Digital Commons Network^™

Model To Demonstrate Effects Of Mass Transfer And Applied Current In An Electrolytic Cell, George Ankrah

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

This study investigates the relationship between applied current and resulting cell potential in an electrolytic system, considering the transport of electroactive species. By applying Michael Faraday's laws of electrolysis and the Nernst-Planck equation, the behavior of electroactive species in diffusion-controlled systems with and without stirring is modeled. The plots demonstrate how stirring enhances ion transport and establishes a stable Nernst diffusion layer, affecting the kinetics of electrochemical reactions. Understanding these dynamics is crucial for optimizing electrolysis processes.

Results Of Experimental Study Of Solar Collector Efficiency, Shakhnoza Sultanova, Ajargul Mambetsheripova, Jasur Safarov

Chemical Technology, Control and Management

The article considers the influence of ambient temperature on the drying efficiency depending on the incident solar radiation, changes in the average temperature of the absorber plate depending on the absorbed power, as well as the thermal efficiency of the collector at significant values of coolant flow.

Analysis Of State Climate Action Plans: What Influences States To Adopt, Ethan Yaroch

Honors Theses

Federal-level policies aimed to address and mitigate the effects that will arise from climate change have become an extremely polarizing issue in the United States. Given this policy stalemate, individual states have stepped up to address the national-level shortcomings by publishing state-level Climate Action Plans (CAPs). CAPs mainly consist of emissions mitigation goals and other non-binding policy initiatives that provide a basis for future compulsory legislation. This paper examines whether party identification in the state legislature, public opinion, susceptibility to the risks associated with climate change, and proximity to neighboring states with published CAPs influence states to adopt CAPs. Employing …

Technology And The Global Economy, Jonathan Eaton, Samuel Kortum

Cowles Foundation Discussion Papers

Interpreting individual heterogeneity in terms of probability theory has proved powerful in connecting behaviour at the individual and aggregate levels. Returning to Ricardo's focus on comparative efficiency as a basis for international trade, much recent quantitative equilibrium modeling of the global economy builds on particular probabilistic assumptions about technology. We review these assumptions and how they deliver a unified framework underlying a wide range of static and dynamic equilibrium models.

Utilization Of Caputo Fractional Derivative In Mhd Nanofluid Flow With Soret And Thermal Radiation Effects, Harshad Patel, Gopal Nanda

Applications and Applied Mathematics: An International Journal (AAM)

In existence of heat diffusion and thermal radiation, an analytical equation is found for unsteady MHD flow past an exponentially accelerating vertical plate in optically thick water based nanofluid. The governing equations are made dimensionless by similarity transformation. A definition of Caputo fractional derivative is applied to generalize governing system of partial differential equations. Laplace transform techniques are applied and obtained the analytical solutions of proposed problems. For a physical point of view, numerical results are obtained using MATLAB software and presented via graphs. From the results, it is concluded that magnetic fields tend to reduce velocity. It is also …

Mathematical Modeling Of Fruit Drying And System Analysis Of The Process (On The Example Of Persimmon), Gani Dadayev, Jasur Safarov, Shakhnoza Sultanova, Qobiljon Muxiddinov

Technical science and innovation

Vegetable raw materials, as an object of drying, are characterized by a large amount of water and a low content of dry substances. Vegetable raw materials have a capillary-porous structure. Food products contain both bound and free moisture at the same time. The removal of moisture from the material during drying depends on the total moisture content and the form of connection of moisture with the material. Adsorption and osmotic - bound moisture is retained at the interface of colloidal particles with the environment. Food products contain both bound and free moisture at the same time. The quantitative ratio between …

Improvement Of Convective Drying Equipment, A Ponasenko, Jasur Safarov, Shaxnoza Sultanova

Technical science and innovation

Drying of agricultural raw materials is an energy-consuming but integral process. Therefore, increasing the efficiency of drying and improving the quality indicators of dried material at minimum material and energy costs is relevant for producers of agricultural products. By present time numerous researches on improvement of constructions and processes of work of dryers providing satisfactory parameters of energy saving have been carried out. In some scientific materials it is shown that the use of generative gas and straw as fuel allows to reduce energy costs for the drying process in the fluidised bed dryer by 10-30%, the quality of seeds …

Mtse 655 - 102: Difussion And Solid State Kinetics, Andres Jerez

Physics Syllabi

No abstract provided.

Essays On International Trade And Economic Growth, Mateo Hoyos

Doctoral Dissertations

In this dissertation I study the relationship between trade and economic growth, with a focus on developing economies. I specifically provide a critical review of the consensus view in trade and growth, according to which a liberal trade regime is generally the best policy stance to promote growth. In the first essay of this dissertation, I provide evidence that the relationship between trade policy and growth may depend on economic structure: tariff reductions are followed by higher levels of GDP per capita for manufacturer countries, but lower levels for nonmanufacturers. Testing for mechanisms, I find the heterogeneity seems to be …

Characterization Analysis And Design Of Mid-Wave Infrared Iii- V-Based Type-Ii Superlattice Nbn Photodetectors For Space Applications, Alexander Timothy Newell

Electrical and Computer Engineering ETDs

The performance of the mid-wave infrared InGaAs/InAsSb nBn photodetector is investigated and its viability for space applications is assessed. Three structures are grown with unique absorber layer doping profiles via molecular beam epitaxy. Material and device characterizations are performed and analyzed to determine the effects of doping on fundamental material parameters and detector performance. Noise-equivalent irradiance is calculated to be a factor of 4x that of an ideal detector exhibiting Rule 07 dark current and 100% quantum efficiency, demonstrating high sensitivity. The structures are then irradiated with 63 MeV protons to evaluate the extent of performance degradation over the course …

Understanding The Contribution Of Recommendation Algorithms On Misinformation Recommendation And Misinformation Dissemination On Social Networks, Royal Pathak, Francesca Spezzano, Maria Soledad Pera

Computer Science Faculty Publications and Presentations

Social networks are a platform for individuals and organizations to connect with each other and inform, advertise, spread ideas, and ultimately influence opinions. These platforms have been known to propel misinformation. We argue that this could be compounded by the recommender algorithms that these platforms use to suggest items potentially of interest to their users, given the known biases and filter bubbles issues affecting recommender systems. While much has been studied about misinformation on social networks, the potential exacerbation that could result from recommender algorithms in this environment is in its infancy. In this manuscript, we present the result of …

Deploying Business Ecosystems To Cope With Ecological Transformation, Arnoud Cyriel Leo De Meyer

Research Collection Lee Kong Chian School Of Business

At a time when businesses must innovate quickly and in support of sustainability, "going it alone" is no longer the most effective or efficient model. Business ecosystems – networks of companies, researchers and other stakeholders each involved in a given value chain – offer an effective route to companies seeking not only to find new advantages, but to drive wider systemic change. When innovation takes place through ecosystems, often, the results are faster to diffuse through an industry or value chain. To address needs of the ecological transformation like the transition to clean fuels, this is exactly what is needed; …

Universal Aspects Of Barrier Crossing Under Bias, Sudeep Adhikari, Kevin S. D. Beach

Faculty and Student Publications

The thermal activation process by which a system passes from one local energy minimum to another is a recurring motif in physics, chemistry, and biology. For instance, biopolymer chains are typically modeled in terms of energy landscapes, with folded and unfolded conformations represented by two distinct wells separated by a barrier. The rate of transfer between wells depends primarily on the height of the barrier, but it also depends on the details of the shape of the landscape along the trajectory. We consider the case of bias due to an external force, analogous to the pulling force applied in optical …

Widespread Dominance Of Methane Ebullition Over Diffusion In Freshwater Aquaculture Ponds, Renske J. E. Vroom, Sarian Kosten, Rafael M. Almeida, Raquel Mendonça, Ive S. Muzitano, Icaro Barbosa, Jonas Nasário, Ernandes S. Oliveira Junior, Alexander S. Flecker, Nathan Barros

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

An ever-increasing demand for protein-rich food sources combined with dwindling wild fish stocks has caused the aquaculture sector to boom in the last two decades. Although fishponds are potentially strong emitters of the greenhouse gas methane (CH₄), little is known about the magnitude, pathways, and drivers of these emissions. We measured diffusive CH₄ emissions at the margin and in the center of 52 freshwater fishponds in Brazil. In a subset of ponds (n = 31) we additionally quantified ebullitive CH₄ fluxes and sampled water and sediment for biogeochemical analyses. Sediments (n = 20) were …

Nonsolvent-Induced Phase Separation Inside Liquid Droplets, Rami Alhasan, Tanner A. Wilcoxson, Dakota S. Banks, Sion Jung, Douglas R. Tree

Faculty Publications

Nonsolvent-induced phase separation (NIPS) is a popular method for creating polymeric particles with internal microstructure, but many fundamental questions remain surrounding the kinetics of the complex coupled mass transfer and phase separation processes. In this work, we use simulations of a phase-field model to examine how (i) finite domain boundaries of a polymer droplet and (ii) solvent/nonsolvent miscibility affect the NIPS process. To isolate the effects of phase separation kinetics and solvent/nonsolvent mass transfer on the NIPS process, we study two different cases. First, we investigate droplet concentrations that originate inside the two-phase region, where phase separation kinetics alone governs …

Ergodic Characterization Of Nonergodic Anomalous Diffusion Processes, Madhur Mangalam, Ralf Metzler, Damian G. Kelty-Stephen

Journal Articles

Anomalous diffusion in various complex systems abounds in nature and spans multiple space and time scales. Canonical characterization techniques that rely upon mean squared displacement break down for nonergodic processes, making it challenging to characterize anomalous diffusion from an individual time-series measurement. Nonergodicity reigns when the time-averaged mean square displacement differs from the ensemble-averaged mean squared displacement even in the limit of long measurement series. In these cases, the typical theoretical results for ensemble averages cannot be used to understand and interpret data acquired from time averages. The difficulty then lies in obtaining statistical descriptors of the measured diffusion process …

Lateralizing Ability Of Magnetic Resonance Spectroscopy And Diffusion Tensor Imaging In Temporal Lobe Epilepsy, Rasha Ali El-Kapany, Ibrahim Al-Sayed Al-Ahmar, Mona Sabry Elkholy, Rasha Abdelhafiz Aly, Ahmed Ali Saad Ali Hassan

Menoufia Medical Journal

Background: Temporal lobe epilepsy (TLE) is the most common type of intractable and partial epilepsies. The only standard treatment for seizure-free status with manifest TLE is surgical which includes amygdala-hippocampectomy. The majority of temporal lobe seizures originate in the mesial temporal structures, primarily in the hippocampus, para hippocampal gyrus and amygdala.

Objectives: To compare lateralizing ability of Magnetic resonance spectroscopy and Diffusion tensor imaging in patients with temporal lobe epilepsy.

Methods: The study recruited 50 participant assigned into two groups: the first group included 25 epileptic cases and the second group included 25normal controls. Age showed a mean ± SD …

Measuring Diffusion Through Carbon Nanotube Arrays With Fluorescent Spectroscopy, Michael Machold

Theses

Carbon nanotube (CNT) arrays are emerging as versatile nanostructures that can be used in many applications including gene transfection technology. To understand the transport of molecules through an array of CNTs, diffusion of molecules was studied experimentally and analytically. A procedure using fluorescent spectroscopy was developed to measure the concentration change of fluorescein salt in a two-reservoir system separated by a CNT array. Experiments were conducted to measure how changing the initial concentration gradient and reservoir volume size impacted the diffusivity of the system. For 2 mL reservoirs, diffusivities were measured between 2.56*10^(-11) m^2/s and 3.51*10^(-11) m^2/s. Diffusivities were measured …

Thermal And Electrical Properties Of Nanocrystalline Superionic Naxcu1.75s (X=0.1, 0.15, 0.2, 25) Compounds, M.M. Kubenova, K.A. Kuterbekov, M.Kh. Balapanov, R.Kh. Ishembetov, B.M. Akhmetgaliev, A.M. Kabyshev, K.Zh. Bekmyrza, M.Kh. Zeleev, R.Sh. Palymbetov, B.U. Baikhozhaeva

Eurasian Journal of Physics and Functional Materials

The paper presents the results of the studies of thermal properties of nanocrystalline superionic Na_xCu_1.75S (x = 0.1, 0.15, 0.2, 25) compositions, and preliminary results of Na_0.1Cu_1.75S using as energy stored cathode material in Na-ion half-cell with NaPF₆ electrolyte and Na anode. The compositions contain a few copper sulfide phases: monoclinic chalcocite Cu₂S, orthorhombic anilite Cu_1.75S, triclinic roxbyite Cu_1.74÷1.82S, also the compositions can contain monoclinic Na₂Cu₄S₃, orthorhombic Na₂S, cubic Cu₂O as inclusion phases. The sizes …

Estimation Of Free Water-Corrected Microscopic Fractional Anisotropy., Nico J J Arezza, Tales Santini, Mohammad Omer, Corey A Baron

Medical Biophysics Publications

Water diffusion anisotropy MRI is sensitive to microstructural changes in the brain that are hallmarks of various neurological conditions. However, conventional metrics like fractional anisotropy are confounded by neuron fiber orientation dispersion, and the relatively low resolution of diffusion-weighted MRI gives rise to significant free water partial volume effects in many brain regions that are adjacent to cerebrospinal fluid. Microscopic fractional anisotropy is a recent metric that can report water diffusion anisotropy independent of neuron fiber orientation dispersion but is still susceptible to free water contamination. In this paper, we present a free water elimination (FWE) technique to estimate microscopic …

Hovering Potato ~ Activity Plan, Admin Stem For Success

STEM for Success Showcase

This experiment is a great example of chemistry. This experiment relies heavily on density and diffusion.

• Water is less dense than half of a potato. Therefore, the potato sinks.

• Sugar water is more dense than half of a potato. Therefore, the potato floats.

By slowly adding water to sugar water, two layers are formed which allows the potato to hover in between. Slowly adding the water allows for diffusion to occur at a minimum.

Experimental Determination Of Zinc, Potassium And Rubidium Diffusion Coefficients In Olivine, Christopher J. Willingham

MSU Graduate Theses

One of NASA’s key strategies is to learn more about the early solar system and its formation. Chondrites were formed from the most primitive materials at the collapse of the solar system and over time have been classified into different categories based on their elemental abundance. These chondrites have fallen to Earth and have even formed entities such as asteroids and planetary bodies. It has been found through studies that one of these chondrites is close to the elemental abundance of the Sun. The other types of chondrites were up to two orders of magnitude less in concentration …

Modeling Vascular Diffusion Of Oxygen In Breast Cancer, Tina Giorgadze

Senior Projects Spring 2023

Oxygen is a vital nutrient necessary for tumor cells to survive and proliferate. Oxygen is diffused from our blood vessels into the tissue, where it is consumed by our cells. This process can be modeled by partial differential equations with sinks and sources. This project focuses on adding an oxygen diffusion module to an existing 3D agent-based model of breast cancer developed in Dr. Norton’s lab. The mathematical diffusion module added to an existing agent-based model (ABM) includes deriving the 1-dimensional and multi-dimensional diffusion equations, implementing 2D and 3D oxygen diffusion models into the ABM, and numerically evaluating those equations …

Effects Of Confinement On Ionic Liquids And Deep Eutectic Solvents For The Design Of Catalytic Systems, Electrochemical Devices, And Separations, Andrew Drake

Theses and Dissertations--Chemical and Materials Engineering

Confinement of ionic liquids (ILs) and deep eutectic solvents (DESs) within mesoporous materials such as silica helps to control the local environment within the pores for applications such as catalysis, electrochemistry, and absorption. Silica thin films with 2.5 and 8 nm pores and micron-sized silica particles with pore diameters of 5.4 and 9 nm were synthesized to study the effect of nanoconfinement on ILs 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]), 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), and DESs reline and ethaline (choline chloride and urea or ethylene glycol). Silica thin films with vertically aligned, well ordered, and accessible pores were synthesized via the evaporation-induced …

Simulation Of Coherent Remission In Planar Disordered Medium, Pablo Jara-Palacios, Ho Chun Lin, Chia Wei Hsu, Hui Cao, Alexey Yamilov

Physics Faculty Research & Creative Works

Waves remitted from a scattering medium carry information that can be used for non-invasive imaging and sensing. Such techniques are usually limited by a low photon budget. Recent progress in optical wavefront shaping has enabled coherent control with an order-of-magnitude enhancement of remission [1]. This experimental study necessitated increasingly demanding numerical simulations. Extending this line of research requires more sophisticated computational techniques capable of simulating multiple instances of even larger systems. Here, we demonstrate that remission geometry can be efficiently simulated using a novel open-source software package [2] Maxwell's Equations Solver with Thousands of Inputs (MESTI). To verify its numerical …

A Fully Coupled Implementation Approach To Study Hydrogen Embrittlement In Metals Using Finite Element Analysis, Sofia Yassir

Theses and Dissertations

Diverse hypotheses are behind the strength degradation in metals due to hydrogen diffusion, leading to a severe, sudden failure. These diverse hypotheses of hydrogen embrittlement include various mechanisms that are responsible for the embrittlement of metals due to hydrogen exposure in their microstructures. This research study focuses on one hydrogen embrittlement mechanism: Hydrogen-Enhanced-Localized-Plasticity (HELP). The HELP is the only single mechanism characterized by promoting localization of plastic flow ahead of the crack by increasing dislocation motion in that region. The current state of the art is a development of a numerical model representing a fully diffusion-mechanical coupled model. This fully …

Sustainable Material For Urea Delivery Based On Chitosan Cross-Linked By Glutaraldehyde Saturated Toluene: Characterization And Determination Of The Release Rate Mathematical Model, Jayanudin Jayanudin, Retno S. D. Lestari, Indar Kustiningsih, Dandi Irawanto, Rozak Rozak, Reyonaldo L. A. Wardana, Fakhri Muhammad

Karbala International Journal of Modern Science

The aims of this study were to characterize the urea-loaded chitosan microspheres and determine the release kinetic constants and diffusion coefficients. An emulsion cross-linking method was used to prepare the urea-loaded chitosan microspheres. Urea was dissolved in a solution of chitosan then put into vegetable oil and stirred to form an emulsion. Glutaraldehyde saturated toluene (GST) was added into the emulsion dropwise while continuously stirring for the solidification process. Chitosan microspheres filled with urea were washed, dried, and then analyzed. Characterization of the urea-loaded chitosan microspheres was conducted using a scanning electron microscope (SEM), Raman spectroscopy, X-ray diffraction, and particle …

Mocmin: Convex Inferring Of Modular Low-Rank Contact Networks Over Covid Diffusion Data, Emre Sefer

Turkish Journal of Electrical Engineering and Computer Sciences

SEIR (which consists of susceptible, exposed, infected, and recovered states) is a common diffusion model which could model different disease propagation dynamics across various domains such as influenza and COVID diffusion. As a motivation, across these domains, observing the node states is relatively easier than observing the network edges over which the diffusion is taking place, or it may not even be possible to observe the underlying network. This paper focuses on the problem of predicting modular low-rank human contact network edges only if a SEIR diffusion dynamics spreading among the human on their contact network can be observed. Such …

Is There A Strategic Organization In The Behavioral Theory Of The Firm? Looking Back And Looking Forward, Henrich R. Greve, Cyndi Man Zhang

Research Collection Lee Kong Chian School Of Business

In the 20 years of Strategic Organization, how well has knowledge drawn from the behavioral theory of the firm contributed to the field of strategy? We see progress both in the pages of SO! and elsewhere in the field of strategy, but this progress has been held back by divisions between strategy and organization theory in what theories should predict, what mechanisms are preferable predictors, and what outcomes are of interest. Despite these divisions, the last few years have seen particularly rapid progress, turning the behavioral theory of the firm into one of multiple organization theory sources of strategy knowledge. …

Fractional Order Study Of The Impact Of A Photo Thermal Wave On A Semiconducting Medium Under Magnetic Field And Thermoplastic Theories, Hanan S. Gafel

Information Sciences Letters

The study aims to estimate the extent to which the reflection wave is affected by the initial stress, magnetic field, and fractional parameter within a semiconductor photothermal diffusion medium when taking into account the Classical (CT) theory and the dual-phase-lag (DPL) theory. Its problem is defined in examining the generalized framework concerning plasma, thermoelastic waves under the thermomechanical responding of reflecting the photothermal diffusion for the semiconductor constituent. It applies the Maxwells equations while considering the absence of the medium of infinite conducting and displacement current. Moreover, it applies the boundary settings for the Maxwells and mechanical stress, diffusion, chemical …