Engineering Commons^™

Biogenic Synthesis, Photocatalytic, And Photoelectrochemical Performance Of Ag–Zno Nanocomposite, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The development of coupled photoactive materials (metal/semiconductor) has resulted in significant advancements in heterogeneous visible light photocatalysis. This work reports the novel biogenic synthesis of visible light active Ag–ZnO nanocomposite for photocatalysis and photoelectrode using an electrochemically active biofilm (EAB). The results showed that the EAB functioned as a biogenic reducing tool for the reduction of Ag+, thereby eliminating the need for conventional reducing agents. The as-prepared Ag–ZnO nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic experiments showed that the Ag–ZnO nanocomposite possessed excellent visible light photocatalytic activity …

Nanohub - Crystal Viewer 2.0, Kevin Margatan, Gerhard Klimeck

Gerhard Klimeck

nanoHUB is an online compilation of tools for simulations. Equipped with 3-D simulations and a capability to solve very complex calculations, nanoHUB provides its users worldwide with various tools to help them finish their assignments. One of the tools available is called a Crystal Viewer Tool, an advanced crystal visualization tool. This tool allows users to generate various crystal types including their every single detail. Currently, a newer version, called Crystal Viewer 2.0, is being tested prior to its release. However, this tool is lacking some important features and a GUI that is not as user friendly as expected. The …

Next Generation Crystal Viewing Tool, Zach Schaffter, Gerhard Klimeck

Gerhard Klimeck

The science and engineering community is limited when it comes to crystal viewing software tools. Each tool lacks in a different area such as customization of structures or visual output. Crystal Viewer 2.0 was created to have all of these features in one program. This one tool simulates virtually any crystal structure with any possible material. The vtkvis widget offers users advanced visual options not seen in any other crystal viewing software. In addition, the powerful engine behind Crystal Viewer 2.0, nanoelectronic modeling 5 or (NEMO5), performs intensive atomic calculations depending on user input. A graphical user interface, or GUI, …

Reflectance Anisotropy Of Gd5si2ge2 And Tb5si2.2ge1.8, S. J. Lee, Joong Mok Park, J. E. Snyder, David C. Jiles, Deborah L. Schlagel, Thomas A. Lograsso, A. O. Pecharsky, David W. Lynch

Professor David Lynch

Reflectance difference (RD) spectra for the a–b plane of the single crystals of Gd5Si2Ge2and b–c planes of Gd5Si2Ge2 and Tb5Si2.2Ge1.8 were obtained in the photon energy range of 1.5–5.5 eV. Several peaks were observed for these crystals in the measured spectrum range. Similar features were observed in the RD spectra for the b–c planes ofGd5Si2Ge2 and Tb5Si2.2Ge1.8, while different features were observed for the a–b plane and b–c plane of Gd5Si2Ge2. The RD spectra for the crystals arise not only from the surface anisotropy but also from the bulk anisotropy due to the monoclinic structure of the bulk crystal.

Effect Of Bio Field Treatment On The Physical And Thermal Characteristics Of Silicon, Tin And Lead Powders, Mahendra Kumar Trivedi, Shrikant Patil, Rama Mohan Tallapragada

Mahendra Kumar Trivedi

Scaling Reversible Adhesion In Synthetic And Biological Systems, Michael D. Bartlett

Michael Bartlett

Tailoring The Ferh Magnetostructural Response With Au Diffusion, M. Loving, M. A. De Vries, F. Jimenez-Villacorta, C. Le Graët, X. Liu, R. Fan, S. Langridge, D. Heiman, C. H. Marrows, L. H. Lewis

Donald Heiman

Factors which contribute to magnetostructural transition control have been demonstrated by study of the effects of Au incorporation on the magnetic and structural character of CsCl-structured equiatomic FeRh thin films. Sputtered films were capped with 2 nm of Au deposited at 873 K and at 323 K and subsequently characterized with magnetometry and synchrotron-based structural probes. Diffusion of Au into the FeRh film layer at 873 K is confirmed by a reduction in the Au capping layer thickness relative to the film capped at 323 K. The impact of Au diffusion on the FeRh magnetostructural character is noted by a …

Tailoring The Ferh Magnetostructural Response With Au Diffusion, M. Loving, M. A. De Vries, F. Jimenez-Villacorta, C. Le Graët, X. Liu, R. Fan, S. Langridge, D. Heiman, C. H. Marrows, L. H. Lewis

Laura H. Lewis

Factors which contribute to magnetostructural transition control have been demonstrated by study of the effects of Au incorporation on the magnetic and structural character of CsCl-structured equiatomic FeRh thin films. Sputtered films were capped with 2 nm of Au deposited at 873 K and at 323 K and subsequently characterized with magnetometry and synchrotron-based structural probes. Diffusion of Au into the FeRh film layer at 873 K is confirmed by a reduction in the Au capping layer thickness relative to the film capped at 323 K. The impact of Au diffusion on the FeRh magnetostructural character is noted by a …

Tailoring The Ferh Magnetostructural Response With Au Diffusion, M. Loving, M. A. De Vries, F. Jimenez-Villacorta, C. Le Graët, X. Liu, R. Fan, S. Langridge, D. Heiman, C. H. Marrows, L. H. Lewis

Felix Jiménez-Villacorta

Factors which contribute to magnetostructural transition control have been demonstrated by study of the effects of Au incorporation on the magnetic and structural character of CsCl-structured equiatomic FeRh thin films. Sputtered films were capped with 2 nm of Au deposited at 873 K and at 323 K and subsequently characterized with magnetometry and synchrotron-based structural probes. Diffusion of Au into the FeRh film layer at 873 K is confirmed by a reduction in the Au capping layer thickness relative to the film capped at 323 K. The impact of Au diffusion on the FeRh magnetostructural character is noted by a …

Strain-Driven Transition From E-Type To A-Type Magnetic Order In Ymno₃ Epitaxial Films, F. Jiménez-Villacorta, J. A. Gallastegui, I. Fina, X. Marti, J. Fontcuberta

Felix Jiménez-Villacorta

Single-crystal (100)-oriented YMnO3 thin films grown on (110)-oriented SrTiO3 substrates have been studied by polarized extended x-ray absorption fine structure to determine the Mn-O bond lengths. Using a simple geometrical model and previously reported x-ray diffraction data on the same samples, the Mn-O-Mn bonding angles are calculated. We show that the epitaxy-induced in-plane anisotropic strain has a dramatic impact on the bonding angles, allowing the rationalization of the reported existence of cycloidal magnetic order and concomitant ferroelectricity in moderately strained films and the gradual suppression by larger strains. We shall argue that epitaxial strain allows shifting YMnO3 from an E-type …

Development Of A Novel Handheld Device For Active Compensation Of Physiological Tremor, Abhijit Saxena

Abhijit Saxena

In microsurgery, the human hand imposes certain limitations in accurately positioning the tip of a device such as scalpel. Any errors in the motion of the hand make microsurgical procedures difficult and involuntary motions such as hand tremors can make some procedures significantly difficult to perform. This is particularly true in the case of vitreoretinal microsurgery. The most familiar source of involuntary motion is physiological tremor. Real-time compensation of tremor is, therefore, necessary to assist surgeons to precisely position and manipulate the tool-tip to accurately perform a microsurgery. In this thesis, a novel handheld device (AID) is described for compensation …

Peridynamic Model For Dynamic Fracture In Unidirectional Fiber-Reinforced Composites, Wenke Hu, Youn Doh Ha, Florin Bobaru

Florin Bobaru Ph.D.

We propose a computational method for a homogenized peridynamics description of fiber-reinforced composites and we use it to simulate dynamic brittle fracture and damage in these materials. With this model we analyze the dynamic effects induced by different types of dynamic loading on the fracture and damage behavior of unidirectional fiber-reinforced composites. In contrast to the results expected from quasi-static loading, the simulations show that dynamic conditions can lead to co-existence of and transitions between fracture modes; matrix shattering can happen before a splitting crack propagates. We observe matrix–fiber splitting fracture, matrix cracking, and crack migration in the matrix, including …

Influence Of Van Der Waals Forces On Increasing The Strength And Toughness In Dynamic Fracture Of Nanofibre Networks: A Peridynamic Approach, Florin Bobaru Ph.D.

Florin Bobaru Ph.D.

The peridynamic method is used here to analyse the effect of van der Waals forces on the mechanical behaviour and strength and toughness properties of three-dimensional nanofibre networks under imposed stretch deformation. The peridynamic formulation allows for a natural inclusion of long-range forces (such as van der Waals forces) by considering all interactions as ‘long-range’. We use van der Waals interactions only between different fibres and do not need to model individual atoms. Fracture is introduced at the microstructural (peridynamic bond) level for the microelastic type bonds, while van der Waals bonds can reform at any time. We conduct statistical …

Studies Of Dynamic Crack Propagation And Crack Branching With Peridynamics, Youn Doh Ha Ph.D., Florin Bobaru Ph.D.

Florin Bobaru Ph.D.

In this paper we discuss the peridynamic analysis of dynamic crack branching in brittle materials and show results of convergence studies under uniform grid refinement (m-convergence) and under decreasing the peridynamic horizon (δ-convergence). Comparisons with experimentally obtained values are made for the crack-tip propagation speed with three different peridynamic horizons.We also analyze the influence of the particular shape of themicro-modulus function and of different materials (Duran 50 glass and soda-lime glass) on the crack propagation behavior. We show that the peridynamic solution for this problem captures all the main features, observed experimentally, of dynamic crack propagation and branching, as well …

Band Gap Narrowing Of Titanium Dioxide (Tio2) Nanocrystals By Electrochemically Active Biofilm And Their Visible Light Activity, S. Kalathil, Mohammad Mansoob Khan Dr, Sajid A. Ansari, M. H. Cho, J. Lee

Dr. Mohammad Mansoob Khan

We report a simple biogenic-route to narrow the band gap of TiO2 nanocrystals for visible light application by offering a greener method. When an electrochemically active biofilm (EAB) was challenged with a solution of Degussa-TiO2 using sodium acetate as electron donor, greyish blue-colored TiO2 nanocrystals were obtained. Band gap study showed that band gap of the modified TiO2 nanocrystals was significantly reduced (Eg = 2.85 eV) compared to the unmodified white Degussa TiO2 (Eg = 3.10 eV).

Solution Chemistry Control To Make Well Defined Submicron Continuous Fibres By Electrospinning: The (Ch3ch2ch2o)4ti/Acoh/Poly(N-Vinylpyrrolidone) System, Gustavo Larsen, Maciej Skotak

Maciej Skotak

The (CH3CH2CH2O)4Ti/AcOH/poly(N-vinylpyrrolidone) system has been shown to yield suitable formulations for electrohydrodynamic (EHD) processing into continuous fibres and particles. The EHD processability of this, and generally most sol–gel-based formulations, into well defined fibres and particles with narrow submicron-range diameter distributions depends not only on the EHD process variables (electric field and flow rates), but also on the stability of key physical properties (e.g., conductivity, viscosity, surface tension, density and dielectric constant) of the sol over time. Sols that were almost certainly still undergoing hydrolysis and condensation reactions have been processed via EHD by many research groups to make materials with …

Modeling Complex Properties Of Ferroelectric Nanocomposites, Raymond T. Walter

Raymond Walter

No abstract provided.

Effect Of Ph On The Synthesis Of Cuo Nanosheets By Quick Precipitation Method, Mahdi Shahmiri

mahdi shahmiri

In this paper, copper oxide nanosheets were successfully fabricated in polyvinylpyrrolidone (PVP) via a quick precipitation method. The synthesized CuO nanostructures were characterized by X-ray diffraction (XRD), UV-vis spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy, energy dispersive analysis of X-ray, and Fourier transform infrared (FT-IR) spectroscopy. The effect of pH on the final product was investigated. The results show that a higher volume ratio of NaOH results in well-defined CuO nanosheets. XRD results confirmed the formation of pure CuO with a monoclinic structure at higher pH, whereas gerhardtite was formed at lower pH. TEM results indicate that …

Incorporating Polaritonic Effects In Semiconductor Nanowire Waveguide Dispersion, Lambert K. Van Vugt, Brian Piccione, Ritesh Agarwal

Lambert K Van Vugt

We present the calculated and measured energy-propagation constant (E-ß) dispersion of CdS nanowire waveguides at room temperature, where we include dispersive effects via the exciton-polariton model using physical parameters instead of a phenomenological equation. The experimental data match well with our model while the phenomenological equation fails to capture effects originating due to light-matter interaction in nanoscale cavities. Due to the excitonic-polaritonic effects, the group index of the guided light peaks close to the band edge, which can have important implications for optical switching and sensor applications.

Altin Metalurji̇si̇nde Yeni̇ Geli̇şmeler, Fathi Habashi

Fathi Habashi

Effect Of Bio Field Treatment On The Physical And Thermal Characteristics Of Vanadium Pentoxide Powders, Mahendra Kumar Trivedi, Shrikant Patil, Rama Mohan Tallapragada

Mahendra Kumar Trivedi

Voltage Tuning Of Ferromagnetic Resonance With Bistable Magnetization Switching In Energy-Efficient Magnetoelectric Composites, Ming Liu, Ziyao Zhou, Tianxiang Nan

Tianxiang Nan

No abstract provided.

Scaling Reversible Adhesion In Synthetic And Natural Adhesive Systems., Michael D. Bartlett, Duncan J. Irschick, Alfred J. Crosby

Michael Bartlett

No abstract provided.

Scaling Normal Adhesion Force Capacity With A Generalized Parameter, Michael D. Bartlett, Alfred J. Crosby

Michael Bartlett

Field Trip To Gold Mines In Canada And 25th Cmpnoq (In Turkish), Ahmet Deniz Bas

Ahmet Deniz Bas

No abstract provided.