Digital Commons Network^™

Modelling Lagrangian Velocity And Acceleration In Turbulent Flows As Infinitely Differentiable Stochastic Process, Bianca Fontanin Viggiano, Jan Friedrich, Romain Volk, Mickael Bourgoin, Raúl Bayoán Cal, Laurent Chevillard

Mechanical and Materials Engineering Faculty Publications and Presentations

We develop a stochastic model for Lagrangian velocity as it is observed in experimental and numerical fully developed turbulent flows. We define it as the unique statistically stationary solution of a causal dynamics, given by a stochastic differential equation. In comparison to previously proposed stochastic models, the obtained process is infinitely differentiable at a given finite Reynolds number, and its second-order statistical properties converge to those of an Ornstein-Uhlenbeck process in the infinite Reynolds number limit. In this limit, it exhibits furthermore intermittent scaling properties, as they can be quantified using higher-order statistics. To achieve this, we begin with generalizing …

Actionable Patient Safety Solution (Apss) #3d: Pediatric Adverse Drug Events, Ron Jordan, Jerika Lam, Nathaniel Sims, Sun Coco Yang, Christopher Jerry

Pharmacy Faculty Articles and Research

Preventing ADEs in pediatric patients poses unique challenges because children are particularly vulnerable to adverse outcomes from medication errors (preventable adverse events due to wrong medication use). However, it can create a safety culture, which is a culture that promotes patient safety and quality of care while reducing preventable risks and harm.

Crowdsourcing Image Extraction And Annotation: Software Development And Case Study, Ana Jofre, Vincent Berardi, Kathleen P.J. Brennan, Aisha Cornejo, Carl Bennett, John Harlan

Psychology Faculty Articles and Research

We describe the development of web-based software that facilitates large-scale, crowdsourced image extraction and annotation within image-heavy corpora that are of interest to the digital humanities. An application of this software is then detailed and evaluated through a case study where it was deployed within Amazon Mechanical Turk to extract and annotate faces from the archives of Time magazine. Annotation labels included categories such as age, gender, and race that were subsequently used to train machine learning models. The systemization of our crowdsourced data collection and worker quality verification procedures are detailed within this case study. We outline a data …

Removal Of Blocking Artifacts From Jpeg-Compressed Images Using Neural Network, Md Nurul Amin

Theses and Dissertations

The goal of this research was to develop a neural network that will produce considerable improvement in the quality of JPEG compressed images, irrespective of compression level present in the images. In order to develop a computationally efficient algorithm for reducing blocky and Gibbs oscillation artifacts from JPEG compressed images, we integrated artificial intelligence to remove blocky and Gibbs oscillation artifacts. In this approach, alpha blend filter [7] was used to post process JPEG compressed images to reduce noise and artifacts without losing image details. Here alpha blending was controlled by a limit factor that considers the amount of compression …

Self-Efficacy Of Nacep Accredited Concurrent-Enrollment Program Instructors In Rural Community Colleges, Cecil B. Holland

Theses and Dissertations

Across the United States, high schools and community colleges are collaborating to offer students non-traditional educational programs that allow them to gain college credit including those accredited by the National Alliance of Concurrent Enrollment Partnerships (NACEP). Those teaching these classes must have high self-efficacy and enjoy their work if they are going to make a positive impact on the students they are educating. The theoretical framework for this research is based on Bandura’s Self-Efficacy Theory. The methodology for this qualitative research study utilized an integrated approach. Data collection consisted of one-on-one interviews with instructors who teach NACEP courses, administrators who …

Case Judgments And Juror Perceptions Of The Stereotypical Defendant, Mariah Sorby

Theses and Dissertations

Stereotypes and prejudice have been shown to bias information processing and decision making. There are physical traits that are stereotypically associated with criminals, i.e. tattoos, dark skin-tone, facial untrustworthiness, Afrocentric facial features. These features have been shown to influence verdict decisions and sentencing outcomes. However, there is a paucity of research investigating the additive effects of these features while also considering individual levels of prejudice and egalitarian views. The current research aimed to investigate the effects of several combinations of features on defendant verdict, sentencing, and criminal appearance ratings, rather than assessing the features in isolation, while controlling for prejudice …

Safety Culture In Collegiate Aviation: A Cross-Sectional Analysis Between Multiple Universities, Robert Foster

Theses and Dissertations

A concurrent-embedded mixed method was used to evaluate observed outcomes of safety culture among multiple collegiate aviation programs in the U.S. A hypothesized model that measures the relationships between scales of safety management systems (SMS), safety motivation (mediator), and safety behaviors (safety compliance, safety reporting, and safety participation) was assessed using structural equation modeling/path analysis (SEM/PA). Demographic differences in safety culture were also evaluated. Semi-structured interviews were used further to understand the impacts of SMS on safety culture. Findings suggest significant predictive relationships between SMS and observed safety culture outcomes. There was also a significant mediation role of safety motivation …

Design Of Spouted Fluidized Bed Computational Models For Advanced Energy Applications, Ryder Shallbetter

Theses and Dissertations

Fluidization process technology has been widely studied since its first commercial uses during the 1920s. Initially, developmental progress was slow as fluidized beds are complex in design and often hard to scale up in size. However, with the emergence of computational fluid dynamics (CFD), researchers were able to simulate wide ranges of fluidization and create new fluidization designs to help solve complex problems. This study aims to determine if CFD can be effective in designing spout-fluid beds with draft tubes for advanced energy applications. CFD has been employed for studying the fluidization characteristics, design, and optimization of spouted beds. However, …

Investigating The Impact Of Explanation On Repairing Trust In Ai Diagnostic Systems For Re-Diagnosis, Lamia Alam

Dissertations, Master's Theses and Master's Reports

AI systems are increasingly being fielded to support diagnoses and healthcare advice for patients. One promise of AI application is that they might serve as the first point of contact for patients, replacing routine tasks, and allowing health care professionals to focus on more challenging and critical aspects of healthcare. For AI systems to succeed, they must be designed based on a good understanding of how physicians explain diagnoses to patients, and how prospective patients understand and trust the systems providing the diagnosis, as well as the explanations they expect. In this thesis, I examine this problem across three studies. …

Virus Purification Framework And Enhancement In Aqueous Two-Phase System, Pratik Umesh Joshi

Dissertations, Master's Theses and Master's Reports

Viral infections regularly pose detrimental health risks to humans. Preventing viral infections through global immunization requires the production of large doses of vaccines. The increasing demand for vaccines, especially during pandemics such as COVID-19, has challenged current manufacturing strategy to develop advanced unit operations with high throughput capability. Over the decade, the upstream processing responsible for synthesizing viral products in cell cultures has shown significant success in yielding high titers of viruses and virus-like particles. The progress in the upstream stage has now shifted the bottleneck to the downstream processing (DSP). Overlooked for decades, the DSP responsible for viral product …

A Novel Pixel-Based Multiple-Point Geostatistical Simulation Method For Stochastic Modeling Of Earth Resources, Adel Asadi

Dissertations, Master's Theses and Master's Reports

Uncertainty is an integral part of modeling Earth's resources and environmental processes. Geostatistical simulation technique is a well-established tool for uncertainty quantification of earth systems modeling. Multiple-point statistical (MPS) algorithms are specifically advantageous when dealing with the complexity and heterogeneity of geological data. MPS algorithms take advantage of using training images to mimic physical reality. This research presents a novel and efficient pixel-based multiple-point geostatistical simulation method for mineral resource modeling. Pixel-based simulation implies the sequential modeling of individual points on the simulation grid by borrowing spatial information from the training image and honoring conditioning data points. The developed method …

Stochastic Inversion Integrating Seismic Data, Litho-Facies Physical Properties, And Multiple-Point Geostatistics For Reservoir Characterization, Mohamed Mohamed

Dissertations, Master's Theses and Master's Reports

We proposed a novel seismic inversion approach that integrates the physical properties of litho-facies, and geophysical data, within the multiple-point geostatistical frameworks to reduce the uncertainty in predictions of litho-facies spatial arrangement away from wells or control points. The litho-facies groups (rock-type) in the well locations are defined and conditioned to the distribution of elastic properties, including P-wave velocity (Vp) and facies density (ρ) in the well locations. A conceptual geological model (training image) is utilized within a wavelet-based multiple-point geostatistical simulation (WAVESIM) algorithm to generate litho-facies realizations. In our inversion algorithm, the forward model is created by implementing the …

Modeling Genetic Risk Factor Of Alzheimer's Disease "Sorl1" Using Patient Specific Pluripotent Stem Cells, Kamonchanok Kongsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Alzheimer’s disease is the most common neurodegenerative; cause of dementia and trends to increase in elder society. There is still not cure. A new strategy development for treatment is needed. SORL1 is a major genetic risk factor associated with sporadic AD. It correlates with degrading amyloid beta (Aβ) by sorting to lysosome. SORL1 overexpression has been reported that reduce Aβ production. However, the molecular mechanism that regulate in neurons is still unclear. The purpose of this study is to generate an effective drug discovery platform for identifying molecules that can modulate SORL1 level in human neurons by using induced pluripotent …

Effect Of Food Impaction In The Interproximal Of Implant Supported Fixed Restoration Towards Oral Health Related Quality Of Life, Souknilan Chanthasan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objectives: To investigate the effect of food impaction between dental implant and adjacent teeth to the patients’ quality of life and periodontal/peri-implant tissue conditions. Materials and methods: Patients with implant supported single crown (ISSC) having implant checkup at the Faculty of Dentistry, Chulalongkorn University between July 2019 and July 2020 were recruited. Food impaction was evaluated by either patients’ experience or clinical examination by dentist. Self-administrative Oral impacts on Daily Performance questionnaire was used to assess the effect of food impaction to patients’ quality of life. Clinical and radiographic examination was performed to evaluate periodontal/peri-implant tissue conditions. Results: Totally 178 …

The Deactivation Study Of Titanium Dioxide Catalyst In Thermochemical Processes Via Density Functional Theory, Chinanang Ngamlaor

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, the investigation of catalytic deactivation of TiO2 by coking was performed using DFT. The effect of the Hubbard U, which was varied as U equal 4 to 6 eV and Van der Waal corrections on electronic properties were also investigated. The effect of temperature in the range of 400-1000°C was also studied. This work aims to understand relatives of coke formation, oxygen vacancy, phase transformation. The increment of the Hubbard U values provide a more accurate quantitative cited by the energy gap from the experimental investigation, the appropriate U value of the A-TiO2 (101) is 4 eV, …

Deactivation Of Manganese Dioxide Electrocatalyst In Zinc-Air Batteries Studied Via Density Functional Theory, Puwit Buapin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Manganese dioxide (MnO2) is the effective electrocatalysts used as a cathode for Zn-Air batteries (ZABs) accounted for the acceleration of the oxygen reduction reaction (ORR). There are various studies on the ORR activity of MnO2 rather than deactivation mechanisms. In this work, the deactivation mechanisms of α-MnO2 and β-MnO2 was investigated by density functional theory and computational hydrogen electrode. It was found that, the phase transformation from the α-MnO2 (211) to β-MnO2 (110) shows that the catalyst deactivation is due to the higher overpotential of β-MnO2 (110) making electrocatalyst efficiency low. For Ov surfaces, it illustrates that the performance is …

The Deactivation Of Gamma-Alumina Based Catalyst During Aqueous Phase Reaction Using Density Function Theory, Phakaorn Aphichoksiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, biomass conversion has become a more attractive process to produce fuels and various high-value chemicals from biological materials. From many kinds of catalysts, the metal-supported gamma-alumina (γ-Al2O3) is a widely used catalyst for various transformation processes, especially in the aqueous phase reaction. Typically, coke formation on γ-Al2O3 causes catalyst deactivation in the thermal reaction process. Moreover, incorporation of aqueous phase medium initiates hydroxylation of γ-Al2O3 and phase transformation of γ-AlOOH, leading to the catalyst deactivation. Not only coke formation and phase transformation are the cause of catalytic deactivation, but the oxygen vacancy, changing the activity of the catalyst, should …

การประมาณปริมาตรของมันสำปะหลังโดยใช้กล้อง Rgb-D, ชนิกานต์ บัญชาจารุรัตน์

Chulalongkorn University Theses and Dissertations (Chula ETD)

มันสำปะหลังเป็นพืชที่ปลูกง่ายและปลูกเป็นจำนวนมากในประเทศไทย เครื่องมือที่เกี่ยวข้องในการตรวจวัดคุณภาพมันสำปะหลังหลังการเก็บเกี่ยวจนไปถึงก่อนแปรรูปที่ใช้ในปัจจุบันเป็นเครื่องมือที่ใช้หลักการวัดทางกลพื้นฐานและใช้ความรู้สึกของผู้ประเมินร่วมด้วย ทำให้มีโอกาสที่จะได้ผลประเมินที่ไม่เป็นความจริง วิทยานิพนธ์นี้เสนอแนวทางการตรวจวัดคุณภาพมันสำปะหลังในห่วงโซ่อุปทานโดยใช้กล้อง Kinect ซึ่งเป็นกล้อง RGB-D ถ่ายรูปภาพของหัวมันสำปะหลังเพื่อหาปริมาตรของมันสำปะหลัง การศึกษาทำโดยถ่ายภาพมันสำปะหลังพันธุ์เกษตรศาสตร์ 50 จำนวน 90 ตัวอย่างแล้วนำมาวิเคราะห์หาปริมาตรด้วยโปรแกรม MATLAB และใช้วิธีการประมาณปริมาตรมันสำปะหลัง 2 วิธีได้แก่ การประมาณปริมาตรโดยใช้ Depth image และการประมาณปริมาตรโดยใช้ Point Cloud image ทั้งสองวิธีการนี้มีพื้นฐานมาจากการหาปริมาตรของรูปทรงเรขาคณิต ผลการหาปริมาตรของมันสำปะหลังจากการประมาณด้วยวิธีการ depth image และวิธีการ point cloud image เมื่อนำมาพล็อตกับปริมาตรของมันสำปะหลังที่ได้จากวิธีการแทนที่น้ำให้ค่าความคลาดเคลื่อน RMSE เท่ากับ 66.94 มิลลิลิตรและ 41.4 มิลลิลิตร หรือคิดเป็นร้อยละ 21.12 และ 13.06 ตามลำดับเมื่อเทียบกับค่าเฉลี่ยของปริมาตรของหัวมันสำปะหลังจากวิธีการแทนที่น้ำ และค่า R-squared ที่ได้จากการประมาณทั้งสองวิธีมีค่า 0.9561 และ 0.9626 ดังนั้นจึงสรุปได้ว่าการประมาณปริมาตรหัวมันสำปะหลังด้วยวิธีการใช้รูป point cloud จะดีกว่าจากค่า R-squared ที่มากกว่าและค่า RMSE ที่น้อยกว่า ปริมาตรของมันสำปะหลังที่ประมาณด้วยรูปถ่ายนี้สามารถนำไปประยุกต์หาเปอร์เซ็นต์แป้งมันสำปะหลังได้

กระบวนการพัฒนาโปรแกรมตัวส่งระหว่างโมเดลเชิงวัตถุและเชิงสัมพันธ์ด้วยเทคนิคโลวโค้ดบนโอดู, โสภณวิชญ์ พิชิตเธียรธรรม

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้นำเสนอมอดูลเจนเนอเรเตอร์ ซึ่งเป็นเครื่องมือสำหรับการเขียนโปรแกรมตัวส่งระหว่างโมเดลเชิงวัตถุและเชิงสัมพันธ์บนโอดู โอดูเป็นซอฟต์แวร์อีอาร์พีแบบเปิดเผยรหัสต้นฉบับที่รวบรวมมอดูลที่จำเป็นสำหรับการจัดการธุรกิจต่าง ๆ และผู้พัฒนาสามารถพัฒนามอดูลเพื่อขยายขีดความสามารถของโอดูได้ โดยในช่วงไม่กี่ปีที่ผ่านมาการพัฒนาซอฟต์แวร์บนโอดู มักต้องใช้เวลาในการเรียนรู้เพราะมีความซับซ้อนของเฟรมเวิร์ก จึงมีการนำแนวทางการพัฒนาซอฟต์แวร์แบบโลวโค้ด (การเขียนโค้ดที่น้อยกว่าปกติ) มาใช้ในการพัฒนามอดูลเจนเนอเรเตอร์ขึ้น เพื่อให้เป็นเครื่องมือสำหรับออกแบบและสร้างรหัสต้นฉบับสำหรับมอดูล ทำให้ผู้พัฒนาซอฟต์แวร์บนโอดูไม่ต้องกังวลเรื่องข้อผิดพลาดอันเนื่องมาจากความซับซ้อนของเฟรมเวิร์ก และให้ความสำคัญกับการเขียนโปรแกรมในด้านอื่น ๆ ได้มากขึ้น โดยเครื่องมือนี้ถูกพัฒนาด้วยภาษา ไพธอนให้เป็นเว็บแอปพลิเคชันทำงานบนเว็บเบราว์เซอร์ และได้มีการทดสอบการใช้งานกับทั้งผู้พัฒนามอดูลบนโอดู ผู้ใช้งานโอดูที่มีทักษะการเขียนโปรแกรม ผู้ที่ไม่เคยมีประสบการณ์กับโอดู และอาสาสมัครภายนอกบริษัท ซึ่งได้ผลลัพธ์ว่า ผู้ทดสอบทั้งหมดสามารถพัฒนามอดูลโดยใช้มอดูลเจนเนอเรเตอร์ได้สำเร็จ เครื่องมือนี้จึงสามารถช่วยให้ผู้ที่ไม่มีประสบการณ์ในการพัฒนามอดูลบนโอดูสามารถพัฒนามอดูลขึ้นมาได้โดยใช้เวลาไม่นาน และเมื่อเปรียบเทียบเวลาที่ใช้ในการพัฒนามอดูลของกลุ่มผู้พัฒนามอดูลบนโอดู ระหว่างแบบปกติที่เขียนโค้ดด้วยตนเองกับการใช้ มอดูลเจนเนอเรเตอร์ พบว่าการใช้เครื่องมือนี้สามารถลดเวลาการพัฒนามอดูลโดยเฉลี่ยได้ถึง 20% อีกทั้งมอดูลเจนเนอเรเตอร์ยังนำไปใช้ได้จริงในโครงการการพัฒนาซอฟต์แวร์ของบริษัท

The Hidden Value Of Abandoned Applications To The Patent System, Christopher A. Cotropia, David L. Schwartz

Law Faculty Publications

Some inventors abandon their patent applications without ever receiving a patent. Although patent scholars view such abandoned patent applications as essentially worthless, we question that conventional wisdom. Conducting an empirical analysis of a recently released patent application dataset in light of a 1999 change that requires publication of most abandoned applications, we find that the United States Patent and Trademark Office (USPTO) often uses abandoned applications as “prior art” when examining future patent applications. Abandoned applications thus generate an “administrative disclosure” that prevents the issuance of broader patent rights to later applicants. By narrowing the scope of new patents, abandoned …

Patent-Eligible Subject Matter... Still Wielding The Wrong Weapon - 12 Years Later, Kristen Jakobsen Osenga

Law Faculty Publications

I am delighted to have participated in the Second Annual Intellectual Property Redux Conference and to publish this essay. I rarely look back at my older articles, but in Fall 2018 I was asked to give a keynote address at a conference held by the Biotechnology Innovation Organization (BIO), where the organizers asked me to speak about 35 U.S.C. § 101 and patent-eligible subject matter. In preparing my remarks, I had the opportunity to refer back to one of my earliest scholarly pieces—a 2007 article entitled Ants, Elephant Guns, and Statutory Subject Matter, published in the Arizona State Law Journal.1 …

Upstream Water Flow At Kotri Barrage, Sindh Pakistan, Rakhshinda Bano, Mehdi Khiadani, Steven Burian

Research Datasets

The dataset contains the water flow data at Kotri barrage, Sindh Pakistan

The Effects Of Modulating Accommodative-Vergence Stress Within The Context Of Operator Performance On Automated System Tasks, Kyle Anthony Bernhardt

Theses and Dissertations

Automated systems (e.g., self-driving cars, autopilot) can reduce an operator’s (i.e., driver, pilot, baggage screener) task engagement, which can result in mind wandering, distraction, and loss of concentration. Consequently, unfavorable performance outcomes, such as missed critical signals and slow responses to emergency events, can occur. Because automation reverts the operator to a “visual monitoring” role, the oculomotor accommodative-vergence responses (the oculomotor responses that maintain a single focused image on the retina) may play a vital role in human-automation interactions. Prior research has shown that individuals with deficits in the accommodative-vergence responses can exhibit inattentive symptoms (e.g., poor concentration) characteristic of …

Automated Fractional Snow Cover Monitoring From Near-Surface Remote Sensing In Grassland, Anai Caparo Bellido

Theses and Dissertations

Snow cover is an important variable in both climatological and hydrological studies because of its relationship to environmental energy and mass flux. However, variability in snow cover can confound satellite-based efforts to monitor vegetation phenology.

This research explores the utility of the PhenoCam network cameras to estimate Fractional Snow Cover (FSC) in grassland. The goal is to operationalize FSC estimates from PhenoCams to inform and improve satellite-based determination of phenological metrics.

The study site is the Oakville Prairie Biological Field Station, located near Grand Forks, North Dakota. I developed a mostly semi-automated process to estimate FSC from PhenoCam images through …

Mapping And Quantifying The Spatial Characteristics Of Agricultural Drainage Systems In Red River Valley Of The North, Eohjin Lee

Theses and Dissertations

The purpose of the study is to map agricultural drainage systems (ADS) at the watershed scale using remote sensing and GIS techniques and examine the effect of ADS. For achieving the purpose of the study, this study selected the Red River Valley (RRV) of the North in which agriculture is a primary industry at the region. Excessive nutrients, sediment, and pesticide from this agricultural area flow into the Red River throughout subsurface drainages. The ADS aims to remove excessed water from agricultural fields, and this ADS is divided into two systems - uncontrolled drainage system (UCDS) and controlled drainage system …

Polymer Flooding: Predicting Permafrost Stability For The Wsak And Ugnu Alaska North Slope Reservoirs, Shane Namie

Theses and Dissertations

The heavy oil reserves of the Ugnu and West Sak Formations in Alaska offer major production challenges, including proximity to the permafrost layer and exceptionally high viscosities. Despite deeper reserves, most of the untouched heavy oil deposits in the West Sak and Ugnu sands are at shallow depths with a low API gravity (< 15 degrees). The objective of this study is to evaluate permafrost subsidence while extracting heavy oil from shallow reservoir using polymer flooding. The approach to this study will focus on using geological properties taken from well logs, completion logs and available core data from 32 wells and applying them to a numerical fluid flow model. Calculations were completed for eight cross-sections taking into consideration the following outcomes: Formation tops, permafrost depth, porosity, water saturation, and permeability. Eleven numerical models were created showing polymer flooding is an effective enhanced oil recovery (EOR) process that minimizes permafrost subsidence.

Asylum Under Attack: Is It Time For A Constitutional Right?, Steve Meili

Articles

No abstract provided.

The Invisible Hand Of Evolutionary Psychology: The Importance Of Kinship In First-Generation Family Firms, Xiaodong Yu, Laura Stanley, Yuping Li, Kimberly A. Eddleston, Franz W. Kellermanns

Research Collection Lee Kong Chian School Of Business

While previous studies focus on differences between family and nonfamily firms regarding CEO selection and executive compensation, this study investigates differences among family firms with different types of kinship ties. We find that, compared with family firms with close kinship ties, those with distant kinship ties are more likely to appoint a nonfamily CEO and to pay nonfamily executives lower salaries. This relationship is moderated by firm performance and family ownership. Based on evolutionary psychology, we propose that family firms with close versus distant kinships have different motivation levels to preserve socioemotional wealth.

Forecasting Model For The Transfer Line Exchanger Outlet Temperature Of A Cracking Furnace, Apisara Aungsutarn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to use an application of a data analytic approach to improve the cracking furnace operation since the current process is operated based on past experience without data consideration leading to an inefficient operation. To improve the process, relationships between process input variables to the transfer line exchanger outlet temperature (TLExOT) were studied and the forecasting models for TLExOT were developed as TLExOT is a key parameter which can represent the process conditions. The models were developed to forecast TLExOT for the same day, 1, 3, and 7 days ahead for short and long term analysis. The significant …

Effect Of Hydrochloric Acid Modification On Different Clay Catalystsfor Esterification Of Ethanol And Acetic Acid, Kwanchanok Netcharoen

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to investigate the catalytic performance and characteristics of different clays with 0.5 M hydrochloric acid modification such as montmorillonite (HA-MMT), montmorillonite modified with Al (HA/Al-MMT), and kaolinite (HA-K) as a solid catalysts for esterification of ethanol and acetic acid. The reaction was performed in a batch reactor at 80oC, molar ratio of ethanol/acetic acid at 1.5, atmospheric pressure, and catalyst 10%wt of acetic acid for 1 hour. It revealed that hydrochloric acid-activated did not affect to the main structure and functional group of clays. All catalysts were tested for the catalytic performance in esterification of ethanol and …