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Full-Text Articles in Materials Science and Engineering

Effect Of Graphene Oxide On Spectral-Luminescenct Properties Of Xanthene Dye, E. V. Seliverstova, E. Zh. Alikhaidarova, N. Kh. Ibrayev Dec 2022

Effect Of Graphene Oxide On Spectral-Luminescenct Properties Of Xanthene Dye, E. V. Seliverstova, E. Zh. Alikhaidarova, N. Kh. Ibrayev

Eurasian Journal of Physics and Functional Materials

The effect of graphene oxide on the spectral and luminescent properties of xanthene dyes was studied. During the interaction of graphene oxide (GO) with a cationic dye, aggregation of Rhodamine 6G occurs, which is expressed as an increase in the optical density of the short-wavelength shoulder in the absorption spectrum of the dye. GO sheets can act as adsorption centers for dye molecules due to the influence of the Coulomb and intermolecular forces between GO and Rhodamine 6G. This effect is practically not pronounced for anionic dyes. The quenching of the dye fluorescence intensity in the presence of GO was …


Tunable Electronic Structure Via Dna-Templated Heteroaggregates Of Two Distinct Cyanine Dyes, Jonathan S. Huff, Matthew S. Barclay, Azhad U. Chowdhury, Lance K. Patten, Simon K. Roy, Aaron Sup, Austin Biaggne, Lan Li, Jeunghoon Lee, Paul H. Davis, Bernard Yurke, William B. Knowlton, Daniel B. Turner, Ryan D. Pensack Oct 2022

Tunable Electronic Structure Via Dna-Templated Heteroaggregates Of Two Distinct Cyanine Dyes, Jonathan S. Huff, Matthew S. Barclay, Azhad U. Chowdhury, Lance K. Patten, Simon K. Roy, Aaron Sup, Austin Biaggne, Lan Li, Jeunghoon Lee, Paul H. Davis, Bernard Yurke, William B. Knowlton, Daniel B. Turner, Ryan D. Pensack

Materials Science and Engineering Faculty Publications and Presentations

Molecular excitons are useful for applications in light harvesting, organic optoelectronics, and nanoscale computing. Electronic energy transfer (EET) is a process central to the function of devices based on molecular excitons. Achieving EET with a high quantum efficiency is a common obstacle to excitonic devices, often owing to the lack of donor and acceptor molecules that exhibit favorable spectral overlap. EET quantum efficiencies may be substantially improved through the use of heteroaggregates─aggregates of chemically distinct dyes─rather than individual dyes as energy relay units. However, controlling the assembly of heteroaggregates remains a significant challenge. Here, we use DNA Holliday junctions to …


Study Of The Thermodynamic Properties Absorbation Sulfur Storage Gas Of Zinc And Copper Industry, Berdiyarov Tilovkabulovich Berdiyarov Dr., Sh. T. Khojiev, S. T. Matkarimov, Sh. Munosibov Dec 2021

Study Of The Thermodynamic Properties Absorbation Sulfur Storage Gas Of Zinc And Copper Industry, Berdiyarov Tilovkabulovich Berdiyarov Dr., Sh. T. Khojiev, S. T. Matkarimov, Sh. Munosibov

Technical science and innovation

The article considers the problems of utilization of industrial gases formed in the production of copper and ore containing sulfur anhydrides. Currently, the composition of process gases entering the gas purification department is approximately 6-7% SO2, 0.2-0.3% SO3 and other gases, until sulfuric acid is obtained from these gases, the sulfate is treated in a counter-scheme with 8% sulfate acid. The aim is to first reduce the temperature of the exhaust gases and second to avoid flying components such as as As, F, Se. As a result of the studies, the amount of SO2 in the …


Moisture Characterization Of Thermoplastics And Thermosets For Use As Matrices In Fiber Reinforced Composites, Kieran Hook, Ray Hsu Jun 2019

Moisture Characterization Of Thermoplastics And Thermosets For Use As Matrices In Fiber Reinforced Composites, Kieran Hook, Ray Hsu

Materials Engineering

Epoxy matrix composites are widely used in aerospace industry for lighter aircraft while thermoplastic-matrix composites have traditionally been underutilized despite their excellent fracture resistance, impact strength, and the ability to be recycled. Toray Advanced Composites (Morgan Hill, CA) wants to investigate the structural integrity of thermoplastic matrices in common aircraft operating environments. An experiment was conducted to observe the effect of moisture absorption on thermoplastic composites’ mechanical strength. PEEK, PPS, and PEI matrices were compared to an epoxy matrix in this experiment. Samples were submerged in 160ºF distilled water to accelerate moisture absorption. For two months, the changes in mass …


Modeling The Peak Absorption Of Meh-Ppv In Various Solvents Using Density Functional Theory, Corell H. Moore Jan 2019

Modeling The Peak Absorption Of Meh-Ppv In Various Solvents Using Density Functional Theory, Corell H. Moore

Theses and Dissertations

Density Functional Theory (DFT) and time-dependent Density Functional Theory (TD-DFT) are powerful tools for modeling orbital energy in conjugated molecules and have been useful tools for research in organic photovoltaics. In this work, DFT is first used to explain the red shift in the absorption spectrum and increased absorption observed in MEH-PPV. Initially, the modeling of the red-shift in the absorption peak of MEH-PPV is studied using Gaussian 03 software with the global hybrid functional B3LYP for exchange-correlation and the 6-31G basis set. DFT and TD-DFT are used to separately study the effects of polymer chain length, carbon-carbon double-bond stretching, …


Transient Transmission Oscillations In Doped And Undoped Lithium Niobate Induced By Near-Infrared Femtosecond Pulses, Bryan J. Crossman, Gregory J. Taft Dec 2018

Transient Transmission Oscillations In Doped And Undoped Lithium Niobate Induced By Near-Infrared Femtosecond Pulses, Bryan J. Crossman, Gregory J. Taft

Physics Faculty Publications

Transient transmission oscillations in X-cut and Z-cut congruent, iron-doped, and magnesium-doped lithium niobate samples were measured using 50 fs, 800 nm, 0.5 nJ pulses from a self-mode-locked Ti:sapphire laser in an optical pump–probe system. Several Raman-active oscillation modes excited by these pulses were observed as changes in the transmitted probe intensity versus time delay between the pump and probe pulses. The samples were rotated to determine how the incident polarization of the pump pulses affects the mode excitations. The observed Raman-active oscillations correspond to previously reported symmetry modes measured with traditional, continuous-wave, Raman spectroscopy using the same scattering …


Decreasing Of The Concentration Quenching Of Fluorescent Dye In A Solution By Introducing It To Nanoparticles Of Silicon Dioxide, A. I. Mantel, A. E. Yensebayeva, S. B. Smatov, I. S. Irgibayeva Jun 2018

Decreasing Of The Concentration Quenching Of Fluorescent Dye In A Solution By Introducing It To Nanoparticles Of Silicon Dioxide, A. I. Mantel, A. E. Yensebayeva, S. B. Smatov, I. S. Irgibayeva

Eurasian Journal of Physics and Functional Materials

The technique of introduction a fluorescent dye Tris(bipyridine)ruthenium (II) chloride into nanoparticles of silicon dioxide in isopropyl alcohol was tested. The preparation of nanoparticles was carried out by means of the Stober method. The optimal reaction conditions were determined. It was found out that the penetration of a dye into silicon dioxide nanoparticles reduced the effect of concentration quenching of the dye and made it possible to achieve an increase in fluorescence intensity in the solution more than twofold. An attempt was made to functionalize the obtained particles by introducing amino groups onto the particle surface. Fused silver nanoparticles were …


Qualification Of Blue Laser Cutting Tool And Design Of Test Procedure For Determining Cutting Parameters, Gaia Righi Jun 2017

Qualification Of Blue Laser Cutting Tool And Design Of Test Procedure For Determining Cutting Parameters, Gaia Righi

Materials Engineering

No abstract provided.


Defect-Related Optical Absorption Bands In Cdsip2 Crystals, Elizabeth M. Scherrer, Brant T. Kananen, Eric M. Golden, F. Kenneth Hopkins, Kevin T. Zawilski, Peter G. Schunemann, Larry E. Halliburton, Nancy C. Giles Mar 2017

Defect-Related Optical Absorption Bands In Cdsip2 Crystals, Elizabeth M. Scherrer, Brant T. Kananen, Eric M. Golden, F. Kenneth Hopkins, Kevin T. Zawilski, Peter G. Schunemann, Larry E. Halliburton, Nancy C. Giles

Faculty Publications

When used as optical parametric oscillators, CdSiP2 crystals generate tunable output in the mid-infrared. Their performance, however, is often limited by unwanted optical absorption bands that overlap the pump wavelengths. A broad defect-related optical absorption band peaking near 800 nm, with a shoulder near 1 µm, can be photoinduced at room temperature in many CdSiP2 crystals. This absorption band is efficiently produced with 633 nm laser light and decays with a lifetime of ∼0.5 s after removal of the excitation light. The 800 nm band is accompanied by a less intense absorption band peaking near 1.90 µm. Data …


Interactive Physics And Characteristics Of Photons And Photoelectrons In Hyperbranched Zinc Oxide Nanostructures, Garrett Edward Torix Dec 2016

Interactive Physics And Characteristics Of Photons And Photoelectrons In Hyperbranched Zinc Oxide Nanostructures, Garrett Edward Torix

Graduate Theses and Dissertations

As is commonly known, the world is full of technological wonders, where a multitude of electronic devices and instruments continuously help push the boundaries of scientific knowledge and discovery. These new devices and instruments of science must be utilized at peak efficiency in order to benefit humanity with the most advanced scientific knowledge. In order to attain this level of efficiency, the materials which make up these electronics, or possibly more important, the fundamental characteristics of these materials, must be fully understood. The following research attempted to uncover the properties and characteristics of a selected family of materials. Herein, zinc …


Feasibility Study: The Evaluation Of Polymer Coatings To Prevent Weathering Of Weak Rocks, Lauren Distler May 2015

Feasibility Study: The Evaluation Of Polymer Coatings To Prevent Weathering Of Weak Rocks, Lauren Distler

Senior Honors Projects, 2010-2019

The weathering and erosion of weak rocks along roadways can cause dangerous and potentially fatal rockfalls.   Various slope stabilization methods exist, but each presents a set of challenges and trade-offs.   The focus of the project is to understand the feasibility of utilizing of a polymerbased slope stabilization technique. Rock samples were collected along US Route 33 in Virginia and West Virginia, and preliminary tests were conducted to evaluate the absorption of water (% mass) and durability. The study evaluates three polymer options in regard to the following criteria: adhesion to rock, layer thickness, semi-permeability, insolubility, and non-toxicity. The polymer selection …


Development Of Low Temperature, Aqueous Synthesis Method Of Lead Sulfide Quantum Dots, Albert Nakao, Colin Yee Jun 2014

Development Of Low Temperature, Aqueous Synthesis Method Of Lead Sulfide Quantum Dots, Albert Nakao, Colin Yee

Materials Engineering

Quantum dots have become an active area of research in the past decade due to their unique properties. Quantum confinement effects allow for efficient spectral conversion and size tunable fluorescence and absorption peaks. Near infrared spectral converting lead sulfide quantum dots have potential applications in solar power, biological imaging and communications technology. However at Cal Poly, lead sulfide dots have not been synthesized. The quantum dot synthesis currently adapted at Cal Poly encompasses organometallic precursors at high reaction temperatures, producing cadmium selenium dots. The organometallic approach has been found to produce nanocrystals with high quality photoluminescence, but due to its …


Solar Cell Design Using Metamaterials, Yang Liu, Yitung Chen, Jichun Li Apr 2013

Solar Cell Design Using Metamaterials, Yang Liu, Yitung Chen, Jichun Li

College of Engineering: Graduate Celebration Programs

Natural structure with simultaneous negative permittivity and permeability has not been discovered yet. However, using specially-designed metal embedded in dielectric bodies can achieve a kind of artificial negative index. This periodic structure which is smaller than the guided wavelength is known as a metamaterial. However, recent designs of metamaterials have some disadvantages when they are used in the application of solar cell. The perfect absorption is only within a narrow band, and for most of the solar spectrum, the absorption is no more than 10%. Here, a new kind of absorber for the solar spectrum has been designed and analyzed, …


Sound Absorption Properties Of Functionally Graded Polyurethane Foams, Olivier Doutres Ph.D., Noureddine Atalla Pr. Aug 2012

Sound Absorption Properties Of Functionally Graded Polyurethane Foams, Olivier Doutres Ph.D., Noureddine Atalla Pr.

Olivier Doutres Ph.D.

Noise control over a wide frequency band is an increasingly important design criterion in the building and transport industries. Examples of well known broadband passive concepts for optimal sound absorption are multi-layering with graded properties across the thickness and optimization of the material shape (e.g., wedges). However, for typical applications, the material thickness is limited and shaping or use of different material costly. Thus, there is growing interest for developing acoustical materials having microstructure properties gradient at the micro- or meso-scale; also known as Functionally Graded Materials (FGM). Even if sophisticated models are available to predict the acoustic behavior of …


Characterization And Modification Of Helmet Padding System To Improve Shockwave Dissipation, Katelyn Howay May 2010

Characterization And Modification Of Helmet Padding System To Improve Shockwave Dissipation, Katelyn Howay

All Theses

Currently soldiers are being exposed a much higher number of improvised explosive devices (IEDs) and the resulting shockwaves. These shockwaves can cause traumatic brain injuries (TBIs) even without the occurrence of ballistic impact. The focus of this research was to reduce the amount of shockwaves soldiers are exposed to by inserting fibers and woven fabrics into a foam padding system. These fibers and fabrics facilitate the dissipation of the shockwave energy before it is able to penetrate the padding and cause TBIs.
The sound velocity of high-performance fibers, commodity fibers and woven fabric was measured using a Dynamic Modulus Tester. …


Surface Reactivity Of Aliphatic Nitriles On Chalcopyrite And Sphalerite, Gary Mitton May 1955

Surface Reactivity Of Aliphatic Nitriles On Chalcopyrite And Sphalerite, Gary Mitton

Bachelors Theses and Reports, 1928 - 1970

This thesis reports an investigation concerning the adsorption of aliphatic nitriles by chalcopyrite, activated sphalerite, and unactivated sphalerite. The experimental evidence suggests that abstraction, chelation and re-adsorption may take place. On the basis of the experimental results, an equilibrium-type adsorption hypothesis is proposed.