Physical Sciences and Mathematics Commons^™

Significantly Enhanced Oxygen Reduction Reaction Activity In Co-N-C Catalysts Through Synergistic Boron Doping, Chang Lan, Jing-Sen Bai, Xin Guan, Shuo Wang, Nan-Shu Zhang, Yu-Qing Cheng, Jin-Jing Tao, Yu-Yi Chu, Mei-Ling Xiao, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The weak adsorption energy of oxygen-containing intermediates on Co center leads to a considerable performance disparity between Co-N-C and costly Pt benchmark in catalyzing oxygen reduction reaction (ORR). In this work, we strategically engineer the active site structure of Co-N-C via B substitution, which is accomplished by the pyrolysis of ammonium borate. During this process, the in-situ generated NH₃ gas plays a critical role in creating surface defects and boron atoms substituting nitrogen atoms in the carbon structure. The well-designed CoB₁N₃ active site endows Co with higher charge density and stronger adsorption energy toward oxygen species, …

Scaling Symmetry Of The Hodgkin-Huxley Mathematical Model, Vladimir Valerievich Galanin

Progress in Scale Modeling, an International Journal

A computational method based on the application of a scaling transformation to the Hodgkin-Huxley mathematical model of the biological neuron and its generalizations to the case of various neural systems is proposed. The method makes it possible: 1) to obtain invariants of the scaling transformation of the Hodgkin-Huxley model; 2) to find self-similarity regions corresponding to the modes of neural activity; 3) to determine the conditions for the similarity of models of various types of biological neurons; 4) to reduce the order of the system of differential equations of the Hodgkin-Huxley model for neural systems with synchronous activity. The capabilities …

Early-Life Exposure To Organic Chemical Pollutants As Assessed In Primary Teeth And Cardiometabolic Risk In Mexican American Children: A Pilot Study, Vidya S. Farook, Feroz Akhtar, Rector Arya, Alice Yau, Srinivas Mummidi, Juan Lopez Alvarenga, Alvaro Diaz-Badillo, Roy G. Resendez, John Blangero

Human Genetics Publications

Early-life exposure to organic chemicals (OCs) may influence childhood obesity and associated cardiometabolic risk. These conditions have been shown to disproportionately affect minority populations such as Mexican Americans (MAs). However, information on the impact of organic chemicals on cardiometabolic risk in MA children is limited. Therefore, we conducted a pilot study to assess the extent to which exposure to organic chemicals influences cardiometabolic traits (CMTs) in MA children. We recalled 25 children from a previous study and collected 25 primary teeth from them. Chemical analyses of the teeth were performed using established protocols. Target analytes included acetaminophen (APAP); 3,5,6-trichloro-2-pyridinol (TCPy), …

X-Ray Microcalorimeter Observations Of High-Mass X-Ray Binaries With The Resolve Instrument Onboard Xrism, Pragati Pradhan, Masahiro Tsujimoto

Publications

The X-ray Imaging and Spectrometer Mission (XRISM) was put into orbit successfully in September 2023. Resolve, one of the scientific instruments onboard XRISM, hosts an X-ray spectrometer based on X-ray microcalorimetery technology. It excels in high spectral resolution, a large throughput, a large bandpass, low background, and good timing accuracy. These properties are suited to bring new insights especially in high-mass X-ray binaries (HMXB). We describe these unique features of Resolve and present initial highlights of two HMXB sources.

The Giant Outburst Of Exo 2030+375, P. Thalhammer, R. Ballhausen, E. Sokolova-Lapa, J. Stierhof, A. Zainab, R. Staubert, K. Pottschmidt, J.B. Coley, R.E. Rothschild, G.K. Jaisawal, B. West, P.A. Becker, Pragati Pradhan, P. Kretschmar, J. Wilms

Publications

The Be X-ray binary EXO 2030+375 went through its third recorded giant outburst from June 2021 to early 2022. We present the results of both spectral and timing analysis based on NICER monitoring, covering the 2−10 keV flux range from 20 to 310 mCrab. Dense monitoring with observations carried out about every second day and a total exposure time of ∼160 ks allowed us to closely track the source evolution over the outburst. Changes in the spectral shape and pulse profiles showed a stable luminosity dependence during the rise and decline. The same type of dependence has been seen in …

The Unaltered Pulsar: Gro J1750-27, A Supercritical X-Ray Neutron Star That Does Not Blink An Eye, C. M. Malacaria, L. Moritz Ducci, M. Falanga, D. A. Altamirano, E. Bozzo, S. J. Guillot, G.K. Jaisawal, P. Kretschmar, M. Ng, Pragati Pradhan, R. Rothschild, A. Sanna, P. Thalhammer, J. Wilms

Publications

When accreting X-ray pulsars (XRPs) undergo bright X-ray outbursts, their luminosity-dependent spectral and timing features can be analyzed in detail. The XRP GRO J1750-27 recently underwent one such episode, during which it was observed with NuSTAR and monitored with NICER. Such a data set is rarely available, as it samples the outburst over more than 1 month at a luminosity that is always exceeding ∼5 × 1037 erg s−1 . This value is larger than the typical critical luminosity value, where a radiative shock is formed above the surface of the neutron star. Our data analysis of the joint spectra …

Determining The Light Curve And 3d Shape Of Asteroid Eunomia And Egeria Using Relative Photometry, Skylar G. Butler, Jackson Ladd Sackrider

Discovery Day - Daytona Beach

Asteroids are relics of our solar system’s early formation, preserving valuable information about planetary evolution. Understanding their rotational properties and surface features provides deeper insights into the dynamical and thermophysical processes that shape their evolution. This study aims to conduct photometric observations of two main-belt asteroids, Egeria and Eunomia, using the Embry-Riddle Aeronautical University 1-meter telescope. Observations will be conducted in the red band on February 28 and March 14, 2025, over five-hour sessions, capturing full rotational light curves for each asteroid. These data will be analyzed using MPO Canopus to generate 3D surface models through photometric inversion techniques. The …

The Calvin University Math Department History 1920-2020, Michael Stob

University Histories

No abstract provided.

Wmu Maritime Affairs Conference 2025 : Transforming A Maritime Future : Digitalization And Decarbonization, World Maritime University

Books

No abstract provided.

Energy Statistic-Based Goodness-Of-Fit Test For The Lindley Distribution With Application To Lifetime Data, Joseph Njuki, Ryan Avallone

Mathematics and Statistics

In this article, we propose a goodness-of-fit test for a one-parameter Lindley distribution based on energy statistics. The Lindley distribution has been widely used in reliability studies and survival analysis, especially in applied sciences. The proposed test procedure is simple and more powerful against general alternatives. Under different settings, Monte Carlo simulations show that the proposed test is able to be well controlled for any given nominal levels. In terms of power, the proposed test outperforms other existing similar methods in different settings. We then apply the proposed test to real-life datasets to demonstrate its competitiveness and usefulness.

This article …

The Effect Of Mesoscale Frontal Waves On Landfalling Atmospheric Rivers And Their Associated Precipitation Over The Green River Watershed, Washington, Joseph Michael Riedl

Dissertations and Theses

In this study, the effect of mesoscale frontal waves (MFWs) on extreme precipitation (EP) in the Upper Green River Watershed (UGRW), Washington is investigated. 205 EP days (>95th percentile) are identified in the UGRW between the years 1980 and 2021. To characterize the range of large-scale meteorological conditions associated with EP days, the self-organizing map (SOM) approach is used to cluster daily integrated water vapor transport (IVT) on EP days. To further diagnose the meteorological drivers, composites of several other diagnostic fields are constructed for each SOM node and the preceding days. Together, these results illustrate common orientations of …

Unraveling Crop Nitrogen-Water Dynamics With Hyperspectral-Thermal Sensing In Northern Central Valley, California, Shahryar Fazli, Surendra Maharjan, Wenzhao Li, Joshua B. Fisher, Rejoice Thomas, Fernando Romero Galvan, Gabriela Shirkey, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Ensuring global food security in the face of climate change requires optimizing crop water use and nutrient management. This study investigates the relationship between canopy nitrogen (N) and evapotranspiration (ET) across sunflower, rice, walnut, alfalfa, and plum crops using advanced remote sensing technologies. High-resolution hyperspectral data from NASAs Earth Surface Mineral Dust Source Investigation (EMIT) and thermal multispectral data from the Landsat-based OpenET system were analyzed over 1,135 km² in California. Regression analysis revealed strong spatial association between canopy N and ET for sunflower (R² = 0.82), rice (R² = 0.71), and walnut (R² = 0.68), …

Hawc, Veritas, Fermi-Lat, And Xmm-Newton Follow-Up Observations Of The Unidentified Ultra-High-Energy Gamma-Ray Source Lhaaso J2108+5157, C. B. Adams, P. Bangale, W. Benbow, J. H. Buckley, Y. Chen, J. L. Christiansen, S. Groetsch, P. Hüntemeyer, M. Najafi, R. Turner, X. Wang, Et. Al

Michigan Tech Publications

We report observations of the ultra-high-energy gamma-ray source LHAASO J2108+5157, utilizing VERITAS, HAWC, Fermi-LAT, and XMM-Newton. VERITAS has collected ∼40 hr of data that we used to set ULs to the emission above 200 GeV. The HAWC data, collected over ∼2400 days, reveal emission between 3 and 146 TeV, with a significance of 7.5σ, favoring an extended source model. The best-fit spectrum measured by HAWC is characterized by a simple power law with a spectral index of 2.45 ± 0.11stat. Fermi-LAT analysis finds a point source with a very soft spectrum in the LHAASO J2108+5157 region, consistent with the 4FGL-DR3 …

Fault Morphology Along A Sinistral Active Fault Near A Continental Triple Junction: The Ilıca Segment At The Northern Termination Of The East Anatolian Fault Zone, Türkiye, Aynur Di̇kbaş, Hani̇fe Merve Önal

Turkish Journal of Earth Sciences

The East Anatolian fault zone (EAFZ) is an approximately 430 km long sinistral transform fault that bounds the southwestern margin of the Anatolian microplate between Karlıova (Bingöl) and Kahramanmaraş. It constitutes part of the Karlıova triple junction (KTJ) in eastern Anatolia. Near the KTJ, the Ilıca and Karlıova segments delineate the EAFZ. The Ilıca segment, approximately 38 km long, exhibits distinct fault-related geological structures, including linear valleys, elongated ridges, saddles, sag ponds, shutter ridges, thermal springs, and travertines. Based on extensive mapping using high-resolution imagery and field investigations, the Ilıca segment has been categorized into three sections: section 1 and …

Quick Antiquing Of Natural Stones In The Restoration Process, Hakan Elçi̇

Turkish Journal of Earth Sciences

When ancient buildings are restored, even though the restored section uses natural stone with the same lithological characteristics and texture as the building, there is a noticeable color difference between the restored and ancient portions of the building, signifying an old/new difference. This color difference, which is caused by the deterioration of the natural stone used in the ancient structure over many years, gives the natural stone a black or brown appearance. In this study, white marble, travertine, and sandstone were treated with antiquing techniques described in the literature. The goal was to identify the technique that produces the most …

Polymorphism Crystal Structure Prediction With Adaptive Space Group Diversity Control, Sadman Saadeed Omee, Lai Wei, Jianjun Hu

Faculty Publications

Crystalline materials can form different structural arrangements (i.e., polymorphs) with the same chemical composition, exhibiting distinct physical properties depending on how they are synthesized or the conditions under which they operate. For example, carbon can exist as graphite (soft, conductive) or diamond (hard, insulating). Computational methods that can predict these polymorphs are vital in materials science, which help understand stability relationships, guide synthesis efforts, and discover new materials with desired properties without extensive trial-and-error experimentation. However, effective crystal structure prediction (CSP) algorithms for inorganic polymorph structures remain limited. ParetoCSP2 is proposed, a multi-objective genetic algorithm for polymorphism CSP that incorporates …

Orphan Basalts: Understanding The Origins Of Unassigned Eastern Oregon Basalts, Angela Rae Stetson

Dissertations and Theses

For more than a century, scientists have studied the geologic stratigraphy of eastern Oregon, which chronicles a rich history of volcanic activity spanning millions of years. Recent and ongoing geologic mapping of the northeastern Harney Basin -- along a corridor east of Highway 395 between the towns of Burns and John Day -- provides a more detailed understanding of an area originally mapped only in reconnaissance during the 1960s. At that time, geologic units were poorly delineated, often with entire quadrangles mapped as a single unit. For example, over 90% of the Calamity Butte quadrangle was previously mapped as 'Tba' …

Coseismic Surface Deformation Analyses Using Sar And Optical Images: 2023 Kahramanmaraş Earthquake Sequence, Türkiye, Han-Kyung Bae, Gwang-Woo Oh, Jin-Hyuck Choi

Turkish Journal of Earth Sciences

The 2023 Kahramanmaraş earthquake sequence in Türkiye, including Mw 7.7 and 7.6 mainshocks, caused significant surface ruptures along the East Anatolian Fault (EAF) and Sürgü–Çardak Fault (SCF). We calculated the coseismic displacement fields through pixel offset tracking (POT) analysis of Sentinel-1 SAR data and optical image correlation (OIC) analysis of Sentinel-2 imagery. Our results reveal distinct sinistral motion along both the EAF and SCF, with maximum offsets of about 7 and 9 m, respectively. Deformation zones were identified both on and off the fault, highlighting the relationship between the rupture geometry and the broader deformation field. A comparative evaluation of …

Geomagnetic Activity For The Kp = 7.3 Geomagnetic Storm In November 2023 Assessed By Observational Data, Eli̇f Çi̇ftçi̇, Özlem Hacioğlu

Turkish Journal of Earth Sciences

The geomagnetic storm of 4–6 November 2023, driven by an Earth-directed coronal mass ejection (CME), was a significant event marked by a peak geomagnetic activity index (Kp) of 7.3 on a 0–9 scale, indicating severe disturbance in Earth’s magnetic field. This CME-induced storm was characterized by intense auroral displays and reached a G3 level (Dst = −172 nT) around 12:40 UT on 5 November, with auroras observed at midlatitudes across Europe. This study examines the effects of the storm on the horizontal (H), declination (D), and vertical (Z) components of the geomagnetic field using data from sunlit-side magnetometer measurements. Planetary …

Preliminary Petrological, Mineralogical, And Geochemical Evaluation Of A Newly Discovered Lignite Field In Yatağan, Muğla (Sw Türkiye), Işik Hacimustafaoğlu, Mehmet Akbulut, Hülya İnaner, Kimon Christanis

Turkish Journal of Earth Sciences

Thirty-two coal and seven inorganic core samples from a newly discovered coalfield in the Yatağan region of the Muğla Basin were analysed to reconstruct the depositional palaeoenvironment. The coal has an average bed moisture of 34.60%, an ash yield of 33.73% (db), a volatile matter yield of 57.91% (daf), and a gross calorific value of 12.18 MJ/kg (maf). It is composed of mainly huminite macerals (up to 91 vol.%, on whole-rock basis), predominantly densinite, along small amounts of liptinite and inertinite macerals. The average random reflectance of huminite is 0.28%, and the primary minerals identified include pyrite, quartz, and clay …

Fungal Palynomorphs From The Lower Cretaceous (Berriasian–Albian) Of Jangareddygudem Area Of The Chintalapudi Subbasin, Andhra Pradesh, South Part Of India, Harinam Joshi, Neerja Jha, Sarah Gonçalves Duarte, Sari̇ye Duygu Durak, Haytham Elatfy

Turkish Journal of Earth Sciences

A diverse array of thalli, fruiting bodies, spores, and other fungal structures has been observed in palynological samples collected from the sedimentary sequence MJR-11, drilled in the Jangareddygudem area of the Chintalapudi subbasin, Andhra Pradesh, southern India. The sedimentary sequence is dated to the Kimmeridgian–early Albian, based on palynology. However, the focus of the present work is on the Early Cretaceous (Berriasian–early Albian). A well-developed and diverse fungal assemblage consistently occurred throughout most of the succession, together with predominant conifer pollen grains and highly diversified pteridophytic and bryophytic spores. Furthermore, the recorded palynomorphs suggest deposition under both continental and marine …

First Insights Into The Origin Of Iron In Eastern Cilicia During The Iron Age, Using Osmium Isotope And Trace Element Analysis, Ivan Stepanov, Hüseyi̇n Öztürk, Michael Brauns, Ernst Pernicka, Nurullah Hanilçi, Ümi̇t Güder

Turkish Journal of Earth Sciences

Due to the abundance of ore resources and the probable technological advances of the Hittite civilisation, the Anatolian plateau is conventionally regarded as “the birthplace” of iron smelting technology. The present paper presents a complex archaeometric investigation of iron production remains from the Middle and Late Iron Age phases (c. 750–575 BC) at Kinet Höyük, a major trading port on the coast of eastern Cilicia (modern-day Dörtyol, Hatay). To provide an initial insight into the sources of iron processed at Kinet Höyük and to generate an overview of the 187Os/188Os and 187Re/188Os isotope ratios expected from eastern Anatolian iron ores, …

Re: August 2025 Berkeley Pit Migratory Waterfowl Protection Monthly Report, Mark Thompson, Loren Burmeister

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Creating Wildfire-Resilient Communities In Utah: Fuel Treatments In The Wildland-Urban Interface, Luke Dutson, Kendall Becker, Katlyn Stemmler, J. Bradley Washa, Larissa L. Yocom Kent, Aish Chandrasekaran, Joseph D. Birch, Scott Hotaling

All Current Publications

In the western United States, decades of wildfire suppression and grazing have led to changes in the amount and type of wildland fuels. In many lower montane forests, fuels such as logs, dead trees, and fallen leaves have accumulated. In many sagebrush-dominated rangelands, annual grasses have invaded, and pinyon pine and juniper woodlands have encroached. These areas now threaten to burn at uncharacteristically high fire severity, a metric based on how much vegetation is killed. Climate change and rapid population growth have exacerbated this issue in Utah, increasing the threat wildfire poses to the state’s communities, infrastructure, and ecosystems. Fuel …

Multi-Wavelength Study Of 1erass J085039.9−421151 With Erosita, Nustar, And X-Shooter, A. Zainab, A. Avakyan, V. Doroshenko, P. Thalhammer, E. Sokolova-Lapa, R. Ballhausen, N. Zalot, J. Stierhof, S. Hämmerich, C. M. Diez, P. Weber, T. Dauser, K. Berger, P. Kretschmar, K. Pottschmidt, Pragati Pradhan, N. Islam, C. Maitra, J.B. Coley, P. Blay, R.H.D. Corbet, R.E. Rothschild, K. Wood, A. Santangelo, U. Heber, J. Wilms

Publications

The eROSITA instrument on board Spectrum-Roentgen-Gamma (SRG) has completed four scans of the X-ray sky, leading to the detection of almost one million X-ray sources in eRASS1 alone, including multiple new X-ray binary candidates. We report on analysis of the X-ray binary 1eRASS J085039.9−421151, using a ∼55 ks long NuSTAR observation, following its detection in each eROSITA scan. An analysis of the eROSITA and NuSTAR X-ray spectra in combination with X-shooter data of the optical counterpart provide evidence of an X-ray binary with a red supergiant (RSG) companion, confirming previous results. However, we did determine a cooler spectral type for …

Stable Coronal X-Ray Emission Over 20 Yr Of Xz Tau, Steven M. Silverberg, Hans Moritz Günther, Pragati Pradhan, David A. Principe, P.C. Schneider, Scott J. Wolk

Publications

XZ Tau AB is a frequently observed binary young stellar object in the Taurus Molecular Cloud; XZ Tau B has been classified as an EXOr object. We present new Chandra/HETG-ACIS-S observations of XZ Tau AB, complemented with variability monitoring of the system with XMM-Newton, to constrain the variability of this system and identify high-resolution line diagnostics to better understand the underlying mechanisms that produce the X-rays. We observe two flares with XMM-Newton but find that outside of these flares the coronal X-ray spectrum of XZ Tau AB is consistent over 20 yr of observations. We compare the ensemble of XZ …

Fourier Analyses Of Optical Profilometry As An Inferential Measurement For Impact Coverage., Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

A critical consideration in peening process design is achieving sufficient impact coverage. Conventional methods for assessing coverage rely on manual inspection, which is time-consuming and poorly suited for automated control. In this work, we investigate the use of frequency-domain analysis to quantify surface modification in peened samples using optical profilometry (OP) data. Three-dimensional surface maps of Almen strips were acquired using a high-resolution OP system and analyzed via fast Fourier transform (FFT) to compute spatial power spectral densities (PSDs). PSD maps and radially averaged profiles reveal consistent amplification of harmonic components similar to the nominal particle size, with increasing intensity …

Reduced Order Approach For Peening Stress Field Variability, Langdon Feltner, Paul Mort

15th International Conference on Shot Peening

A common goal in shot peening research is to connect operational parameters to resultant residual stress fields, providing a means to control and optimize the effectiveness of surface treatment. In practice, experimental measurements of residual stresses are often averaged values over regions that are large in comparison to an impact dimple. In fact, the stochastic nature of impact locations leads to residual stress fields that are distributed. Finite element peening simulations confirm this observation. The goal of this report is to connect operational parameters to localized fluctuations in residual stress through probabilistic reasoning (Figure 1). In particular, the development of …

Synthesis And Characterization Of Fe-Zn Bimetallic Nanoparticles Via Two-Step Laser Ablation And Their Antibacterial Activity, Hudhaifa M. Mohammed, Sahar Naji Rashid

Karbala International Journal of Modern Science

In this study, Nd: YAG laser at a wavelength of (1064 nm), energies of (300 and 400 mJ), and a pulse repetition rate of (3 Hz) was used to synthesize metallic nanoparticles from iron and zinc individually using a one-step pulsed laser ablation approach, followed by the two-step synthesis of bimetallic nanoparticles. The physical properties of the synthesized nanoparticles were then investigated using UV-visible (UV-Vis), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and energy-dispersive X-ray (EDX) techniques. The results of characterization of the obtained NPs confirmed the formation of core-shell nanocomposites, as evidenced by the increased absorbance intensity of …

Enrichment Factors And Play Fairway Mapping Of Helium In Typical Zones Of The Ordos Basin, Gao Jianrong, Tao Shizhen, Liu Xiangbai, Yang Wei, Zhao Zhenyu, Chen Xiuyan, Xu Wanglin, Zhang Chunlin, Song Wei, Chen Yue, Huang Junping, Ma Zhanrong

Coal Geology & Exploration

Background The Ordos Basin enjoys abundant natural gas resources, which generally bear helium, making this basin hold great helium resource potential. In this case, detailed exploration is essential for the future transition from natural gas-helium joint exploration to special helium exploration in the basin.Objective and Method To systematically investigate the distribution and potential of helium resources in the Ordos Basin, natural gas samples were taken from different areas of the basin for analysis and tests. To examine the primary factors controlling helium accumulation and enrichment, this study conducted a systematic analysis of the basement, sedimentary rock layers, fault systems, …