Physical Sciences and Mathematics Commons^™

Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin

Coal Geology & Exploration

To study the mesoscopic failure characteristics of the layered red shale, uniaxial mechanical experiments were carried out by applying DSTD-1000 electro-hydraulic servo rigid pressure on the red shale with different bedding angles. Meanwhile, SEM and XRD experiments were implemented on debris to obtain its mechanical parameters, failure characteristics, microstructure, and relative content of components. Based on this, models of the red shale with different bedding angles were constructed using the discrete element PFC^3D for the uniaxial compression experiments to study the mesoscopic failure characteristics of red shale. The results show that: (1) When the bedding angle θ=30°, 45°, …

Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun

Coal Geology & Exploration

In-seam waves are commonly applied to the advance detection of hidden faults in front of mining faces. However, coal seams, which have viscoelasticity actually, imposing absorptive and attenuation effects on in-seam waves. To investigate the wave field characteristics and propagation patterns of in-seam waves in viscoelastic coal seam media, this study built a three-dimensional geological model of coal measures with faults based on Kelvin-Voigt’s first-order velocity-stress equation. Using this equation, three-dimensional finite-difference numerical simulation was carried out. The results indicate that (1) for reflected in-seam waves in viscoelastic media, which exhibit high energy attenuation, their propagation and attenuation characteristics are …

Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang

Coal Geology & Exploration

In order to improve the support efficiency of coal mine roadway and the automation intelligence of heading face, an anchor drilling robot integrating the cantilever roadheader and the six-degree-of-freedom manipulator was designed, and studied on the anchor drilling sequence planning strategy and the drilling boom trajectory planning method. Firstly, the kinematics model of the manipulator structure was established based on the improved DH method. On this basis, the forward and inverse kinematics solutions were analyzed, and the spatial position and the corresponding joint variable values of the drilling rig were calculated. Secondly, the manipulator space was analyzed based on Monte …

Postsynthetic Modification Of The Nonanuclear Node In A Zirconium Metal−Organic Framework For Photocatalytic Oxidation Of Hydrocarbons, Rebecca Shu Hui Khoo, Christian Fiankor, Sizhuo Yang, Wenhui Hu, Chongqing Yang, Jingzhi Lu, Martha D. Morton, Xu Zhang, Yi Liu, Jier Huang, Jian Zhang

Department of Chemistry: Faculty Publications

Heterogeneous catalysis plays an indispensable role in chemical production and energy conversion. Incorporation of transition metals into metal oxides and zeolites is a common strategy to fine-tune the activity and selectivity of the resulting solid catalysts, as either the active center or promotor. Studying the underlying mechanism is however challenging. Decorating the metal-oxo clusters with transition metals in metal−organic frameworks (MOFs) via postsynthetic modification offers a rational approach to construct well-defined structural models for better understanding of the reaction mechanism. Therefore, it is important to expand the materials scope beyond the currently widely studied zirconium MOFs consisting of Zr_{6 …}

Breakdown Of The Drift-Diffusion Model For Transverse Spin Transport In A Disordered Pt Film, Kirill D. Belashchenko, Giovanni G. Baez Flores, Wuzhang Fang, Alexey Kovalev, Mark Van Schilfgaarde, Paul M. Haney, Mark D. Stiles

Department of Physics and Astronomy: Faculty Publications

Spin-accumulation and spin-current profiles are calculated for a disordered Pt film subjected to an in-plane electric current within the nonequilibrium Green's function approach. In the bulklike region of the sample, this approach captures the intrinsic spin Hall effect found in other calculations. Near the surfaces, the results reveal qualitative differences with the results of the widely used spin-diffusion model, even when the boundary conditions are modified to try to account for them. One difference is that the effective spin-diffusion length for transverse spin transport is significantly different from its longitudinal counterpart and is instead similar to the mean-free path. This …

Understanding The Nature Of Pulsars And Characterizing Propagation Effects Using Pulsar Timing, Pratik Kumar

Physics & Astronomy ETDs

Pulsars are highly magnetized stellar remnants, among the densest known objects, and primarily produce radio emission in the form of lighthouse beams sweeping across the line of sight as a regular train of pulses. Apart from providing tests for matter in high-density regimes, general relativity, and plasma emission; perhaps the most notable characteristic is their applicability as precise astronomical clocks to measure various effects. Pulsar Timing Arrays (PTAs) are galactic scale detectors analogous to ground-based detectors of Gravitational Waves (GWs) like LIGO, with the aim of detecting low-frequency nano-Hz GWs from coalescing binary supermassive black holes. PTAs consist of a …

Sequence-Defined Ionic Peptoid Polymers: Synthesis, Characterization, And The Role Of Charge Patterning, Bailee N. Barrett

LSU Doctoral Dissertations

This work explores the role of positionally defined charges on the self-assembly behavior of a series of sequence-defined peptoid block copolymers. The unique ability to precisely control the number and position of each monomer unit along the polymer chain makes this system particularly well suited for uncovering how changes in monomer sequence alter the resulting structures. We employ a number of scattering techniques to uncover how systematically repositioning a single ionizable monomer, along an otherwise neutral polymer chain, alters the self-assembled micellar structures and subsequently their responsiveness to changes in their local environment.

Chapter 1 reviews previous efforts to transition …

Planning Cities Using Leed Standards, Jason Kliwinski

Sustainability Seminar Series

Jason Kliwinski focuses on three main areas in Sustainability Science: Sustainable Architecture, Consulting and Education. As a practicing Architect, Jason’s work includes the sustainable renovation, preservation, and adaptive reuse of existing buildings as well as creation of many new environmentally responsible & healthy buildings for twenty years. Jason’s work is diverse and includes commercial, institutional, educational, hospitality, retail and residential clients in public and private sectors. As a Consultant, Jason has assisted clients across multiple markets in pursuing LEED™ & WELL™ certifications and carbon neutrality/net zero energy on dozens of projects over the last two decades. His philosophy has always …

Does The Design And Personalization Of Mailed Invitations Influence Online Survey Response Rates?, Brock Ternes

The SUNY Journal of the Scholarship of Engagement: JoSE

Nonresponse to online surveys has been a notable concern of survey methodologists, who continue to implement strategies and incentives to boost returns. Don Dillman’s methods emphasize tailored designs to maximize response rates, and this paper assesses how mailed notification designs and requested deadlines for completion influence online survey response rates. Using a target population of rural Kansans, this paper assesses how minor changes in printed notifications are connected to participation in an online survey. Postcards were mailed to private water well owners inviting recipients to complete a 40-item online questionnaire about their water usage; notifications varied in their personalization of …

The Contractual Liability Arising From The Violation Of Negotiations Through Modern Means Of Communication In The Jordanian Legislation, Yassin Al Qudah, Juhainah Al Momani

This study aims to show the effects of contractual liability for breach of negotiation via electronic means of communication in Jordanian legislation. Where it became clear that preliminary electronic negotiations are a previous basic stage in the electronic contracting process, in terms of organizing the conduct of negotiations by putting forward ideas and offers between the negotiating parties, and discussing among them to reach mutual agreement until the negotiated contract is concluded. As a result, at this stage, a set of obligations is created by each of the parties, otherwise civil liability may arise on the breaching party. This study …

The Effectiveness Of Field Training In Qualifying Students Of Media Faculties For The Labor Market: Yarmouk And Middle East Universities As A Model, Saddam Al-Masshaqbah, Ramez Abuhasirah

The study aimed to identify the effectiveness of the field training course in raising the capabilities of students of media faculties in public and private Jordanian universities and qualifying them for the labor market. The results showed that the degree of students' commitment to attendance during the field training period in media institutions came to a "huge" degree, at a rate of (39.8%), while the degree of their benefit from field training came to a "medium" degree, at a rate of (29.2%). In: "Journalism Editing," Preparation of Radio and Television Programs," and "The Art of Speaking and Presentation." training" with …

Palestinian Journalists' Trends Towards Freelance Platforms As An Alternative Of Traditional Work In Journalistic Work And The Gratifications Achieved "A Field Study", Amin Wafi

This study aims to identify the trends of media students towards the use of digital freelancer platforms in media work as an alternative to traditional journalism by knowing the degree of interest of students in digital freelancer platforms. The degree to which they are exposed، the reasons for exposure، the most important subjects to which they are exposed، the most important platforms they pursue، the most important skill needs، motivations، and stimuli that drive them to deal with freelancer platforms as an alternative to traditional journalism. It is a descriptive study and applied the survey curriculum in the framework of …

Book Review: Australian Caves And Karst Systems, John Webb, Susan White, Garry K. Smith, Jo De Waele

International Journal of Speleology

No abstract provided.

Characterization Of Environmental Levels Of Pesticide Residues In Household Air And Dust Samples Near A Bioenergy Plant Using Treated Seed As Feedstock, Jabeen Taiba, Eleanor G. Rogan, Daniel D. Snow, Chandran Achutan, Muhammad Zahid

Nebraska Water Center: Faculty Publications

Exposure to neonicotinoid insecticides is associated with adverse human health outcomes. There is environmental contamination in Saunders County, Nebraska, due to the accumulation of fungicides and insecticides from a now-closed ethanol plant using seed corn as stock. A pilot study quantified environmental contamination in nearby houses from residual pesticides by measuring dust and air (indoor/outdoor) concentrations of neonicotinoids and fungicides at the study site (households within two miles of the plant) and control towns (20–30 miles away). Air (SASS^® 2300 Wetted-Wall Air Sampler) and surface dust (GHOST wipes with 4 × 4-inch template) samples were collected from eleven study …

Wics Conference 2023: Moving Beyond The Ordinary, Daren Redfearn, Daran Rudnick

Water and Integrated Cropping Systems Conferences

The theme of this year’s WICS Conference is Moving Beyond the Ordinary with the goal of addressing Team Science. Our vision is to provide opportunities and connection points among IANR faculty to leverage their individual knowledge, skills, abilities, and passions. A tendency for land grant institutions is often to deliver information biased from a single, primary discipline and perspective. This is known as comfort zone mega bias and has been defined as “the tendency to drag a problem into our comfort zone and solve the problem that we know how to solve, rather than solving the problem that needs to …

Evaluating Methods For Improving Dnn Robustness Against Adversarial Attacks, Laureano Griffin

USF Tampa Graduate Theses and Dissertations

Deep learning has become more widespread as advances in the field continue. As aresult, making sure deep learning is safe has become a priority. A seemingly normal image with intentional pixel changes can cause a well-trained model to misclassify the image with high confidence. Those kinds of images are called adversarial attacks. Adversarial training has been developed to defend against adversarial attacks. This thesis evaluates different adversarial training methods against a variety of adversarial attacks. The key metrics for evaluation are classification accuracy and training time. This thesis also experiments with an improvement on an existing adversarial training method, the …

Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) 2023 Residential Metals Abatement Program (Rmap) Field Sampling Plan (Fsp) – Indoor Dust – Group 9 - Montana Technological University (Prospector Residence Hall) (Dated September 25, 2023), Nikia Greene

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Chemical Analysis Of Metabolites From Mangrove Endophytic Fungus, Sefat E Munjerin

USF Tampa Graduate Theses and Dissertations

Natural products hold a significant place in drug discovery for their abundant and unique secondary metabolites. These secondary metabolites which encompass a range of organic compounds such as alkaloids, phenols, peptides, flavonoids, polyketides, and terpenoids, can easily be exploited for drug development. Endophytic fungi, residing harmoniously with its host, have emerged as generous producers of bioactive secondary metabolites, displaying efficacy against a wide array of human pathogens, including the challenging ESKAPE pathogens.

The research explores endophytic fungi and their prospective for drug discovery and development through the synthesis of distinctive secondary metabolites. Endophytic fungus, HM13-26C-2B, collected from Honeymoon Island, Florida …

Majorana Bound States In A D-Wave Superconductor Planar Josephson Junction, Hamed Vakili, Moaz Ali, Mohamed Elekhtiar, Alexey Kovalev

Department of Physics and Astronomy: Faculty Publications

We study phase-controlled planar Josephson junctions comprising a two-dimensional electron gas with strong spin-orbit coupling and d-wave superconductors, which have an advantage of a high critical temperature. We show that a region between the two superconductors can be tuned into a topological state by the in-plane Zeeman field, and can host Majorana bound states. The phase diagram as a function of the Zeeman field, chemical potential, and the phase difference between superconductors exhibits the appearance of Majorana bound states for a wide range of parameters. We further investigate the behavior of the topological gap and its dependence on the …

Nuclear Dimension Of Graph C∗-Algebras With Condition (K), Gregory Faurot, Christopher Schafhauser

Department of Mathematics: Faculty Publications

We prove that for any countable directed graph E with Condition (K), the associated graph C^*-algebra C^*(E) has nuclear dimension at most 2. Furthermore, we provide a sufficient condition producing an upper bound of 1.

Islands In The Rain: Isolating The Influence Of Rainfall On Erosion On Volcanic Ocean Islands, Kimberly Huppert

Sustainability Seminar Series

Volcanic ocean islands are well suited for studying climatic controls on erosion because they typically have relatively homogeneous bedrock, dramatic rainfall gradients, and remnant surfaces that constrain their age, initial topography, and vertical motions relative to sea level. In this talk, I’ll examine the influence of rainfall and discharge variability on bedrock river incision on the Hawaiian Island of Kaua‘i. I’ll also present a new compilation of basin-averaged cosmogenic erosion rates measured on ocean islands worldwide, as well as >800 million year-scale basin-averaged erosion rates inferred from eroded canyon volumes and lava flow ages across the Azores, Hawaiian, Cape Verde, …

On A Stationary Random Knot, Andrey A. Dorogovtsev

Journal of Stochastic Analysis

No abstract provided.

Does Drought Stress Eliminate The Benefit Of Elevated Co2,/Sub> On Soybean Yield? Using An Improved Model To Link Crop And Soil Water Relations, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy

Daugherty Water for Food Global Institute: Faculty Publications

Crop simulation models are indispensable tools that facilitate studies to assess climate impacts and adaptation responses, but have not been adequately tested in terms of accurately predicting crop growth and water stress responses to high carbon dioxide concentrations [CO₂]. The soybean model, GLYCIM, previously modified with a coupled leaf-level gas exchange – energy balance model, was integrated with a two-dimensional convectivediffusive root growth module which linked soil and leaf water potentials with the regulation of stomatal conductance. We evaluated the accuracy of this modified GLYCIM using experimental data from a Free-Air CO₂ Enrichment (FACE) site, SoyFACE, and …

An Incremental Gray-Box Physical Adversarial Attack On Neural Network Training, Rabiah Al-Qudah, Moayad Aloqaily, Bassem Ouni, Mohsen Guizani, Thierry Lestable

Machine Learning Faculty Publications

Neural networks have demonstrated remarkable success in learning and solving complex tasks in a variety of fields including cognitive cities. Nevertheless, the rise of those networks in modern computing has been accompanied by concerns regarding their vulnerability to adversarial attacks. In this work, we propose a novel gradient-free, gray box, incremental attack that targets the training process of neural networks. The proposed attack, which implicitly poisons the intermediate data structures that retain the training instances between training epochs acquires its high-risk property from attacking data structures that are typically unobserved by professionals. Hence, the attack goes unnoticed despite the damage …

Harris Hawks Feature Selection In Distributed Machine Learning For Secure Iot Environments, Neveen Hijazi, Moayad Aloqaily, Bassem Ouni, Fakhri Karray, Merouane Debbah

Machine Learning Faculty Publications

The development of the Internet of Things (IoT) has dramatically expanded our daily lives, playing a pivotal role in the enablement of smart cities, healthcare, and buildings. Emerging technologies, such as IoT, seek to improve the quality of service in cognitive cities. Although IoT applications are helpful in smart building applications, they present a real risk as the large number of interconnected devices in those buildings, using heterogeneous networks, increases the number of potential IoT attacks. IoT applications can collect and transfer sensitive data. Therefore, it is necessary to develop new methods to detect hacked IoT devices. This paper proposes …

A Song In A Cold Place: The Role Of Emotions In Motivating Youth Activism And Advancing Justice At The Cop, Julia Coombs Fine, Summer Gray, Corrie Grosse, Brigid Mark

Environmental Studies Faculty Publications

The emotions of youth climate justice activists are often demeaned or misrepresented both by popular media and by COP organisers. The COP itself, as a cold, bureaucratic, and repressive space that tokenises frontline voices to create an optics of care, is a source of frustration and disappointment for many youth activists. Despite this misrepresentation and repression, youth activists use their emotions to strengthen their movements and actions at the COP. Drawing on collaborative event ethnography spanning a decade, this paper analyses how Global South youth climate justice activists strategically navigate and channel emotion through acts of emotional solidarity, emotional concealment, …

The High Pressure Dependence Of X-Ray Induced Decomposition Of Cadmium Oxalate, Adrian F. Lua Sanchez, Petrika Cifligu, Marc Graff, Michael Pravica, Pradip K. Bhowmik, Changyong Park, Egor Evlyukhin

Physics & Astronomy Faculty Research

The high proclivity of x rays to destabilize and distort molecular structures has been previously utilized in the synthesis of novel compounds. Here, we show that x-ray induced decomposition of cadmium oxalate induces chemical and structural transformations only at 0.5 and 1 GPa. Using x-ray diffraction and Raman spectroscopy, the synthesized product is identified as cadmium carbonate with cadmium oxalate remnants, which is stable under ambient conditions. At ambient and >1 GPa pressures, only degradation of the electronic density distribution is observed. The transformation kinetics are examined in terms of Avrami’s model, which demonstrates that despite the necessity of high …

Directional Microwave Emission From Femtosecond-Laser Illuminated Linear Arrays Of Superconducting Rings, Thomas J. Bullard, Kyle Frische, Charlie Ebbing, Stephen J. Hageman, John Morrison, John Bulmer, Enam A. Chowdury, Michael L. Dexter, Timothy J. Haugan, Anil K. Patnaik

Faculty Publications

We examine the electromagnetic emission from two photo-illuminated linear arrays composed of inductively charged superconducting ring elements. The arrays are illuminated by an ultrafast infrared laser that triggers microwave broadband emission detected in the 1–26 GHz range. Based on constructive interference from the arrays a narrowing of the forward radiation lobe is observed with increasing element count and frequency demonstrating directed GHz emission. Results suggest that higher frequencies and a larger number of elements are achievable leading to a unique pulsed array emitter concept that can span frequencies from the microwave to the terahertz (THz) regime.

Use Of Silica Dust And Lunar Simulants For Assessing Lunar Regolith Exposure, Layzamarie Irizarry-Colon

USF Tampa Graduate Theses and Dissertations

The utilization of the lunar regolith holds immense potential for future space exploration, but the potential health risks associated with lunar regolith are a significant concern. This literature review seeks to critically assess the use of silica and lunar simulants standards and permissible exposure limits (PELs) to evaluate the adverse health effects of lunar regolith. The literature review covers an extensive analysis of existing research, health risks, toxicological properties, and physical and chemical composition associated with silica, lunar simulants, and lunar regolith by using three main sources: regulations, scholarly articles, and Kennedy Space Center (KSC) discussion. This comprehensive analysis forms …

Stable Isotope Analysis On Yellowfin And Blackfin Tuna Eye Lenses Reveals Life History Patterns In The Gulf Of Mexico, Kylee M. Rullo

USF Tampa Graduate Theses and Dissertations

Spatial geography, ontogenetic movement, and trophic patterns of mobile species are key elements of effective marine resource management. A number of methods are currently available for tracking movements of pelagic migratory species, including the use of conventional and electronic tags. However, tagging campaigns can take years to provide useful data, can be expensive, and only capture a portion of a fish’s lifetime. For this project, I used stable-isotopic ratios of nitrogen (δ15N) and carbon (δ13C) in metabolically inert, chronologically-layered fish-eye lenses to explore lifetime movement and trophic patterns of yellowfin tuna (Thunnus albacares) and blackfin tuna (Thunnus atlanticus) in the …