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# Physical Sciences and Mathematics Commons™

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261,931 Full-Text Articles 330,423 Authors 78,898,844 Downloads 443 Institutions

## All Articles in Physical Sciences and Mathematics

261,931 full-text articles. Page 3 of 8466.

Cryogenic Ridges: A New Speleothem Type, 2023 University of South Florida, USA

#### Cryogenic Ridges: A New Speleothem Type, Bogdan P. Onac, Daniel M. Cleary, Oana A. Dumitru, Victor J. Polyak, Ioan Povara, Jonathan G. Wynn, Yemane Asmerom

##### International Journal of Speleology

Cryogenic cave carbonates have been described from several formerly or presently glaciated karst caves. In most of these occurrences, they precipitated as loose grains or aggregates with various morphologies and sizes. Here, we report on a new speleothem type (cryogenic ridges) identified in Sohodoalele Mici Cave (SW Romania) within a large chamber near the entrance shaft. This study was motivated by the presence of a network of calcite ridges over the stalactites’ surface and by the observation that during winter, these speleothems are covered by a thin ice layer. The higher δ18O (−3.5 to –1‰) and …

Dual Ionic Liquid-Functionalized Cellulosic Materials: Thermal, Mechanical And Conductive Properties, 2023 Murray State University

#### Dual Ionic Liquid-Functionalized Cellulosic Materials: Thermal, Mechanical And Conductive Properties, Elizabeth Mcgrew, Kevin M. Miller Phd

##### Posters-at-the-Capitol

Cellulose, an inexpensive and renewable biomacromolecule, represents an intriguing synthetic foundation for new materials with task-specific properties. Here, we wish to report a synthetic route for functionalizing cellulose with a side chain containing two ionic liquid functional groups using azide-alkyne ‘click’ cyclization strategy, followed by quaternization of the two resulting heterocycles (1,2,3-triazole and imidazole). Through this functionalization strategy, the resulting cellulosic materials exhibited significant softening, with several glass transition (Tg) values observed below room temperature, indicating the amorphous nature of the materials, with the Tg dependent on both the length of the side chain and the …

Counting Power Domination Sets In Complete M-Ary Trees, 2023 Gonzaga University

#### Counting Power Domination Sets In Complete M-Ary Trees, Hays Whitlatch, Katharine Shultis, Olivia Ramirez, Michele Ortiz, Sviatlana Kniahnitskaya

##### Theory and Applications of Graphs

Motivated by the question of computing the probability of successful power domination by placing k monitors uniformly at random, in this paper we give a recursive formula to count the number of power domination sets of size k in a labeled complete m-ary tree. As a corollary we show that the desired probability can be computed in exponential with linear exponent time.

Survey On Outdoor Navigation Applications For People With Visual Impairment, 2023 Technological University Dublin

#### Survey On Outdoor Navigation Applications For People With Visual Impairment, Luis Miralles-Pechuán

##### Datasets

Outdoor navigation is a very challenging activity for People who suffer from Blindness or Visually Impairment (PBVI). Having examined the current literature, we conclude that there are very few publications providing a nuanced understanding of how PBVI undertake a journey in an outdoor environment and what their main challenges and obstacles are. To throw some light on this gap, we conducted a questionnaire in collaboration with the National Council for the Blind Ireland (NCBI) for 49 PBVI. Our questionnaire gathers information about key aspects related to PBVI outdoor navigation such as support tools/devices, hazards, journey preparation, crossing roads, and understanding …

Cop 15 - Can We Meet Biodiversity Goals & Targets?, 2023 WellBeing International

#### Cop 15 - Can We Meet Biodiversity Goals & Targets?, Andrew N. Rowan, Kathleen Rowan

##### WellBeing News

The 15th Conference of Parties (COP15) for the UN Convention on Biological Diversity was held in two parts (in Kunming, China, in October 2021 and in Montreal, Canada, in December 2022). One primary goal for COP15 was the development of a Global Biodiversity Framework (GBF) covering the coming decade (from 2023 through 2030). The GBF produced by the participating countries at COP15 included four long-term global goals for 2050 linked to the 2050 Vision for Biodiversity, along with 23 global targets for immediate action and completed by 2030. One outcome of the negotiations was the identification of the need …

Measuring Biodiversity And Biodiversity Trends, 2023 WellBeing International

#### Measuring Biodiversity And Biodiversity Trends, Andrew N. Rowan

##### WellBeing News

The 15th Conference of Parties (COP15) for the UN Convention on Biological Diversity was held in two parts (in Kunming, China, in October 2021 and in Montreal, Canada, in December 2022). One primary goal for COP15 was the development of a Global Biodiversity Framework (GBF) covering the coming decade (from 2023 through 2030). The GBF produced by the participating countries at COP15 included four long-term global goals for 2050 linked to the 2050 Vision for Biodiversity, along with 23 global targets for immediate action and completed by 2030. One outcome of the negotiations was the identification of the need …

From Mirrors To Wallpapers: A Virtual Math Circle Module On Symmetry, 2023 Central New Mexico Community College

#### From Mirrors To Wallpapers: A Virtual Math Circle Module On Symmetry, Nicole A. Sullivant, Christina L. Duron, Douglas T. Pfeffer

##### Journal of Math Circles

Symmetry is a natural property that children see in their everyday lives; it also has deep mathematical connections to areas like tiling and objects like wallpaper groups. The Tucson Math Circle (TMC) presents a 7-part module on symmetry that starts with reflective symmetry and culminates in the deconstruction of wallpapers into their ‘generating tiles’. This module utilizes a scaffolded, hands-on approach to cover old and new mathematical topics with various interactive activities; all activities are made available through free web-based platforms. In this paper, we provide lesson plans for the various activities used, and discuss their online implementation with Zoom, …

How Hurricanes Impact Florida's Tourism Industry, 2023 University of Central Florida

#### How Hurricanes Impact Florida's Tourism Industry, Arthur Huang

##### Rosen Research Review

Almost every year, hurricanes bear down upon the state of Florida. The storms appear to be growing in occurrence and severity. While the media cover the damage and death toll, the impacts on the state's critical tourism sector remain largely anecdotal. The full story lies buried in data. Dr. Arthur Huang from UCF's Rosen College of Hospitality Management has investigated different data sets to understand the impact of hurricanes on the tourism industry. What has been uncovered has significance not only for Florida but for tourism sectors elsewhere affected by these giant storms.

Strategies For Identifying Important Residues In The Trna Modification Protein Trm732, 2023 Northern Kentucky University

#### Strategies For Identifying Important Residues In The Trna Modification Protein Trm732, Alex K. Mullins, Natalie N. Creech, Holly Funk, Michael Guy

##### Posters-at-the-Capitol

Post-transcriptional tRNA modifications are required for efficient protein translation. In yeast, the Trm7 methyltransferase forms a complex with Trm732 to modify tRNA at position 32. In humans, lack of the human homolog for Trm7, FTSJ1, causes intellectual disability. Little is known about the function of Trm732, although we have shown that one conserved motif in Trm732 is important for tRNA modification. We have identified other residues important for function using two strategies. First, we compared Trm732 proteins of different organisms using protein alignments to determine conserved regions to mutate for testing. We have generated four new Trm732 variants and have …

Lesker Pvd75 E-Beam/Thermal Evaporator (Pvd-02) Standard Operating Procedure, 2023 University of Pennsylvania

#### Lesker Pvd75 E-Beam/Thermal Evaporator (Pvd-02) Standard Operating Procedure, David S. Barth, Jason A. Röhr

##### Standard Operating Procedures

Standard Operating Procedure for the Lesker PVD75 E-beam/Thermal Evaporator (PVD-02) located at the Quattrone Nanofabrication Facility within the Singh Center for Nanotechnology at the University of Pennsylvania

Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, 2023 Louisiana State University

#### Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan

##### LSU Doctoral Dissertations

Classical novae are stellar explosions that contribute to the nucleosynthesis of isotopes on the proton-rich side of the valley of stability up to 40Ca. In ONe novae, the incompletely understood reaction rate of 30P(p,γ)31S is known to strongly influence the production rate of several stable isotopes such as 30Si, 31P, and 32,33,34S. A precise measurement of this reaction rate has several potential implications towards matching astrophysical observables to the physical composition of the nova site -- the observed elemental abundance ratios of O/S and S/Al have been suggested as useful `thermometers' to gauge …

Balancing Renewable Energy And River Resources By Moving From Individual Assessments Of Hydropower Projects To Energy System Planning, 2023 The University of Texas Rio Grande Valley

#### Balancing Renewable Energy And River Resources By Moving From Individual Assessments Of Hydropower Projects To Energy System Planning, Jeffrey J. Opperman, Juan Pablo Carvallo, Rafael Kelman, Rafael J. P. Schmitt, Rafael M. Almeida, Emily Chapin, Alexander Flecker, Marc Goichot, Guenther Guenther Grill, Julien J. Harou

##### Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

As governments and non-state actors strive to minimize global warming, a primary strategy is the decarbonization of power systems which will require a massive increase in renewable electricity generation. Leading energy agencies forecast a doubling of global hydropower capacity as part of that necessary expansion of renewables. While hydropower provides generally low-carbon generation and can integrate variable renewables, such as wind and solar, into electrical grids, hydropower dams are one of the primary reasons that only one-third of the world’s major rivers remain free-flowing. This loss of free-flowing rivers has contributed to dramatic declines of migratory fish and sediment delivery …

2023 University of Windsor

#### Uniformity Test Based On The Empirical Bernstein Distribution, Ran Sun

##### Major Papers

In this paper, we firstly review the origin of Bernstein polynomial and the various application of it. Then we review the importance of goodness-of-fit test, especially the uniformity test, and we examine lots of different test statistics proposed by far. After that we suggest two new statistics for testing the uniformity. These two statistics are based on Komogorov-Smirnov test type and Cramér-Von Mises test type, respectively. Also we embed Bernstein polynomial into those test type and take advantage of great approximation performance of this polynomial. Finally, we run a Monte-Carlo simulation to compare the performance of our statistics to those …

Optimal Speed Of A Machine In An Assembly Line Using The Continuous Time Markov Chain Rate Matrix, 2023 University of Windsor

#### Optimal Speed Of A Machine In An Assembly Line Using The Continuous Time Markov Chain Rate Matrix, Chandi Darshani Rupasinghe

##### Major Papers

The optimal speed of a machine in an assembly line is determined using a Markov decision process type model. We develop the rate matrix that represents the inter-event time of a machine, either repair time or time to breakdown, as a function of speed. We consider the rate of time to breakdown with a variety of functions of speed. We find limiting probabilities and express profit in terms of these probabilities. We then find the optimal speed to maximize profit. Further, we assume an underlying function of speed and simulate data using R. From the simulated data, we estimate the …

A Dynamical System Model Of Dengue Transmission For Rio De Janeiro, Brazil, 2023 Utah Tech University

#### A Dynamical System Model Of Dengue Transmission For Rio De Janeiro, Brazil, Gregory Schmidt, Benjamin Whipple, Vinodh Chellamuthu, Xiaoxia Xie

##### Spora: A Journal of Biomathematics

The dengue virus is a serious concern in many parts of the world, including Brazil. As data indicates, a prominent vector for dengue is the mosquito Aedes aegypti. By using the dengue incidence records from the Brazilian SINAN database, we estimate the population of A. aegypti within the city of Rio de Janeiro. Using historical climate data for Rio de Janeiro and the computed population estimates, we extend an existing model for the population dynamics of mosquitoes to incorporate precipitation in aquatic stages of development for A. aegypti.

Hs-Integral And Eisenstein Integral Mixed Circulant Graphs, 2023 Indian Institute of Technology Guwahati

#### Hs-Integral And Eisenstein Integral Mixed Circulant Graphs, Monu Kadyan, Bikash Bhattacharjya

##### Theory and Applications of Graphs

A mixed graph is called \emph{second kind hermitian integral} (\emph{HS-integral}) if the eigenvalues of its Hermitian-adjacency matrix of the second kind are integers. A mixed graph is called \emph{Eisenstein integral} if the eigenvalues of its (0, 1)-adjacency matrix are Eisenstein integers. We characterize the set $S$ for which a mixed circulant graph $\text{Circ}(\mathbb{Z}_n, S)$ is HS-integral. We also show that a mixed circulant graph is Eisenstein integral if and only if it is HS-integral. Further, we express the eigenvalues and the HS-eigenvalues of unitary oriented circulant graphs in terms of generalized M$\ddot{\text{o}}$bius function.

Crow Search Algorithm With Time Varying Flight Length Strategies For Feature Selection, 2023 Ahmadu Bello University, Zaria, Nigeria

#### Crow Search Algorithm With Time Varying Flight Length Strategies For Feature Selection, Mohammed Abdullahi, Abdulhameed Adamu, Ibrahim Hayatu Hassan

##### Future Computing and Informatics Journal

Feature Selection (FS) is an efficient technique use to get rid of irrelevant, redundant and noisy attributes in high dimensional datasets while increasing the efficacy of machine learning classification. The CSA is a modest and efficient metaheuristic algorithm which has been used to overcome several FS issues. The flight length (fl) parameter in CSA governs crows' search ability. In CSA, fl is set to a fixed value. As a result, the CSA is plagued by the problem of being hoodwinked in local minimum. This article suggests a remedy to this issue by bringing five new concepts of time dependent fl …

Predicting Young’S Modulus Of Indian Coal Measure Rock Using Multiple Regression And Artificial Neutral Network, 2023 Department of Mining Engineering, Indian Institute of TechnologyKharagpur, India

#### Predicting Young’S Modulus Of Indian Coal Measure Rock Using Multiple Regression And Artificial Neutral Network, Sayantan Chakraborty, Rohan Bisai, Rohit Roy, Sathish Kumar Palaniappan, Samir Kumar Pal, Karanam Uma Maheshwar Rao

##### Journal of Sustainable Mining

Accurate information on Young’s modulus (E) is required for simulating rock deformation in mines; on the other hand, it is very cumbersome to obtain in the laboratory and collecting drilled cores in sufficient amounts, especially in the case of soft rocks, is quite impossible. Empirical equations were deducted for E from easily determinable rock properties, and the final model was selected through different statistical strength parameter tests. The generalization of the equation was verified through the normal distribution tests of residues of the equation. R2 came to be 0.609 and was validated using an artificial neural network with an improved …

Gravity And Electrostatic Separation Of Unburned Coal From A Selected Fly Ash, 2023 Central Mining Institute, Department of Environmental Monitoring, Poland

#### Gravity And Electrostatic Separation Of Unburned Coal From A Selected Fly Ash, Krzysztof Wierzchowski, Agnieszka Klupa, Barbara Białecka, Joanna Całus Moszko

##### Journal of Sustainable Mining

Unburned coal grains make it difficult to use fly ash economically, which causes energy losses in the fuel. The article presents the possibilities of separating unburned coal from selected fly ash. In order to assess the possibility of separation of unburned carbon, the analysis of grain density and ash composition was used. Unburned coal was separated by four methods – one wet gravity and three dry methods. It has been found that despite very fine ash grains, the quality and quantity of separation products are significantly dependent on the separation method used and the separated grains’ qualitative characteristics. The analysis …

Exploring The Characterization, Liberation And Flotation Response Of A Nigerian Low-Grade Copper Ore, 2023 Mineral Processing Research Centre, Department of Metallurgy, University of Johannesburg, Doornfontein Campus, P O Box 17911, Johannesburg 2028, South Africa

#### Exploring The Characterization, Liberation And Flotation Response Of A Nigerian Low-Grade Copper Ore, Willie Nheta, Omoyemi O. Ola-Omole

##### Journal of Sustainable Mining

This study explores the characterization, liberation and flotation response of low-grade copper ore from Anka area, Zamfara state Nigeria. The ore was crushed, milled and sieved in accordance with BS 410 standard. It was characterized with XRD, XRF, SEM-EDS and AAS. Froth flotation was carried out with varying %solids, pH, retention time and collector dosages using SEX and sodium oleate. Particle size distribution of the ore shows its economic liberation between -150 and +106 µm while 80% passing corresponds to 175.7 µm using the Gaudin Schuhmann equation. However, according to metallurgical balance calculation, 63 µm proved to have the highest …