Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

224,961 Full-Text Articles 290,406 Authors 68,761,115 Downloads 426 Institutions

All Articles in Physical Sciences and Mathematics

Faceted Search

224,961 full-text articles. Page 8 of 6494.

Suzuki Coupling Catalyzed By (8-(Dimesitylboryl)Quinoline)Palladium(0) Species: A Theoretical Analysis, Haley S. Rust 2021 University of South Dakota

Suzuki Coupling Catalyzed By (8-(Dimesitylboryl)Quinoline)Palladium(0) Species: A Theoretical Analysis, Haley S. Rust

Honors Thesis

The Suzuki reaction is a catalyzed cross-coupling reaction which is of upmost importance in the formation of carbon-carbon (C-C) bonds in modern organic synthesis. Recently a new catalyst including an 8-(dimesitylboryl)quinoline for the coupling of aryl halides with phenylboronic acids was synthetized. We synthesized ligand that includes a frustrated Lewis pair, (quinolin-8-yl)dimesitylborane (DMBQ), complexed it with group X metals (nickel (Ni), palladium (Pd), and platinum (Pt)), and studied the process of oxidative addition with carbon-fluorine (C-F) bonds and activation towards Suzuki coupling. Mayer bond analysis and electron localization function maps showed a bond between the boron center ...


Transient Electronics As Sustainable Systems: From Fundamentals To Applications, Reihaneh Jamshidi, Mehrnoosh Taghavimehr, Yuanfen Chen, Nicole Hashemi, Reza Montazami 2021 University of Hartford

Transient Electronics As Sustainable Systems: From Fundamentals To Applications, Reihaneh Jamshidi, Mehrnoosh Taghavimehr, Yuanfen Chen, Nicole Hashemi, Reza Montazami

Mechanical Engineering Publications

The unique attribute of transient technology is that it promotes the potential for the design and implementation of sustainable systems through their capability to fully or partially disintegrate after a predefined period of stable operation. Transient electronics have a wide range of potential applications as biomedical implants, environmental sensors, and hardware‐secured devices. Controlled disintegration of such systems without the need for harsh solvents is a step toward realizing green and sustainable electronics. In this short review, recent progress in the development of transient electronics is studied. First, an overview of the transient materials, both the substrate and electronic component ...


Denver - 1989 University & I-25, 2021 University of Denver

Denver - 1989 University & I-25

United States Data - Colorado

No abstract provided.


Grand Junction - 2001, 2021 University of Denver

Grand Junction - 2001

United States Data - Colorado

No abstract provided.


Ute Pass - 1989, 2021 University of Denver

Ute Pass - 1989

United States Data - Colorado

No abstract provided.


Lexicographic Sensitivity Functions For Nonsmooth Models In Mathematical Biology, Matthew D. Ackley 2021 University of Maine

Lexicographic Sensitivity Functions For Nonsmooth Models In Mathematical Biology, Matthew D. Ackley

Electronic Theses and Dissertations

Systems of ordinary differential equations (ODEs) may be used to model a wide variety of real-world phenomena in biology and engineering. Classical sensitivity theory is well-established and concerns itself with quantifying the responsiveness of such models to changes in parameter values. By performing a sensitivity analysis, a variety of insights can be gained into a model (and hence, the real-world system that it represents); in particular, the information gained can uncover a system's most important aspects, for use in design, control or optimization of the system. However, while the results of such analysis are desirable, the approach that classical ...


Alfalfa Forage Processing And Industry Development In China, S. H. Luo, F. Y. Liu 2021 Chengdu Daye International Investment Co. Ltd., China

Alfalfa Forage Processing And Industry Development In China, S. H. Luo, F. Y. Liu

International Grassland Congress Proceedings

No abstract provided.


Do Silicon Fertilizers Improve The Fodder Value Of Tropical Grass Species?, Valentin Kindomihou, Jianfeng Ma, Brice Sinsin, Pierre Meerts 2021 University of Abomey-Calavi, Benin

Do Silicon Fertilizers Improve The Fodder Value Of Tropical Grass Species?, Valentin Kindomihou, Jianfeng Ma, Brice Sinsin, Pierre Meerts

International Grassland Congress Proceedings

No abstract provided.


Variation In Forage Quality Of Three Rangeland Species In Different Phenological Stages, S. A. Javadi, H. Arzani 2021 Islamic Azad University, Iran

Variation In Forage Quality Of Three Rangeland Species In Different Phenological Stages, S. A. Javadi, H. Arzani

International Grassland Congress Proceedings

No abstract provided.


Influence Of Germination On The Soluble Carbohydrates In Feed Legumes, María Felicia Díaz, María A. Martín‐Cabrejas, Yolanda Aguilera, Vanesa Benítez, Esperanza Mollá, Rosa M. Esteban 2021 Instituto de Ciencia Animal, Cuba

Influence Of Germination On The Soluble Carbohydrates In Feed Legumes, María Felicia Díaz, María A. Martín‐Cabrejas, Yolanda Aguilera, Vanesa Benítez, Esperanza Mollá, Rosa M. Esteban

International Grassland Congress Proceedings

No abstract provided.


Analysis Of Students’ Multi-Representation Ability In Augmented Reality-Assisted Learning, Sri Jumini, Edy Cahyono, Muhamad Miftakhul Falah 2021 Universitas Sains Al-Qur'an of Central Java in Wonosobo

Analysis Of Students’ Multi-Representation Ability In Augmented Reality-Assisted Learning, Sri Jumini, Edy Cahyono, Muhamad Miftakhul Falah

Library Philosophy and Practice (e-journal)

Not all learning sources can directly and cheaply be presented, so augmented reality media is needed to be applied to students with various talents and intelligence. This study aims to analyze students’ multi-representation ability through the use of augmented reality media. The research method was carried out through pre-experiment with one group posttest only design. Test question items were given to see the students’ multi-representation ability. Data analysis was carried out through the percentage of the number of students achieving test scores of more than or equal to 80 on a scale of 100. The results showed that 88% (28 ...


Streaming Down The Stern-Brocot Tree: Finding And Expressing Solutions To Pell's Equation In Sl(2,Z), Marcus L. Shell 2021 Jacksonville State University

Streaming Down The Stern-Brocot Tree: Finding And Expressing Solutions To Pell's Equation In Sl(2,Z), Marcus L. Shell

Theses

This paper explores and elaborates on a method of solving Pell’s equation as introduced by Norman Wildberger. In the first chapters of the paper, foundational topics are introduced in expository style including an explanation of Pell’s equation. An explanation of continued fractions and their ability to express quadratic irrationals is provided as well as a connection to the Stern-Brocot tree and a convenient means of representation for each in terms of 2×2 matrices with integer elements. This representation will provide a useful way of navigating the Stern-Brocot tree computationally and permit us a means of computing continued ...


Qualitative Analysis Of Corequisite Instruction In A Quantitative Reasoning Course, Zachary Beamer 2021 Piedmont Virginia Community College

Qualitative Analysis Of Corequisite Instruction In A Quantitative Reasoning Course, Zachary Beamer

Inquiry: The Journal of the Virginia Community Colleges

In corequisite models of instruction, marginally prepared students are placed directly into college-level coursework, taught with a paired support course. Initial research suggests that such models yield significant improvements in the number of students passing credit-level mathematics when compared to previous models of prerequisite remediation. The present study employs qualitative methods to investigate methods of instruction at one community colleges to understand how instructors identify and respond to student needs. It concludes with recommendations for practice and highlights advantages of small format corequisite classes taught by the same instructor.


Benchmarking Clustering And Classification Tasks Using K-Means, Fuzzy C-Means And Feedforward Neural Networks Optimized By Pso, Adam Pickens, Adam Pickens 2021 Murray State University

Benchmarking Clustering And Classification Tasks Using K-Means, Fuzzy C-Means And Feedforward Neural Networks Optimized By Pso, Adam Pickens, Adam Pickens

Honors College Theses

Clustering is a widely used unsupervised learning technique across data mining and machine learning applications and finds frequent use in diverse fields ranging from astronomy, medical imaging, search and optimization, geology, geophysics and sentiment analysis to name a few. It is therefore important to verify the effectiveness of the clustering algorithms in question and to make reasonably strong arguments for the acceptance of the end results generated by the validity indices that measure the compactness and separability of clusters. This work aims to explore the successes and limitations of popular clustering mechanisms such as K-Means and Fuzzy C-Means by comparing ...


El Paso / Juarez - 1993, 2021 University of Denver

El Paso / Juarez - 1993

United States Data - Texas

No abstract provided.


Influence Of Seasonal Changes And Variety On The Water‐Soluble Carbohydrate (Wsc) Content Of Varieties Of Lolium Perenne In Sweden, Magnus A. Halling 2021 Swedish University of Agricultural Sciences, Sweden

Influence Of Seasonal Changes And Variety On The Water‐Soluble Carbohydrate (Wsc) Content Of Varieties Of Lolium Perenne In Sweden, Magnus A. Halling

International Grassland Congress Proceedings

No abstract provided.


Yield And Nutritive Value Of Warm‐Season Grasses, Renato S. Fontaneli, Rob S. Fontaneli, R. Orth 2021 EMBRAPA, Brazil

Yield And Nutritive Value Of Warm‐Season Grasses, Renato S. Fontaneli, Rob S. Fontaneli, R. Orth

International Grassland Congress Proceedings

No abstract provided.


Yield Of Double Purpose Winter Species As Pasture And Silage, Renato S. Fontaneli, H. P. dos Santos, A. do Nascimento Junior, E. Caierãol, Rob S. Fontaneli 2021 EMBRAPA, Brazil

Yield Of Double Purpose Winter Species As Pasture And Silage, Renato S. Fontaneli, H. P. Dos Santos, A. Do Nascimento Junior, E. Caierãol, Rob S. Fontaneli

International Grassland Congress Proceedings

No abstract provided.


Pharyngeal Constriction As A Cause For Late Acquisition And Speech Sound Disorders Of Rhotic Sounds In English, Spanish, And French, Connor Mahon 2021 Cleveland State University

Pharyngeal Constriction As A Cause For Late Acquisition And Speech Sound Disorders Of Rhotic Sounds In English, Spanish, And French, Connor Mahon

The Downtown Review

This paper attempts to explain why rhotic sounds are cross-linguistically late developing among the sound inventory of children. Included is a summary of the current literature regarding classification of rhotic sounds, an examination of the articulatory movement of the tongue root, and an overview of the clinical implications on the field of speech-language pathology. The evidence presented supports the hypothesis that pharyngeal constriction is characteristic of rhotic sounds in many languages, and that it is related to the relative late acquisition and higher rate of speech sound disorders, as seen in English, Spanish, and French.


Development Of A Rapid Drug Detection Method For Insects Using Paper Spray Ionization Mass Spectrometry (Psi-Ms), Alexandria Plyler 2021 Duquesne University

Development Of A Rapid Drug Detection Method For Insects Using Paper Spray Ionization Mass Spectrometry (Psi-Ms), Alexandria Plyler

Undergraduate Research and Scholarship Symposium

Insects have the ability to reflect the chemical environment that they have developed in. Thus, necrogenous insects can reflect the chemical environment of cadavers they have fed on. Forensic scientists can potentially utilize insect larvae as an alternate biological matrix to detect drugs in cadavers that are skeletonized, burned, or otherwise badly damaged. Analysis of insects using paper spray ionization mass spectrometry (PSI-MS), an analytical method requiring little to no sample preparation, could prove a rapid, cost-effective, and non-destructive alternative form of toxicological analysis. Traditional tissue analysis via GC and LC-MS often require lengthy sample preparation, use expensive reagents, and ...


Digital Commons powered by bepress