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

Physical Sciences and Mathematics Commons™

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

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 53641 - 53670 of 302586

Full-Text Articles in Physical Sciences and Mathematics

Big Earth Data Research Topic Evolution And Influence Analysis, Peijun An, Xiantao Xiao, Huadong Guo, Dongmei Yan, Jialei Li Aug 2021

Big Earth Data Research Topic Evolution And Influence Analysis, Peijun An, Xiantao Xiao, Huadong Guo, Dongmei Yan, Jialei Li

Bulletin of Chinese Academy of Sciences (Chinese Version)

Big data driven data-intensive scientific discovery, and the Big Earth Data is the base and engine of Earth system science. Based on observation of natural geographical elements on different scales and acquisition of data, and the data obtained during the interdisciplinary research processes, integration and mining analysis will promote the development of Earth science to achieve significant innovation. The Big Earth Data has also become the important national strategic resources, and exerted influence on international cooperation and diplomatic relationship. In this study by means of literature metrology, the Big Earth Data literature from the Science Citation Index (SCI) and Social …

Go to article

Trends Observation: International Big Earth Data Research Situation And Hot Trends Aug 2021

Trends Observation: International Big Earth Data Research Situation And Hot Trends

Bulletin of Chinese Academy of Sciences (Chinese Version)

No abstract provided.

Go to article

To Know The Land With Hands And Minds: Negotiating Agricultural Knowledge In Late-Nineteenth-Century New England And Westphalia, Justus Hillebrand Aug 2021

To Know The Land With Hands And Minds: Negotiating Agricultural Knowledge In Late-Nineteenth-Century New England And Westphalia, Justus Hillebrand

Electronic Theses and Dissertations

Ever since the eighteenth century, experts have tried to tell farmers how to farm. The agricultural enlightenment in Europe marked the beginning of a long arc of new experts aiming to change agricultural knowledge and practice. This dissertation analyzes the pivotal period in the late nineteenth and early twentieth century in Germany and the United States when scientists, improvers, and market agents began to develop comprehensive ways to communicate agricultural innovation to farmers. In a functional approach to analyzing the negotiation of agricultural knowledge through its communication in things, words, and practices, this dissertation argues that the process of change …

Go to article

Application Of Machine Learning Techniques To Classify And Identify Galaxy Merger Events In The Candels Field, Alex Koch Aug 2021

Application Of Machine Learning Techniques To Classify And Identify Galaxy Merger Events In The Candels Field, Alex Koch

Electronic Theses and Dissertations

Galaxy mergers are dynamic systems that offer us a glimpse into the evolution of the cosmos and the galaxies that constitute it. However, with the advent of large astronomical surveys, it is becoming increasingly difficult to rely on humans to classify the vast number of astronomical images collected every year and find the images that capture these systems. In recent years, researchers have increasingly relied on machine learning and computer vision classifiers, and while these techniques have proven useful for classifying broad galaxy morphologies, they have struggled to identify galaxy mergers. A random forest classifier was applied to a subset …

Go to article

An Investigation Of Students' Use And Understanding Of Evaluation Strategies, Abolaji R. Akinyemi Aug 2021

An Investigation Of Students' Use And Understanding Of Evaluation Strategies, Abolaji R. Akinyemi

Electronic Theses and Dissertations

One expected outcome of physics instruction is that students develop quantitative reasoning skills, including evaluation of problem solutions. To investigate students’ use of evaluation strategies, we developed and administered tasks prompting students to check the validity of a given expression. We collected written (N>673) and interview (N=31) data at the introductory, sophomore, and junior levels. Tasks were administered in three different physics contexts: the velocity of a block at the bottom of an incline with friction, the electric field due to three point charges of equal magnitude, and the final velocities of two masses in an elastic collision. Responses …

Go to article

Discards & Diverse Economies: Reuse In Rural Maine, Brieanne Berry Aug 2021

Discards & Diverse Economies: Reuse In Rural Maine, Brieanne Berry

Electronic Theses and Dissertations

This dissertation presents an ethnographic exploration of diverse reuse economies in rural Maine in an effort to illuminate both how used goods move between people and organizations, as well as the value of that movement for people and communities. In response to a growing number of calls for research into the social dimensions of circular economies, this research explores the varied and uneven impacts of materials reuse as they are experienced by local participants. This work uses a qualitative approach, drawing on two main methods: participant observation in reuse establishments and in-depth, semi-structured interviews with reuse participants. This rich qualitative …

Go to article

Asymmetric Synthesis Of Phosphate Mimics: From Chemistry To Biotechnology, Ahmed Numan Aug 2021

Asymmetric Synthesis Of Phosphate Mimics: From Chemistry To Biotechnology, Ahmed Numan

Electronic Theses and Dissertations

Oligonucleotide based therapeutics have been pursued in the clinic for the treatment of many disease indications. However, unmodified oligonucleotides are polyanionic macromolecules with poor drug-like properties. Modifications of the phosphodiester backbone provide resistance to nucleases in vivo, making them more efficacious than unmodified nucleotides. However, these backbone modifications have added the structural complexity of a stereogenic phosphorus center. Stereochemically pure isomers exhibit differential efficiency dependent on its enantiopurity. The catalytic, stereocontrolled synthesis of a phosphorus-stereogenic center is challenging, and traditionally, depends on a resolution or use of stochiometric auxiliaries. Herein, asymmetric nucleophilic catalysis has been investigated to provide enantio-enriched phosphonates …

Go to article

Luminosity Functions Of Galaxy Clusters In The Aquarius And Microscopium Superclusters, Logan A. Hess Aug 2021

Luminosity Functions Of Galaxy Clusters In The Aquarius And Microscopium Superclusters, Logan A. Hess

Electronic Theses and Dissertations

We examine physical properties of several galaxy clusters located within the Aquarius (AQR) and Microscopium (MSC) super-cluster complexes via their luminosity functions, fitted using Schechter functions. Images of clusters were acquired via the DECam (Dark Energy Camera) imager of the 4-meter diameter telescope at CTIO (Cerro Tololo Inter-American Observatory). We observe six clusters in our sample; four from the Aquarius supercluster (AQR 2541, 2546, 2554, 2555) and two from the Microscopium supercluster (MSC 3695, 3696). Magnitude information and density of member galaxies in each cluster were extracted via the SExtractor software utility from obtained images. We correct for background by …

Go to article

Stable Hydrogen Isotopes Of Aquatic-Emergent Versus Terrestrial Insects In Southern Ontario, Celina Y. Tang Aug 2021

Stable Hydrogen Isotopes Of Aquatic-Emergent Versus Terrestrial Insects In Southern Ontario, Celina Y. Tang

Undergraduate Student Research Internships Conference

Aquatic-emergent insects are vectors of both contaminants and nutrients, linking the aquatic system to the terrestrial system. Aquatic-emergent insects are high in omega-3 fatty acids that benefit terrestrial aerial insectivores, such as bats and birds. With aerial insectivores on a decline, a contributing factor could be a decrease in the quality of insects. We collected insects from lakeshore and inland locations in Southern Ontario. Insects sampled included bees, wasps, ants, beetles, caddisflies, craneflies, dragonflies, marchflies, mayflies, midges, other flies, and true bugs. Insects’ wings and powdered bodies were then analyzed for stable hydrogen isotopes (d2H) in order …

Go to article

Euler's De Serie Lambertina, Translated From Latin To English With Supplementary Notes, Sam Gallagher Aug 2021

Euler's De Serie Lambertina, Translated From Latin To English With Supplementary Notes, Sam Gallagher

Euleriana

Originally published in 1779, Euler's De Serie Lambertina provides one of the early examples of the Lambert W function, a special function used in the solution to certain transcendental equations. Following the work of Johann Heinrich Lambert in 1759, who discussed a series solution to the general polynomial in series, and then particularly the solution of the general trinomial, Euler describes a symmetric form of the trinomial and its series solution. Euler investigates the series' special cases and general properties, and its use in solving certain transcendental equations. He provides several proofs of the validity of the series expansion to …

Go to article

Translation Of Euler's Paper E421, Alexander Aycock Aug 2021

Translation Of Euler's Paper E421, Alexander Aycock

Euleriana

This is paper is the result of Euler’s findings on the Eulerian integral of second kind, i.e. the Γ-function: It summarises results and formulas on and properties of the integral in the title that Euler had obtained up to this point in his career and offers more elegant proofs of those before-mentioned results, formulas and properties. The results include a derivation of the integral in the title from an algebraic integral, the reflection formula for the Γ-function and finally a formula equivalent to the Gaußian multiplication formula for the Γ-function, expressed by Euler using mere integrals of algebraic functions.

Go to article

Euler And The Multiplication Formula For The Gamma Function, Alexander Aycock Aug 2021

Euler And The Multiplication Formula For The Gamma Function, Alexander Aycock

Euleriana

We show that an apparently overlooked result of Leonhard Euler (1707-1783) from [E421] is essentially equivalent to the general multiplication for- mula for the Γ-function that was proven by Carl Friedrich Gauss (1777-1855) in [Ga28].

Go to article

On The Rectilinear Motion Of Three Bodies Mutually Attracting Each Other, Sylvio R. Bistafa Aug 2021

On The Rectilinear Motion Of Three Bodies Mutually Attracting Each Other, Sylvio R. Bistafa

Euleriana

This is an annotated translation from Latin of E327 -- De motu rectilineo trium corporum se mutuo attrahentium (“On the rectilinear motion of three bodies mutually attracting each other”). In this publication, Euler considers three bodies lying on a straight line, which are attracted to each other by central forces inversely proportional to the square of their separation distance (inverse-square law). Here Euler finds that the parameter that controls the relative distances among the bodies is given by a quintic function.

Go to article

Euler's Three-Body Problem, Sylvio R. Bistafa Aug 2021

Euler's Three-Body Problem, Sylvio R. Bistafa

Euleriana

In physics and astronomy, Euler's three-body problem is to solve for the motion of a body that is acted upon by the gravitational field of two other bodies. This problem is named after Leonhard Euler (1707-1783), who discussed it in memoirs published in the 1760s. In these publications, Euler found that the parameter that controls the relative distances among three collinear bodies is given by a quintic equation. Later on, in 1772, Lagrange dealt with the same problem, and demonstrated that for any three masses with circular orbits, there are two special constant-pattern solutions, one where the three bodies remain …

Go to article

Euler's Miracle, William Dunham Aug 2021

Euler's Miracle, William Dunham

Euleriana

This article features some genuine Eulerian magic. In 1748, Leonhard Euler considered a modification of the harmonic series in which negative signs were attached to various terms by a rule that was far from self-evident. With his accustomed flair, he determined its sum, and the result was utterly improbable. There are a few occasions in mathematics when the term “breathtaking” is not too strong. This is one of them.

Go to article

Spotlight On The Euler Archive, Cynthia J. Huffman Ph.D. Aug 2021

Spotlight On The Euler Archive, Cynthia J. Huffman Ph.D.

Euleriana

A spotlight on the Euler Archive with a special emphasis on contributions by Dr. C. Edward Sandifer.

Go to article

Ed Sandifer: An Eulerian Marathoner, Robert E. Bradley Aug 2021

Ed Sandifer: An Eulerian Marathoner, Robert E. Bradley

Euleriana

Ed Sandifer was the founding secretary of the Euler Society. He published a remarkable quantity of Euler scholarship at the time of Euler’s Tercentenary in 2007.

Go to article

Review: A History Of Mathematics In The United States And Canada (Vol. 1), By David Zitarelli, Lawrence D'Antonio Aug 2021

Review: A History Of Mathematics In The United States And Canada (Vol. 1), By David Zitarelli, Lawrence D'Antonio

Euleriana

This is a review of the 2019 text by David ZItarelli, A History of Mathematics in the United States and Canada. Volume 1: 1492 - 1900

Go to article

Sharing Contributions To Euler Scholarship, Erik R. Tou, Christopher Goff Aug 2021

Sharing Contributions To Euler Scholarship, Erik R. Tou, Christopher Goff

Euleriana

A summary of this issue's contents.

Go to article

Hessian Formulas And Estimates For Parabolic Schrödinger Operators, Xue-Mei Li Aug 2021

Hessian Formulas And Estimates For Parabolic Schrödinger Operators, Xue-Mei Li

Journal of Stochastic Analysis

No abstract provided.

Go to article

Remembering Kunita-San, Ken-Iti Sato Aug 2021

Remembering Kunita-San, Ken-Iti Sato

Journal of Stochastic Analysis

No abstract provided.

Go to article

Analysis And Countermeasure Of Unbalanced Ecology System Of Chinese Temperate Grassland, Xinshi Lu, Lin Ai Aug 2021

Analysis And Countermeasure Of Unbalanced Ecology System Of Chinese Temperate Grassland, Xinshi Lu, Lin Ai

IGC Proceedings (1993-2023)

No abstract provided.

Go to article

Natural Grassland Of China, Changcun Lin, Tingcheng Zhu Aug 2021

Natural Grassland Of China, Changcun Lin, Tingcheng Zhu

IGC Proceedings (1993-2023)

No abstract provided.

Go to article

Comparative Analysis For Herdsmen's Income Under The Different Background Systems, Jiri Xi Aug 2021

Comparative Analysis For Herdsmen's Income Under The Different Background Systems, Jiri Xi

IGC Proceedings (1993-2023)

No abstract provided.

Go to article

Critical Pasture, Seasonal Grazing And Sustainable Development Of Grassland Animal Husbandry Production In China, Quangong Chen, Yulin Mao Aug 2021

Critical Pasture, Seasonal Grazing And Sustainable Development Of Grassland Animal Husbandry Production In China, Quangong Chen, Yulin Mao

IGC Proceedings (1993-2023)

No abstract provided.

Go to article

Practice Of Rangeland Co‐Management In Hongyuan, Bai Ze Aug 2021

Practice Of Rangeland Co‐Management In Hongyuan, Bai Ze

IGC Proceedings (1993-2023)

No abstract provided.

Go to article

Finding New Strategies To Rehabilitate Grasslands In Western China, David R. Kemp, Z. B. Nan, J. P. Wu, J. F. Yun, Z. Xu Aug 2021

Finding New Strategies To Rehabilitate Grasslands In Western China, David R. Kemp, Z. B. Nan, J. P. Wu, J. F. Yun, Z. Xu

IGC Proceedings (1993-2023)

No abstract provided.

Go to article

The Research And Implementation Of Film Virtual Photography Harware-In-The-Loop Simulation, Baihong Lu, Jianjun Zhao, Gesan Liu Aug 2021

The Research And Implementation Of Film Virtual Photography Harware-In-The-Loop Simulation, Baihong Lu, Jianjun Zhao, Gesan Liu

Journal of System Simulation

Abstract: Film virtual photography is an important part of the film virtual Previs. Aiming at the problems of high cost, poor user experience, and bad simulation of existing virtual photography, a hardware-in-the-loop simulation system for film virtual photography is proposed. It uses a hardware-in-the-loop simulation virtual photography module that is consistent with the operation method of the film creator in real shooting for virtual photography, which solves the problems of difficult virtual photography operations and not in line with the real operating habits in the past. It provides a virtual photography method that is more in line with movie …

Go to article

Metallogenic Characteristics Of Some Localities Of Gold Mineralization Along Shear Zones Of Elgaab, Dum El Tor And Sodri - Um Bader, (Sudan), Mohamed Osman Elgizouli, Badr El Din Khalil, Mohammed Y. Abedelgalil Aug 2021

Metallogenic Characteristics Of Some Localities Of Gold Mineralization Along Shear Zones Of Elgaab, Dum El Tor And Sodri - Um Bader, (Sudan), Mohamed Osman Elgizouli, Badr El Din Khalil, Mohammed Y. Abedelgalil

Bulletin of the Mineral Research and Exploration

Study area is located in the eastern sector of Saharan Meta - Craton that includes the western part of Bayuda Terrane and extend southwest to Sodri - Um Badir shear zones. The sector is dominated by metasediments, metavolcanic - sedimentary series represented by chlorite - schist, quartzite, calc - silicate, and marble. Low - grade metamorphic arc - related volcano - sedimentary sequence occurs as thin narrow bands and subjected to tectono - thermal events of Pan - African orogeny during the Late - Proterozoic era (900 - 550 Ma). All these rock sequences have been intruded by syn to …

Go to article

Immobilized-Enzyme Reactors Integrated Into Analytical Platforms: Recent Advances And Challenges, Bert Wouters Dr, Sinead Currivan, Noor Abdulhussain, T. Hankemeier, Peter J. Schoenmakers Aug 2021

Immobilized-Enzyme Reactors Integrated Into Analytical Platforms: Recent Advances And Challenges, Bert Wouters Dr, Sinead Currivan, Noor Abdulhussain, T. Hankemeier, Peter J. Schoenmakers

Articles

Immobilized-enzyme reactors (IMERs) are flow-through devices containing enzymes that are physically confined or localized with retention of their catalytic activities. IMERs can be used repeatedly and continuously and have been applied for (bio)polymer degradation, proteomics, biomarker discovery, inhibitor screening, and detection. Online integration of IMERs with analytical instrumentation, such as high-performance liquid chromatography (HPLC) systems, reduces the time needed for multi-step workflows, reduces the need for sample handling, and enables automation. However, online integration can also be challenging, as reaching its full potential requires complex instrumental setups and experienced users. This review aims to provide an assessment of recent advances …

Go to article

First Prev Next Last