Digital Commons Network^™

Self-Pulsing And Chaos In Distributed Feedback Bistable Optical Devices, Herbert G. Winful, Gene D. Cooperman

Gene D. Cooperman

We show that the light transmitted by a nonlinear distributed feedback structure can be steady (time independent), periodic, or chaotic depending on the intensity of the input cw beam. The feasibility of an experimental demonstration of such behavior is discussed.

Corrections To Enhanced Optical Nonlinearity Of Superlattices, Gene D. Cooperman, L. Friedman, W. L. Bloss

Gene D. Cooperman

In recent publications, a large enhancement of the third order nonlinear optical susceptibility was predicted for GaAs-GaAIAs superlattices, as a result of the band nonparabolicities introduced by the additional periodicity of the superlattice. These predictions, based on the tight binding model, are here extended to the more realistic Kronig-Penney model. Results show that corrections to tight binding are non-negligible; however, enhancements of χ⁽³⁾ are still large, but reduced by approximately 30%-50% over previous estimates.

Leaching Mechanism Of Semiconducting Minerals, Fathi Habashi

Fathi Habashi

The mechanism of leaching of semiconducting minerals such as PbS, ZnS, UO2, etc., has been the subject of intensive speculation by hydrometallurgists in the early 1950s. The electrochemical mechanism proposed in 1970 by the author in volume 2 of his Principles of Extractive Metallurgy avoids the assumption of forming intermediate complexes that cannot be isolated or identified.

Plant Ecophysiology Of Mycorrhizal Fungi, Gregory Keith Bartley Jr.

Gregory Keith Bartley Jr.

No abstract provided.

Regulating Factors In Anthocyanin Biosynthesis, Gregory Keith Bartley Jr.

Gregory Keith Bartley Jr.

No abstract provided.

Microstructural Effects During Chemical Mechanical Planarization Of Copper, Patrick J. Andersen, Mariela N. Bentancur, Amy J. Moll, Megan Frary

Amy J. Moll

Novel die-stacking schema using through-wafer interconnects require vias to be filled with electroplated Cu, resulting in thick copper films, and requiring an aggressive first-step CMP. This work investigates the effects of microstructure on CMP of copper films, which are not presently well understood. Bulk and local removal rates were investigated for several different microstructures. Surface orientation maps were created and the orientations of individual grains were correlated with topographical data to elucidate local removal behavior. Cu removal depends on the details of the microstructure, and certain microstructures allowed for either faster or more uniform removal of thick Cu films.

Diverse Corrugation Pattern In Radially Shrinking Carbon Nanotubes, Hiroyuki Shima, Motohiro Sato, Kohtaroh Iiboshi, Susanta Ghosh, Marino Arroyo

Susanta Ghosh

A New Multilayer Composite With Functionally Graded Design For Endodontic Application., Ahmed A. Madfa

Ahmed A. Madfa

Multilayer composite with FG structure were fabricated using zirconia (ZrO), alumina (AI2O3), Hydroxyapatite (HA) and titanium (Ti) micropowders. Powder selection and their combination in each layer were according to the results of finite element analysis.

Structural, Magnetic, And Defect Properties Of Co-Pt-Type Magnetic-Storage Alloys: Density-Functional Theory Study Of Thermal Processing Effects, Aftab Alam, Brent Kraczek, Duane D. Johnson

Duane D. Johnson

Using an optimized-basis Korringa-Kohn-Rostoker-coherent-potential approximation method, we calculate formation enthalpies ΔEf, structural, and magnetic properties of paramagnetic (PM) and ferromagnetic, disordered A1 and ordered L10 CoPt, FePd, and FePt systems that are of interest for high-density magnetic-recording media. To address processing effects, we focus on the point defects that dictate thermal properties and planar defects (e.g., c domain and antiphase boundaries) which can serve as pinning centers for magnetic domains and affect storage properties. We determine bulk Curie (Tc) and order-disorder (To-d) transition temperatures within 4% of observed values, and estimates for nanoparticles. Planar-defect energies γhklx show that the favorable …

Nanotechnology, Biology, Ethics And Society: Overcoming The Multidisciplinary Teaching Challenges, Linda Vanasupa, Matthew Ritter, Barbara Schader, Katherine C. Chen, Richard N. Savage, Peter Schwartz, Lynne Slivovsky

Peter V. Schwartz

One of the inherent challenges of teaching any emerging technology like nanotechnology, is the fact that its core competencies flux in the new disciplines' early stages. Nanotechnology presents an additional challenge in that its underpinnings cross multiple traditional disciplinary boundaries. We have designed a course that aims to address some of these challenges through a handful of structural features: team-based learning; a "reverse of the learning pyramid" approach; team-teaching; embedded information literacy techniques; and application-centered content. Our course is organized around four applications that are in their developmental stages: gold nanoshells for cancer treatment; molecular manufacturing; tissue engineering of a …

Turning Packaging Into Profit, Rihaz Z. Chughatta

Rihaz Z Chughatta

Packaging can be an expensive function to maintain, but it doesn’t have to be. In fact, Packaging can be a source of income for a company. More accurately, what if you took a look at your company’s Profit and Loss and saw Packaging as a negative expense? That’s right, you can turn packaging into profit for your company. How do you accomplish this feat? Glad you asked … read on to find three simple ways to start this process (and satisfy your curiosity) …

Optimisation Acoustique De Paroi Par Algorithme Génétique Et Influence De L’Habillage Par Une Couche Poreuse, Nicolas Dauchez, Olivier Doutres, Jean-Michel Genevaux, Jean-Christophe Le Roux

Olivier Doutres Ph.D.

L’amélioration du confort acoustique dans les habitacles passe en particulier par l’optimisation de la transparence acoustique de parois simple ou double au moyen de matériaux viscoélastiques et poreux. Une méthode d’optimisation de paroi basée sur un algorithme génétique couplé à un calcul par matrices de transfert est présentée. Cette technique permet une exploitation efficace des itérations précédentes sans coût de calcul supplémentaire. Les résultats obtenus pour une simple et une double paroi sont analysés. Dans un deuxième temps, l’influence d’un habillage poreux est présenté en fonction de la nature du squelette : mousse polymère ou fibreux. On montre, à l’aide …

Mesure Des Propriétés Mécaniques Des Matériaux Poreux À L’Aide D’Un Transducteur Électrodynamique Sans Fer, Nicolas Dauchez, Olivier Doutres, Jean-Michel Génevaux, Guy Lemarquand, Sylvain Mezil

Olivier Doutres Ph.D.

Un banc de mesure des propriétés mécaniques des matériaux poreux est présenté. Il permet d'étendre les méthodes quasistatiques basées sur la compression d'un échantillon vers les hautes fréquences. Les méthodes quasistatiques sont limitées en fréquence (< 100 Hz) parce qu'elles négligent les éléments inertiels et le couplage avec l'air ambiant. Dans la méthode présentée, l'échantillon est placé dans une cavité étanche pour limiter l'effet de l'air ambiant et ainsi permettre une meilleure estimation du facteur de perte. Un transducteur électrodynamique a été conçu spécifiquement pour permettre une excitation sur une large gamme de fréquence : les premiers modes de l'équipage mobile sont au dela de 5 kHz. De plus, son architecture sans fer et sans suspension viscoélastique permet de l'utiliser comme capteur par le biais de son impédance électrique. L'impédance mécanique de l'échantillon est obtenue en inversant le modèle électromécanique du transducteur et les propriétés viscoélastiques - module d'Young et facteur de perte - sont obtenues par recalage d'un modèle analytique utilisant la théorie de Biot-Allard. Les résultats sont présentés pour une mousse polymère à cellule ouvertes. Le calcul des incertitudes montre que la méthode permet une bonne estimation jusque 500 Hz et permet de définir les conditions d'extension de la plage de fréquence.

Effects Of Fully Developed Vesicular Arbuscular Mycorrhizal Hyphae On Seed Germination Of Lolium Perenne, G Keith Bartley Jr, Richard J. Gualandi Jr, Robert M. Augé

Gregory Keith Bartley Jr.

Previous studies demonstrate that the inoculation of mycorrhizal spores in seeds can improve speed of germi- nation and establishment in grass seedlings. The universally positive effects of arbuscular mycorrhiza on plants suggest that fully developed mycorrhizal hyphae could potentially induce faster germination in seeds. This study presents data indicating that the inoculation of full grown hyphae in seeds of Lolium perenne inhibits speed of germination, independent of level of available soil nutrients. Daily measurements of seedling height between in- fected and non-infected plants at different starter fertilization rates in a sand profile showed that abuscular mycor- hiza influenced seeds emerged …

Point-Of-Contact, Dna-Based Amplifier For Detecting Cancer-Related Micro-Rna In Blood Serum, Elton Graugnard, Amber Cox, Jeunghoon Lee, Cheryl Jorcyk, Bernard Yurke, William L. Hughes

Elton Graugnard

No abstract provided.

Morphological Evolution Of Single-Crystal Ultrathin Solid Films, Mikhail Khenner

Mikhail Khenner

An introduction to mathematical modeling of ultrathin solid films and the role of such modeling in nanotechnologies: Educational/Research presentation for senior physics majors

Metals: Typical And Less Typical, Transition And Inner Transition, Fathi Habashi

Fathi Habashi

While most chemists agree on what is a metal and what is a non-metal there is a disagreement with respect to what is a metalloid and what is a transition metal. It is believed that this problem can be solved if two new terms are adopted: typical and less typical metals. These new terms will also help reconcile the European Periodic Table versus the North American regarding numbering of groups as well as the IUPAC numbering which could be as well abandoned in favour of group names as will be shown in the manuscript.

The Future Of Southern Agriculture, Gregory Keith Bartley Jr.

Gregory Keith Bartley Jr.

The increasing demand for the supply of energy in the south heavily impacts the allocation of water for use in agriculture. With such a high percentage of the south's freshwater going towards energy production, little can make its way into food, feed, and fiber. Because the need for this exponential energy production in the south is currently greater than its agricultural importance, southern farmers are left to endure heavy irrigation restrictions. The solution to this problem can manifest itself in one of two ways. Southern states can either implement strategies that can reduce plant water consumption without reducing yield, or …

Beethoven: Patriotism And Social Justice, Fathi Habashi

Fathi Habashi

Digital Printing Of Inkjet And Toner Technologies Related To Color Gamut And Reproduction Characteristics, Bilge N. Altay

Bilge Nazli Altay

No abstract provided.

Phosphate Industry And The Radon Problem, Fathi Habashi

Fathi Habashi

The problem of radon generated during the treatment of phosphate rock by sulfuric acid to produce fertilizers can be solved by using nitric acid. In this case radium, which is the source of radon, goes into solution and can be precipitated by a controlled method and safely disposed of. A variety of options are discussed. Text in Farsi with English translation.

Nanoparticle Effects On The Morphology And Mechanicalproperties Of Polypropylene Spunbond Webs, Raghavendra Hegde, Gajanan S. Bhat

Raghavendra R Hegde Dr

We report morphology and mechanical properties of natural nanoclay incorporated spunbond polypropylene composite webs. Nanocomposite spunbond webs were produced with up to 5 wt % natural nanoclay additives on ReicofilVR -2 spunbond line. Influence of nanoclay on the resin rheological properties, processibility, and mechanical properties of webs were studied. Wide angle X-ray diffraction and transmission electron microscopy analysis were used to investigate the nanocomposite morphology. Intercalated and flocculated morphology was observed for all the concentrates and for all the spunbond fiber webs. The microstructure and polymer morphology in the presence of additives was characterized using a polarized optical microscope. At …

Microstructural Characteristics Of Functionally Graded Materials Designed As Dental Post, Ahmed A. Madfa

Ahmed A. Madfa

To study the interfaces and microstructure of multilayered materials fabricated based on functionally graded concept for use as dental posts.

Theoretical Description Of A Dna-Linked Nanoparticle Self-Assembly, Chia Wei Hsu, Francesco Sciortino, Francis Starr

Francis Starr

No abstract provided.

Current Issues In Research On Structure-Property Relationships In Polymer Nanocomposites, J. Jancar, J. Douglas, Francis Starr, S. Kumar, P. Cassagnau, A. Lesser, S. Sternstein, M. Buehler

Francis Starr

No abstract provided.

Porosity Reduction Model In Functionally Graded Metal-Ceramic Composites Using Shrinkage Measurement, Ahmed Madfa

Ahmed A. Madfa

Porosity of metal-ceramic functionally graded materials (FGMs) was investigated experimentally to verify its mathematical models.

Extraction Of Silver From Waste X-Ray Films By Thiosulphate Leaching, Ersin Y. Yazici, Ahmet Deniz Bas, Haci Deveci

Ahmet Deniz Bas

No abstract provided.

Effective Sba-15 Supported Gold Catalysts For Gluconic Acid Synthesis, K. Odrozek, J. J. Malinowski, J. Mrowiec-Bialon

Janusz J. Malinowski

No abstract provided.

Possibility Of Secondary Lead Slag Stabilization In Concrete With Presence Of Selected Additives, Zeljko J. Kamberovic

Zeljko J Kamberovic

A comparative technical and environmental evaluation of products arising from the stabilization/solidification of secondary lead metallurgical slag into a cement matrix was performed. Provided samples of an industrial slag generated in the process of recovery of lead from automotive batteries (Engitec CX process), were used in experimental work. Characterization of slag by X-ray Diffraction (XRD), Atomic Absorption Spectrometry (AAS) and Optical Microscopy (OM) revealed that slag contains a certain percentage of sodium and lead, in the form of oxides and sulphides, as well as unreacted coke and iron compounds. Dissolving of the slag components causes migration of ions into water …

Ultrathin, Ultrasmooth And Low-Loss Silver Films Via Wetting And Annealing, Weiqiang Chen, Kuo-Ping Chen, Mark Daniel Thoreson, Alexander Kildishev, Vladimir M. Shalaev

Weiqiang Chen

We have demonstrated that a thermal annealing treatment can reduce the optical losses in ultrathin, ultrasmooth, silver films deposited on a Ge wetting layer to values as low as the bulk material value and at the same time maintain an ultrasmooth surface. The annealing effect is sensitive to the annealing temperature and time, both of which should be carefully controlled. This annealing treatment is also effective for Ag–SiO2 multilayer composite films.