Materials Science and Engineering Commons^™

Silicone Tubing Extractables And Their Relationship To Particulates, Csilla Kollar

Single-Use Technologies: Bridging Polymer Science to Biotechnology Applications

Extractables and particulates information of single-use components including tubing is one of the primary considerations for their selection for pharmaceutical applications. The information is used to assess risk to patient safety, product compatibility, process performance and demonstrate due diligence to regulatory agencies. Many factors need to be considered in the extractables study design such as solvent choice, testing conditions including time, temperature and agitation, surface area to volume ratio, wall thickness, selection of analytical techniques, detection/quantitation limits, and expression of results. Studies must be performed under similar conditions that reflect those that can be encountered during use.

We have been …

Polyolefins And Their Influence On Single Use Technology For Bioprocessing, Amy Plancon, Marnik Vaes

Single-Use Technologies: Bridging Polymer Science to Biotechnology Applications

The presentation will focus on polyolefins and their use in single use systems for bioprocessing and the manufacture of biologic drugs. The nature of polyethylene and polypropylene will be explored, as well as material properties and how those properties can be influenced by the polymer manufacturer to meet specific needs in the market. This influence might include the introduction of additives, the substitution of specific ingredients, and the promotion/development of particular processing conditions. The impact of antioxidants will be presented, along with an overview of extractables and leachables protocol as they relate to the polyolefin family.

Pre-Construction Rock Treatment And Soil Modification Program Using Low Mobility Grout To Mitigate Future Sinkhole Development In A 2,787.1 Square Meter (30,000 Sf) Maintenance Facility, Steven W. Shifflett

Sinkhole Conference 2015

The US Army required construction of a 2,787.1 square meters (30,000 sf) maintenance facility supported on shallow foundations at the Fort Campbell Military Installation. During the subsurface investigation a seven foot air-filled void was encountered in the bedrock within the building footprint. Electrical Resistivity Imaging (ERI) was conducted in an attempt to determine the lateral extent of the encountered void and to establish the general prevalence of karst features at the site. Due to uncertainty in the subsurface conditions, a rock treatment and soil modification program was developed which consisted of a series of targeted exploratory grout holes advanced in …

Crystallization Engineering As A Route To Epitaxial Strain Control, Andrew R. Akbashev, Aleksandr V. Plokhikh, Dmitri Barbash, Samuel Lofland, Jonathan E. Spanier

College of Science & Mathematics Departmental Research

The controlled synthesis of epitaxial thin films offers opportunities for tuning their functional properties via enabling or suppressing strain relaxation. Examining differences in the epitaxial crystallization of amorphous oxide films, we report on an alternate, low-temperature route for strain engineering. Thin films of amorphous Bi–Fe–O were grown on (001)SrTiO3 and (001)LaAlO3substrates via atomic layer deposition. In situ X-ray diffraction and X-ray photoelectron spectroscopy studies of the crystallization of the amorphous films into the epitaxial (001)BiFeO3 phase reveal distinct evolution profiles of crystallinity with temperature. While growth on (001)SrTiO3 results in a coherently strained film, the same films obtained on (001)LaAlO3 …

Incorporation Of Fibrin Into A Collagen–Glycosaminoglycan Matrix Results In A Scaffold With Improved Mechanical Properties And Enhanced Capacity To Resist Cell-Mediated Contraction, Claire Brougham, Tanya J. Levingstone, Stefan Jockenhoevel, Thomas C. Flanagan, Fergal J. O'Brien

Articles

Fibrin has many uses as a tissue engineering scaffold, however many in vivo studies have shown a reduction in function resulting from the susceptibility of fibrin to cell-mediated contraction. The overall aim of the present study was to develop and characterise a reinforced natural scaffold using fibrin, collagen and glycosaminoglycan (FCG), and to examine the cell-mediated contraction of this scaffold in comparison to fibrin gels. Through the use of an injection loading technique, a homogenous FCG scaffold was developed. Mechanical testing showed a sixfold increase in compressive modulus and a thirtyfold increase in tensile modulus of fibrin when reinforced with …

Guest Of Honour Speech, Er Chew Keat Chuan

Shotcrete for Underground Support XII

No abstract provided.

Vernissage Flyer, Gina Klapperich

Shotcrete for Underground Support XII

No abstract provided.

Conference Program, Lu Ming, Oskar Sigl, Guojun Li

Shotcrete for Underground Support XII

No abstract provided.

Shotcrete For Underground Support Xii: Opening Comments, Herbert Klapperich

Shotcrete for Underground Support XII

No abstract provided.

Studying Fatigue Damage Evolution At Grain Boundaries Using Micro Mechanical Test Methods, Christian Motz

Nanomechanical Testing in Materials Research and Development V

Fatigue of materials and components is one of the main reasons that limit their lifetime and impacts sustainability. The ongoing miniaturization in many areas of modern technology, e.g. microelectronics, medical devices etc., requires the knowledge of mechanical properties in small dimensions to guarantee their reliability. The size of typical fatigue dislocation structures, which control the damage evolution, is in the order of micrometers. Hence, reducing the size of parts and components down into this regime raises the question, whether such microstructures can occurs or not and how this affects the damage evolution. For this reason, the development of fatigue microstructures …

Some Recent Advances In Nanomechanical Testing: High Strain Rates, Variable Temperatures, Fatigue And Stress Relaxation, Combinatorial Experimentation, J. Michler, J. Wehrs, G. Moharty, J. Schwiedrzik, G. Guillonneau, R. Schoeppner, J. Best, J.M. Wheeler, J.M. Breguet, Marcelo Conte

Nanomechanical Testing in Materials Research and Development V

In the first part of the talk, I will present two recently developed platforms for high temperature nanomechanical testing. The first platform allows for variable temperature and variable strain rate testing of micropillars in situ in the scanning electron microscope. By utilizing an intrinsically displacement-controlled micro-compression setup, which applies displacement using a miniaturized piezo-actuator, we’ve recently extended the attainable range of strain rates to up to~ 10³ s⁻¹, and enabled cyclic loading up to 10⁷ cycles and load relaxation tests. Stable, variable temperature indentation/micro-compression in the range of -45°C to 600°C is achieved through independent heating …

Limits Of Determining Stress States By Fib Method Due To Ga Implantation, Diana Courty, Alla Sologubenko, Stephan Gerstl, Ralph Spolenak

Nanomechanical Testing in Materials Research and Development V

In order to assess the stress state in different kinds of materials in a reliable and flexible way, a Focused Ion Beam Microscope (FIB) routine has been developed to obtain information on the stress state in a material, in particular in thin films [A-C]. This method, named FIB-DIC micron-scale ring-core method, is based on monitoring relaxation of the material during a progressively deeper milling with a FIB beam. With digital image correlation (DIC), the change in the feature position can be analyzed and converted in residual strain and then with some modelling to residual stress. The method has already been …

Cracking In Brittle Materials During Nanoindentation: New Insights Gained From Cohesive Zone Finite Element Modeling, George Pharr

Nanomechanical Testing in Materials Research and Development V

Cracking during nanoindentation of brittle solids with sharp pyramidal indenters like the Vickers and Berkovich has been modeled and systematically examined using cohesive zone finite element simulations. Although the initial stages of crack initiation cannot be adequately captured by these techniques, the cracks that form eventually evolve into long-crack geometries that behave much like those observed in experiment, provided the crack length is approximately ten times greater than the cohesive zone size. Once this is achieved, the simulations accurately describe how cracks grow and change during loading and unloading and how the sequence of cracking events depends on material parameters …

Thermo-Mechanical Characterization Of Polymer Samples Using Nanoindentation - From Bulk Characterization To Thin Film Properties, Dennis Bedorf, Martin Knieps, Wolfgang Stein

Nanomechanical Testing in Materials Research and Development V

Polymer films for the use of coating or structuring applications for small scale devices are widely used. For the raw bulk material the thermal and mechanical data are easily accessible and often supplied by the manufacturer. For the final use as a thin film, the verification of these properties is more difficult. Nanoindentation techniques can be used for the characterization of thin film due to the small-scaled mechanical stress field of the nanoindenter tip. Studies comparing nanoindentation data on bulk polymer samples with conventional DMA data show a good agreement in storage and in loss modulus [1]. Since thermal properties …

In-Situ Fracture Tests Of Brittle Materials At The Microscale, Giorgio Sernicola, Giovannini Tommaso, Rui Hao, T. Ben Britton, Finn Giuliani

Nanomechanical Testing in Materials Research and Development V

The fracture toughness of ceramics is often dominated by the structure of their grain boundaries. Our ability to improve life of ceramic components depends on our ability to investigate properties of individual grain boundaries.

This requires development of new fracture testing methods allowing high spatial resolution and high control over the area to test. Further benefits of these ‘small scale’ approaches will enable testing of specimens for which big volumes are not available (e.g. thin films, coating, or simply samples of dimensions limited by production process).

Recently, several techniques have been developed using small scaled mechanical testing, based within a …

Accessing The Phase Transformation And Deformation Behavior Of Metastable Stainless Steels Through Cyclic Nanoindentation, Ina Sapenzanskaia, J.J. Roa, A. Mateo, A. Redjaimia, R. Kouitat

Nanomechanical Testing in Materials Research and Development V

Austenitic metastable stainless steels are a materials group distinguished by their excellent mechanical properties, offering high potential for further improvement by thermo-mechanical treatments. Under deformation, these steels undergo a complex deformation and phase transformation. Their mechanical properties at macroscale, such as strength, ductility or fatigue behavior, have been largely investigated, yet they are not always predictable, as they highly depend on the microstructural characteristics of the material. In order to achieve a better understanding at the microstructural level, this work aims at the investigation of the deformation mechanisms in metastable stainless steels at sub-grain level and the interaction between grains. …

Extraction Of Crystal Plasticity Parameters Of In718 Using High Temperature Micro-Compression, Bin Gan, Aitor Cruzado, Marcos Jimenez, Koldo Ostolaza, Arantza Linaza, Javier Segurado, Javier Lloca, Jon Molina

Nanomechanical Testing in Materials Research and Development V

Ni-based superalloys are widely utilized in structural applications in aeroengine and power generation industries, owing to their exceptional high temperature mechanical properties in corrosive and oxidizing environments. Depending on the application fields, different types of superalloys with disparate microstructures are employed. For the turbine discs and some static components, forged or cast polycrystalline Ni-based superalloys are usually used. In the present investigation, site-specific micropillars with the diameter varying from 1 um to 18 um were milled out by Focused Ion Beam (FIB) from a polycrystalline IN718 superalloy specimen and then measured with high temperature micro-compression techniques up to 575 ºC. …

Fracture Toughness Measurement With Microscopic Chevron-Notched Specimens, Goran Zagar, Martin Mueller, Vaclay Pejchal, Lionel Michelet, Marta Fornabaio, Marco Cantoni, Andreas Morensen

Nanomechanical Testing in Materials Research and Development V

The fracture toughness of a material is, in theory, a rather well defined mechanical material property; for ideally brittle material, it is the stress intensity of a sharp crack present in the material at the moment when crack propagation becomes unstable. Measuring the fracture toughness of materials, however, has always been difficult, mainly because meeting the conditions under which the property is well defined can be a challenge. In testing of macroscopic samples the validity of measurements is most often deduced by confronting results of various established testing protocols and sample configurations with criteria derived on the basis of analysis …

Mechanical Properties Of Lithiated Silicon: A Candidate Electrode For Lithium Ion Batteries, William Nix, Lucas Berla

Nanomechanical Testing in Materials Research and Development V

Recent advances in nanoindentation of lithiated silicon are described. Silicon, due to its high theoretical specific capacity for electrochemical lithium incorporation, has emerged as one of the most appealing materials to replace conventional graphitic anodes in lithium ion batteries^. But inserting lithium into silicon causes a large volume expansion (~300%) that can promote fracture during lithiation/delithiation cycling, thereby reducing the practical capacity of silicon lithium ion battery anodes. Understanding these mechanical behavior problems is essential for their management and control. Current FEM modeling is based on only estimates of the elastic and properties of lithiated Si. Better knowledge of …

Nanoindentation Induced Deformation Anisotropy In Wc, Β-Si3n4 And Zrb2 Crystals, Tamas Csanadi, Dusan Nemeth, Alexandra Kovalcikova, Jan Dusza

Nanomechanical Testing in Materials Research and Development V

The influence of crystal orientation on elastic and plastic response of WC, β-Si₃N₄ and ZrB₂ ceramic grains is important to understand, model and enhance its composite mechanical properties. In order to investigate this, nanoindentation testing was carried out using Berkovich tip on selected surface areas which were mapped by electron backscatter diffraction (EBSD) prior to the tests. To study the surface morphology after nanoindentation and to characterize the resulted deformation fields around the imprints additional EBSD, atomic force microscopy (AFM) and scanning electron microscopy (SEM) investigations were performed. Considerable elastic and plastic anisotropy was found is …