Engineering Commons^™

Molecularly Targeted Nanoparticles For Modulation Of Inflammatory Mediators In Atherosclerosis, Rohun Udatta Palekar

McKelvey School of Engineering Theses & Dissertations

The enzyme thrombin has been demonstrated through experimental and clinical studies to play a crucial role in mediating both inflammation and thrombosis in atherosclerosis. The cellular effects of thrombin in promoting atherosclerosis involve the activation of signaling pathways that result in the secretion of a host of various chemokines, cytokines, cell adhesion molecules, etc. that promote vascular inflammation. Due in part to thrombin and other pro-atherogenic molecules, this prolonged inflammatory state in atherosclerosis results in the deterioration of the endothelium, increasing the risk of focal thrombosis. Current treatment strategies to address the role of thrombin in atherosclerosis, despite efficacy of …

Synthesis And Functional Evaluation Of Peptide Modified Poly (Lactic-Co-Glycolic Acid) Nanoparticles To Inhibit Porphyromonas Gingivalis Biofilm Formation., Paridhi Kalia

Electronic Theses and Dissertations

Periodontal disease is an oral inflammatory disorder that afflicts roughly 46% of the adults in the U.S. Currently, treatment of periodontal disease involves the removal of plaque from the gingival pocket (with possible antibiotic treatment) and if necessary, gingival surgery. To our knowledge, no therapeutic approach exists that promotes host-biofilm homeostasis by limiting pathogen recolonization of the oral cavity after prophylaxis or treatment. The interaction of the pathogen Porphyromonas gingivalis with commensal streptococci is critical for initiation of periodontitis and represents a target for limiting P. gingivalis colonization of the oral cavity. Previous studies showed that a synthetic peptide …

In Vacuo Fabrication And Electronic Structure Characterization Of Atomic Layer Deposition Thin Films, Michael Schaefer

USF Tampa Graduate Theses and Dissertations

Improvement of novel electronic devices is possible by tailor-designing the electronic structure at device interfaces. Common problems observed at interfaces are related to unwanted band alignment caused by the chemical diversity of interface partners, influencing device performance negatively. One way to address this problem is by introducing ultra-thin interfacial dipole layers, steering the band alignment in a desired direction. The requirements are strict in terms of thickness, conformity and low density of defects, making sophisticated deposition techniques necessary. Atomic layer deposition (ALD) with its Ångstrom-precise thickness control can fulfill those requirements.

The work presented here encompasses the implementation of an …

Toward Higher-Order Mass Detection: Influence Of An Adsorbate’S Rotational Inertia And Eccentricity On The Resonant Response Of A Bernoulli-Euler Cantilever Beam, Stephen M. Heinrich, Isabelle Dufour

Civil and Environmental Engineering Faculty Research and Publications

In this paper a new theoretical model is derived, the results of which permit a detailed examination of how the resonant characteristics of a cantilever are influenced by a particle (adsorbate) attached at an arbitrary position along the beam’s length. Unlike most previous work, the particle need not be small in mass or dimension relative to the beam, and the adsorbate’s geometric characteristics are incorporated into the model via its rotational inertia and eccentricity relative to the beam axis. For the special case in which the adsorbate’s (translational) mass is indeed small, an analytical solution is obtained for the particle-induced …

Cobalt Ferrite Nanoparticles Fabricated Via Co-Precipitation In Air: Overview Of Size Control And Magnetic Properties, Dennis Toledo

FIU Electronic Theses and Dissertations

Cobalt Ferrite has important, size-dependent magnetic properties. Consequently, an overview of particle size is important. Co-precipitation in air was the fabrication method used because it is comparatively simple and safe. The effects of three different reaction times including 1, 2, 3 hour(s) on particle size were compared. Also, the effectiveness of three different capping agents (Oleic Acid, Polyvinylpyrollidone (PVP), and Trisodium Citrate) in reducing aggregation and correspondingly particle size were examined. Using Welch’s analysis of variance (ANOVA) and the relevant post hoc tests, there was no significant difference (p=0.05) between reaction times of 1 hour and 2 hours, but there …

Size-Dependent Mechanical Properties Of Crystalline Nanoparticles, Dan | Mordehai

Nanomechanical Testing in Materials Research and Development V

Defect-free crystalline nanostructures reach strengths which are close to their ultimate shear strength, since their deformation is controlled by dislocation nucleation from the surfaces. In this talk we examine how the size and shape of defect-free nanoparticles affect their mechanical properties. In the first part we discuss the indentation response. Earlier experiments on Au nanoparticles showed that they become easier to indent as they are smaller [1]. With large scale Molecular Dynamics Simulations, we show how the lateral dimensions give rise to size effect in indentation through the competition between dislocation storage and depletion on free surfaces. The latter mechanism …

Dissolution Of Chalcogens In Amine Thiol Solvents For Use In Nanoparticles, Gaurav A. Mittal, Caleb K. Miskin, Rakesh Agrawal

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lead chalcogenide quantum dots have been shown to be ideal materials for solar cells due to their tunable band gap. Developing a dissolution procedure for chalcogens will help lower the production cost of the solar cells produced by the associated nanoparticles. Dissolution was performed in both aqueous and nonaqueous solutions. Precursors for sulfur and selnium were dissolved in both the aqueous solution of ammonium thioglycolate and ammonium hydroxide and in combinations of amines and thiols. Precursors for tellurium were dissolved in ethylenediamine and different thiols. Lead telluride forms larger microparticles that can be suitable for thermoelectric devices. The optimum solutions …

Carbon Dioxide Sequestration To Form Calcium Carbonate Nanoparticles, Krista E. Stump, Michael T. Harris

The Summer Undergraduate Research Fellowship (SURF) Symposium

The emission of carbon dioxide caused by burning fossil fuels is one of the leading sources of global warming. Reducing the amount of CO₂ released into the atmosphere through carbon sequestration can mitigate this problem. One method of carbon sequestration is the use of a carbon dioxide scrubber. Once captured, CO₂ can be used to create a valuable chemical commodity such as calcium carbonate nanoparticles. To create CaCO₃ particles in the 50-100 nanometer range, a chemical additive is necessary to limit particle size. The study used a laboratory scale carbon dioxide scrubber to react CO₂ with …

Tin Nanoparticles Encapsulated In Hollow Tio2 Spheres As High Performance Anode Materials For Li-Ion Batteries, Xiang Pan

Theses and Dissertations

Tin, an anode material with a high capacity for lithium-ion batteries, has poor cyclic performance because of the high volume expansion upon lithiation. Based on a literature review of the applications of lithium-ion batteries and current research progress of the tin-based anode materials for lithium-ion batteries, we developed a method to synthesize hollow TiO2 spheres with tin nanoparticles anchored on the inner surface of the TiO2 shell. Such a unique tin/TiO2 composite alleviates the volume change of tin–based anode materials in charge-discharge processes. SnCl2·2H2O (Tin (II) chloride dihydrate) and titanium (IV) isopropoxide (TIPT) were used as the Sn source and …

Spectrally-Selective All-Inorganic Scattering Luminophores For Solar Energy-Harvesting Clear Glass Windows, Ramzy Alghamedi, Mikhail Vasiliev, Mohammad Alam, Kamal Alameh

Mikhail Vasiliev

All-inorganic visibly-transparent energy-harvesting clear laminated glass windows are the most practical solution to boosting building-integrated photovoltaics (BIPV) energy outputs significantly while reducing cooling- and heating-related energy consumption in buildings. By incorporating luminophore materials into lamination interlayers and using spectrally-selective thin-film coatings in conjunction with CuInSe2 solar cells, most of the visible solar radiation can be transmitted through the glass window with minimum attenuation while ultraviolet (UV) radiation is down-converted and routed together with a significant part of infrared radiation to the edges for collection by solar cells. Experimental results demonstrate a 10 cm × 10 cm vertically-placed energy-harvesting clear glass …

The Electroreduction Of Carbon Dioxide On Porous Copper Nanoparticles, Monica Alisa Padilla

Chemical and Biological Engineering ETDs

Copper nanoparticles of porous, controlled structure were synthesized using the sacrificial support method (SSM). The precursor weight percent (wt%) of copper (Cu) and fumed silica (EH-5) was varied to determine the optimum ratio for this material. The precursors were reduced at i) 350°C in a 7% H2 atmosphere and ii) at 250°C in a 100% H2 atmosphere. The specific surface areas of the nanoparticles was measured by Brunauer-Emmett-Teller N2 absorption. The morphologies and widths of the nanoparticles were confirmed by imaging the nanoparticles by scanning electron microscopy (SEM). The bulk composition of the nanoparticles was determined by X-ray diffraction (XRD). …

Effect Of Ion Concentration On Mechanosynthesis Of Carbonated Chlorapatite Nanopowders

Faculty of Engineering University of Malaya

Carbonated chlorapatite nanopowders (n-CCAp) with different degrees of substitution were successfully synthesized by the one-step mechanochemical process. Results demonstrated that the formation of n-CCAp was influenced strongly by the carbonate content (x). From X-ray analysis, crystallite size, crystallinity degree, and unit cell volume of n-CCAp decreased significantly as carbonate content (x) increased from 0 to 2. Conversely, the lattice strain and the volume fraction of grain boundaries grew considerably. Microscopic analysis showed the average particle size of the synthesized powders was 15 +/- 10 nm. The influence of carbonate concentration on mechanosynthesis of pure n-CCAp utilizing a facile solid-state process …

In Vitro Studies Of Gold And Gold Silica Nanoparticle Radiosensitization With Kilovoltage X-Rays, Gregory Colarch

UNLV Theses, Dissertations, Professional Papers, and Capstones

Technological advances in the ability to construct and manipulate nanoscale particles have opened up the possibility of using solid metallic nanoparticles and mixed metal nanoshells as a means to increase dose enhancement and treatment efficacy to tumors. In order for nanoparticles to be an effective form of treatment, they must be delivered to tumors in sufficient concentrations so that there is a dose enhancement factor due to ionizing radiation, as well as being essentially non-toxic to healthy cells. Gold nanoparticles and silica-gold nanoshells fit these requirements. Gold has a high atomic number (Z=79), which gives a larger cross section for …

Engineering Of Lipid Nanoparticles For Advanced Drug Delivery Applications, Stephen L. Hayward

Department of Chemical and Biomolecular Engineering: Theses and Student Research

‘Nanomedicine’, the application of nanotechnology principles to the field of medicine, has stimulated the development of nano-platforms for next generation drug delivery. By exploiting nanoscale properties of materials to selectively alter intrinsic characteristics of therapeutics, researchers have improved the efficacy and pharmacokinetic profiles for a variety of drug types. Despite preliminary commercial and clinical success, there still remains a need to develop an improved delivery platform that can provide high cargo entrapment, efficient intracellular delivery, evasion of intracellular degradation pathways, and provide cell population specific targeting.

In this study we engineered a nanocarrier system composed of a core bilayer structure …

Nanoparticle Plasmonics: Going Practical With Transition Metal Nitrides, U. Guler, V. M. Shalaev, A. Boltasseva

U. Guler

Promising designs and experimental realizations of devices with unusual properties in the field of plasmonics have attracted a great deal of attention over the past few decades. However, the high expectations for realized technology products have not been met so far. The main complication is the absence of robust, high performance, low cost plasmonic materials that can be easily integrated into already established technologies such as microelectronics. This review provides a brief discussion on alternative plasmonic materials for localized surface plasmon applications and focuses on transition metal nitrides, in particular, titanium nitride, which has recently been shown to be a …

Effect Of High-Energy Ball Milling On The Formation And Micro Structural Features Of Carbonated Chlorapatite Nanopowders

Faculty of Engineering University of Malaya

Carbonated chlorapatite nanopowders (n-CCAp) were synthesized by mechanochemical process from calcite (CaCO3), phosphorus pentoxide (P2O5), and calcium chloride (CaCl2) as raw materials. Results demonstrated that the formation of n-CCAp was influenced strongly by the milling time. At the beginning of milling (up to 15 min), CaCO3 and CaCl2 were the dominant phases, while P2O5 disappeared entirely due to its very high deliquescent nature. With increasing the milling time to 600 min, the progressive mechanochemical reaction was completed which resulted in the formation of nanostructured carbonated chlorapatite. According to the X-ray diffraction data, crystallite size of the product decreased from 24 …

Physical Properties Of Iron Oxide Nanoparticles, Nicklaus Carter

Honors College

Magnetic Resonance Imaging (MRI) relies heavily on contrast agents such that diagnosis of various diseases can be made with increased confidence. Current contrast agents for MRI depend on various chelated molecules composed of a toxic gadolinium ion, Gd³⁺. In 2006, a discovery was made connecting Nephrogenic Systemic Fibrosis (NSF) and these gadolinium based contrast agents (GBCAs). The connection between life threatening NSF and GBCAs stems from patients with pre-existing kidney malfunctions. It has been proposed that an alternative agent such as iron oxide nanoparticles (IONPs) be investigated. These IONPs theoretically will have similar responses in efficiency of improving …

Tailoring Nanoparticles And Polymers For Cooperative Interfacial And Surface Interactions, Irem Bolukbasi

Doctoral Dissertations

This thesis describes the synthesis of chemically functionalized nanoparticles and their behavior at interfaces and in conjunction with polymers. Solid-liquid, liquid-liquid, and air-liquid interfaces are useful platforms for studying nanoparticle assembly, especially when nanoparticles are functionalized to enable their segregation to the interface. At the liquid-liquid interface, double emulsions droplets, both oil-in-water-in-oil and water-in-oil-in-water, stabilized with nanoparticles were prepared. This involved gold nanoparticles stabilizing oil-in-water droplets, and CdSe quantum dots stabilizing water-in-oil droplets. These double emulsion droplets were by simply shaking to give polydisperse droplets, or in a well-defined fashion by microcapillary flow focusing. When nanoparticle-stabilized double emulsions were sized …

Enhanced Sonocatalytic Treatment Of Ibuprofen By Mechanical Mixing And Reusable Magnetic Core Titanium Dioxide

Faculty of Engineering University of Malaya

As a reusable sonocatalyst, magnetically separable titanium dioxide (MST) was synthesized by a sol-gel method and was evaluated in the removal of ibuprofen (IBP). MST was carefully characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N-2 gas isotherms, band-gap energy, magnetization, zeta potential, and particle size distribution. The kinetics of IBP removal by sonolysis or MST-assisted sonocatalysis was systematically evaluated with various operational parameters such as pH, temperature, ultrasound (US) frequency, and mechanical mixing intensity. For the first time, authors found that mechanical mixing had an opposite effect on the oxidation rate constants of IBP removal by sonolysis …

Surface States In Template Synthesized Tin Oxide Nanoparticles, A. Cabot, J. Arbiol, R. Ferre, J. R. Morante, Fanglin Chen, Meilin Liu

Fanglin Chen

Tin–oxide nanoparticles with controlled narrow size distributions are synthesized while physically encapsulated inside silica mesoporous templates. By means of ultraviolet-visible spectroscopy, a redshift of the optical absorbance edge is observed. Photoluminescence measurements corroborate the existence of an optical transition at 3.2 eV. The associated band of states in the semiconductor gap is present even on template-synthesized nanopowders calcined at 800 °C, which contrasts with the evolution of the gap states measured on materials obtained by other methods. The gap states are thus considered to be surface localized, disappearing with surface faceting or being hidden by the surface-to-bulk ratio decrease.

Effect Of Molybdenum Disulfide Particle Sizes On Wear Performance Of Commercial Lubricant, Innovative Research Publications Irp India, S. M. Muzakkir, Harish Hirani

Innovative Research Publications IRP India

Experimental investigations have been conducted for determination of effectiveness of employing a combination of three particle sizes (40 nm size, 1.75 μm size and 53 μm size) of Molybdenum Disulphide as anti-wear additive in a commercial lubricant. The conformal block and disk configuration has been used to conduct experiments for determination of wear of the sliding surfaces. The performance of the proposed combined particle sizes anti-wear additive is compared with single particle size anti-wear additives to establish its robustness under varying surface conditions.

Too Enthusiastic To Care For Safety: Present Status And Recent Developments Of Nanosafety In Asean Countries

Faculty of Engineering University of Malaya

Nanotechnology has the prospect to vibrate the imagination of human being and has the ability to be used in almost every sector of human need. With its limitless potentials, there are many environmental, health and safety related concerns due to extremely ambivalent effects of nanoparticles. Studies revealed that nanoparticles can enter the human body through the lungs, intestinal tract, and skin. Therefore, the researchers and workers who handle nanoparticles and nanomaterials can theoretically and primarily be affected, whereas on the consumers this will have secondary effects. This paper aims at sharing and evaluating the investment scenario, present status and recent …

Control Of Fluid Dynamics By Nanoparticles In Laser Melting, Chao Ma, Lianyi Chen, Jiaquan Xu, Jingzhou Zhao, Xiaochun Li

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Effective control of fluid dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control fluid dynamics. In this study, laser melting was used to investigate the feasibility of tuning fluid dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the fluid dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the fluid dynamics. Characterizations of surface topographies and microstructures of pure …

Optimal Energy For Cell Radiosensitivity Enhancement By Gold Nanoparticles Using Synchrotron-Based Monoenergetic Photon Beams, Wan Nordiana Rahman, Stephanie Corde, Naoto Yagi, Siti Aishah Abdul Aziz, Nathan Annabell, Moshi Geso

Stéphanie Corde

Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. …

Real-Time Mri-Guided Catheter Tracking Using Hyperpolarized Silicon Particles, Nicholas Whiting, Jingzhe Hu, Jay V. Shah, Maja C. Cassidy, Erik Cressman, Niki Zacharias Millward, David G. Menter, Charles M. Marcus, Pratip K. Bhattacharya

Nicholas Whiting

Eulerian-Lagrangian Analysis Of Solid Particle Distribution In An Internally Heated And Cooled Air-Filled Cavity

Faculty of Engineering University of Malaya

A parametric study has been conducted to investigate particle deposition on solid surfaces during free convection flow in an internally heated and cooled square cavity filled with air. The cavity walls are insulated while several pairs of heaters and coolers (HACs) inside the cavity lead to free convection flow. The HACs are assumed to be isothermal heat source and sinks with temperatures T-h and T-c (T-h > T-c). The problem is numerically investigated using the Eulerian-Lagrangian method. Two-dimensional Navier-Stokes and energy equations are solved using finite volume discretization method. Applying the Lagrangian approach, 5000 particles, distributed randomly in the enclosure, were …

Probing The Enzymatic Activity Of Alkaline Phosphatase Within Quantum Dot Bioconjugates, Jonathan C. Claussen, Anthony Malanoski, Joyce C. Breger, Eunkeu Oh, Scott A. Walper, Kimihiro Susumu, Ramasis Goswami, Jeffrey R. Deschamps, Igor L. Medintz

Jonathan C. Claussen

Enzymes provide the critical means by which to catalyze almost all biological reactions in a controlled manner. Methods to harness and exploit their properties are of strong current interest to the growing field of biotechnology. In contrast to depending upon recombinant genetic approaches, a growing body of evidence suggests that apparent enzymatic activity can be enhanced when located at a nanoparticle interface. We use semiconductor quantum dots (QDs) as a well-defined and easily bioconjugated nanoparticle along with Escherichia coli-derived alkaline phosphatase (AP) as a prototypical enzyme to seek evidence for this process in a de novo model system. We began …

Using Natural Language Processing Techniques To Inform Research On Nanotechnology, Nastassja A. Lewinski, Bridget T. Mcinnes

Chemical and Life Science Engineering Publications

Literature in the field of nanotechnology is exponentially increasing with more and more engineered nanomaterials being created, characterized, and tested for performance and safety. With the deluge of published data, there is a need for natural language processing approaches to semi-automate the cataloguing of engineered nanomaterials and their associated physico-chemical properties, performance, exposure scenarios, and biological effects. In this paper, we review the different informatics methods that have been applied to patent mining, nanomaterial/device characterization, nanomedicine, and environmental risk assessment. Nine natural language processing (NLP)-based tools were identified: NanoPort, NanoMapper, TechPerceptor, a Text Mining Framework, a Nanodevice Analyzer, a Clinical …

Controllable Synthesis Of Concave Cubic Gold Core-Shell Nanoparticles For Plasmon-Enhanced Photon Harvesting, Yang Bai, Teera Butburee, Hua Yu, Zhen Li, Rose Amal, Gao Qing (Max) Lu, Lianzhou Wang

Australian Institute for Innovative Materials - Papers

Well-defined core-shell nanoparticles (NPs) containing concave cubic Au cores and TiO₂ shells (CA@T) were synthesized in colloidal suspension. These CA@T NPs exhibit Localized Surface Plasmon Resonance (LSPR) absorption in the NIR region, which provides a unique property for utilizing the low energy range of the solar spectrum. In order to evaluate the plasmonic enhancement effect, a variety of CA@T NPs were incorporated into working electrodes of dye-sensitized solar cells (DSSCs). By adjusting the shell thickness of CA@T NPs, the plasmonic property can be tuned to achieve maximum photovoltaic improvement. Furthermore, the DSSC cells fabricated with the CA@T NPs exhibit …

On Thermal Aging Prevention In Polymer Core Composite Conductor Rods, Joe D. Hoffman

Electronic Theses and Dissertations

Increased energy usage in the United States and worldwide is driving the demand for new technologies to transmit electrical power in greater quantities and with reliable, safe, and more efficient methods. One recent innovation is to replace the standard Aluminum Conductor Steel Reinforced electrical transmission conductor with a new conductor design that utilizes a fiber reinforced polymer core rod to support a fully annealed aluminum conductor. This new technology that includes a hybrid carbon fiber/epoxy and glass fiber/epoxy support core allows for better efficiency and for greater current to be transmitted in the same size and weight line. These new …