Physical Sciences and Mathematics Commons^™

Allosteric Mechanism On Dream Dimerization And Impact On Its Interactions With Divalent Metal Zn2+, Maria D. Santiago Estevez

FIU Electronic Theses and Dissertations

DREAM belongs to the NCS family, and it is involved in several physiological processes mediated by Ca²⁺ association, which produces changes in its oligomerization state. The mechanism of how Ca²⁺ binds to DREAM remains unknown. A kinetic study of the binding of Ca²⁺ to DREAM suggested that DREAM dimerization is a two-step process, the first step( τ₁= 8±0.1ms) is associated with the binding of Ca²⁺ to the monomer, while the second step (τ₂ = 3.6 ±0.4 s ) corresponds to a conformation relaxation that leads to the dimerization. Furthermore, by analyzing the fast …

Probing The Inner Structure Of Active Galactic Nuclei Through Reverberation Mapping, Viraja Chandrashekhar Khatu

Electronic Thesis and Dissertation Repository

In the centres of massive galaxies, active galactic nuclei (AGN) are supermassive black holes, surrounded by an accretion disk of ionized gas, that release tremendous energy in the form of electromagnetic radiation. Because AGN are unresolved through telescopes, we employ reverberation mapping (RM) to study their structure. RM capitalizes on the fact that AGN are variable – the continuum emission from the accretion disk varies, and surrounding gas (in the broad-line region, BLR) responds to those variations with a positive time lag. RM translates the measured time lag into a size of the BLR. Combined with gas velocities (measured from …

Statistical Extensions Of Multi-Task Learning With Semiparametric Methods And Task Diagnostics, Nikolay Miller

Mathematics & Statistics ETDs

In this dissertation, I propose new approaches to multi-task learning, inspired by statistical model diagnostics and semiparametric and additive modeling. The newly designed additive multi-task model framework allows for flexible estimation of multi-task parametric and nonparametric effects by using an extension of the backfitting algorithm. Further, I propose new methods for statistical task diagnostics, which allow for the identification and remedy of outlier tasks, based on task-specific performance metrics and their empirical distributions. I perform a deep examination of the well-established multi-task kernel method and achieve theoretical and experimental contributions. Lastly, I propose a two-step modeling approach to multi-task modeling, …

Asymmetrical Spectral Continuum Between Anti-Stokes And Stokes Scattering Revealed In Low-Frequency Surface-Enhanced Raman Spectroscopy, Shuo Sun, Dhanusha T.N. Rathnayake, Yinsheng Guo

Chemistry Department: Faculty Publications

An asymmetrical spectral continuum is observed in low-frequency surface-enhanced Raman spectroscopy (LF-SERS) in the terahertz (THz) region. This background continuum appears as a flat baseline in the Stokes side and a slope in the anti-Stokes side. Analysis shows this asymmetry originates from the different scaling of anti-Stokes and Stokes scattering with respect to the Bose−Einstein distribution. Such asymmetry is readily visible, under room temperature, in the low-frequency THz spectral range. Accounting for this spectral intensity asymmetry reveals the intrinsic continuum background of electronic origin, differing from local normal modes and collective relaxational motions. We also describe a numerical method, independent …

Language And Social Justice In Us Climate Movements: Barriers And Ways Forward, Julia Coombs Fine

Environmental Studies Faculty Publications

Climate movements increasingly conceptualize the climate crisis as an issue of social injustice, both in terms of its root causes and its present and future effects. Climate justice calls for participatory decision-making within climate movements, which, as communication scholars have pointed out, necessitates inclusive and accessible communicative practices. Within sociocultural linguistics, a growing body of research has explored sociolinguistic justice, or marginalized groups' struggle for self-determined language use. This analysis interweaves these two research areas, applying the theory of sociolinguistic justice to climate communication in organizing contexts. Drawing on 67 semi-structured interviews and 112 online surveys with climate activists from …

Vortex Sheet Sensitivity To Low-Level Vertical Shear And Airmass Temperature Perturbation, Adam L. Houston, George L. Limpert

Department of Earth and Atmospheric Sciences: Faculty Publications

A theoretical, numerical-modeling-based examination of the sensitivity of vortex sheets along airmass boundaries to the following three characteristics is presented: 1) boundary-normal component of the vertical wind shear, 2) boundary-parallel component of the vertical wind shear, and 3) temperature perturbation within the parent air mass of the boundary. The overall aim of this work is to advance understanding of the sensitivity of micro-α- tomeso-γ-scale vortex generation along airmass boundaries to the ambient environment. Density currents are simulated in a 2D domain that does not allow baroclinic generation of near-surface vertical vorticity (ζ_ns) with parameterized latent heating for convection …

First Search For Exclusive Diphoton Production At High Mass With Tagged Protons In Proton-Proton Collisions At √S =13 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

A search for exclusive two-photon production via photon exchange in proton-proton collisions, pp → pγγp with intact protons, is presented. The data correspond to an integrated luminosity of 9.4 fb⁻¹ collected in 2016 using the CMS and TOTEM detectors at a center-of-mass energy of 13 TeVat the LHC. Events are selected with a diphoton invariant mass above 350 GeVand with both protons intact in the final state, to reduce backgrounds from strong interactions. The events of interest are those where the invariant mass and rapidity calculated from the momentum losses of the forward-moving protons match the mass and rapidity …

Ultrasmall Nanodiamonds: Perspectives And Questions, Shery L.Y. Chang, Philipp Reineck, Anke Krueger, Vadym Mochalin

Chemistry Faculty Research & Creative Works

Nanodiamonds are at the heart of a plethora of emerging applications in areas ranging from nanocomposites and tribology to nanomedicine and quantum sensing. The development of alternative synthesis methods, a better understanding, and the availability of ultrasmall nanodiamonds of less than 3 nm size with a precisely engineered composition, including the particle surface and atomic defects in the diamond crystal lattice, would mark a leap forward for many existing and future applications. Yet today, we are unable to accurately control nanodiamond composition at the atomic scale, nor can we reliably create and isolate particles in this size range. In this …

Development Of Electrochemical Aptamer-Based Sensors For Sensitive And Specific Detection Of Small-Molecule Targets, Yingzhu Liu

FIU Electronic Theses and Dissertations

Electrochemical aptamer-based (E-AB) sensors have been applied for diverse applications such as forensic science, pharmaceutical diagnostics, food safety, environmental monitoring, and personal medical care due to their rapid, accurate, and specific detection of analytes in complex samples. However, limited sensitivity and a lack of portable devices for point-of-care applications have greatly hindered the maturation of E-AB sensors from proof-of-concept designs to commercial systems. This dissertation describes several novel strategies to improve the sensitivities of E-AB sensors and fabricate portable paper-based devices to remedy these problems. We first detail the development of a novel approach to utilize a defined mixture of …

Synthesis, Structure, Growth Mechanism, And Physical Properties Of Transition Metal Sulfide Nanowire Filled Carbon Nanotubes And Carbon Nanoparticles, Yuba R. Poudel

FIU Electronic Theses and Dissertations

Filled carbon nanotubes (CNTs) exhibit unique physical properties due to the synergistic effects between the host CNTs and guest fillers making them attractive for several applications such as energy storage, microwave absorption, sensing applications, and drug delivery, etc. To date, a heterogeneity of inorganic and organic materials has been successfully filled inside the CNT cores and enormous effort has been spent on studying their fundamental electrical, magnetic, electromagnetic, optical, and electrochemical properties. However, the filling of CNTs with transition metal sulfide nanowires has been barely achieved and thus their fundamental properties are still unclear.

In this study, nickel sulfide nanowires …

Boundary Behavior Of Analytic Functions And Approximation Theory, Spyros Pasias

USF Tampa Graduate Theses and Dissertations

In this Thesis we deal with problems regarding boundary behavior of analytic functions and approximation theory. We will begin by characterizing the set in which Blaschke products fail to have radial limits but have unrestricted limits on its complement. We will then proceed and solve several cases of an open problem posed in \cite{Da}. The goal of the problem is to unify two known theorems to create a stronger theorem; in particular we want to find necessary and sufficient conditions on sets $E_1\subset E_2$ of the unit circle such that there exists a bounded analytic function that fails to have …

Time-Varying Resonant Mass At Collider And Beam Dump Experiments, Jinhui Guo, Yuxuan He, Jia Liu, Xiao-Ping Wang, Ke-Pan Xie

Department of Physics and Astronomy: Faculty Publications

A new particle usually manifests itself as a single resonant peak located at its mass. We propose if the new particle mass is time-varying due to environmental effects, then its mass spectrum typically has a novel double-peak feature. A representative model is the kinetic mixing dark photon interacting with an ultralight complex scalar dark matter charged under U(1)'. We reanalyze the existing experiments, showing the constraints on such a model are drastically weakened than those on the traditional single-peak resonance model, due to the reduction of the luminosity exposure in each resonant mass bin. Consequently, for mass around tens …

Multiple Solar Receivers Arrangement For High-Temperature Power Generation And Applications, Diego Jesus Guillen Perez

USF Tampa Graduate Theses and Dissertations

This dissertation presents an investigation of the specification and operation of multiple central solar receivers (CSR) sharing a heliostat field and an analysis of the receiver's thermal performance. A heliostat field was modeled in which different parts of the field aimed at different external or cavity receivers located on the same tower. Optical and thermal performance are analyzed, including the receivers' heat flux, solar thermal efficiency, and annual energy output. Some of the contributions of this research are:

1. Propose a novel configuration for a CSP power generation system using two receivers in a single central tower suitable …

Explainable And Cooperative Autonomy Across Networks Of Distributed Systems, Peter Joseph Jorgensen

USF Tampa Graduate Theses and Dissertations

Large networks of complex systems-of-systems are commonplace and evermore present in both mundane and extraordinary facets of human existence. From the exponential growth of connectivity via the internet and other information networks, to the miniaturization of computers and sensors, to cross-domain sensor and communication networks, these networks of distributed systems-of-systems (NDSS) present incredible benefits and challenges. Autonomy is perhaps the most important and most difficult to achieve enabling technology for efficient performance of the NDSS. Giving each individual agent in a network the ability to manage its internal state in dynamic operating environments and in pursuit of multiple complex and …

Exonuclease Digestion Assay For Streamlining Aptamer Characterization, Engineering, And Sensor Development, Juan Canoura

FIU Electronic Theses and Dissertations

Aptamers are DNA or RNA oligonucleotide-based bioreceptors isolated in vitro through the Systematic Evolution of Ligands by Exponential Enrichment. Given the ease with which a selection can be customized, aptamers can be evolved to function in nearly any chemical environment, making them tailormade for their final application. However, the post-SELEX characterization of the 100-1000’s aptamer candidates remains a significant bottleneck as there are no suitable techniques for high-throughput characterization of each candidate’s affinity/specificity. Moreover, the final aptamer must be engineered to possess signal reporting functionality; this is often done via trail-and-error truncation to yield a structure-switching aptamer. This dissertation describes …

Application Of Numerical Simulation Method In Periodic Pulse Reverse Electroplating Through Hole, Yuan-Hang Zhang, Mao-Zhong An, Pei-Xia Yang, Jin-Qiu Zhang

Journal of Electrochemistry

The upgrade of the fifth generation (5G) communication technology increases the number of communication backplane layers and the aspect ratio of through holes on the board, making it more difficult to use traditional direct current deposition for interconnection. Direct current electrodeposition is more prone to uneven coating in the hole, resulting in poor contact between the coating and components, and open circuit. This has a serious impact on the stability of printed circuit board. The periodic pulse reverse plating method can significantly improve the uniformity of high aspect ratio through-hole plating and improve the production quality of through-hole plating through …

An Investigation On The Interface Corrosion Behaviors Of Cobalt Interconnects In Chemical Mechanical Polishing Slurry, Kai-Xuan Qin, Peng-Fei Chang, Yu-Lin Huang, Ming Li, Tao Hang

Journal of Electrochemistry

Cobalt is widely regarded as the most promising interconnect material for 10 nm node and beyond. The development of a chemical mechanical planarization (CMP) slurry suitable for cobalt interconnect is a critical component for the application of cobalt interconnect. During CMP process of the interconnect layer, the achievement of high-quality surface after planarization is greatly challenged by the metal corrosion in CMP slurry. In this contribution, the corrosion behavior of cobalt in a slurry with potassium persulfate (KPS) as an oxidizer, glycine as a complexing agent, and benzotriazole (BTA) as an inhibitor was investigated. Static erosion rates (SER) of cobalt …

Influences Of Suppressing Additive Malachite Green On Superconformal Cobalt Filling And Nucleation, Xiao-Chuan Ma, Ya-Qiang Li, Pei-Xia Yang, Jin-Qiu Zhang, Mao-Zhong An

Journal of Electrochemistry

As the semiconductor integrated circuits evolve into 7 nm technology and beyond, the resistance of the Cu filling at back-end-of-line interconnects no longer linearly scales with dimension. The metal Co with lower mean free path can be used to replace Cu for reducing the line resistance caused by the scattering on the outer surface and grain boundary in the smaller and smaller size. In this study, CoSO₄ was used as the main salt, boric acid as a buffer and malachite green (MG) as an inhibitor for further research. According to the electrochemical cyclic voltammetric (CV) curves by using a …

Study On Low Voltage Electrodeposition Of Diamond-Like Carbon Film, Li Wang, Min-Xian Wu, Jun Li, Yan-Li Chen, Wen-Chang Wang, Zhi-Dong Chen

Journal of Electrochemistry

Diamond-like carbon (DLC) films are receiving a lot of attention from the scientific community, thanks to the promise of DLC films for applications in microelectronics and optoelectronics. Usually, electrodeposition is the preferred common technique because of low cost, large deposition area and simplicity of the setup. However, when carbon films are electrodeposited on a stainless steel, high cell voltages (≥1000 V) are required owing to the low electric conductivity of the organic solvents. This work has developed a new electrolyte system that could achieve carbon deposition on a stainless steel under a low applied cell voltage. The DLC films were …

Study On Weak Alkaline Cyanide-Free Silver Plating Process For Etching Lead Frame, Jian-Wei Zhao, Hai-Feng Zhu, Xiao-Hui Yu, Gui-Yun Yuan, Zhi Sun

Journal of Electrochemistry

As a new development direction of integrated circuit chip carrier, etched lead frame has been gradually applied in microelectronics industry in recent years. Since the preparation of the etched lead frame requires the use of multiple layers of non-alkali-resistant photoresist films with specific patterns, and the traditional cyanide silver plating is unable to meet this requirement, making that the development of weakly alkaline cyanide free silver plating process has great significance. In this paper, a weak alkaline silver plating process based on 5,5-dimethylhydantoin (DMH) cyanide-free silver plating system was studied. The electrodeposition behavior of the system and the nucleation mechanism …

Electrochemical Sers Study Of Benzotriazole And 3-Mercapto-1-Propanesulfonate In Acidic Solution On Copper Electrode, Yin-Fei Shen, Yan-Li Chen, Sheng-Xu Wang, Ye Zhu, Wen-Chang Wang, Min-Xian Wu, Zhi-Dong Chen

Journal of Electrochemistry

Since the development of acid copper plating technology, the role of additives is indispensable. In addition to the main salt copper sulfate and supporting electrolyte sulfuric acid, suppressors, accelerators, levelers and chlorine ions (Cl^-) are also required to be added into the plating solution. Appropriate additive system can have a significant impact on the coating or the plating solution, which can help improve the quality of the coating and increase the brightness of the coating. Through electrochemical measurement, vibrational spectroscopy, scanning probe microscopy, molecular dynamics simulation and other methods, researches have a deeper understanding in the adsorption configuration …

Study On The Effect Of Additives In The Electrodeposition Of Sn-Ag-Cu Ternary Alloy Solder, Hua Miao, Ming-Rui Li, Wen-Zhong Zou, Guo-Yun Zhou, Shou-Xu Wang, Xiao-Jing Ye, Kai Zhu

Journal of Electrochemistry

Sn-Ag-Cu ternary alloy is the most ideal substitute for Sn-Pb alloy at present, and can be prepared by electrodeposition with high production efficiency, simple equipment, easy maintenance and excellent coating performance. The coordination system of the electroplating solution was investigated through the Hull cell experiment. The type of brighteners used in the plating solution and the ratio of the two brighteners were determined through the microscopic morphologic characterization, electrochemical corrosion test and cathodic polarization curve test. In addition, the dispersant and stabilizer were studied by observing the microscopic morphology and measuring the concentration change of Sn²⁺ ions in the …

Development Status Of Copper Electroplating Filling Technology In Through Glass Via For 3d Interconnections, Zhi-Jing Ji, Hui-Qin Ling, Pei-Lin Wu, Rui-Yi Yu, Da-Quan Yu, Ming Li

Journal of Electrochemistry

With the slow development of Moore's Law, the high density and miniaturization of microelectronic devices put forward higher requirements for advanced packaging technology. As a key technology in 2.5D/3D packaging, interposer technology has been extensively studied. According to different interposer materials, it is mainly divided into organic interposer, silicon interposer and glass interposer. Compared with the through silicon via (TSV) interconnection, the through glass via (TGV) interposer has received extensive attention in the 2.5D/3D advanced packaging field for its advantages of excellent high-frequency electrical characteristics, simple process, low cost, and adjustable coefficient of thermal expansion (CTE). However, the thermal conductivity …

Research Progresses Of Cobalt Interconnect And Superfilling By Electroplating In Chips, Li-Jun Wei, Zi-Han Zhou, Yun-Wen Wu, Ming Li, Su Wang

Journal of Electrochemistry

Copper interconnect using dual damascene technology has always been the main means for metallization in the back end of line process. However, with the size effect becoming more and more obvious due to feature size reduction, copper interconnect can no longer meet the demand for high circuit speed in Post-Moore era. Following copper interconnection, cobalt interconnection in chips attracts much attention as an interconnect technology by the next generation, which has been introduced in 7 nm node of integrated circuit manufacturing and below. The electron mean free path of cobalt (~10 nm) is much shorter than copper’s (39 nm), thus …

Microstructure Of Electrodeposited Copper Foil: Discussion On The Mechanism Model Of Three-Dimensional Electrocrystallization, Ren-Zhi Liu, Ping-Ling Xie, Chong Wang

Journal of Electrochemistry

The manufacturing of electrolytic copper foil has attracted more and more attention with the extensive applications of printed circuit board and lithium battery. The industrial scale is still extending. Compared with the developments of electroplating equipment and electroplating process, there is limited research on the mechanism of electrodeposition. This paper summarizes the manufacturing process of electrodeposited copper foil and analyzes the differences of various electroplating parameters in different electrodeposited copper technologies, and points out the important role of electrodeposition current density in the formation of copper foil. By showing and comparing the microstructures of different electrodeposited copper foils, the influences …

Introduction Of Development And Application Technology Of Organic Additives For Acid Copper Electroplating, Hao-Bin Zou, Chao-Li Tan, Wei Xiong, Dao-Lin Xi, Bin-Yun Liu

Journal of Electrochemistry

Acid copper electroplating is one of the key technologies in buildup multilayer PCB (BUM-PCB) manufacture process and the most important technique to achieve electrical interconnection between any layer and high-density interconnection in a substrate. This article introduces the research focus of organic additives used in acid copper electroplating, and developing different kinds of micro-via filling copper electroplating technique applied in various scenarios, and some other technical problems from applications. First of all, according to the chronopotentiometric (CP) experiment results, the levelers with different polymeric molecular structures exhibited various responses of cupric deposition potential along with their increased concentrations, which is …

Optimization Of Pulse Plating Additives And Plating Parameters For High Aspect Ratio Through Holes, Kai Yang, Ji-Da Chen, Shi-Jin Chen, Wei-Lian Xu, Mao-Gui Guo, Jin-Chao Liao, Zeng-Kun Wu

Journal of Electrochemistry

As an important component in electronic products, printed circuit board (PCB) plays a supporting and interconnecting role for the electronic components in it. With the development of communication technology, electronic products are developing in the direction of “thin, light and small”, and high density interconnection (HDI) comes into being. Due to the high-density interconnection characteristics of HDI boards, the thickness of the board is increasing. At the same time, in order to reserve space for the laying of fine lines on the subsequent board surface, the diameter of the through holes on the board is also decreasing, so the depth-diameter …

Effect Of Sodium Alcohol Thiyl Propane Sulfonate On Electrolysis Of High Performance Copper Foil For Lithium Ion Batteries, Sen Yang, Wen-Chang Wang, Ran Zhang, Shui-Ping Qin, Min-Xian Wu, Naotoshi Mitsuzaki, Zhi-Dong Chen

Journal of Electrochemistry

Electrolytic copper foils have been widely used in printed circuit boards and lithium-ion batteries due to their simple production process and high economic value. In the process of electrolysis foil making, additives can greatly improve the performance of electrolytic copper foils. In this work, the copper foils were prepared in a self-designed plate electrodeposition device of which the operating principles were in accordance with those of actual industrial production. A series of the Virgin Make-up Solution (VMS: 312.5 g·L^-1 CuSO₄·5H₂O, 100 g·L^-1 H₂SO₄, 50 mg·L^-1 Cl^-) containing …

Heat Flow In Terrestrial-Type Bodies From High P,T Electrical Resistivity Measurements Of Au, Fe-Si And Fe-Ni-Si Solid And Liquid Alloys, Meryem Berrada

Electronic Thesis and Dissertation Repository

The source of the fluid stirring mechanism that powers the dynamo of terrestrial-type bodies during their active magnetic field era is debated. Prior to the formation of a solid inner core, thermal convection may cause enough mechanical stirring of the core fluid to generate a magnetic field through dynamo action. After inner core formation, compositional convection in the liquid outer core becomes the main source of fluid stirring mechanism to power a dynamo. Constraints on the likelihood and duration of these convection mechanisms may be obtained by the experimental determination of the thermal properties of core materials. These cores consist …

Online Privacy Challenges And Their Forensic Solutions, Bandr Fakiha

Journal of the Arab American University مجلة الجامعة العربية الامريكية للبحوث

In the digital age, internet users are exposed to privacy issues online. Few rarely know when someone else is eavesdropping or about to scam them. Companies, governments, and individual internet users are all vulnerable to security breaches due to the challenges of online privacy ranging from trust and hierarchical control to financial losses. As systems advance, people are optimistic that forensic science will provide long-term interventions that surpass the current solutions, including setting stronger passwords and firewall protection. The future of online privacy is changing, and more practical interventions, such as email, malware, mobile, and network forensics, must be integrated, …