin Layer Chromatography, Phawida Yodthongchai Jan 2022

Qualitative Analysis Of Agarwood Oil By Two-Dimensional Thin Layer Chromatography, Phawida Yodthongchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

A comprehensive two-dimensional thin layer chromatography (2D-TLC) has been developed for the separation of agarwood oil. The system employed a single stationary phase of silica gel 60 and two different mobile phases from the set of 9:1 (v/v) hexane/ethyl acetate, 1:1 (v/v) hexane/dichloromethane, dichloromethane, and acetonitrile. The best mobile phase system was found to be dichloromethane and 9:1 (v/v) hexane/ethyl acetate in the first and second dimensional separations, respectively. This showed the greater separation results with the orthogonality (A0) of 0.6636 based on the asterisk approximation which separated 14 spots of the agarwood sample compared with 9 spots separated by …

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Effect Of Goethite On Arsenic Migration Under Different Ph And Dissolved Organic Carbon Content, Kunchalika Thongmueang Jan 2022

Effect Of Goethite On Arsenic Migration Under Different Ph And Dissolved Organic Carbon Content, Kunchalika Thongmueang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Currently, the problem of detecting various heavy metals is widely observed. It is essential to consider the impact on groundwater. This study aims to investigate the effect of goethite on the mobility of arsenite (As(III)) under different pH conditions, which is divided into 2 parts. In the first part, batch experiments were conducted at different pH levels (pH 4-10) to determine the sorption efficiency for As(III) and goethite (Gt.). Furthermore, the sorption rates of As(III) and Gt., As(III) and Gt. with humic acid (HA), and As(III) and HA were determined at various concentrations (20-100 mg/l As(III)). In the second part, …

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Production Of Jet-Fuel Range Hydrocarbons From Methanol Through The One-Pot Cascade Reactions In A Fixed-Bed Reactor, Natthanicha Prawiset Jan 2022

Production Of Jet-Fuel Range Hydrocarbons From Methanol Through The One-Pot Cascade Reactions In A Fixed-Bed Reactor, Natthanicha Prawiset

Chulalongkorn University Theses and Dissertations (Chula ETD)

The demand for sustainable and efficient processes for the production of jet fuel range hydrocarbons has been increasing due to the environmental concerns associated with conventional fossil fuel sources. The research focuses on the development and optimization of a catalytic system capable of converting methanol, which can be produced from carbon dioxide, into jet-fuel range hydrocarbons through one-pot cascade reactions in a fixed-bed reactor. The study begins with catalyst screening, HZSM-5 catalyst with a high SiO­2/Al2O3 ratio of 322 was chosen for the firstly converted methanol into light olefins intermediate, and the HZSM-5 catalyst with SiO­2/Al2O3 ratio of 40 was …

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Strain Gradient Shear Deformation Microshells: Formulation, Isogeometric Analysis, And Optimization, Toan Minh Le Jan 2022

Strain Gradient Shear Deformation Microshells: Formulation, Isogeometric Analysis, And Optimization, Toan Minh Le

Chulalongkorn University Theses and Dissertations (Chula ETD)

The rapid development of micro-electro-mechanical system (MEMS) technology has empowered the fabrication of micro-sized, light weighted, and flexible thin-walled components. Due to the complex inherent physics and costly experiments at the microscale, reliable theoretical and numerical instruments for modeling and assisting the design of these innovative structures become desirable. This thesis, therefore, devotes to proposing a general strain-gradient-based shell model, a robust computational formulation, and efficient optimization approaches for microshells. The heart of the novel microshell model is based on the integration between the complete type-II formulation of Mindlin’s strain gradient elasticity, in which the importance of both strain-gradient and …

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เมมเบรนชนิดเส้นใยนาโนแบบกรีนจากพอลิไวนิลแอลกอฮอล์สำหรับการกรองอนุภาคละเอียด, ฐิตาพร ชิตจุ้ย Jan 2022

เมมเบรนชนิดเส้นใยนาโนแบบกรีนจากพอลิไวนิลแอลกอฮอล์สำหรับการกรองอนุภาคละเอียด, ฐิตาพร ชิตจุ้ย

Chulalongkorn University Theses and Dissertations (Chula ETD)

สถานการณ์ฝุ่นละอองขนาดเล็ก (PM2.5) ในปัจจุบันที่ยังคงปรากฏให้เห็นในประเทศไทย โดยเฉพาะฤดูหนาว ส่งผลกระทบและผลเสียต่าง ๆ อย่างมากในแง่ของสุขภาพ หน้ากากกรองอากาศเป็นหนึ่งในอุปกรณ์ที่จำเป็นเพื่อหลีกเลี่ยงและป้องกันปัญหาในสุขภาพ งานวิจัยนี้มุ่งเน้นและให้ความสนใจในเรื่องของการเตรียมเมมเบรนจากพอลิไวนิลแอลกอฮอล์ เพื่อนำมาประยุกต์ใช้เป็นแผ่นกรองอากาศ โดยเฉพาะสามารถกรองฝุ่นละอองขนาดละเอียด (particulate matter, PM2.5) ได้ พอลิไวนิลแอลกอฮอล์เป็นพอลิเมอร์ที่เป็นมิตรต่อสิ่งแวดล้อม ซึ่งนำมาขึ้นรูปเส้นใยนาโนโดยเตรียมจากกระบวนการขึ้นรูปด้วยเทคนิคการปั่นเส้นใยด้วยไฟฟ้าสถิต หรือที่เรียกว่า “อิเล็กโตรสปินนิง” ซึ่งกระบวนการนี้ทำให้เส้นใยที่ได้มีขนาดเล็กในระดับนาโนเมตร มีรูพรุนจำนวนมาก ซึ่งส่งผลต่อพื้นผิวการใช้งานของแผ่นกรองในการใช้งานฟังก์ชันต่าง ๆ จึงเหมาะสำหรับการนำมาขึ้นรูปเป็นเส้นใยนาโนจากพอลิไวนิลแอลกอฮอล์ และการนำไปใช้เป็นเมมเบรนในการกรองอากาศ จากผลการเตรียมเมมเบรนชนิดเส้นใยนาโนอิเล็กโตรสปัน พบว่า จากการเตรียมขึ้นรูปเส้นใยนาโนใช้พารามิเตอร์ที่ความเข้มข้นของสารละลาย 10%wt, ศักย์ไฟฟ้า 20 kV, และ ระยะการปั่น 14 cm เส้นใยนาโนที่ได้มีขนาดเส้นผ่านศูนย์กลางเฉลี่ยอยู่ที่ 235 ± 70 nm ซึ่งอยู่ระหว่าง 100 - 300 นาโนเมตร และมีขนาดเส้นผ่านศูนย์กลางลดลงเฉลี่ยอยู่ที่ 224 ± 53 nm เมื่อทำการเชื่อมขวางด้วยกรดซิตริก 10% และให้ความร้อนแก่เส้นใยนาโนที่อุณหภูมิ 120 และ 140 องศาเซสเซียส พบว่า ขนาดเส้นผ่านศูนย์กลางอยู่ที่ 189 ± 60 nm และ 161 ± 60 nm ซึ่งลักษณะสัณฐานวิทยาของเส้นใยจะมีความสม่ำเสมอ เรียงกันแบบไม่ถักทอ (non-woven fabric) และไม่มีปุ่มปม นอกจากนี้เมื่อคัดเลือกนำเส้นใยทั้ง 3 ชนิด ได้แก่ เมมเบรนชนิดที่ 1 เส้นใยที่ไม่ได้รับการเชื่อมขวางจากกรดซิตริกจากการเตรียมสารละลายที่ความเข้มข้นของสารละลาย 10%wt โดยใช้ศักย์ไฟฟ้า 20 kVและ ระยะการปั่น 14 cm ถัดมาเป็นเมมเบรนชนิดที่ 2 และ 3 เส้นใยที่ได้รับการเชื่อมขวางด้วยกรดซิตริกที่อุณหภูมิ 120 และ 140 องศาเซสเซียส ตามลำดับ ไปทำการทดสอบประสิทธิภาพการกรองอากาศ พบว่า …

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การบำบัดน้ำล้างดินที่มีการปนเปื้อนน้ำมันปิโตรเลียมด้วยระบบฟอร์เวิร์ดออสโมซิส, ลลิตา หลำพึ่ง Jan 2022

การบำบัดน้ำล้างดินที่มีการปนเปื้อนน้ำมันปิโตรเลียมด้วยระบบฟอร์เวิร์ดออสโมซิส, ลลิตา หลำพึ่ง

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้เป็นการศึกษา การบำบัดน้ำล้างดินจากดินปนเปื้อนน้ำมันปิโตรเลียมด้วยวิธีฟอร์เวิร์ดออสโมซิส และประสิทธิภาพในการล้างดินของสารละลายที่เป็นมิตรต่อสิ่งแวดล้อม โดยทำการสังเคราะห์ดินปนเปื้อนน้ำมันที่ใช้ในการทดลองมีความเข้มข้น เท่ากับ 255,517 มิลลิกรัมต่อกิโลกรัม เมื่อผ่านกระบวนการล้างดินด้วยเอทิลแลคเตต พบว่าน้ำล้างดิน (Rinsed water) มีความเข้มข้นของน้ำมันดีเซลและความเข้มข้นของเอทิลแลคเตต เท่ากับ 267 และ 20,033 มิลลิกรัมต่อลิตร ตามลำดับ ซึ่งนำไปกำหนดช่วงในการออกแบบการทดลอง หาสภาวะการบำบัดที่เหมาะสมของระบบฟอร์เวิร์ดออสโมซิสด้วยวิธีพื้นผิวตอบสนอง (Response surface methodology; RSM) แบบ Central composite design (CCD) โดยมีปัจจัยของสารป้อนที่สนใจทั้งหมด 3 ปัจจัย ได้แก่ ความเข้มข้นของน้ำมันดีเซล ความเข้มข้นของเอทิลแลคเตต และค่าพีเอช จากผลการทดลอง ค่า Normalized flux ใช้เป็นตัวแปรตอบสนองในการวิเคราะห์ พบว่าสภาวะที่เหมาะสม คือ ความเข้มข้นน้ำมันดีเซลและความเข้มข้นของเอทิลแลคเตต เท่ากับ 100 และ 16,000 มิลลิกรัมต่อลิตร ตามลำดับ และค่าพีเอช เท่ากับ 6 โดยค่า Normalized flux สูงสุด เท่ากับ 0.56 หลังเดินระบบ 3 ชั่วโมง พบว่า เมมเบรนยอมให้เอทิลแลคเตตผ่านได้ 1.46 เปอร์เซ็นต์ ในขณะที่ป้องกันการแพร่ผ่านของน้ำมันได้ 98 เปอร์เซ็นต์ นอกจากนี้ การมีตะกอนในระบบจะส่งผลต่อการบำบัดทำให้ Normalized flux ลดลง ซึ่งสารดึงที่ได้จากการบำบัดน้ำล้างดินด้วยฟอร์เวิร์ดออสโมซิส มีประสิทธิภาพในการบำบัดน้ำมันออกจากดินปนเปื้อน เท่ากับ 77 เปอร์เซ็นต์

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Factors Associated With The Utilization Of Preventive Dental Treatments Among Elderly Patients In Faculty Of Dentistry, Chulalongkorn University: A Secondary Data Analysis, Weerachon Panthueng Jan 2022

Factors Associated With The Utilization Of Preventive Dental Treatments Among Elderly Patients In Faculty Of Dentistry, Chulalongkorn University: A Secondary Data Analysis, Weerachon Panthueng

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objective: This study aimed to explore the potential factors associated with utilization of preventive dentistry among elderly patients attending a university dental hospital in Thailand. Materials and methods: The research design of this study was a cross-sectional study. This study used secondary data from a cross-sectional study from undergraduate project, conducted completely during July 2021- January 2022 for independent data and dependent variable from dental hospital resource system. The participants were 363 elderly patients who were both males and females in Faculty of Dentistry Chulalongkorn University. Descriptive statistics, chi-square test, and binary logistic regression were performed to analyze the data. …

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A Risk-Based System For Managing Construction Claim Causes: An Integrated Interpretative Structural Modeling And Bayesian Network Approach, Sang Quang Van Jan 2022

A Risk-Based System For Managing Construction Claim Causes: An Integrated Interpretative Structural Modeling And Bayesian Network Approach, Sang Quang Van

Chulalongkorn University Theses and Dissertations (Chula ETD)

Claims are troublesome and often lead to adverse impacts on construction projects, such as delays, cost overruns, and disputes among contracting parties. Numerous studies have been conducted to improve the understanding of claim causes; however, most previous research works have investigated claim causes individually and ignored the interdependences among claim causes. In addition, the determination of response strategies and methods for claim causes has scarcely been addressed. This research develops a risk-based system for managing claim causes in building construction projects. The main objectives of this research are twofold: (1) to quantify the impacts of claim causes considering their interdependences, …

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Occupational Hazards And Mental Health Among Myanmar Migrant Workers In Samut Sakhon Province, Thailand, Myo Myint Kyaw Jan 2022

Occupational Hazards And Mental Health Among Myanmar Migrant Workers In Samut Sakhon Province, Thailand, Myo Myint Kyaw

Chulalongkorn University Theses and Dissertations (Chula ETD)

Background: Myanmar migrant workers play a crucial role in the local workforce, especially in industries like seafood processing and manufacturing. These workers frequently encounter difficult working conditions and are exposed to various occupational hazards, which can negatively affect both their physical and mental well-being. Despite the significance of this issue, only limited research has been conducted to explore the connection between occupational hazards and mental health among this vulnerable population. Objective: To study an association between occupational hazards and levels of depression, anxiety, and stress among Myanmar migrant workers in Samut Sakhon Province, Thailand Method: A cross-sectional survey was conducted …

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Factors Associated With The Dental Attendance Among Elderly Patients In Faculty Of Dentistry, Chulalongkorn University: A Secondary Data Analysis, Narongrit Nampikul Jan 2022

Factors Associated With The Dental Attendance Among Elderly Patients In Faculty Of Dentistry, Chulalongkorn University: A Secondary Data Analysis, Narongrit Nampikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objective: To identify the predisposing factors, enabling factors, and need factors related to dental attendance of elderly patients at dental hospitals, Faculty of Dentistry, Chulalongkorn University using the conceptual framework of the Anderson model. Materials and methods: this study was a secondary analysis study. The participants were 402 elderly patients who were both males and females. Data was collected from telephone questionnaires and dental records of dental hospitals. Faculty of Dentistry Chulalongkorn University. Data were analyzed using chi-square statistics and binary logistic regression analysis. Results: age was the only predisposing factor that was statistically significantly associated with dental attendance among …

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Treatment-Seeking Time Of Patients With Malaria At Private General Practitioners In Myanmar: A Secondary Data Analysis Of Routine Surveillance Data (2018-2022), Pyi Thein Khine Jan 2022

Treatment-Seeking Time Of Patients With Malaria At Private General Practitioners In Myanmar: A Secondary Data Analysis Of Routine Surveillance Data (2018-2022), Pyi Thein Khine

Chulalongkorn University Theses and Dissertations (Chula ETD)

Malaria is a significant global health burden, and prompt treatment is essential for optimum results. Due to their accessibility and convenience, populations in high-risk areas of malaria commonly seek treatment in the private health sector. This study aimed to investigate the factors associated with the delayed treatment-seeking time of patients with malaria at private general practitioners in Myanmar. The secondary data analysis of routine surveillance data included a sample of 4,939 patients with malaria who sought treatment from private quality general practitioners under the Myanmar Medical Association Malaria Project. Nearly 80% of patients sought treatment later than 24 hours and …

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Medical Service Utilization Among International Tourists In Bangkok, Thailand, Ken Lin Jan 2022

Medical Service Utilization Among International Tourists In Bangkok, Thailand, Ken Lin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Medical service utilization is an important concern for international travelers during their trip, especially after the serious COVID-19 pandemic worldwide. In this study, we aim to investigate the medical service utilization and satisfaction among international tourist in Bangkok after the country reopening for international tourist in October 2022.The international tourist in Bangkok was interviewed using the validated questionnaire related to travel information, medical services utilization, and satisfaction. Google form was sent out through social medica platforms, as well as face-to-face interviews at tourist gathering places. In total, 422 participants answered the questionnaire. Taiwan, China, Malaysia, Japan, and South Korea were …

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Cross-Cultural Adaptation And Psychometric Evaluation Of The Myanmar Version Of Oswestry Disability Questionnaire And Roland-Morris Disability Questionnaire For Individuals With Low Back Pain, Phyu Sin Oo Jan 2022

Cross-Cultural Adaptation And Psychometric Evaluation Of The Myanmar Version Of Oswestry Disability Questionnaire And Roland-Morris Disability Questionnaire For Individuals With Low Back Pain, Phyu Sin Oo

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to develop cross-culturally adapted Myanmar versions of the Oswestry Disability Questionnaire (M-ODQ) and Roland-Morris Disability Questionnaire (M-RMDQ), and determine their psychometric properties in individuals with low back pain (LBP). In accordance with the previous guidelines, the original ODQ and RMDQ were translated and cross-culturally adapted into a Myanmar language. The psychometric evaluation of the adapted M-ODQ and M-RMDQ were conducted on 102 individuals with LBP for assessing reliability, validity, and responsiveness. Reliability was assessed using the intraclass correlation coefficient (ICC 2,1) while concurrent and construct validity were examined using the Spearman rank correlation coefficient and correlations with …

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Dental Health Expenditure And Associated Factors Among Elderly Patients In Faculty Of Dentistry, Chulalaongkorn University, Rawitsara Suwannimit Jan 2022

Dental Health Expenditure And Associated Factors Among Elderly Patients In Faculty Of Dentistry, Chulalaongkorn University, Rawitsara Suwannimit

Chulalongkorn University Theses and Dissertations (Chula ETD)

The affordability has been one of the barriers to access dental care for elderly. However, In Thailand and among the elderly, there were very few studies about dental health expenditure and the factors related to it. This study aimed to investigate and identify the factors that are related to dental health expenditure for patients who are over 60 years old and receive treatment at the Faculty of Dentistry, Chulalongkorn University. This study used secondary data from an initial survey and the Medical Record System for oral treatments, among the patients who were over 60 years and received treatments at the …

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Development Of Polymer Blends Of Poly(Methyl Methacrylate) And Poly(Lactic Acid) As Denture Base Material, Taksid Charasseangpaisarn Jan 2022

Development Of Polymer Blends Of Poly(Methyl Methacrylate) And Poly(Lactic Acid) As Denture Base Material, Taksid Charasseangpaisarn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, poly(lactic acid) (PLA) usage in dentistry is increasing due to its mechanical and physical properties close to those of poly(methyl methacrylate) (PMMA). However, the thermal properties of PLA is poor due to its low glass transition temperature, which leads to distortion when used in high temperatures. The blending of polymers is an easy and cost-effective method to improve the desired properties of polymers. The objective of this study was to develop the PMMA/PLA blend in various compositions for use as denture base materials. The three PMMA/PLA blend compositions (M75, M50, and M25) were conducted by melt blending with a …

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Fate And Transport Of Atrazine In Various Agricultural Soils: Experiments And Modelling Studies, Nanchaphorn Udomsri Jan 2022

Fate And Transport Of Atrazine In Various Agricultural Soils: Experiments And Modelling Studies, Nanchaphorn Udomsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to explain the fate and transport of atrazine considering adsorption and degradation through different agricultural soils in tropical areas by batch and soil column experiments with mathematical modeling. Therefore, the solute transport of atrazine at low and high concentrations was simulated using HYDRUS-1D with two-site sorption (chemical nonequilibrium) model under steady-state water flow conditions. Three distinct soils collected from a sugarcane field in Suphan Buri Province, Thailand, identified as Chantuk (Cu) or loamy sand, Ladya (Ly) or sandy loam, and Doembang (Db) or loam soil, were characterized. The atrazine sorption isotherms were well fitted by the Freundlich …

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Comparison On The Effects Of Tiletamine/Zolazepam And Dexmedetomidine With And Without Tramadol Combination Undergoing Calvarial Surgery In Rats., Kaewkarn Manomaya Jan 2022

Comparison On The Effects Of Tiletamine/Zolazepam And Dexmedetomidine With And Without Tramadol Combination Undergoing Calvarial Surgery In Rats., Kaewkarn Manomaya

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to evaluate the perioperative anesthetic quality of a dexmedetomidine and tiletamine/zolazepam combination with or without tramadol during rat calvarial surgery. The study employed adult male Wistar rats (Rattus norvegicus), intraperitoneal (IP) administered with a combination of dexmedetomidine (0.1 mg/kg) and tiletamine/zolazepam (25 mg/kg) - referred to as the DZ group, or the addition of tramadol (12.5 mg/kg) - referred to as the DZT group. The procedures have been approved by the Institutional Animal Care Committee, Chulalongkorn University Laboratory Animal Center. The key parameters for anesthetic quality assessment were anesthetic achievement, the onset of induction, and the onset …

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