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Articles 3331 - 3360 of 33142

Full-Text Articles in Chemistry

Optical Characterization Of Photocatalytic Tungsten Oxide/Tin Oxide (〖Wo〗_3/〖Sno〗_2) Thin Films For Use In Degradation Of Water Pollutants, Victor Isahi, Christopher Maghanga, Mghendi Mwamburi, Onesmus Munyati, Sylvester Hatwaambo, Emmanuel Akoto, Wycliffe Isoe, Mir Waqas Alam Sep 2023

Optical Characterization Of Photocatalytic Tungsten Oxide/Tin Oxide (〖Wo〗_3/〖Sno〗_2) Thin Films For Use In Degradation Of Water Pollutants, Victor Isahi, Christopher Maghanga, Mghendi Mwamburi, Onesmus Munyati, Sylvester Hatwaambo, Emmanuel Akoto, Wycliffe Isoe, Mir Waqas Alam

Tanzania Journal of Science

Organic pollutants in water have been a challenge and pose significant risks to human health. As a result, research efforts to eliminate these pollutants have been on the rise. Photocatalysis has shown incredible potential in water treatment containing organic pollutants since it is affordable and utilizes solar energy. Tin oxide ( ) has ardently been investigated as a photocatalyst for water treatment due to its remarkable properties such as; non-toxicity, and stability. However, its wide band gap and the tendency for some electrons and holes to recombine during its use have been cited to be among limiting factors affecting its …

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Hydro-Geochemistry And Related Processes Controlling The Composition Of Thermal Waters In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai Sep 2023

Hydro-Geochemistry And Related Processes Controlling The Composition Of Thermal Waters In The Lake Natron Basin, Northern Tanzania, Edista A. Abdallah, Charles H. Kasanzu, Crispin P. Kinabo, Akira Imai

Tanzania Journal of Science

Lake Natron Basin (LNB) forms part of the eastern branch of the East African Rift System (EARS) in Tanzania. The basin is endowed with thermal springs flowing towards the lake from the western, northwestern, southwestern and eastern parts. The western, northwestern and south-western thermal springs emanate from fractures in the basaltic rocks while in the east, they originate from the western flank of the Gelai volcano. There are limited studies on these springs, thus their geochemical differences and distributions of physicochemical parameters are not well understood. A hydrogeochemical study was conducted to interpret available geochemical data from the LNB springs, …

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Evaluation Of The Inhibitive Properties Of Silver Nanoparticles In Senna Occidentalis Root Extract As Corrosion Inhibitor Of Mild Steel, Victor O. Egbeneje, Samuel E. Okhale, Chinyere Imoisi, Isaac O. Ogbogo, Omolade Ojo Sep 2023

Evaluation Of The Inhibitive Properties Of Silver Nanoparticles In Senna Occidentalis Root Extract As Corrosion Inhibitor Of Mild Steel, Victor O. Egbeneje, Samuel E. Okhale, Chinyere Imoisi, Isaac O. Ogbogo, Omolade Ojo

Tanzania Journal of Science

The use of nanoparticles as corrosion inhibitors has gained popularity because of its increased corrosion efficiency due to increase surface to volume ratio. Nanoparticles which undergo physisorption/chemisorption to the corrosion metal surface and inhibit the corrosion efficiently also have low toxicity, low cost and easy production. In this research work, weight lost method was applied to study the inhibitive properties of silver nanoparticles (AgNPs) synthesized using Senna occidentalis root extract as environmentally benign corrosion inhibitor of mild steel in 0.5 M H2SO4 medium at 298 K and 308 K. It was observed that the corrosion rate of the steel sample …

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Exploring The Correlation Between Metacognitive Skills And Cognitive Learning Outcomes Across Various Biology Learning Models In High Schools, Ninik Kristiani, Herawati Susilo, Aloysius Duran Corebim, Fatchur Rohman Sep 2023

Exploring The Correlation Between Metacognitive Skills And Cognitive Learning Outcomes Across Various Biology Learning Models In High Schools, Ninik Kristiani, Herawati Susilo, Aloysius Duran Corebim, Fatchur Rohman

Jurnal Pendidikan Sains

In Malang City, a notable observation within the realm of high school biology education suggests a prevalent lack of metacognitive knowledge among teachers, hindering their efficacy in nurturing students' metacognitive capacities. Such deficiency yields implications for diminished cognitive abilities among students. Recognizing this, there emerges a pressing need for an enhanced pedagogical framework capable of fostering metacognitive skills adeptly. One promising approach involves integrating inquiry-based learning and problem- based mindful pedagogy (PBMP). This amalgamation is anticipated to synergistically harness the potential of both methodologies in bolstering metacognitive skills alongside cognitive learning outcomes. This study adopts a correlational research design, wherein …

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Analysis And Unraveling Misconceptions: Examining Tenth-Grade High School Students’ Errors In Hots Questions On Exponential Equations And Effective Scaffolding Strategies, Nunik Indayani, Erry Hidayanto, Sisworo Sisworo Sep 2023

Analysis And Unraveling Misconceptions: Examining Tenth-Grade High School Students’ Errors In Hots Questions On Exponential Equations And Effective Scaffolding Strategies, Nunik Indayani, Erry Hidayanto, Sisworo Sisworo

Jurnal Pendidikan Sains

The objective of this study is to elucidate the errors made by tenth-grade students at SMA Hati Bilingual Boarding School Probolinggo, Indonesia, when tackling Higher Order Thinking Skills (HOTS) questions on exponential equations, along with the scaffolding process employed to mitigate these errors. Employing qualitative research methods, four participants were chosen based on their performance in completing HOTS questions on exponential equations, followed by in-depth interviews. The identified student errors encompass basic errors, appropriate errors, missing information, and partial insights. The analysis aligns these errors predominantly with Brodie’s error taxonomy. Furthermore, the study highlights the efficacy of instructional scaffolding, utilizing …

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The Identification Of Students’ Conceptual Mastery Of Fluid Statics: An Overview Of Gender, Maria Claudia Sodakain, Sentot Kusairi, Nandang Mufti, Jane Koswojo Sep 2023

The Identification Of Students’ Conceptual Mastery Of Fluid Statics: An Overview Of Gender, Maria Claudia Sodakain, Sentot Kusairi, Nandang Mufti, Jane Koswojo

Jurnal Pendidikan Sains

This study aimed to assess the conceptual mastery of fluid statics among students, employing a descriptive quantitative approach. The research involved 22 male and 13 female students from eleventh-grade MIPA at a private school in Surabaya, Indonesia. The primary research instrument comprised 11 multiple-choice and reasoning questions, covering concepts related to Pressure and Hydrostatic Pressure, Pascal’s Law, and Archimedes’ Principle. Results indicated a higher level of conceptual mastery among male students compared to their female counterparts. While both genders demonstrated relatively high conceptual mastery in Pressure and Hydrostatic Pressure, significant disparities were observed in their understanding of Pascal’s Law and …

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Analysis Of Student Engagement And Perceptions Of Community Of Inquiry (Coi)-Based Blended Learning In The Chemical Separation Subject On Chromatography, Agita Dzulhajh Anggraini, Surjani Wonorahardjo, Yudhi Utomo Sep 2023

Analysis Of Student Engagement And Perceptions Of Community Of Inquiry (Coi)-Based Blended Learning In The Chemical Separation Subject On Chromatography, Agita Dzulhajh Anggraini, Surjani Wonorahardjo, Yudhi Utomo

Jurnal Pendidikan Sains

Learning in higher education has often been conducted solely through face-to-face, teacher- centered approaches. Implementing Community of Inquiry (CoI)-based blended learning in chromatography is crucial as it offers students a novel learning experience. This pre- experimental study, utilizing a one-group pretest-posttest design, aimed to describe students’ perceptions of CoI-based blended learning in chromatography. Data were collected using a questionnaire comprising 34 statements. The results indicated that students had a neutral perception of CoI-based blended learning. While a community of inquiry has been established, it has not yet reached its full potential, as students have not fully experienced social presence in …

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Mineralogy And Geochemical Characteristics Of Matamba Kaolin Deposit-Njombe Region South-Western Tanzania: Implications For Industrial Applications, Melania A. Nyimbo, Ronald J. Massawe, Michael M. Msabi Sep 2023

Mineralogy And Geochemical Characteristics Of Matamba Kaolin Deposit-Njombe Region South-Western Tanzania: Implications For Industrial Applications, Melania A. Nyimbo, Ronald J. Massawe, Michael M. Msabi

Tanzania Journal of Science

Kaolin is a commercial clay material composed of hydrated aluminosilicate mineral kaolinite and used in various industrial applications such as ceramics, paper, paints, refractories, fiberglass, plastics, cosmetics and pharmaceuticals. It is formed as a result of strong chemical weathering of crystalline and feldspar-rich rocks or hydrothermal alteration of granitic rocks at relatively low temperature and pressure conditions. The kaolin deposit of Matamba originated from the weathering of leucogabbro rock during the development of the African land surface. In view of highlighted properties, the mineralogy and chemical characteristics of the Matamba kaolin deposit were investigated to determine its industrial applications. As …

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Microplastics In Marine Sediments From Dar Es Salaam Coast: Spatial Distribution And Characterization, Macarius P. Mtega, Matobola J. Mihale, Kessy F. Kilulya Sep 2023

Microplastics In Marine Sediments From Dar Es Salaam Coast: Spatial Distribution And Characterization, Macarius P. Mtega, Matobola J. Mihale, Kessy F. Kilulya

Tanzania Journal of Science

The purpose of the research was to determine the spatial distribution and characterization of microplastics in marine sediments of beaches along the Indian Ocean of Dar es Salaam coast. The sediment samples were extracted in triplicate using floatation method followed by digestion of organic debris, then analyzed using At-FTIR spectrophotometer and stereomicroscope. The mean concentrations of microplastics for Kijichi Beach were 700 ± 907 particles/m2 at 1 cm, 859 ± 839 particles/m2 at 5 cm and 590 ± 782 particles/m2 at 10 cm; from Palm Beach were 157 ± 15 particles/m2 at 1 cm, 130 ± 182 particles/m2 at 5 …

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Molecularly Imprinted Electrochemical Sensor Based On Poly (O-Phenylenediamine) For Sensitive Detection Of Oxycodone In Water, Pranaya Charkravarthula, Amos Mugweru Sep 2023

Molecularly Imprinted Electrochemical Sensor Based On Poly (O-Phenylenediamine) For Sensitive Detection Of Oxycodone In Water, Pranaya Charkravarthula, Amos Mugweru

College of Science & Mathematics Departmental Research

This work was aimed at the development of a sensitive electrochemical detection method for oxycodone in water. Molecularly imprinted electrodes were formed by electro-polymerization process using o-phenylenediamine as a monomer. The electro-polymerization was performed on glassy carbon electrodes in the presence of oxycodone before the extraction of entrapped oxycodone molecules. Various electrochemical techniques were employed to monitor the polymerization and response of the fabricated electrodes toward oxycodone. These techniques included cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The oxycodone concentration was determined using SWV by measuring the change in the oxidation …

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Asymmetric Electrode-Electrolyte Interfaces For High-Performance Rechargeable Lithium-Sulfur Batteries, Jia Chou, Ya-Hui Wang, Wen-Peng Wang, Sen Xin, Yu-Guo Guo Sep 2023

Asymmetric Electrode-Electrolyte Interfaces For High-Performance Rechargeable Lithium-Sulfur Batteries, Jia Chou, Ya-Hui Wang, Wen-Peng Wang, Sen Xin, Yu-Guo Guo

Journal of Electrochemistry

With a high cell-level specific energy and a low cost, lithium-sulfur (Li-S) battery has been intensively studied as one of the most promising candidates for competing the next-generation energy storage campaign. Currently, the practical use of Li-S battery is hindered by the rapidly declined storage performance during battery operation, as caused by irreversible loss of electroactive sulfide species at the cathode, dendrite formation at the anode and parasitic reactions at the electrode-electrolyte interface due to unfavorable cathode-anode crosstalk. In this perspective, we propose to stabilize the Li-S electrochemistry, and improve the storage performance of battery by designing asymmetric electrode-electrolyte interfaces …

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Hydrophobicity Optimization Of Cathode Catalyst Layer For Proton Exchange Membrane Fuel Cell, Hao-Jie Chen, Mei-Hua Tang, Sheng-Li Chen Sep 2023

Hydrophobicity Optimization Of Cathode Catalyst Layer For Proton Exchange Membrane Fuel Cell, Hao-Jie Chen, Mei-Hua Tang, Sheng-Li Chen

Journal of Electrochemistry

Hydrophobicity of the cathode catalyst layers (CCLs) crucially determines the performance of proton exchange membrane fuel cells (PEMFCs) by affecting the transports of oxygen and liquid water. In this regard, polytetrafluoroethylene (PTFE) is usually used as a hydrophobic additive to facilitate the oxygen and water transports in CCLs. So far, there remains lacking systematic effort to optimize the addition methods of PTFE in CCLs and the mechanisms behind. In this work, the effects of the approaches for PTFE addition and the distribution of PTFE on the mass transport of oxygen and the proton conduction in CCLs were studied by using …

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Comparative Study Of Guanidine-, Acetamidine- And Urea-Based Chloroaluminate Electrolytes For An Aluminum Battery, Iwan Sumarlan, Anand Kunverji, Anthony J Lucio, A Robert Hillman, Karl S Ryder Sep 2023

Comparative Study Of Guanidine-, Acetamidine- And Urea-Based Chloroaluminate Electrolytes For An Aluminum Battery, Iwan Sumarlan, Anand Kunverji, Anthony J Lucio, A Robert Hillman, Karl S Ryder

Faculty, Staff and Student Publications

Aluminum-based batteries are a promising alternative to lithium-ion as they are considered to be low-cost and more friendly to the environment. In addition, aluminum is abundant and evenly distributed across the globe. Many studies and Al battery prototypes use imidazolium chloroaluminate electrolytes because of their good rheological and electrochemical performance. However, these electrolytes are very expensive, and so cost is a barrier to industrial scale-up. A urea-based electrolyte, AlCl3:Urea, has been proposed as an alternative, but its performance is relatively poor because of its high viscosity and low conductivity. This type of electrolyte has become known as an ionic liquid …

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Three-Dimensional Two-Phase Cfd Simulation Of Alkaline Electrolyzers, Ling-Yu Gao, Lin Yang, Chen-Hui Wang, Gui-Xuan Shan, Xin-Yi Huo, Meng-Fei Zhang, Wei Li, Jin-Li Zhang Sep 2023

Three-Dimensional Two-Phase Cfd Simulation Of Alkaline Electrolyzers, Ling-Yu Gao, Lin Yang, Chen-Hui Wang, Gui-Xuan Shan, Xin-Yi Huo, Meng-Fei Zhang, Wei Li, Jin-Li Zhang

Journal of Electrochemistry

The structural and operation parameters of the electrolyzer play important roles in the efficiency of alkaline water electrolysis. In this article, a three-dimensional numerical model coupled with the electric field and the Euler-Eulerian k-ε turbulence flow field was first established to simulate accurately the performance of alkaline electrolyzers, based on a compact assembly structure of the industrial alkaline water electrolyzers, especially at current densities higher than 5000 A·m–2. The simulation results are compared with the experimental data to verify the accuracy of the model. Suitable operating conditions for concentration, flow rate and the optimal design method of the …

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Dependence Of Heat Transfer Model On The Structure Of Electrically Coil-Heated Microelectrodes, Ju Li, Sen Yang, Jian-Jun Sun Sep 2023

Dependence Of Heat Transfer Model On The Structure Of Electrically Coil-Heated Microelectrodes, Ju Li, Sen Yang, Jian-Jun Sun

Journal of Electrochemistry

Electrically heated microelectrodes have gained much attention in electroanalytical chemistry in recent years. It has been shown that the promotion of mass transport and reaction kinetics at high-temperatures often results in increased current signals. However, there is no study about the heat transfer inner the microelectrodes which is necessary for the design and operation for microsensors. This report introduces a finite element software (COMSOL) to analyze the factors that influence the surface temperature (Ts), which is crucial for the heating ability of micro-disk electrodes with coils. Distances between the electrode surface and the bottom of the heated copper …

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Fundamental Study Of Ionic Liquid Physicochemical Effects On Thermal Stability Of Model Biological Macromolecules, Austin Keith Clark Sep 2023

Fundamental Study Of Ionic Liquid Physicochemical Effects On Thermal Stability Of Model Biological Macromolecules, Austin Keith Clark

Theses and Dissertations

Ionic Liquids (ILs) are substances with a unique physical attribute compared to that of solid ionic salts. At room temperature, ILs are molten salts that have a variety of physical effects that can play a role in their impact on other molecules, as solvents or solutes. They can play the role of the solvent in a variety of applications, from biofuels to organic catalysis or as excipients in pharmaceutical formulations. These ILs have a desirable use as solvents due to their ability to be tunable substances. Changing the cation or anion of the IL causes a change in its physical …

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Phosphorus And Its Role In Chemical Evolution, Asbel Gonzalez Sep 2023

Phosphorus And Its Role In Chemical Evolution, Asbel Gonzalez

PANDION: The Osprey Journal of Research and Ideas

Phosphorus is a minor element with a cosmic abundance of about 105.5 atoms per 1012 H atoms (Boudreaux, n.d.). Phosphorus was depleted as a volatile throughout the developing solar system, and as a result, volatile forms of phosphorus would have been minimal, even in the colder regions of the solar nebula. Despite its low abundance, phosphorus minerals play key roles in planetary petrology, including through the formation of phosphate minerals that trapped volatiles and rare Earth elements, and in the formation of metal phosphides that may have served as nucleation sites for kamacite and taenite crystal growth in minor planet …

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Synergistic Effect Of Nanoclay And Barium Sulfate Fillers On The Corrosion Resistance Of Polyester Powder Coatings, Jinbao Huang, Marshall Shuai Yang, Chengqian Xian, James Joseph Noel, Yolanda S. Hedberg, Jian Chen, Ubong Eduok, Ivan Barker, Jeffrey Daniel Henderson, Haiping Zhang, Liqin Wang, Hui Zhang, Jesse Zhu Sep 2023

Synergistic Effect Of Nanoclay And Barium Sulfate Fillers On The Corrosion Resistance Of Polyester Powder Coatings, Jinbao Huang, Marshall Shuai Yang, Chengqian Xian, James Joseph Noel, Yolanda S. Hedberg, Jian Chen, Ubong Eduok, Ivan Barker, Jeffrey Daniel Henderson, Haiping Zhang, Liqin Wang, Hui Zhang, Jesse Zhu

Chemistry Publications

No abstract provided.

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Antibacterial Testing On Silver/Zinc Oxide Nanoparticles/Organoclay Reinforced Chitosan Biocomposites, Lisna Junaeni Muiz, Ariadne Lakshmidevi Juwono, Zulkarnaen Paputungan, Yuni Krisyuningsih Krisnandi Sep 2023

Antibacterial Testing On Silver/Zinc Oxide Nanoparticles/Organoclay Reinforced Chitosan Biocomposites, Lisna Junaeni Muiz, Ariadne Lakshmidevi Juwono, Zulkarnaen Paputungan, Yuni Krisyuningsih Krisnandi

Makara Journal of Science

Herein, bionanocomposites of chitosan (CS)/silver nanoparticle/organoclay/zinc oxide nanoparticle (CS/Ag/OC/ZnO) were prepared for antibacterial food packaging. This study examines the time variation in the AgNP synthesis method by comparing local (74˗85% deacetylated) and commercial chitosan (75%˗85% deacetylated) as a reducing and capping agent and seeks to reconstruct the optimum ratio formulations of AgNPs and ZnONPs in bionanocomposites for food packaging. The results reveal that the synthesis of AgNPs was successfully carried out using a local chitosan solution as a reducing and capping agent. The CS/Ag/OC/ZnO films exhibit structural, mechanical, and optical properties suitable for food packaging and antibacterial activity on Staphylococcus …

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Synthesis, Characterization, Antibacterial Activity, And Potential Water Filter Application Of Copper Oxide/Zeolite Composite, Elfa Aida Kamila, Zaenal Abidin, Irma Isnafia Arief, Trivadila Trivadila Sep 2023

Synthesis, Characterization, Antibacterial Activity, And Potential Water Filter Application Of Copper Oxide/Zeolite Composite, Elfa Aida Kamila, Zaenal Abidin, Irma Isnafia Arief, Trivadila Trivadila

Makara Journal of Science

Detection of E. coli bacteria in water samples can indicate the presence of other bacterial contamination in feces. Bacterial contamination can be treated with antibiotics, but excessive use of antibiotics leads to the emergence of multiresistant bacteria. Therefore, alternative antibacterial agents must be explored. Copper ion/zeolite composite has been widely studied as an antibacterial agent. However, the released copper ions accumulate in water and are toxic to humans; this can be prevented by converting copper ions into copper oxides (CuO and Cu2O). In this study, copper oxide/zeolite composite is synthesized and characterized using the heating method, followed by …

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Exploring Students’ Epistemological Understanding Of Atomic Structure Models, Claire V. Ward, Morgan Balabanoff Sep 2023

Exploring Students’ Epistemological Understanding Of Atomic Structure Models, Claire V. Ward, Morgan Balabanoff

The Cardinal Edge

Developing a robust understanding of atomic structure and the nature of matter is foundational across chemistry and STEM courses. The development of this concept is challenging because it relies on models to illustrate something not directly observable. Scientific models are important tools used to explain phenomena, particularly phenomena that are not directly observable. In general chemistry, students are typically asked to consider four different models: (1) the particle model, (2) the nuclear model, (3) the Bohr model, and (4) the Quantum model. Each depiction has its own advantages and limitations, where instructors introduce each model to explain specific parts of …

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Characterization And Electrolysis Of Zn And Cu 2,6-Diacetylpyridine Bis(2-Hydrazinopyridine), Bailee G. Duff, Christine Phipps, Craig Grapperhaus Sep 2023

Characterization And Electrolysis Of Zn And Cu 2,6-Diacetylpyridine Bis(2-Hydrazinopyridine), Bailee G. Duff, Christine Phipps, Craig Grapperhaus

The Cardinal Edge

With increasing demands for fuel and concerns over climate change, the search for sustainable energy sources is ever growing. Hydrogen is a potential solution to these issues, as it is clean, recyclable, and efficient. However, hydrogen must be generated, unlike other fuel sources that are naturally ready for use. The most sustainable method for hydrogen production involves water electrolysis, as no pollution is generated. The water splitting process contains a cathodic hydrogen evolution reaction (HER) and an anodic oxygen evolution reaction (OER). These reactions require a catalyst to overcome the kinetic barrier present and meet the high voltage requirements for …

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Exploring Retrieval Difficulties And Self-Confidence In An Assessment Of General Chemistry Students, Karen Julian, Morgan Balabanoff Sep 2023

Exploring Retrieval Difficulties And Self-Confidence In An Assessment Of General Chemistry Students, Karen Julian, Morgan Balabanoff

The Cardinal Edge

Developing self-assessment skills is an important aspect of learning. Framed by assessment developed for the year-long sequence of general chemistry, students were asked to rate their ability to answer conceptual questions. Using cognitive interviews, this study revealed that people rely on a range of characteristics other than content knowledge to assess their confidence, including doubt, retrieval difficulty, and test-taking methods. These findings imply that more explicit instruction may be required to encourage correct self-assessment. Students can develop their metacognitive skills and calibrate their perceived ability by completing examinations meant to emphasize content knowledge gaps.

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Eggshell-Alginate Composites (Eacs) As Eco-Friendly Adsorbents For Rhodamine B Uptake From Aqueous Solutions, Rusnadi Rusnadi, Mar’Atus Sholihah, Nurrahmi Handayani, Muhammad Ali Zulfikar Sep 2023

Eggshell-Alginate Composites (Eacs) As Eco-Friendly Adsorbents For Rhodamine B Uptake From Aqueous Solutions, Rusnadi Rusnadi, Mar’Atus Sholihah, Nurrahmi Handayani, Muhammad Ali Zulfikar

Karbala International Journal of Modern Science

The contamination of wastewater by Rhodamine B (RhB) poses a significant environmental concern due to its negative impacts on aesthetics, ecosystems, and human well-being. This study successfully synthesized eco-friendly egg-shell-alginate composites (EACs) as adsorbents by combining alginate solution, eggshell powder, and a 2% CaCl2 solu-tion. Characterization techniques including FTIR, SEM, TGA, and SAA were employed to analyze the EACs. FTIR analysis revealed characteristic absorption peaks corresponding to -OH groups, C=O groups, C-O groups, and the pres-ence of CO32-. The structural analysis confirmed the physical mixture of functional groups from eggshells and alginate, resulting in a homogeneous EACs mixture. TGA analysis …

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Synthesizing Of Alginate Coated-Silver Nanoparticles Core-Shell For Detecting Of S-Naproxen Enantiomer In Pharmaceutical Formulation, Abdolrasol Barazandeh, Ghasem Najafpour-Darz, Afshar Alihossein, Sohrab Kazemi Sep 2023

Synthesizing Of Alginate Coated-Silver Nanoparticles Core-Shell For Detecting Of S-Naproxen Enantiomer In Pharmaceutical Formulation, Abdolrasol Barazandeh, Ghasem Najafpour-Darz, Afshar Alihossein, Sohrab Kazemi

Karbala International Journal of Modern Science

Core-shell nanoparticles were used in a unique direct UV-Vis spectrophotometric technique to detect the S-naproxen enantiomer. Silver nanoparticles (Ag NPs) covered with sodium alginate (Alg) shell, a naturally occurring biopolymer, made the core of the nanostructure. To name a few, TEM, FESEM, UV-Visible, DLS, ZP, AFM, XRD, EDX and FT-IR are among the analytical methods used to analyze the creation of the core-shell structure. Based on obtained results, spherical Ag@ Alg NPs with an average size of 27.4 nm (DTEM), hydrolytic size of 46 nm (DDLS) and surface charge of -60.9 mV were successfully synthesized. The effect of various reaction …

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Anharmonic Ir Absorption Spectra Of The Prototypical Interstellar Pahs Phenanthrene, Pyrene, And Pentacene In Their Neutral And Cation States, Vincent J. Esposito, Louis J. Allamandola, Christiaan Boersma, Jesse D. Bregman, Ryan C. Fortenberry, Alexandros Maragkoudakis, Pasquale Temi Sep 2023

Anharmonic Ir Absorption Spectra Of The Prototypical Interstellar Pahs Phenanthrene, Pyrene, And Pentacene In Their Neutral And Cation States, Vincent J. Esposito, Louis J. Allamandola, Christiaan Boersma, Jesse D. Bregman, Ryan C. Fortenberry, Alexandros Maragkoudakis, Pasquale Temi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Combination band and overtone transitions of polycyclic aromatic hydrocarbon (PAH) cations in the 2000–2900 cm-1 (5-3.5 µm) region are implicated as carriers of the ‘quasi-continuum’ observed in the near-infrared (IR) emission spectra of many astronomical objects. In neutral PAHs, the strongest absorption features are concentrated in the 700–900 cm-1 (14–11 µm) range, which are associated with CH out-of-plane bending motions. Upon ionization, this shifts to the 1000–1600 cm-1 (10–6 µm) range, where bands are associated with C=C stretches and CH in-plane bends. Anharmonicity is required to accurately characterize the IR absorption spectrum of PAHs, indicated herein by …

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Thermodynamic And Kinetic Modeling Of Electrocatalytic Reactions Using A First-Principles Approach, M. Vasanthapandiyan, Shagun Singh, Fernanda Bononi, Oliviero Andreussi, Naiwrit Karmodak Sep 2023

Thermodynamic And Kinetic Modeling Of Electrocatalytic Reactions Using A First-Principles Approach, M. Vasanthapandiyan, Shagun Singh, Fernanda Bononi, Oliviero Andreussi, Naiwrit Karmodak

Chemistry and Biochemistry Faculty Publications and Presentations

The computational modeling of electrochemical interfaces and their applications in electrocatalysis has attracted great attention in recent years. While tremendous progress has been made in this area, however, the accurate atomistic descriptions at the electrode/electrolyte interfaces remain a great challenge. The Computational Hydrogen Electrode (CHE) method and continuum modeling of the solvent and electrolyte interactions form the basis for most of these methodological developments. Several posterior corrections have been added to the CHE method to improve its accuracy and widen its applications. The most recently developed grand canonical potential approaches with the embedded diffuse layer models have shown considerable improvement …

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Mechanistic Investigations Of A Novel Braf Regulatory Switch And Braftide, An Allosteric Peptide Inhibitor Of Braf, Alison Yu Sep 2023

Mechanistic Investigations Of A Novel Braf Regulatory Switch And Braftide, An Allosteric Peptide Inhibitor Of Braf, Alison Yu

Theses and Dissertations

RAF kinases (ARAF/BRAF/CRAF or Raf-1) are serine/threonine kinases in the MAPK (RAS-RAF-MEK-ERK) pathway. The MAPK pathway is crucial in development and normal cell function. These same roles are dysregulated in cancer; BRAF is the most frequently mutated isoform in cancers and in particular, activation loop mutants BRAF V600E/K mutants have the highest mutational incidence. Three FDA approved inhibitors potently inhibit BRAF V600E/K mutants. However, these same inhibitors fail to address the non-V600E/K mutations and result in paradoxical activation of the MAPK pathway. Two strategies were employed to address the limitations of the FDA-approved inhibitors: provide novel regulatory details of RAF …

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Time-Resolved Cryo-Em (Tr-Em) Analysis Of Substrate Polyubiquitination By The Ring E3 Anaphase-Promoting Complex/Cyclosome (Apc/C), Tatyana Bodrug, Kaeli A. Welsh, Derek L. Bolhuis, Ethan Paulаkonis, Raquel C. Martinez-Chacin, Bei Liu, Nicholas Pinkin, Thomas Bonacci, Liying Cui, Pengning Xu, Olivia Roscow, Sascha Josef Amann, Irina Grishkovskaya, Michael J. Emanuele, Joseph S. Harrison, Joshua P. Steimel, Klaus M. Hahn, Wei Zhang, Ellen D. Zhong, David Haselbach, Nicholas G. Brown Sep 2023

Time-Resolved Cryo-Em (Tr-Em) Analysis Of Substrate Polyubiquitination By The Ring E3 Anaphase-Promoting Complex/Cyclosome (Apc/C), Tatyana Bodrug, Kaeli A. Welsh, Derek L. Bolhuis, Ethan Paulаkonis, Raquel C. Martinez-Chacin, Bei Liu, Nicholas Pinkin, Thomas Bonacci, Liying Cui, Pengning Xu, Olivia Roscow, Sascha Josef Amann, Irina Grishkovskaya, Michael J. Emanuele, Joseph S. Harrison, Joshua P. Steimel, Klaus M. Hahn, Wei Zhang, Ellen D. Zhong, David Haselbach, Nicholas G. Brown

Pacific Faculty Work

Substrate polyubiquitination drives a myriad of cellular processes, including the cell cycle, apoptosis and immune responses. Polyubiquitination is highly dynamic, and obtaining mechanistic insight has thus far required artificially trapped structures to stabilize specific steps along the enzymatic process. So far, how any ubiquitin ligase builds a proteasomal degradation signal, which is canonically regarded as four or more ubiquitins, remains unclear. Here we present time-resolved cryogenic electron microscopy studies of the 1.2 MDa E3 ubiquitin ligase, known as the anaphase-promoting complex/cyclosome (APC/C), and its E2 co-enzymes (UBE2C/UBCH10 and UBE2S) during substrate polyubiquitination. Using cryoDRGN (Deep Reconstructing Generative Networks), a neural …

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Investigation Of The Thermodynamics For The Removal Of As(Iii) And As(V) From Water Using Synthesized Zno Nanoparticles And The Effects Of Ph, Temperature, And Time, Helia M. Morales Ramirez, Grecia Torreblanca, Arnulfo Mar, Mataz Alcoutlabi, Thomas Eubanks, Erik Plata, Jason Parsons Sep 2023

Investigation Of The Thermodynamics For The Removal Of As(Iii) And As(V) From Water Using Synthesized Zno Nanoparticles And The Effects Of Ph, Temperature, And Time, Helia M. Morales Ramirez, Grecia Torreblanca, Arnulfo Mar, Mataz Alcoutlabi, Thomas Eubanks, Erik Plata, Jason Parsons

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

In the present study, the removal of both As(III) and As(V) from aqueous solutions using synthesized ZnO nanomaterials was achieved. The ZnO nanomaterial was synthesized using a precipitation technique and characterized using XRD, SEM, and Raman spectroscopy. XRD confirmed the ZnO nanoparticles were present in the hexagonal wurtzite structure. SEM of the particles showed they were aggregates of triangular and spherical particles. The average nanoparticle size was determined to be 62.03 ± 4.06 nm using Scherrer’s analysis of the three largest diffraction peaks. Raman spectroscopy of the ZnO nanoparticles showed only ZnO peaks, whereas the after-reaction samples indicated that As(V) …

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