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Articles 40231 - 40260 of 294391

Full-Text Articles in Physical Sciences and Mathematics

Neutrosophic Gsα* - Open And Closed Maps In Neutrosophic Topological Spaces, P. Anbarasi Rodrigo, S. Maheswari Jul 2023

Neutrosophic Gsα* - Open And Closed Maps In Neutrosophic Topological Spaces, P. Anbarasi Rodrigo, S. Maheswari

Neutrosophic Systems with Applications

The main aim of this paper is to introduce a new concept of Neu-mapping namely Neugsa*-open maps and Neugsa* -closed maps in Neu-topological spaces. Additionally, we relate the properties and characterizations of these mappings with the other mappings in Neu-topological spaces.


Idempotent Completions Of Equivariant Matrix Factorization Categories, Michael K. Brown, Mark E. Walker Jul 2023

Idempotent Completions Of Equivariant Matrix Factorization Categories, Michael K. Brown, Mark E. Walker

Department of Mathematics: Faculty Publications

We prove that equivariant matrix factorization categories associated to henselian local hypersurface rings are idempotent complete, generalizing a result of Dyckerhoff in the non- equivariant case.


Artificial Intelligence Frameworks To Detect And Investigate The Pathophysiology Of Spaceflight Associated Neuro-Ocular Syndrome (Sans), Joshua Ong, Ethan Waisberg, Mouayad Masalkhi, Sharif Amit Kamran, Kemper Lowry, Prithul Sarker, Nasif Zaman, Phani Paladugu, Alireza Tavakkoli, Andrew G Lee Jul 2023

Artificial Intelligence Frameworks To Detect And Investigate The Pathophysiology Of Spaceflight Associated Neuro-Ocular Syndrome (Sans), Joshua Ong, Ethan Waisberg, Mouayad Masalkhi, Sharif Amit Kamran, Kemper Lowry, Prithul Sarker, Nasif Zaman, Phani Paladugu, Alireza Tavakkoli, Andrew G Lee

Student Papers, Posters & Projects

Spaceflight associated neuro-ocular syndrome (SANS) is a unique phenomenon that has been observed in astronauts who have undergone long-duration spaceflight (LDSF). The syndrome is characterized by distinct imaging and clinical findings including optic disc edema, hyperopic refractive shift, posterior globe flattening, and choroidal folds. SANS serves a large barrier to planetary spaceflight such as a mission to Mars and has been noted by the National Aeronautics and Space Administration (NASA) as a high risk based on its likelihood to occur and its severity to human health and mission performance. While it is a large barrier to future spaceflight, the underlying …


Neutrosophic Gsα* - Open And Closed Maps In Neutrosophic Topological Spaces, P. Anbarasi Rodrigo, S. Maheswari Jul 2023

Neutrosophic Gsα* - Open And Closed Maps In Neutrosophic Topological Spaces, P. Anbarasi Rodrigo, S. Maheswari

Neutrosophic Systems with Applications

The main aim of this paper is to introduce a new concept of Neu-mapping namely Neugsa*-open maps and Neugsa* -closed maps in Neu-topological spaces. Additionally, we relate the properties and characterizations of these mappings with the other mappings in Neu-topological spaces.


A Dilation Theoretic Approach To Approximation By Inner Functions, Daniel Alpay, Tirthankar Bhattacharyya, Abhay Jindal, Poornendu Kumar Jul 2023

A Dilation Theoretic Approach To Approximation By Inner Functions, Daniel Alpay, Tirthankar Bhattacharyya, Abhay Jindal, Poornendu Kumar

Mathematics, Physics, and Computer Science Faculty Articles and Research

Using results from the theory of operators on a Hilbert space, we prove approximation results for matrix-valued holomorphic functions on the unit disc and the unit bidisc. The essential tools are the theory of unitary dilation of a contraction and the realization formula for functions in the unit ball of . We first prove a generalization of a result of Carathéodory. This generalization has many applications. A uniform approximation result for matrix-valued holomorphic functions which extend continuously to the unit circle is proved using the Potapov factorization. This generalizes a theorem due to Fisher. Approximation results are proved for matrix-valued …


Deep Learning For Multi-Structured Javanese Gamelan Note Generator, Arik Kurniawati, Eko Mulyanto Yuniarno, Yoyon Kusnendar Suprapto Jul 2023

Deep Learning For Multi-Structured Javanese Gamelan Note Generator, Arik Kurniawati, Eko Mulyanto Yuniarno, Yoyon Kusnendar Suprapto

Knowledge Engineering and Data Science

Javanese gamelan, a traditional Indonesian musical style, has several song structures called gendhing. Gendhing (songs) are written in conventional notation and require gamelan musicians to recognize patterns in the structure of each song. Usually, previous research on gendhing focuses on artistic and ethnomusicological perspectives, but this study is to explore the correlation between gendhing as traditional music in Indonesia and deep learning technology that replaces the task of gamelan composers. This research proposes CNN-LSTM to generate notation of ricikan struktural instruments as an accompaniment to Javanese gamelan music compositions based on balungan notation, rhythm, song structure, and gatra …


Change In Grassland Science: Implications For Training, Research And Grassland Societies, G. Lemaire, R. J. Wilkins, J. Hodgson Jul 2023

Change In Grassland Science: Implications For Training, Research And Grassland Societies, G. Lemaire, R. J. Wilkins, J. Hodgson

IGC Proceedings (1977-2023)

In most of the world the priority for production-oriented research has been succeeded by the need for grassland research to focus on systems which satisfy requirements relating to the stability and protection of land, water and atmospheric resources and to biodiversity, in addition to production efficiency. This dictates not only a new approach to research, but also new approaches for the organisation of research, the training and development of research scientists and the activities of Grassland Societies and associated organisations.


Citizen Scientists: Efforts By The Tri-Societies To Inject Science Into Us Policymaking, E. Bergfeld, K. Glasener Jul 2023

Citizen Scientists: Efforts By The Tri-Societies To Inject Science Into Us Policymaking, E. Bergfeld, K. Glasener

IGC Proceedings (1977-2023)

The Tri-Societies (American Society of Agronomy, Crop Science Society of America and Soil Science Society of America), the largest life science professional societies in the United States (US) dedicated to the agronomic, crop and soil sciences, encompass approximately 18,000 members globally and include approximately 14,000 certified professionals who are a direct conduit to the farming communities across the US. The Tri-Societies' US-based federal science policy programmes have been active for decades. There is a Washington, DC-based Director of Science Policy, Congressional Science Fellows (CSF) and Science Policy Interns.


Electron Scattering From 1-Methyl-5-Nitroimidazole: Cross-Sections Formodeling Electron Transport Through Potential Radiosensitizers, Ana I. Lozano, Lidia Álvarez, Adrián García-Abenza, Carlos Guerra, Fábris Kossoski, Jaime Rosado, Francisco Blanco, Juan Carlos Oller, Mahmudul Hasan, Martin Centurion, Thorsten Weber, Daniel S. Slaughter, Deepthy M. Mootheril, Alexander Dorn, Sarvesh Sarvesh, Paulo Limão-Vieira, Rafael Colmenares, Gustavo García Jul 2023

Electron Scattering From 1-Methyl-5-Nitroimidazole: Cross-Sections Formodeling Electron Transport Through Potential Radiosensitizers, Ana I. Lozano, Lidia Álvarez, Adrián García-Abenza, Carlos Guerra, Fábris Kossoski, Jaime Rosado, Francisco Blanco, Juan Carlos Oller, Mahmudul Hasan, Martin Centurion, Thorsten Weber, Daniel S. Slaughter, Deepthy M. Mootheril, Alexander Dorn, Sarvesh Sarvesh, Paulo Limão-Vieira, Rafael Colmenares, Gustavo García

Department of Physics and Astronomy: Faculty Publications

In this study, we present a complete set of electron scattering cross-sections from 1-Methyl-5- Nitroimidazole (1M5NI) molecules for impact energies ranging from 0.1 to 1000 eV. This information is relevant to evaluate the potential role of 1M5NI as a molecular radiosensitizers. The total electron scattering cross-sections (TCS) that we previously measured with a magnetically confined electron transmission apparatus were considered as the reference values for the present analysis. Elastic scattering cross-sections were calculated by means of two different schemes: The Schwinger multichannel (SMC) method for the lower energies (below 15 eV) and the independent atom model-based screening-corrected additivity rule with …


Accuracy Vs. Energy: An Assessment Of Bee Object Inference In Videos From On-Hive Video Loggers With Yolov3, Yolov4-Tiny, And Yolov7-Tiny, Vladimir A. Kulyukin, Aleksey V. Kulyukin Jul 2023

Accuracy Vs. Energy: An Assessment Of Bee Object Inference In Videos From On-Hive Video Loggers With Yolov3, Yolov4-Tiny, And Yolov7-Tiny, Vladimir A. Kulyukin, Aleksey V. Kulyukin

Computer Science Faculty and Staff Publications

A continuing trend in precision apiculture is to use computer vision methods to quantify characteristics of bee traffic in managed colonies at the hive's entrance. Since traffic at the hive's entrance is a contributing factor to the hive's productivity and health, we assessed the potential of three open-source convolutional network models, YOLOv3, YOLOv4-tiny, and YOLOv7-tiny, to quantify omnidirectional traffic in videos from on-hive video loggers on regular, unmodified one- and two-super Langstroth hives and compared their accuracies, energy efficacies, and operational energy footprints. We trained and tested the models with a 70/30 split on a dataset of 23,173 flying bees …


The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology, Lori E. Porter, Benne Holwerda, Sandor Kruk, Maritza Lara-López, Kevin A. Pimbblet, Christopher P A Henry, Sarah Casura, Lee S. Kelvin Jul 2023

The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology, Lori E. Porter, Benne Holwerda, Sandor Kruk, Maritza Lara-López, Kevin A. Pimbblet, Christopher P A Henry, Sarah Casura, Lee S. Kelvin

Faculty and Staff Scholarship

The large-scale structure of the Universe is comprised of galaxy filaments, tendrils, and voids. The majority of the Universe’s volume is taken up by these voids, which exist as underdense, but not empty, regions. The galaxies found inside these voids are expected to be some of the most isolated objects in the Universe. This study, using the Galaxy and Mass Assembly (GAMA) and Galaxy Zoo surveys, aims to investigate basic physical properties and morphology of void galaxies versus field (filament and tendril) galaxies. We use void galaxies with stellar masses (⁠M∗" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; …


Self-Supervised Learning Application On Covid-19 Chest X- Ray Image Classification Using Masked Autoencoder, Xin Xing, Gongbo Liang, Chris Wang, Nathan Jacobs, Ai-Ling Lin Jul 2023

Self-Supervised Learning Application On Covid-19 Chest X- Ray Image Classification Using Masked Autoencoder, Xin Xing, Gongbo Liang, Chris Wang, Nathan Jacobs, Ai-Ling Lin

All Faculty Scholarship (Archived)

The COVID-19 pandemic has underscored the urgent need for rapid and accurate diagnosis facilitated by artificial intelligence (AI), particularly in computer-aided diagnosis using medical imaging. However, this context presents two notable challenges: high diagnostic accuracy demand and limited availability of medical data for training AI models. To address these issues, we proposed the implementation of a Masked AutoEncoder (MAE), an innovative self-supervised learning approach, for classifying 2D Chest X-ray images. Our approach involved performing imaging reconstruction using a Vision Transformer (ViT) model as the feature encoder, paired with a custom-defined decoder. Additionally, we fine-tuned the pretrained ViT encoder using a …


Foreword From Editor - 13th Edition, Yandi Andri Yatmo Jul 2023

Foreword From Editor - 13th Edition, Yandi Andri Yatmo

ASEAN Journal of Community Engagement

The current AJCE edition brings together meaningful discussions of community engagement programs as ways to disseminate various skills towards better society livelihood, focusing on product-making skills, women-led soft skills for families, and marketing skills. Elaborating on these objectives, this issue consists of four research-based articles and three case-based articles. The authors of this edition come from the background of economy, chemistry, community, psychology, and education—enabling diverse understanding of skills for the community and the means of how these skills can be acquired from different knowledge backgrounds.


Towards Crisp‐Bc: 3tic Specification Framework For Blockchain Use‐Cases, Pouyan Jahanbin, Ravi S. Sharma, Stephen T. Wingreen, Nir Kshetri, Kim‐Kwang Raymond Choo Jul 2023

Towards Crisp‐Bc: 3tic Specification Framework For Blockchain Use‐Cases, Pouyan Jahanbin, Ravi S. Sharma, Stephen T. Wingreen, Nir Kshetri, Kim‐Kwang Raymond Choo

All Works

The application of Blockchain and augmented technologies such as IoT, AI, and Big Data platforms present a feasible approach for resolving the implementation challenges of trusted, decentralized platforms. This article proposes a DevOps framework for the specification of Blockchain use‐cases that enables evaluation, replication, and benchmarking. Specifically, it could be applied to specify the requirements and design characteristics of Blockchain applications in terms of key attributes such as: (i) transparency; (ii) traceability; (iii) tamper‐resistance; (iv) immutability; and (v) compliance. The article first introduces the design characteristics of Blockchain as a Platform and then examines successful use‐cases for its implementation using …


Functionalized Go Nanoplatelets With Folic Acid As A Novel Material For Boosting Humidity Sensing Of Chitosan/Pva Nanocomposites For Active Food Packaging, Mohamed Morsy Jul 2023

Functionalized Go Nanoplatelets With Folic Acid As A Novel Material For Boosting Humidity Sensing Of Chitosan/Pva Nanocomposites For Active Food Packaging, Mohamed Morsy

Nanotechnology Research Centre

No abstract provided.


Synthesis And Reactivity Of Dihydrogen Diruthenium Complexes., Ryder J. Downey, Robert Chin Jul 2023

Synthesis And Reactivity Of Dihydrogen Diruthenium Complexes., Ryder J. Downey, Robert Chin

Summer Undergraduate Research Program (SURP) Symposium

Having two open coordination sites on the diruthenium complex makes for the ability to be able to be more precise when interacting with other compound. The side-on bonding of the bis(dihydrogen) gives it unique characteristics as well as unique capabilities. The Oganotransition Metal Chemistry book says that the dihydrogen is bonded by the donation of electrons from the H-H sigma bond as well as the back donation of electron density through the transition metal.3

In the past, many groups have studies on a mononuclear Ruthenium compound similar to the one we are synthesizing (see figure one). Our goal was to …


Integrating External Sensors With Crazyflie Drones, Xiaowen Wang, Dheryta Jaisinghani, Andrew Berns Jul 2023

Integrating External Sensors With Crazyflie Drones, Xiaowen Wang, Dheryta Jaisinghani, Andrew Berns

Summer Undergraduate Research Program (SURP) Symposium

  • Drones are widely used: Mini drones such as Crazyflie 2.1 are used in a variety of fields.
  • Grove Sound Sensor function: Grove Sound Sensor can capture sound, providing more application possibilities for drones.
  • The potential of Crazyflie 2.1: Although Crazyflie 2.1 has the potential to be an integrated sensor platform, prior to this project, it was uncertain whether sensors could be connected on it.
  • Project motivation: Our project aims to explore whether Crazyflie 2.1 can be connected to the Grove Sound Sensor and collect and process data from the sensor.
  • Impact of the project: If successful, this project will open …


Forecasting Wildfire Smoke Particulate Matter Using Hysplit Model, Kevin Du, Alexa Sedlacek Jul 2023

Forecasting Wildfire Smoke Particulate Matter Using Hysplit Model, Kevin Du, Alexa Sedlacek

Summer Undergraduate Research Program (SURP) Symposium

Wildfire smoke can reduce visibility and affect human health. Particulate matter with a diameter smaller than 2.5μm from wildfire smoke can travel through the respiratory tract to the lungs and enter the bloodstream. PM2.5 can be especially harmful to individuals with lung conditions such as asthma, chronic bronchitis, emphysema, and COPD, as well as infants and adults over sixty- five. This project uses NOAA’s Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to forecast the transport and dispersion of particulate matter using meteorological files, wildfire location, burning areas, and starting time. Forecast data of the HYSPLIT model can be verified against …


Surficial Geology Of The Fulton Quadrangle, Avery Merkley, Starr Claussen, Sage Cappi, Chad Heinzel Jul 2023

Surficial Geology Of The Fulton Quadrangle, Avery Merkley, Starr Claussen, Sage Cappi, Chad Heinzel

Summer Undergraduate Research Program (SURP) Symposium

  • The Fulton 7.5’ Quadrangle lies within a geographic region known as the East-Central Iowa Drift Plain.
  • The East-Central Iowa Drift Plain is characterized by glacial deposits that occurred over 1.8 million years ago. These glacial deposits are part of what makes up the loose soil material, which overlays a bedrock surface that is about 360-485 million years old.
  • This area experiences significant change in elevation from the highest points to the lowest points in the Quadrangle.


A Tale Of Two Rivers: Unveiling Water's Secrets Across Continents, Jace Bell, Mohammad Iqbal Jul 2023

A Tale Of Two Rivers: Unveiling Water's Secrets Across Continents, Jace Bell, Mohammad Iqbal

Summer Undergraduate Research Program (SURP) Symposium

Dry Run Creek outside of Cedar Falls, Iowa in the United States and New Town Rivulet surrounding Hobart, Tasmania in Australia are two comparable hydrological water flows. From the natural sources of the water flows to the watershed impacts from industrial, municipal, and agricultural practices further downstream, the similarities and differences of the physical, chemical, and geomorphological properties of these two hydrological systems on separate continents will permit further understanding of Earth’s comprehensive ecosystem on two continents.

Water from seven sites along the Cedar River and the Mississippi River and at Prairie Lake, Alice Wyth Lake, and Big Woods Lake …


Geometric Curves From P-Circles, Isaiah Dempsey, Bill Wood Jul 2023

Geometric Curves From P-Circles, Isaiah Dempsey, Bill Wood

Summer Undergraduate Research Program (SURP) Symposium

p-Circles are a generalization of the usual circle satisfying the equation |x|p + |y|p = 1. The 1-circle is the square with vertices (1,0),(0,1),(-1,0),(0,-1). As p goes to infinity the p-circle equation becomes max(|x|, |y|) = 1. So the ∞-circle is the square with vertices (1,1),(-1,1),(-1,-1),(1,-1). From 1≤p≤2 the p-circle smoothly transforms from a square to a circle, and from 2≤p≤∞ the p-circle smoothly transforms from a circle to a square.


Molybdenum Disulfide (Mos₂) As A Nanocellulose Substrate, Mariana Torres, Dylan Seiffert, Elise Hong-Miller, T. E. Kidd Jul 2023

Molybdenum Disulfide (Mos₂) As A Nanocellulose Substrate, Mariana Torres, Dylan Seiffert, Elise Hong-Miller, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Cellulose is a substance abundant in nature, found in fruits and vegetables, plant cell walls (National Center for Biotechnology Information, 2023), and wood (Sjostrom, 1993). The abundance of cellulose is attributable to its linear chemical structure, as it is composed of long strands of glucose molecules linked together by hydrogen atoms, which enable the substance to withstand significant pressure without breaking (Rongpipi et al., 2019). This property—known as high tensile strength—is joined by its non-toxicity and sustainability, given cellulose may be degraded and renewed naturally (Kaur, 2021). These various properties indicate versatility, and its resultant current and desired uses—such as …


Flow Through Processing Of Nanocellulose For Space Exploration Applications, Dylan Seiffert, T. E. Kidd Jul 2023

Flow Through Processing Of Nanocellulose For Space Exploration Applications, Dylan Seiffert, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Nanocellulose is synthesized from cellulose, which is the most abundant organic molecule found in nature. Nanocellulose solids are biodegradable and have a strength-to-weight ratio eight times that of steel1. The production of nanocellulose solids is challenging due to the large volume loss that occurs during the curing process as well as the time and cost associated with ultrasonic processing. The loss of volume during curing often results in cracking and deformation of the cured solid. The issues caused by the large volume loss can be mitigated using additives that do not compromise the strength, shape, or machineability of …


Electronic, Magnetic, And Structural Properties Of Covmnsb: Ab Initio Study, Pavel Lukashev, Adam Ramker, Brandon Schmidt, Paul M. Shand, Parashu Kharel, Vagharsh Mkhitaryan, Zhenhua Ning, Liqin Ke Jul 2023

Electronic, Magnetic, And Structural Properties Of Covmnsb: Ab Initio Study, Pavel Lukashev, Adam Ramker, Brandon Schmidt, Paul M. Shand, Parashu Kharel, Vagharsh Mkhitaryan, Zhenhua Ning, Liqin Ke

Summer Undergraduate Research Program (SURP) Symposium

  • Spin degree of freedom in electronic devices.
  • Ideal candidate – room temperature half-metal.
  • Heusler compounds attractive because of high Curie temperature
  • Various mechanisms altering spin polarization – mechanical strain, structural disorder, temperature, termination surface/interface, etc.
  • CoVMnSb: nearly spin gapless semiconductor.


Impacts And Applications Of Vegetable Glycerin On Nanocellulose, Elise Hong-Miller, Dylan Seiffert, T. E. Kidd Jul 2023

Impacts And Applications Of Vegetable Glycerin On Nanocellulose, Elise Hong-Miller, Dylan Seiffert, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Nanocellulose is created by breaking down cellulose, the most common organic molecule found in nature. Nanocellulose has attractive properties, such as a very high strength-to-weight ratio, for many different applications. A major challenge is that nanocellulose has a very high shrinkage % (~90%) when it is dried, as well as a strong probability to crack. Different additives can be added in varying amounts to either mitigate or intensify these aspects, as well as affect its drying conditions. This investigation is helping the National Aeronautics and Space Administration (NASA) and the U.S. Army to find a use for this highly renewable …


Investigation Of A Magnet Falling Through A Copper Pipe, Brianna Williams, Paul M. Shand Jul 2023

Investigation Of A Magnet Falling Through A Copper Pipe, Brianna Williams, Paul M. Shand

Summer Undergraduate Research Program (SURP) Symposium

  • The goal of this research is to explore the effects of wall thickness and temperature on the rate at which a magnet falls through a copper pipe.
  • A magnet is not attracted to copper. Copper is not magnetic; however, it is a great conductor of electricity.
  • Due to Faraday’s law and Lenz’s law, we know that a changing magnetic flux will produce an electric current that opposes the change in magnetic flux that produced it. These laws together explain why a magnet will fall slowly in a copper pipe even though it is not attracted.


Exploration Of Pocketlab Devices For Uni’S Campus, Classrooms, And Community, Isabel Harms, Alexa Sedlacek Jul 2023

Exploration Of Pocketlab Devices For Uni’S Campus, Classrooms, And Community, Isabel Harms, Alexa Sedlacek

Summer Undergraduate Research Program (SURP) Symposium

PocketLab devices by Myriad Sensors were acquired by UNI’s Earth and Environmental Science department in the fall of 2022 through the Carver Grant. These citizen science devices are incredibly useful in educating and exploring real life issues in the environmental sciences that we are experiencing today. Issues such as air quality and weather are increasingly important topics to examine as the climate warms. During the summer of 2023, Iowa has had multiple cases of unhealthy air quality levels due to particulate matter from fires in Canada. Southern states have experienced extreme heat indexes, pointing to the need to consider the …


Watermark Hiding In Hdr Image Based On Visual Saliency And Tucker Decomposition, Roa'a M. Al-Airaji, Ibtisam A. Aljazaery, Haider Th. Salim Alrikabi Jul 2023

Watermark Hiding In Hdr Image Based On Visual Saliency And Tucker Decomposition, Roa'a M. Al-Airaji, Ibtisam A. Aljazaery, Haider Th. Salim Alrikabi

Karbala International Journal of Modern Science

Recently, great attention has been paid to high dynamic range (HDR) images because of their richly detailed and high dynamic range of intensity. The need for pre-processing of the HDR image format with tone mapping (TM) operators makes it unique; the TM operators are provided on display with a low dynamic range (LDR). On the other hand, TM can be regarded as an inevitable attack when protecting HDR image ownership is considered. An adaptive approach for concealing watermarks based on visual saliency and Tucker decomposition has been presented in this article. In the first step, three feature maps were produced …


Spherical Bouguer Effect Of Topography On Gravity With Constant And Laterally Varying Density, Mehmet Si̇mav Jul 2023

Spherical Bouguer Effect Of Topography On Gravity With Constant And Laterally Varying Density, Mehmet Si̇mav

Turkish Journal of Earth Sciences

Gravitational attraction of the Earth's visible topography above the mean sea level is generally regarded as an unwanted signal in various geoscience applications. It should be removed from the observations to reveal the remaining signals of subsurface anomalous density distribution or to satisfy the boundary condition in solving the geodetic boundary value problems. However, the task of determining the gravimetric terrain effects involves tedious numerical computations when high-resolution elevation data is used. While the traditional computational approach relies on flat-Earth approximation and neglects the topographic masses beyond some fixed integration radius, e.g., planar complete Bouguer correction, the modern methods apply …


A Controlled Source Tomography In Sarımeşe, İzmit, At The Western Section Of North Anatolian Fault Zone, Tuğçe Ergün Jul 2023

A Controlled Source Tomography In Sarımeşe, İzmit, At The Western Section Of North Anatolian Fault Zone, Tuğçe Ergün

Turkish Journal of Earth Sciences

A high-resolution two-dimensional tomographic velocity image in the eastern Marmara region along a 1.2 km long N-S trending seismic profile, which crosses the surface rupture of the İzmit earthquake on the North Anatolian Fault (NAF) is presented. A vibroseis source at more than 180 points with 50 receivers was used along the long profile. A regularized inversion technique was applied to the first arrival travel times. More than 6500 first arrivals from 129 shot gathers were analyzed to construct velocity images and were qualitatively evaluated for the fault zone-related effects. The velocity model was constrained to a maximum depth of …