Designing and Validating Parallel Wire Suspension Bridge Wire Strands for Neutron Diffraction Stress Mapping

2017 ◽  
Vol 905 ◽  
pp. 123-130
Author(s):  
Adrian Brügger ◽  
Seung Yub Lee ◽  
İsmail Cevdet Noyan ◽  
Raimondo Betti
Keyword(s):  
Neutron Diffraction ◽  
Steel Wire ◽  
National Laboratory ◽  
Suspension Bridge ◽  
Galvanized Steel ◽  
Element Analysis ◽  
Parallel Wire ◽  
Oak Ridge ◽  
Contact Points ◽  
Suspension Bridge Cables

Suspension-bridge cables are constructed from strands of galvanized steel wire. They are failure-critical structural members, so a fundamental understanding of their mechanics is imminently important in quantifying suspension bridge safety. The load-carrying capabilities of such strands after local wire failures have been the subject of many theoretical studies utilizing analytical equations and finite-element analysis. Little experimental data, however, exists to validate these models.Over the past five years we have developed a methodology for measuring stress/strain transfer within parallel wire strands of suspension bridge cables using neutron diffraction [1,2]. In this paper we describe the design and verification of parallel cable strands used in our studies. We describe the neutron diffraction strain measurements performed on standard 7-wire and expanded 19-wire models in various configurations at both the Los Alamos National Laboratory Spectrometer for Materials Research at Temperature and Stress (LANL SMARTS) and at the Oak Ridge National Laboratory VULCAN Engineering Materials Diffractometer (ORNL VULCAN). Particular attention is placed on the challenges of aligning and measuring multibody systems with high strain gradients at body-to-body contact points.

scholarly journals Preface: Special Topic on Advances in Modern Neutron Diffraction at Oak Ridge National Laboratory

2018 ◽  
Vol 89 (9) ◽  
pp. 092601
Author(s):  
Katharine Page ◽  
Bianca Haberl ◽  
Leighton Coates ◽  
Matthew Tucker
Keyword(s):  
Neutron Diffraction ◽  
National Laboratory ◽  
Special Topic ◽  
Oak Ridge ◽  
Oak Ridge National Laboratory

Neutron macromolecular crystallography

2018 ◽  
Vol 2 (1) ◽  
pp. 39-55 ◽  
Author(s):  
Matthew P. Blakeley ◽  
Alberto D. Podjarny
Keyword(s):  
Neutron Diffraction ◽  
Fluorescent Proteins ◽  
National Laboratory ◽  
Direct Determination ◽  
Drug Binding ◽  
Proton Accelerator ◽  
Biological Macromolecules ◽  
Macromolecular Crystallography ◽  
Neutron Sources ◽  
Oak Ridge

Neutron diffraction techniques permit direct determination of the hydrogen (H) and deuterium (D) positions in crystal structures of biological macromolecules at resolutions of ∼1.5 and 2.5 Å, respectively. In addition, neutron diffraction data can be collected from a single crystal at room temperature without radiation damage issues. By locating the positions of H/D-atoms, protonation states and water molecule orientations can be determined, leading to a more complete understanding of many biological processes and drug-binding. In the last ca. 5 years, new beamlines have come online at reactor neutron sources, such as BIODIFF at Heinz Maier-Leibnitz Zentrum and IMAGINE at Oak Ridge National Laboratory (ORNL), and at spallation neutron sources, such as MaNDi at ORNL and iBIX at the Japan Proton Accelerator Research Complex. In addition, significant improvements have been made to existing beamlines, such as LADI-III at the Institut Laue-Langevin. The new and improved instrumentations are allowing sub-mm3 crystals to be regularly used for data collection and permitting the study of larger systems (unit-cell edges >100 Å). Owing to this increase in capacity and capability, many more studies have been performed and for a wider range of macromolecules, including enzymes, signalling proteins, transport proteins, sugar-binding proteins, fluorescent proteins, hormones and oligonucleotides; of the 126 structures deposited in the Protein Data Bank, more than half have been released since 2013 (65/126, 52%). Although the overall number is still relatively small, there are a growing number of examples for which neutron macromolecular crystallography has provided the answers to questions that otherwise remained elusive.

Towards cryogenic neutron crystallography on the reduced form of [NiFe]-hydrogenase

2020 ◽  
Vol 76 (10) ◽  
pp. 946-953
Author(s):  
Takeshi Hiromoto ◽  
Koji Nishikawa ◽  
Seiya Inoue ◽  
Hiroaki Matsuura ◽  
Yu Hirano ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Data ◽  
Active Site ◽  
National Laboratory ◽  
Reduced Form ◽  
Desulfovibrio Vulgaris ◽  
X Rays ◽  
Oak Ridge ◽  
Fe Complex ◽  
Cryogenic Conditions

A membrane-bound hydrogenase from Desulfovibrio vulgaris Miyazaki F is a metalloenzyme that contains a binuclear Ni–Fe complex in its active site and mainly catalyzes the oxidation of molecular hydrogen to generate a proton gradient in the bacterium. The active-site Ni–Fe complex of the aerobically purified enzyme shows its inactive oxidized form, which can be reactivated through reduction by hydrogen. Here, in order to understand how the oxidized form is reactivated by hydrogen and further to directly evaluate the bridging of a hydride ligand in the reduced form of the Ni–Fe complex, a neutron structure determination was undertaken on single crystals grown in a hydrogen atmosphere. Cryogenic crystallography is being introduced into the neutron diffraction research field as it enables the trapping of short-lived intermediates and the collection of diffraction data to higher resolution. To optimize the cooling of large crystals under anaerobic conditions, the effects on crystal quality were evaluated by X-rays using two typical methods, the use of a cold nitrogen-gas stream and plunge-cooling into liquid nitrogen, and the former was found to be more effective in cooling the crystals uniformly than the latter. Neutron diffraction data for the reactivated enzyme were collected at the Japan Photon Accelerator Research Complex under cryogenic conditions, where the crystal diffracted to a resolution of 2.0 Å. A neutron diffraction experiment on the reduced form was carried out at Oak Ridge National Laboratory under cryogenic conditions and showed diffraction peaks to a resolution of 2.4 Å.

scholarly journals Preliminary neutron diffraction analysis of challenging human manganese superoxide dismutase crystals

2017 ◽  
Vol 73 (4) ◽  
pp. 235-240 ◽  
Author(s):  
Jahaun Azadmanesh ◽  
Scott R. Trickel ◽  
Kevin L. Weiss ◽  
Leighton Coates ◽  
Gloria E. O. Borgstahl
Keyword(s):  
Neutron Diffraction ◽  
Manganese Superoxide Dismutase ◽  
National Laboratory ◽  
Large Crystal ◽  
Neutron Data ◽  
Data Set ◽  
Cyclic Reduction ◽  
Oak Ridge ◽  
Manganese Superoxide ◽  
Enzymatic Mechanisms

Superoxide dismutases (SODs) are enzymes that protect against oxidative stress by dismutation of superoxide into oxygen and hydrogen peroxide through cyclic reduction and oxidation of the active-site metal. The complete enzymatic mechanisms of SODs are unknown since data on the positions of hydrogen are limited. Here, methods are presented for large crystal growth and neutron data collection of human manganese SOD (MnSOD) using perdeuteration and the MaNDi beamline at Oak Ridge National Laboratory. The crystal from which the human MnSOD data set was obtained is the crystal with the largest unit-cell edge (240 Å) from which data have been collectedvianeutron diffraction to sufficient resolution (2.30 Å) where hydrogen positions can be observed.

scholarly journals Neutron diffraction analysis ofPseudomonas aeruginosapeptidyl-tRNA hydrolase 1

2016 ◽  
Vol 72 (3) ◽  
pp. 220-223 ◽  
Author(s):  
Hana McFeeters ◽  
Venu Gopal Vandavasi ◽  
Kevin L. Weiss ◽  
Leighton Coates ◽  
Robert L. McFeeters
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Polyethylene Glycol ◽  
Neutron Diffraction ◽  
Room Temperature ◽  
Isopropyl Alcohol ◽  
National Laboratory ◽  
Neutron Diffraction Data ◽  
Batch Crystallization ◽  
Polyethylene Glycol 4000 ◽  
Oak Ridge

Perdeuterated peptidyl-tRNA hydrolase 1 fromPseudomonas aeruginosawas crystallized for structural analysis using neutron diffraction. Crystals of perdeuterated protein were grown to 0.15 mm3in size using batch crystallization in 22.5% polyethylene glycol 4000, 100 mMTris pH 7.5, 10%(v/v) isopropyl alcohol with a 20-molar excess of trilysine as an additive. Neutron diffraction data were collected from a crystal at room temperature using the MaNDi single-crystal diffractometer at Oak Ridge National Laboratory.

scholarly journals Extracting grain-orientation-dependent data fromin situtime-of-flight neutron diffraction. I. Inverse pole figures

2014 ◽  
Vol 47 (6) ◽  
pp. 2019-2029 ◽  
Author(s):  
G. M. Stoica ◽  
A. D. Stoica ◽  
K. An ◽  
D. Ma ◽  
S. C. Vogel ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
National Laboratory ◽  
Inverse Pole Figure ◽  
Face Centered Cubic ◽  
Oak Ridge ◽  
Weighting Factors ◽  
Quasi Monte Carlo ◽  
Grain Orientations ◽  
Engineering Materials

The problem of calculating the inverse pole figure (IPF) is analyzed from the perspective of the application of time-of flight neutron diffraction toin situmonitoring of the thermomechanical behavior of engineering materials. On the basis of a quasi-Monte Carlo (QMC) method, a consistent set of grain orientations is generated and used to compute the weighting factors for IPF normalization. The weighting factors are instrument dependent and were calculated for the engineering materials diffractometer VULCAN (Spallation Neutron Source, Oak Ridge National Laboratory). The QMC method is applied to face-centered cubic structures and can be easily extended to other crystallographic symmetries. Examples include 316LN stainless steelin situloaded in tension at room temperature and an Al–2%Mg alloy, substantially deformed by cold rolling andin situannealed up to 653 K.

Structural Performance of Eccentric Ferrocement Reinforced Concrete Columns

2019 ◽  
Vol 11 (9) ◽  
pp. 1213-1225
Author(s):  
Abeer M. Erfan ◽  
Hossam H. Ahmed ◽  
Bishoy A. Mina ◽  
Taha A. El-Sayed
Keyword(s):  
Reinforced Concrete ◽  
Volume Fraction ◽  
Steel Wire ◽  
Concrete Columns ◽  
Galvanized Steel ◽  
Experimental Program ◽  
Element Analysis ◽  
Reinforced Concrete Columns ◽  
Steel Mesh ◽  
Wire Meshes

This research proposed a method for producing reinforced composite concrete columns, reinforced with different types of steel wire meshes. The experimental program included casting and testing of nine square columns with dimensions of 200 mm × 200 mm × 1500 mm under eccentric compression load, with an eccentricity equaling 25 mm from the column center in x direction. The experimental program specimens comprised of four designation series to make comparative study between conventionally reinforced concrete columns. Concrete columns reinforced with steel bars and stirrups as control specimen and other groups were expanded steel mesh and welded steel mesh but the fourth group used modified and galvanized steel wire meshes of expanded and welded type. The main variables were type of reinforcing materials, number of layers and volume fraction of reinforcement. The main objective was to evaluate the effectiveness of employing the new materials in reinforcing the composite concrete columns in enhancing the confinement of concrete column and resistance for eccentric loads. Results indicated that this methodology of concrete columns reinforcement can be developed in high strength, crack resistance, high ductility and energy absorption properties. Moreover, Non-linear finite element analysis (NLFEA) was carried out to simulate the behaviour of the reinforced concrete columns under eccentric loads. The analytical model was agreed with experimental results employing ANSYS-14.5 Software.

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