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Full-Text Articles in Chemistry

การพัฒนาบล็อกคอนกรีตปูพื้นจากกากของเสียในกระบวนการเผาไหม้แบบฟลูอิไดซ์เบด, ณัฐวรรณ ดวงแก้ว Jan 2023

การพัฒนาบล็อกคอนกรีตปูพื้นจากกากของเสียในกระบวนการเผาไหม้แบบฟลูอิไดซ์เบด, ณัฐวรรณ ดวงแก้ว

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ศึกษาการใช้ประโยชน์เถ้าลอย และทรายของเสีย (ขนาดละเอียดและหยาบ) จากกระบวนการเผาไหม้แบบฟลูอิไดซ์เบดเพื่อนำความร้อนมาใช้ในการอบแห้งในกระบวนการผลิตกระดาษ มาใช้เป็นวัตถุดิบในการเตรียมบล็อกคอนกรีต 2 ประเภทวัสดุ คือ คอนกรีตฐานปูนซีเมนต์ปอร์ตแลนด์ และคอนกรีตฐานจีโอพอลิเมอร์ สำหรับการเตรียมคอนกรีตฐานปูนซีเมนต์ปอร์ตแลนด์ ได้ศึกษาผลของการใช้เถ้าลอยทดแทนส่วนของปูนซีเมนต์ปอร์ตแลนด์ (วัสดุประสาน) และศึกษาอัตราส่วนของทรายของเสีย (มวลรวม) ต่อวัสดุประสาน ที่มีต่อสมบัติของคอนกรีต ขึ้นรูปด้วยวิธีการอัด บ่มชิ้นงานเป็นเวลา 1 7 และ 28 วัน พบว่าตัวอย่างที่มีเถ้าลอยทดแทนปูนซีเมนต์ปอร์ตแลนด์ร้อยละ 15 โดยน้ำหนักของวัสดุประสาน และมีอัตราส่วนของ มวลรวมต่อวัสดุประสาน เท่ากับ 1:1 โดยน้ำหนัก ที่อายุ 7 วัน มีค่ากำลังอัด 45 MPa เป็นไปตามมาตรฐาน มอก.827-2531 นอกจากนั้นยังได้นำส่วนผสมดังกล่าวมาเตรียมบล็อกประสานปูพื้นฐานปูนซีเมนต์ปอร์ตแลนด์ที่มีขนาดและรูปทรงตามมาตรฐานดังกล่าวด้วยเครื่องผลิตบล็อกคอนกรีต พบว่าสามารถเตรียมบล็อกประสานปูพื้นฐานปูนซีเมนต์ปอรต์แลนด์ที่มีเถ้าลอยทดแทนส่วนของปูนซีเมนต์ปอร์ตแลนด์ได้ ในส่วนของการศึกษาความเป็นไปได้ในการผลิตบล็อกฐานจีโอพอลิเมอร์เป็นการทดลองเตรียมจีโอพอลิเมอร์แบบส่วนเดียว โดยใช้เถ้าลอยร่วมกับสารแอลคาไลซึ่งประกอบด้วย โซเดียมซิลิเกตและโซเดียมไฮดรอกไซด์ (วัสดุประสาน) และผสมกับมวลรวมในสัดส่วนของวัสดุประสานต่อมวลรวมเท่ากับ 1:1 เช่นเดียวกับการเตรียมบล็อกคอนกรีตฐานซีเมนต์ ใช้อัตราส่วนผสมน้ำต่อวัสดุประสานเท่ากับ 0.31 ขึ้นรูปด้วยวิธีการอัด โดยศึกษาผลของสัดส่วนของเถ้าลอยต่อสารอัลคาไล และสัดส่วนของโซเดียมซิลิเกตต่อโซเดียมไฮดรอกไซด์ ที่มีต่อสมบัติของคอนกรีต พบว่าชิ้นงานที่ใช้เถ้าลอยร้อยละ 80 โดยน้ำหนักของวัสดุประสาน และใช้สารอัลคาไล (โซเดียมซิลิเกตต่อโซเดียมไฮดรอกไซด์เท่ากับ 60:40 โดยน้ำหนัก) ร้อยละ 20 โดยน้ำหนักของวัสดุประสาน ที่อายุ 28 วัน มีกำลังอัด 5.45 MPa ซึ่งเป็นค่าที่ต่ำกว่าค่าตามมาตรฐาน มอก.827-2531 จึงไม่สามารถใช้ทำบล็อกประสานปูพื้นได้ แต่ค่ากำลังอัดของบล็อกฐานจีโอพอลิเมอร์ก็สูงมากพอสำหรับผลิตบล็อกกลวงไม่รับน้ำหนักตาม มอก.58-2560

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Kinetic Mechanism Of Dimethylsulfone Monooxygenase And Its Immobilized Magnetic Nanoparticles, Montisa Mangkalee Jan 2023

Kinetic Mechanism Of Dimethylsulfone Monooxygenase And Its Immobilized Magnetic Nanoparticles, Montisa Mangkalee

Chulalongkorn University Theses and Dissertations (Chula ETD)

The dimethyl sulfone monooxygenase system is a two-component flavoprotein catalyzing the monooxygenation of dimethyl sulfone (DMSO2) by oxidative cleavage producing methanesulfinate and formaldehyde. The reductase component (DMSR) is a flavoprotein with FMN as a cofactor catalyzing flavin reduction using NADH. The oxygenase (DMSMO) uses reduced flavin from the reductase and oxygen for substrate monooxygenation. DMSMO can bind to FMN and FMNH– with a Kd of 17.4 ± 0.9 µM and 4.08 ± 0.8 mM, respectively. The binding of FMN to DMSMO is required prior to binding DMSO2. Substituting reduced DMSR with FMNH– demonstrated the same oxidation kinetics, indicating that FMNH- …

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การจำลองซีเอฟดีสามมิติของไรเซอร์ดักจับคาร์บอนไดออกไซด์แบบอุณหภูมิไม่คงที่ที่มีท่อน้ำหล่อเย็น, อลีนา ดำเนินสวัสดิ์ Jan 2023

การจำลองซีเอฟดีสามมิติของไรเซอร์ดักจับคาร์บอนไดออกไซด์แบบอุณหภูมิไม่คงที่ที่มีท่อน้ำหล่อเย็น, อลีนา ดำเนินสวัสดิ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

แก๊สเรือนกระจกที่สำคัญและมีปริมาณมากที่สุดคือ แก๊สคาร์บอนไดออกไซด์ แก๊สคาร์บอนไดออกไซด์จากการผลิตไฟฟ้าถือเป็นแหล่งแก๊สเรือนกระจกที่สำคัญ เทคโนโลยีการดักจับแก๊สคาร์บอนไดออกไซด์ทำได้หลายวิธี เช่น การดักจับก่อนการเผาไหม้ การเผาไหม้ด้วยออกซิเจน และการดักจับหลังการเผาไหม้ การศึกษานี้มุ่งเน้นไปที่เทคโนโลยีการดักจับคาร์บอนไดออกไซด์หลังการเผาไหม้โดยใช้เครื่องปฏิกรณ์ฟลูอิไดซ์เบดแบบหมุนเวียนดักจับแก๊สคาร์บอนไดออกไซด์ออกจากแก๊สเผาไหม้ แก๊สเผาไหม้ถูกป้อนเข้าไปยังหอดูดซับเพื่อดูดซับคาร์บอนไดออกไซด์ก่อนที่จะปล่อยออกสู่ชั้นบรรยากาศ โพแทสเซียมคาร์บอเนตบนตัวรองรับแกมมา-อะลูมินาถูกใช้เป็นตัวดูดซับ การวิจัยนี้เป็นการพัฒนาแบบจำลองพลศาสตร์ของไหลเชิงคำนวณของเครื่องปฏิกรณ์ ฟลูอิไดซ์เบดแบบหมุนเวียนที่มีการติดตั้งท่อน้ำหล่อเย็นในไรเซอร์ซึ่งเป็นบริเวณที่เกิดการดักจับแก๊สคาร์บอนไดออกไซด์ อุณหภูมิในเครื่องปฏิกรณ์สามารถเปลี่ยนสมดุลของปฏิกิริยาเพื่อให้สามารถดักจับคาร์บอนไดออกไซด์ได้มากขึ้น เครื่องปฏิกรณ์จำลองเป็นรูปสี่เหลี่ยมจัตุรัสขนาด 0.05 x 0.05 ม. และสูง 1.1 ม. แบบจำลองทางคณิตศาสตร์ที่ใช้คือ แบบออยเลอเรียน-ออยเลอเรียน โดยได้เพิ่มสมการการเกิดปฏิกิริยาเคมีของโพแทสเซียมคาร์บอนเนต คาร์บอนไดออกไซด์ และน้ำเข้าไปด้วย จากการทดสอบแบบจำลองพบว่า จำนวนเซลล์ที่เหมาะสมที่ใช้ในการจำลองคือ 500,000 เซลล์ และช่วงเวลาที่ใช้ในการจำลองจะอยู่ที่ 250 - 500 วินาที ตัวแปรที่ใช้ศึกษาประกอบด้วย ความเร็วของแก๊สขาเข้า ความเร็วของน้ำหล่อเย็น และลักษณะการจัดเรียงท่อน้ำหล่อเย็นภายในหอดูดซับ จากการจำลองกระบวนการพบว่า ตัวแปรที่ส่งผลต่อประสิทธิภาพการดักจับแก๊สคาร์บอนไดออกไซด์ในหอดูดซับอย่างมีนัยสำคัญ คือ ความเร็วของแก๊สขาเข้า และ ลักษณะการจัดเรียงท่อน้ำหล่อเย็นภายในหอดูดซับ ส่วนความเร็วของน้ำหล่อเย็นไม่ส่งผลต่อประสิทธิภาพการดักจับแก๊สคาร์บอนไดออกไซด์อย่างมีนัยสำคัญ

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Development And Assessment Of Gamified Process-Oriented Guided Inquiry Learning Activities In Undergraduate Large Lecture Chemistry Courses, Nathan Turner Jan 2023

Development And Assessment Of Gamified Process-Oriented Guided Inquiry Learning Activities In Undergraduate Large Lecture Chemistry Courses, Nathan Turner

Electronic Theses and Dissertations

Students who take general chemistry and do not perform well are more likely to pursue an alternative degree or remove themselves from STEM curriculum entirely. Poor academic performance and high student attrition rates in general chemistry courses have resulted in the perception of chemistry courses being gatekeepers for students in pursuit of STEM degrees. Process-Oriented Guided Inquiry Learning (POGIL) has shown promising results in both lecture and laboratory teaching on student performance in chemistry while gamification has been used to enhance student learning experiences to help students grasp chemistry concepts. The current project blends two student-centered approaches, gamification and POGIL, …

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Development Of Novel Cellular Assay Model And Therapeutic Deep Eutectic Solvents To Optimize The Activity Of Anticancer Agents, Nizam Uddin Jan 2023

Development Of Novel Cellular Assay Model And Therapeutic Deep Eutectic Solvents To Optimize The Activity Of Anticancer Agents, Nizam Uddin

Electronic Theses and Dissertations

Multidrug resistance (MDR) is the major burden behind chemotherapeutic treatment failure. It is the principal mechanism by which cancer cells evade chemotherapeutic treatment. As a result, aggressive cancer cells survive and continue uncontrolled cell division. Multidrug resistance affects survival rate of almost all types of cancer patients and death toll rises at an alarming rate. There are seven different mechanisms for evolving MDR. The most common mechanism in efflux activity of overexpressed ABC transporters. MRP1 is a prominent ABC transporter that pumps out a wide variety of anticancer drugs from the cells and thereby reduces intracellular drug concentrations and develops …

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Design, Synthesis, And Biological Evaluation Of Novel Steroidal Analogs: Potential Anticancer Agents, Trevor Ostlund Jan 2023

Design, Synthesis, And Biological Evaluation Of Novel Steroidal Analogs: Potential Anticancer Agents, Trevor Ostlund

Electronic Theses and Dissertations

Cancer is a malicious disease with low survivability rates primarily due to lack of reliable treatment options. Treatments are often non-specific for patients, and cancer resistance to treatment is becoming more prevalent as fast as new therapies are created. Previous studies in our laboratory have focused on the Epidermal Growth Factor Receptor (EGFR) and its downstream kinase family members as a key target for cancer. This cascade controls cell proliferation, anti-apoptotic effects, cell regulation, and other survival factors. Additionally, ABC transporters, responsible for efflux of chemotherapeutic material from cells, are key targets to combat drug resistance. We first evaluated a …

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Comprehensive Analysis And Forensic Investigation Of Cyanide, Thiocyanate, And 2-Amino-2-Thiazoline-4-Carboxylic Acid In-Ante- And Postmortem Blood Utilizing Advanced Analytical Techniques, Abdullah Hamad Alluhayb Jan 2023

Comprehensive Analysis And Forensic Investigation Of Cyanide, Thiocyanate, And 2-Amino-2-Thiazoline-4-Carboxylic Acid In-Ante- And Postmortem Blood Utilizing Advanced Analytical Techniques, Abdullah Hamad Alluhayb

Electronic Theses and Dissertations

Cyanide (CN), present as cyanide anion (CN-) or hydrogen cyanide (HCN), is a deadly poison. The main mechanism of CN toxicity is blocking terminal electron transfer, leading to cellular hypoxia, cytotoxic anoxia, and potential death. Determining blood CN concen-trations along with its major metabolite, thiocyanate (SCN-), is crucial. A sensitive method for concurrent detection of CN and SCN- from human ante- and post-mortem blood via liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis was devel-oped. The method involved active microdiffusion with chemical modification using naph-thalene-2,3-dicarboxaldehyde (NDA) and taurine, while monobromobimane (MBB) mod-ification was used for SCN-. The method showed good sensitivity for …

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Synthesis And Kinetic Investigation Of Oxidation In A Palladium-Methyl System, Richard A. Cardrino , '23 Jan 2023

Synthesis And Kinetic Investigation Of Oxidation In A Palladium-Methyl System, Richard A. Cardrino , '23

Senior Theses, Projects, and Awards

The current industrial syngas process for transforming methane to methanol is an indirect process that requires the initial oxidation of methane to carbon monoxide with a subsequent reduction to form methanol under high pressure and temperature conditions. An alternative green chemical process is desirable, especially one that directly oxidizes gaseous methane to liquid methanol under mild conditions with an environmentally benign oxidant, such as dioxygen. The current study investigates the synthesis of a novel palladium complex with activated methane and the selective oxidation of this complex resulting in the liberation of methanol under more ambient conditions, a model system for …

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Exogenous Factors That Impact Huntingtin Aggregation, Adam Skeens Jan 2023

Exogenous Factors That Impact Huntingtin Aggregation, Adam Skeens

Graduate Theses, Dissertations, and Problem Reports (ETD)

While expansion of a polyglutamine (polyQ) domain is the immediate cause of huntingtin (htt) aggregation associated with Huntington’s Disease (HD), other cellular factors modify aggregation. These include interactions with cellular membranes, protein biding partners, molecular crowding, and proteinaceous seeds. Here, two important factors are biophysically characterized: 1) the interaction of htt with endomembranes and 2) proteinaceous seeds obtained from a variety of htt-derived peptides. In the first project, the aggregation of htt at bilayer interfaces and in the presence of divalent cations was investigated. A major cellular factor implicated in altered htt aggregation is the binding of lipids. Furthermore, the …

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Solid State Nmr Analysis Of Insect Wing Membranes, Samuel Eddy Jan 2023

Solid State Nmr Analysis Of Insect Wing Membranes, Samuel Eddy

Graduate Theses, Dissertations, and Problem Reports (ETD)

Solid State NMR is a powerful tool for analyzing the chemical composition of insects. Previous studies have used Solid State NMR to investigate the chemical composition and investigate the sclerotization (tanning) process of insect exoskeletons. Acquiring sufficient exoskeleton sample for analysis has been relatively simple. This is however not the case for other components of an insect’s physiology, particularly the wing membrane material. The wings of an insect only compose a small percentage of their overall body mass, and many hundreds to thousands of insects must be processed in order to achieve a few milligrams of wing membrane sample. The …

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Sound The (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide Pgpp, Areej Malik, Megan A. Hept, Erin B. Purcell Jan 2023

Sound The (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide Pgpp, Areej Malik, Megan A. Hept, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

It has recently become evident that the bacterial stringent response is regulated by a triphosphate alarmone (pGpp) as well as the canonical tetra- and pentaphosphate alarmones ppGpp and pppGpp [together, (p)ppGpp]. Often dismissed in the past as an artifact or degradation product, pGpp has been confirmed as a deliberate endpoint of multiple synthetic pathways utilizing GMP, (p)ppGpp, or GDP/GTP as precursors. Some early studies concluded that pGpp functionally mimics (p)ppGpp and that its biological role is to make alarmone metabolism less dependent on the guanine energy charge of the cell by allowing GMP-dependent synthesis to continue when GDP/GTP has been …

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Infrared Spectra Of Small Radicals For Exoplanetary Spectroscopy: Oh, Nh, Cn, And Ch: The State Of Current Knowledge, Svatopluk Civiš, Adam Pastorek, Martin Ferus, Sergei N. Yurchenko, Noor-Ines Boudjema Jan 2023

Infrared Spectra Of Small Radicals For Exoplanetary Spectroscopy: Oh, Nh, Cn, And Ch: The State Of Current Knowledge, Svatopluk Civiš, Adam Pastorek, Martin Ferus, Sergei N. Yurchenko, Noor-Ines Boudjema

Chemistry & Biochemistry Faculty Publications

In this study, we present a current state-of-the-art review of middle-to-near IR emission spectra of four simple astrophysically relevant molecular radicals—OH, NH, CN and CH. The spectra of these radicals were measured by means of time-resolved Fourier transform infrared spectroscopy in the 700–7500 cm−1 spectral range and with 0.07–0.02 cm−1 spectral resolution. The radicals were generated in a glow discharge of gaseous mixtures in a specially designed discharge cell. The spectra of short-lived radicals published here are of great importance, especially for the detailed knowledge and study of the composition of exoplanetary atmospheres in selected new planets. Today, …

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Thermotrophy Exploratory Study, James Weifu Lee Jan 2023

Thermotrophy Exploratory Study, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

The question of whether environmental heat energy could be utilized as a source of energy for biological metabolism is the center of this exploratory research. In 1979, this author postulated a hypothesis for the existence of thermotrophs that could isothermally utilize environmental heat energy as a source of their energy on Earth. According to this hypothesis, the thermotrophs could be the first primitive forms of life in the early Earth environment. The chemotrophs and phototrophs that we currently are all well familiar with might have been evolved somehow from the primitive thermotrophs. Furthermore, all the organisms currently regarded as the …

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Halogen Bonding Interactions Of Haloaromatic Endocrine Disruptors And The Potential For Inhibition Of Iodothyronine Deiodinases, Craig A. Bayse Jan 2023

Halogen Bonding Interactions Of Haloaromatic Endocrine Disruptors And The Potential For Inhibition Of Iodothyronine Deiodinases, Craig A. Bayse

Chemistry & Biochemistry Faculty Publications

Halogen bonding (XB) is a potential mechanism for the inhibition of the thyroid-activating/deactivating iodothyronine deiodinase family of selenoproteins through interactions with halogenated endocrine disrupting compounds (EDCs). Trends in XB interactions were examined using density functional theory for a series of polyhalogenated dibenzo-1,4-dioxins, biphenyls, and other EDCs with methylselenolate, a simple model of the Dio active site selenocysteine. The strengths of the interactions depend upon the halogen (Br>Cl), the degree of substitution, and the position of the acceptor. In terms of donor-acceptor energies, interactions at the meta position are often the strongest, suggesting a link to the topology of THs, …

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Para-Methoxybenzylidene Acetal-Protected D-Glucosamine Derivatives As Ph-Responsive Gelators And Their Applications For Drug Delivery, Jonathan Bietsch, Logan Baker, Anna Duffney, Alice Mao, Mary Foutz, Cheandri Ackermann, Guijun Wang Jan 2023

Para-Methoxybenzylidene Acetal-Protected D-Glucosamine Derivatives As Ph-Responsive Gelators And Their Applications For Drug Delivery, Jonathan Bietsch, Logan Baker, Anna Duffney, Alice Mao, Mary Foutz, Cheandri Ackermann, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based low molecular weight gelators (LMWGs) are compounds with the capability to self-assemble into complex molecular networks within a solvent, leading to solvent immobilization. This process of gel formation depends on noncovalent interactions, including Van der Waals, hydrogen bonding, and π–π stacking. Due to their potential applications in environmental remediation, drug delivery, and tissue engineering, these molecules have emerged as an important area of research. In particular, various 4,6-O-benzylidene acetal-protected D-glucosamine derivatives have shown promising gelation abilities. In this study, a series of C-2-carbamate derivatives containing a para-methoxy benzylidene acetal functional group were synthesized and characterized. These compounds exhibited good …

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Telp Theory: Elucidating The Major Observations Of Rieger Et Al. 2021 In Mitochondria, James Weifu Lee Jan 2023

Telp Theory: Elucidating The Major Observations Of Rieger Et Al. 2021 In Mitochondria, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

The transmembrane-electrostatically localized protons (TELP) theory may represent a complementary development to Mitchell's chemiosmotic theory. The combination of the two together can now excellently explain the energetics in mitochondria. Our calculated transmembrane-attractive force between an excess proton and an excess hydroxide explains how TELP may stay within a 1-nm thin layer at the liquid-membrane interface. Consequently, any pH sensor (sEcGFP) located at least 2–3 nm away from the membrane surface will not be able to see TELP. This feature as predicted from the TELP model was observed exactly in the experiment of Rieger et al., 2021. In contrast to their …

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Synthesis And Self-Assembling Properties Of Carbohydrate- And Diarylethene-Based Photoswitchable Molecular Gelators, Pramod Aryal, Joedian Morris, Surya B. Adhikari, Jonathan Bietsch, Guijun Wang Jan 2023

Synthesis And Self-Assembling Properties Of Carbohydrate- And Diarylethene-Based Photoswitchable Molecular Gelators, Pramod Aryal, Joedian Morris, Surya B. Adhikari, Jonathan Bietsch, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based low-molecular-weight gelators are interesting new materials with many potential applications. These compounds can be designed to include multiple stimuli-responsive functional groups. In this study, we designed and synthesized several chemically responsive bola-glycolipids and dimeric carbohydrate- and diarylethene-based photoswitchable derivatives. The dimeric glycolipids formed stable gels in a variety of solvent systems. The best performing gelators in this series contained decanedioic and dithienylethene (DTE) spacers, which formed gels in eight and nine of the tested solvents, respectively. The two new DTE-containing esters possessed interesting photoswitching properties and DTE derivative 7 was found to have versatile gelation properties in many solvents, …

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Detection And Quantification Of Antiviral Drug Tenofovir Using Silver Nanoparticles And Surface Enhanced Raman Spectroscopy (Sers) With Spatially Resolved Hotspot Selection, Marguerite R. Butler, Jana Hrncirova, Terry A. Jacot, Sucharita Dutta, Meredith R. Clark, Gustavo F. Doncel, John B. Cooper Jan 2023

Detection And Quantification Of Antiviral Drug Tenofovir Using Silver Nanoparticles And Surface Enhanced Raman Spectroscopy (Sers) With Spatially Resolved Hotspot Selection, Marguerite R. Butler, Jana Hrncirova, Terry A. Jacot, Sucharita Dutta, Meredith R. Clark, Gustavo F. Doncel, John B. Cooper

Chemistry & Biochemistry Faculty Publications

This study introduces a convenient and ultra-sensitive method of detection and quantification of the antiviral drug, tenofovir (TFV), by surface-enhanced Raman spectroscopy (SERS). Novel spatially resolved instrumentation for spectral acquisition and subsequent statistical analysis for hot spot selection was developed for convenient quantification of TFV in an aqueous matrix. Methods of statistical analysis include the use of partial least squares (PLS) regression vector analysis and spectral ranking by quality indices computed using CHAOS theory. Hydroxylamine-reduced Ag colloidal nanoparticles evaporated to dryness on an aluminum well-plate were used as the SERS substrate. To our knowledge, quantification of TFV down to 25 …

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S-Type Stars: Line List For The A²Π-X²Σ⁺ Band System Of Lao, P. F. Bernath, R. Dodangodage, J. Liévin Jan 2023

S-Type Stars: Line List For The A²Π-X²Σ⁺ Band System Of Lao, P. F. Bernath, R. Dodangodage, J. Liévin

Chemistry & Biochemistry Faculty Publications

LaO bands are found in the spectra of cool S-type stars. The bands of the A2Π–X2Σ+ transition with v' ⩽ 3 and v'' ≤ 4 are rotationally analyzed, providing spectroscopic constants for the A2Π state. Line strengths are calculated using an ab initio transition dipole moment function, and radiative lifetimes for the A2Π state have also been computed. A line list for the A2Π–X2Σ+ transition of LaO is provided and can be used to determine LaO stellar abundances.

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Enhancing The Conformational Stability Of The Cl-Par-4 Tumor Suppressor Via Site-Directed Mutagenesis, Samjhana Pandey, Krishna K. Raut, Antoine Baudin, Lamya Djemri, David S. Libich, Komala Ponniah, Steven M. Pascal Jan 2023

Enhancing The Conformational Stability Of The Cl-Par-4 Tumor Suppressor Via Site-Directed Mutagenesis, Samjhana Pandey, Krishna K. Raut, Antoine Baudin, Lamya Djemri, David S. Libich, Komala Ponniah, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Intrinsically disordered proteins play important roles in cell signaling, and dysregulation of these proteins is associated with several diseases. Prostate apoptosis response-4 (Par-4), an approximately 40 kilodalton proapoptotic tumor suppressor, is a predominantly intrinsically disordered protein whose downregulation has been observed in various cancers. The caspase-cleaved fragment of Par-4 (cl-Par-4) is active and plays a role in tumor suppression by inhibiting cell survival pathways. Here, we employed site-directed mutagenesis to create a cl-Par-4 point mutant (D313K). The expressed and purified D313K protein was characterized using biophysical techniques, and the results were compared to that of the wild-type (WT). We have …

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Synthesis Of A Series Of Trimeric Branched Glycoconjugates And Their Applications For Supramolecular Gels And Catalysis, Jonathan Bietsch, Anji Chen, Dan Wang, Guijun Wang Jan 2023

Synthesis Of A Series Of Trimeric Branched Glycoconjugates And Their Applications For Supramolecular Gels And Catalysis, Jonathan Bietsch, Anji Chen, Dan Wang, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Carbohydrate-derived molecular gelators have found many practical applications as soft materials. To better understand the structure and molecular gelation relationship and further explore the applications of sugar-based gelators, we designed and synthesized eight trimeric branched sugar triazole derivatives and studied their self-assembling properties. These included glucose, glucosamine, galactose, and maltose derivatives. Interestingly, the gelation properties of these compounds exhibited correlations with the peripheral sugar structures. The maltose derivative did not form gels in the tested solvents, but all other compounds exhibited gelation properties in at least one of the solvents. Glucose derivatives showed superior performance, followed by glucosamine derivatives. They …

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Developing Mesoporous Silica Nanoparticle-Based Stimuli-Responsive Nanocarriers For Delivery Of Small Molecule Therapeutics Against Colon Cancer Cells, Nisitha Lakmal Wellala Wijewantha Jan 2023

Developing Mesoporous Silica Nanoparticle-Based Stimuli-Responsive Nanocarriers For Delivery Of Small Molecule Therapeutics Against Colon Cancer Cells, Nisitha Lakmal Wellala Wijewantha

Dissertations and Theses

This dissertation delves into the innovative application of mesoporous silica nanoparticles (MSNs) for targeted drug delivery in colorectal cancer (CRC), one of the most prevalent and deadly forms of cancer worldwide. The initial focus of the research is on developing enzyme-responsive MSNs loaded with veratridine (VTD), an alkaloid derived from natural sources that demonstrates potent anticancer activity. The nanoparticles have been engineered to deliver VTD selectively to CRC cells, releasing the payload upon being exposed to specific enzymes primarily secreted by these cells. This strategy has dual advantages of amplifying the anticancer effects while minimizing potential side effects on healthy …

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Designing Metal-Organic Supercontainers For Functional Applications: From Selective Anion Binding To Surface Enhanced Raman Scattering, Kriti Chitrakar Jan 2023

Designing Metal-Organic Supercontainers For Functional Applications: From Selective Anion Binding To Surface Enhanced Raman Scattering, Kriti Chitrakar

Dissertations and Theses

Synthetic container molecules that emulate biological structures and feature well-defined nanocavities have attracted tremendous interest among supramolecular chemists due to their promising potentials in ion recognition, catalysis, and chemical sensing. Our laboratory has developed a new class of container molecules, namely, metal-organic supercontainers (MOSCs), which feature both endo and exo cavities suitable for binding guest molecules. The overarching theme of this thesis was to use synthetic manipulations to modify the chemical structure and enhance the functional application of MOSCs in two specific areas, anion binding and chemical sensing. For the application of anion binding, we have designed and synthesized a …

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Computational Investigation Of The Ionization Potential Of Lead Sulfide Quantum Dots, Jessica Beyer Jan 2023

Computational Investigation Of The Ionization Potential Of Lead Sulfide Quantum Dots, Jessica Beyer

Scripps Senior Theses

The purpose of this work was to determine the impact of quantum dot size on ionization potential and to determine how the presence of carbonyl-based ligands affect the ionization potential of lead sulfide quantum dot systems. Ionization potential (IP) is defined as the energy required to remove an electron from an atom, molecule, or material. IP helps scientists determine how reactive the material of interest is, which is crucial information when manufacturing nanomaterials. Accurate quantum chemical calculations of ionization potential are challenging due to the computational cost associated with the numerical solution of the Dyson equation. In this work, the …

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How Akron Affects The Water Quality Of The Cuyahoga River, Allyson Darst Jan 2023

How Akron Affects The Water Quality Of The Cuyahoga River, Allyson Darst

Williams Honors College, Honors Research Projects

The purpose of this study was to analyze whether the city of Akron had negative effects on the Cuyahoga river, and determine if the Cuyahoga River was naturally able to remediate these effects downstream. The pollutants measured in this study include hardness, bromine, residual chlorine, iron, copper, lead, nitrate, nitrite, ammonium chloride, total chlorine, fluoride, carbonate, pH, total alkalinity and cyanuric acid. This study was done using water testing strips (JNW Direct) to test the water at four different locations along the Cuyahoga River downstream (North) of Akron. This study found that the city of Akron does have a negative …

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Probe–Integrated Electrochemical Sensing Platform For Measuring Trace Levels Of Parathion Pesticides Residues In Water Using Au- Nanoparticles Anchored Nafion Nano Composite Modified Glassy Carbon Electrode, H. Alwael, S.H. Al-Sedran, Mohamed Oubaha, N.A.A. Asiri, A.S. Bashammakh, A.S. Alharthy, N.A. Albassami, T.N. Abduljabbar, G.I. Mohamed, H.M. Nassef, E.A. Bahaidarah, B.G. Alhogbi, M.S. El-Shahawi Jan 2023

Probe–Integrated Electrochemical Sensing Platform For Measuring Trace Levels Of Parathion Pesticides Residues In Water Using Au- Nanoparticles Anchored Nafion Nano Composite Modified Glassy Carbon Electrode, H. Alwael, S.H. Al-Sedran, Mohamed Oubaha, N.A.A. Asiri, A.S. Bashammakh, A.S. Alharthy, N.A. Albassami, T.N. Abduljabbar, G.I. Mohamed, H.M. Nassef, E.A. Bahaidarah, B.G. Alhogbi, M.S. El-Shahawi

Articles

Nanomaterial represents a principal driver to the adoption of electrochemical sensors for pesticides residues in water. Thus, the current strategy reports facile and highly sensitive electrochemical probe for monitoring parathion residues in water. The probe was based upon the use of Au nanoparticles (AuNPs) functionalized Nafion nanocomposites modified glassy carbon electrode (Au NPs/Nafion/GCE). The surface morphology, effective surface area and electrocatalytic performance of the Au NPs/Nafion/GCE were recorded and assigned using a scanning electron microscopy (SEM), cyclic voltammetry (CV) and electronic spectra. A straightforward protocol based upon combination of Au NPs/Nafion/GCE and square wave- adsorptive cathodic stripping voltammetry at pH …

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Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody Jan 2023

Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody

Articles

The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …

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Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar Jan 2023

Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar

Chemistry & Biochemistry Faculty Publications

Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg …

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Skin Lesion Segmentation In Dermoscopic Images With Noisy Data, Norsang Lama, Jason Hagerty, Anand Nambisan, Ronald Joe Stanley, William Van Stoecker Jan 2023

Skin Lesion Segmentation In Dermoscopic Images With Noisy Data, Norsang Lama, Jason Hagerty, Anand Nambisan, Ronald Joe Stanley, William Van Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

We Propose a Deep Learning Approach to Segment the Skin Lesion in Dermoscopic Images. the Proposed Network Architecture Uses a Pretrained Efficient Net Model in the Encoder and Squeeze-And-Excitation Residual Structures in the Decoder. We Applied This Approach on the Publicly Available International Skin Imaging Collaboration (ISIC) 2017 Challenge Skin Lesion Segmentation Dataset. This Benchmark Dataset Has Been Widely Used in Previous Studies. We Observed Many Inaccurate or Noisy Ground Truth Labels. to Reduce Noisy Data, We Manually Sorted All Ground Truth Labels into Three Categories — Good, Mildly Noisy, and Noisy Labels. Furthermore, We Investigated the Effect of Such …

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The Affect Of Dha Concentration On Lipid Membrane Fluidity, Elise Rezabeck Jan 2023

The Affect Of Dha Concentration On Lipid Membrane Fluidity, Elise Rezabeck

Williams Honors College, Honors Research Projects

My proposed project will be creating large unilaminar vesicles with varying concentrations of DHA in the vesicles. The diffusion in and out of these vesicles will be tracked by using singular lipid molecules. These singular lipid molecules will be tagged with fluorescence and viewed using an internal reflection fluorescence microscope. The data collected over the course of this project will then be analyzed using Matlab. The result of the project will be to find the specific lipid diffusion constant of these unilaminar vesicles. The relationship between the concentration of DHA and lipid diffusion and membrane fluidity will be found as …

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