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Full-Text Articles in Physical Sciences and Mathematics

Differentiation Of Human, Dog, And Cat Hair Fibers Using Dart Tofms And Machine Learning, Laura Ahumada, Erin R. Mcclure-Price, Chad Kwong, Edgard O. Espinoza, John Santerre Dec 2023

Differentiation Of Human, Dog, And Cat Hair Fibers Using Dart Tofms And Machine Learning, Laura Ahumada, Erin R. Mcclure-Price, Chad Kwong, Edgard O. Espinoza, John Santerre

SMU Data Science Review

Hair is found in over 90% of crime scenes and has long been analyzed as trace evidence. However, recent reviews of traditional hair fiber analysis techniques, primarily morphological examination, have cast doubt on its reliability. To address these concerns, this study employed machine learning algorithms, specifically Linear Discriminant Analysis (LDA) and Random Forest, on Direct Analysis in Real Time time-of-flight mass spectra collected from human, cat, and dog hair samples. The objective was to develop a chemistry- and statistics-based classification method for unbiased taxonomic identification of hair. The results of the study showed that LDA and Random Forest were highly …


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 …


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 …


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.


Principles Of Chemistry-1, Rajnish Singh Feb 2023

Principles Of Chemistry-1, Rajnish Singh

KSU Distinguished Course Repository

Principles of Chemistry, chem 1211, is a 3 credit hour course, the first in a two-semester sequence covering the fundamental principles and applications of chemistry for science majors. Course content includes electronic structure of atoms and molecules, bonding fundamentals, fundamentals of chemical reactions, and gas laws. The course is taught asynchronously and the final exam being a national exam offered by the American chemical society, (ACS), that has to be taken in person.


Geothermal Energy And Its Impacts On The Environment, Aditi Gorthy, Nathan Tran, Laureen Pierre-Louis Jan 2023

Geothermal Energy And Its Impacts On The Environment, Aditi Gorthy, Nathan Tran, Laureen Pierre-Louis

Mako: NSU Undergraduate Student Journal

From the multitude of energy sources that we have developed throughout the eons, renewable energy or “clean energy” has been on the rise to combat global warming and climate change which burning nonrenewable sources of energy have contributed to. Before geothermal energy is used as part of the mainstream energy sources some aspects must be analyzed and resolved. Unfortunately, geothermal power plants still release pollutants, such as carbon dioxide and sulfur dioxide, into the environment and cause general environmental disruptions due to drilling and changes in land formations. Recent and future studies have been and should be conducted to find …


Synthesis Of New Ligand-Based Phosphazo Ring And Its Transition Metal Complexes As Cancer Inhibitor: Spectroscopic, Dft, Antimicrobial, And Molecular Docking Investigations, Asmaa A. Hamed, Ahmed A. El-Sherif, Carmen M. Sharaby, Yousry A. Ammar, Mona F. Amine Jan 2023

Synthesis Of New Ligand-Based Phosphazo Ring And Its Transition Metal Complexes As Cancer Inhibitor: Spectroscopic, Dft, Antimicrobial, And Molecular Docking Investigations, Asmaa A. Hamed, Ahmed A. El-Sherif, Carmen M. Sharaby, Yousry A. Ammar, Mona F. Amine

Al-Azhar Bulletin of Science

A condensation between 2-sulfanilamidopyrimidine and a p-toluidine dimer of cyclodiazadiphosphetidine resulted in the formation of a new ligand, 2,2,4,4-tetrachloro-1,3-di-[p-tolyl]-2,4-di-[N-(pyrimidin-2-yl) benzenesulfonamide]-1,3,2,4-diazadiphosphetidine, (H2L). We investigated the chemical behavior of the newly prepared ligand was investigated by treating it with some chosen metal ions at a stoichiometric ratio of 1:2 (L:M), where M = Fe(III), Fe(II), Cu(II), Zn(II), Cd(II), and Ag(I), to provide colored complexes with accepted yields. Then, we characterized the ligand and related complexes using spectroscopic and analytical techniques. Investigations revealed that the geometrical structure of the complexes was octahedral, except for the silver complex was tetrahedral. From the spectral analyses, …


Novel Technique In Production Of Pb (Ii)- Imprinted Polymers, Ehab Mohammed, Mostafa M. Elsheikh, Adham A. El-Zomrawy, Farag A. Ahmed Jan 2023

Novel Technique In Production Of Pb (Ii)- Imprinted Polymers, Ehab Mohammed, Mostafa M. Elsheikh, Adham A. El-Zomrawy, Farag A. Ahmed

Al-Azhar Bulletin of Science

Ion imprinting techniques were used to produce ion imprinted polymer (IIP) particles for the selective removal of Pb2+ from aqueous environments. As the Templating monomers, acrylic acid, acrylic amine ligand, and Methylene Bisacrylamide crosslinker were chosen. The imprinted polymer was prepared by free radical polymerization. By leaching with 0.1 M HCl, the (Pb2+) ion was removed from the template. The polymer particles were characterized by IR spectroscopy, Thermal analysis and potentiometric analysis. The produced polymer was mechanically crushed into fine particles, assembled into a sensor probe, and linked to a bare HB graphite pencil electrode (GPE). The sensor has a …


Enhanced Adsorption Of Anionic Dyes Using Sr-Doped Zno Nanoparticles: Nonlinear Kinetics And Isotherm Studies, Mostafa H. Mohamed, Taha M. Elmorsi, H. M. Abdelbary Jan 2023

Enhanced Adsorption Of Anionic Dyes Using Sr-Doped Zno Nanoparticles: Nonlinear Kinetics And Isotherm Studies, Mostafa H. Mohamed, Taha M. Elmorsi, H. M. Abdelbary

Al-Azhar Bulletin of Science

Using a co-precipitation process, sr-doped ZnO was prepared and demonstrated to be effective in the removal of anionic congo red dye, since its surface positive charge was increased to 17.3 mV. To investigate the surface morphology and physicochemical characteristics of Sr-doped ZnO, FTIR spectroscopy, scanning electron microscopy (SEM), elemental analysis, and point of zero charges (pHPZC) were employed. We conducted batch adsorption experiments to investigate the effects of contact time (180 minutes), pH (3.5–11), adsorbent dosage (0.5–3.0 g L−1), and temperature (288–328 K). The kinetic study was modeled using several equations, including pseudo-firstorder (PFO), pseudo-second-order (PSO), Elovich, and intra-particle diffusion …


Dr. Lawrence J. Berliner, Anit Tyagi May 2022

Dr. Lawrence J. Berliner, Anit Tyagi

DU Undergraduate Research Journal Archive

An interview with Dr. Lawrence J. Berliner.


Strategic Consideration And Recommendation On Development Of Chemistry In China, Yanlin Cheng, Shuxian Wu, Qing Dai, Chunying Chen, Yuliang Zhao Mar 2022

Strategic Consideration And Recommendation On Development Of Chemistry In China, Yanlin Cheng, Shuxian Wu, Qing Dai, Chunying Chen, Yuliang Zhao

Bulletin of Chinese Academy of Sciences (Chinese Version)

Chemistry, as a central science linking all the other sciences, has played an influential role in promoting the development of the whole scientific and technological field and the prosperity of economy and society. Developed countries strongly support the development of chemistry and effectively promote the level of chemical research and chemical industry. Since the founding of the People's Republic of China, chemical research has been supported among the field of natural sciences, and its current level is at the forefront of the world. However, there are still problems in the field of chemistry research in China, such as insufficient major …


Correlation Effects On Intramolecular C-H...Oh And O-H...O Hydrogen Bond Interactions In Azelaic Acid: An Ab Initio Study, Sabina Kalata, Alina Huang, Ruben Parra Aug 2021

Correlation Effects On Intramolecular C-H...Oh And O-H...O Hydrogen Bond Interactions In Azelaic Acid: An Ab Initio Study, Sabina Kalata, Alina Huang, Ruben Parra

DePaul Discoveries

Electron correlation effects on both conventional, O-H…O, and nonconventional, C-H…O, intramolecular hydrogen bonds present in a selected azelaic acid folded conformation were evaluated ab initio using HF and MP2 methodologies. The relative strength of the hydrogen bonds was examined through different indicators derived from geometry, vibrational frequencies, and electron density along the hydrogen bond path. The HF method results in weaker O-H…O and C-H…O hydrogen bonds when compared with the corresponding results using the MP2 method. Additionally, the stability of the folded azelaic conformation is found to depend on the level of theory used. Accordingly, the zero-point corrected energies of …


Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo Jul 2020

Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo

Journal of Science Education for Students with Disabilities

This article examines the tools and techniques currently available that enable blind and visually impaired (BVI) individuals to visualize three-dimensional objects used in learning chemistry concepts. How BVI individuals engage with and visualize molecular structure is discussed and recent tactile (or haptic) and auditory methods for visualization of various chemistry concepts are summarized. Remaining challenges for chemistry education researchers are described with the aim of highlighting the potential value of educational research in further enabling BVI students to pursue careers in science, technology, engineering, and mathematics (STEM) fields.


New Innovation In The Flipped Chemistry Classroom Jan 2020

New Innovation In The Flipped Chemistry Classroom

The Graduate Review

No abstract provided.


Serendipitous Discovery Of A New Method For The Catalytic Synthesis Of Indole-Fused Benzazepanes, Edward Gluzman, Paul A. Vadola Jul 2016

Serendipitous Discovery Of A New Method For The Catalytic Synthesis Of Indole-Fused Benzazepanes, Edward Gluzman, Paul A. Vadola

DePaul Discoveries

We report here on our investigations into the application of 1,5-hydride transfer cyclization mechanisms to the synthesis of 2,3-disubstituted benzofurans and indoles. We found that PtI4 in MeCN at 120 ºC was indeed capable of activating the alkyne, however, the expected 2,3-disubstituted indole product was not observed. Instead we isolated an indolyl-3-benzazepane via an unexpected intramolecular Steven’s rearrangement/ring expansion. While this transformation has been previously reported our method may prove to have increased substrate scope and more practical reaction conditions. Further studies are underway to optimize the reaction conditions and to fully explore the scope and mechanism of the …


Ambiguity In Speaking Chemistry And Other Stem Content: Educational Implications, Mick D. Isaacson, Michelle Michaels Sep 2015

Ambiguity In Speaking Chemistry And Other Stem Content: Educational Implications, Mick D. Isaacson, Michelle Michaels

Journal of Science Education for Students with Disabilities

Ambiguity in speech is a possible barrier to the acquisition of knowledge for students who have print disabilities (such as blindness, visual impairments, and some specific learning disabilities) and rely on auditory input for learning. Chemistry appears to have considerable potential for being spoken ambiguously and may be a barrier to accessing knowledge and to learning. Educators in chemistry may be unaware of, or have limited awareness of, potential ambiguity in speaking chemistry and may speak chemistry ambiguously to their students. One purpose of this paper is to increase awareness of potential ambiguity in speaking chemistry and other STEM fields …


Learning Chemistry Through Experimentation, Brent Kamba `, Dr. Jennifer Nielson Apr 2015

Learning Chemistry Through Experimentation, Brent Kamba `, Dr. Jennifer Nielson

Journal of Undergraduate Research

There is a great need for students to learn scientific skills in Uganda. Very few students pass the national chemistry exams (about 40%) and even fewer go on to study science fields in higher education. The teaching methods in Uganda are a little bit old fashion where students often just learn facts and practise rote memorization. Rarely do they develop the critical and analytical skills to help them succeed in science jobs. Teachers also express that the curriculum is very theoretical, and not experimental.


Surge Of Green: A Sustainable Approach To Conductive Polymers, Bethany Masten Jan 2007

Surge Of Green: A Sustainable Approach To Conductive Polymers, Bethany Masten

Undergraduate Review

No abstract provided.


Hydromination Of Alkynes, Enynes, And Dienes Using Titanium Catalysts, Taryn Palluccio Jan 2007

Hydromination Of Alkynes, Enynes, And Dienes Using Titanium Catalysts, Taryn Palluccio

Undergraduate Review

No abstract provided.


Development Of Dirhodium Sugar-Substituted Carboxylate And Acetamide Complexes And Evaluation Of Their Potential As Lectin Inhibitors, Bethany Masten Jan 2006

Development Of Dirhodium Sugar-Substituted Carboxylate And Acetamide Complexes And Evaluation Of Their Potential As Lectin Inhibitors, Bethany Masten

Undergraduate Review

No abstract provided.


Using Microenvironmental Effects To Increase Loading And Stereoselectivity For Polymer Bound Nabh4 Reagents., James R. Blanton Jan 2004

Using Microenvironmental Effects To Increase Loading And Stereoselectivity For Polymer Bound Nabh4 Reagents., James R. Blanton

Journal of the South Carolina Academy of Science

No abstract provided.


The Development Of A General Education College Chemistry Course, Luther Arnold May 1956

The Development Of A General Education College Chemistry Course, Luther Arnold

Journal of the Minnesota Academy of Science

No abstract provided.


Semi-Micro Procedure In High School Laboratories, Karl J. Aaberg May 1954

Semi-Micro Procedure In High School Laboratories, Karl J. Aaberg

Journal of the Minnesota Academy of Science

No abstract provided.


Chemical Magic Experiments, Leonard A. Ford May 1952

Chemical Magic Experiments, Leonard A. Ford

Journal of the Minnesota Academy of Science

No abstract provided.


The Inductive Compared With The Deductive Approach To Teaching Secondary School Chemistry, Clarence H. Boeck Apr 1951

The Inductive Compared With The Deductive Approach To Teaching Secondary School Chemistry, Clarence H. Boeck

Journal of the Minnesota Academy of Science

No abstract provided.


Chemistry-Restricted, Robert Molkenbur Apr 1948

Chemistry-Restricted, Robert Molkenbur

Journal of the Minnesota Academy of Science

No abstract provided.


Two Physical Methods For The Quantitative Determination Of One Component Of A Mixture Of Gases, Marvin M.D. Williams, Hugh O. Brown, William B. Dublin, Walter M. Boothby Apr 1945

Two Physical Methods For The Quantitative Determination Of One Component Of A Mixture Of Gases, Marvin M.D. Williams, Hugh O. Brown, William B. Dublin, Walter M. Boothby

Journal of the Minnesota Academy of Science

No abstract provided.


Chemistry Demonstrations In Public, Leonard A. Ford Apr 1941

Chemistry Demonstrations In Public, Leonard A. Ford

Journal of the Minnesota Academy of Science

No abstract provided.


Applications Of Artificial Radioactivity To Problems In Chemistry, D. E. Hull Apr 1940

Applications Of Artificial Radioactivity To Problems In Chemistry, D. E. Hull

Journal of the Minnesota Academy of Science

No abstract provided.


The Biological Use Of The Stable Mass Isotopes, Allan Hemingway Apr 1940

The Biological Use Of The Stable Mass Isotopes, Allan Hemingway

Journal of the Minnesota Academy of Science

No abstract provided.