Journal articles: 'Ex-situ testing'

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Hintsala, Eric D., Syed Asif, and Douglas D. Stauffer. "Correlative Nanomechanical Measurements for Complex Engineered Systems." MRS Advances 1, no. 12 (2016): 799–804. http://dx.doi.org/10.1557/adv.2016.76.

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ABSTRACTMultilayered film stacks, with length scales less than 10 nm are commonly used in a variety of devices, but present significant challenges to mechanical testing and evaluation. This is due to property convolution of the different layers. Both the properties of the individual layers and the combined response of the film stack are important input for design optimization. Here, we present ex-situ nanoindentation of a film stack representative of a perpendicular magnetic recording (PMR) hard disc drive (HDD), with more than 10 layers. We then compare this with in-situ transmission electron microscopy indentation to visualize deformation of individual layers of the stack. The ex-situ testing reveals early plastic deformation, with an initially high contact pressure (13 GPa) and modulus ( >160 GPa), followed by significant softening (8 GPa contact pressure and 140 GPa modulus), then slight hardening to 9 GPa. From in-situ testing, it is revealed that the metallic layer directly under the diamond like carbon (DLC) contributes the majority of the deformation and plastic flow, which is in turn constrained by a metallic oxide.

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Jiménez Zárate, Marian Teresa, Gisela Virginia Campos Angeles, Gerardo Rodríguez Ortiz, José Raymundo Enríquez del Valle, and Vicente Arturo Velasco Velasco. "Caracterización física ex-situ de Chamaedorea metallica como recurso forestal no maderable." E-CUCBA 9, no. 17 (December 29, 2021): 38–42. http://dx.doi.org/10.32870/ecucba.vi17.209.

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Seed quality analysis determines factors that can affect a seed lot or samples. The aim of the studio was determine physical qualityof a lot of seeds of the Chamaedorea metallica collected in two fruiting periods; March to September 2018 and February to April2019; They were collected from mother plants of Chamaedorea metallica in the Ye`tsil garden at the Technological Institute of theValley of Oaxaca. The fruits presented purple-purple coloration in the exocarp; they were cleaning process to obtain the seeds,which consisted of soaking the fruits in water for 48 hours, they washed with running water until the mesocarp was completelydetached. The seeds dried under shade for five days on bond paper. The analysis carried out according to the minimum parametersmentioned by the International Seed Testing Association (ISTA). Data of percentage of purity, weight, number of seeds per kgandmoisture content obtained. The data from the physical analysis differed in both years, obtaining the best results in moisture contentand weight in the seeds collected in 2019. We concluded that the seeds of the mother plants of Chamaedorea metallica are of goodquality; that the collection period and the time of the fruit on the plant influence their quality.

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Neyko, Ihor, Zinoviy Yurkiv, Mykhailo Matusiak, and Olena Kolchanova. "The current state and efficiency use of in situ and ex situ conservation units for seed harvesting in the central part of Ukraine." Folia Forestalia Polonica 61, no. 2 (July 1, 2019): 146–55. http://dx.doi.org/10.2478/ffp-2019-0014.

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Abstract Significant increase of biological stability, timber volume, and economic value of forests is impossible without refinement and improvement of the organization, and implementation of forest seed production on a genetic and breeding basis. It is possible to solve this task by creating and efficiently functioning in situ and ex situ facilities. In Ukraine, the basic principles of plus selection are envisaged, which include the selection and testing progeny of plus trees. The total number of progeny tests in Ukraine is 106 plots, in which 1,079 genotypes of plus trees are presented. Taking into account the total number of plus trees in Ukraine (4,560), only 23.7% was subjected to progeny tests. The largest number of progeny tests are represented by Scots pine (Pinus sylvestris L.) – 76 plots and a significantly smaller number of plots for English oak (Quercus robur L.) – 21. The corresponding representation of genotypes is for pine – 520, for oak – 365. The area of tree breeding units in Ukraine is very small (0.4–0.6%) of the total forest area in the region. Despite the available areas, the use of in situ and ex situ objects for harvesting seed in Ukraine is low, around 30%. In the central region of Ukraine, the share of in situ and ex situ objects from the total forest area is 0.1–0.5%. On these sites, from 0 to 54% is harvested, which is insufficient. According to the results of the conducted research, it was established that the areas of permanent forest-seed base (in situ and ex situ units) are insignificant and their use is insufficient. Testing of more than 70% of the selected plus trees is required. An important trend is to study the genotype-environment interaction in connection with trends of global climate change.

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Jayusman, A. Fiani, S. Pudjiono, and L. Hakim. "Ex-situ conservation through selection and breeding: A Review On 15 Years Toona sinensis Roem. & Toona sureni Merr. base populations." IOP Conference Series: Earth and Environmental Science 912, no. 1 (November 1, 2021): 012034. http://dx.doi.org/10.1088/1755-1315/912/1/012034.

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Abstract The ex-situ conservation of Toona sinensis and Toona sureni or surian weren’t supported list threatened species threat but by reduction of huge trees and leaving only small trees that are identical with the reduction of their genetic potential. Genetic potential plays a crucial role within the development of basic and breeding populations. The existence of the 15-year ex-situ conservation plot requires evaluation for simpler management to extend conservation value. The conservation area has collected genetic material from 52 populations from various islands in Indonesia and the progeny test area by testing 100 families from 10 selected populations because the basic source for assembling selected genetic material to supply superior seeds. Currently, genetic material from surian ex-situ conservation has been wont to develop genetic tests that are converted into seed orchards. Limitations of ex-situ conservation include maintenance of genetic material in artificial habitats, decreased genetic diversity, depression of close relative mating, adaptation to climate stress, and the potential for accumulation of weak alleles.it’s many constraints in terms of personnel, costs, and reliance on electrical power sources. supported the challenges within the future, efforts are needed to revamp through the unification of ex-situ conservation and progeny test management to support breeding population development. Strengthening the ex-situ conservation value of T. sinensis & T. sureni can be optimalization through solving all identified challenges and strengthening long-term management.

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Davison, Thomas A., Mark A. Norris, Joel L. Pfeffer, Jonathan J. Davies, and Robert A. Crain. "An EAGLE’s view of ex situ galaxy growth." Monthly Notices of the Royal Astronomical Society 497, no. 1 (June 24, 2020): 81–93. http://dx.doi.org/10.1093/mnras/staa1816.

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ABSTRACT Modern observational and analytical techniques now enable the direct measurement of star formation histories and the inference of galaxy assembly histories. However, current theoretical predictions of assembly are not ideally suited for direct comparison with such observational data. We therefore extend the work of prior examinations of the contribution of ex situ stars to the stellar mass budget of simulated galaxies. Our predictions are specifically tailored for direct testing with a new generation of observational techniques by calculating ex situ fractions as functions of galaxy mass and morphological type, for a range of surface brightnesses. These enable comparison with results from large field of view (FoV) Integral Field Unit (IFU) spectrographs, and increasingly accurate spectral fitting, providing a look-up method for the estimated accreted fraction. We furthermore provide predictions of ex situ mass fractions as functions of galaxy mass, galactocentric radius, and environment. Using z = 0 snapshots from the 100 and 25 cMpc3 EAGLE (Evolution and Assembly of GaLaxies and their Environments) simulations, we corroborate the findings of prior studies, finding that ex situ fraction increases with stellar mass for central and satellite galaxies in a stellar mass range of 2 × 107 to 1.9 × 1012 M⊙. For those galaxies of mass M* > 5 × 108 M⊙, we find that the total ex situ mass fraction is greater for more extended galaxies at fixed mass. When categorizing satellite galaxies by their parent group/cluster halo mass, we find that the ex situ fraction decreases with increasing parent halo mass at fixed galaxy mass. This apparently counterintuitive result may be due to high passing velocities within large cluster haloes inhibiting efficient accretion on to individual galaxies.

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Zhao, Nana, Harry Riley, Chaojie Song, Zhengming Jiang, Keh-Chyun Tsay, Roberto Neagu, and Zhiqing Shi. "Ex-Situ Evaluation of Commercial Polymer Membranes for Vanadium Redox Flow Batteries (VRFBs)." Polymers 13, no. 6 (March 17, 2021): 926. http://dx.doi.org/10.3390/polym13060926.

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Polymer membranes play a vital role in vanadium redox flow batteries (VRFBs), acting as a separator between the two compartments, an electronic insulator for maintaining electrical neutrality of the cell, and an ionic conductor for allowing the transport of ionic charge carriers. It is a major influencer of VRFB performance, but also identified as one of the major factors limiting the large-scale implementation of VRFB technology in energy storage applications due to its cost and durability. In this work, five (5) high-priority characteristics of membranes related to VRFB performance were selected as major considerable factors for membrane screening before in-situ testing. Eight (8) state-of-the-art of commercially available ion exchange membranes (IEMs) were specifically selected, evaluated and compared by a set of ex-situ assessment approaches to determine the possibility of the membranes applied for VRFB. The results recommend perfluorosulfonic acid (PFSA) membranes and hydrocarbon anion exchange membranes (AEMs) as the candidates for further in-situ testing, while one hydrocarbon cation exchange membrane (CEM) is not recommended for VRFB application due to its relatively high VO2+ ion crossover and low mechanical stability during/after the chemical stability test. This work could provide VRFB researchers and industry a valuable reference for selecting the polymer membrane materials before VRFB in-situ testing.

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Köhler, Daniel, Behdad Sadeghian, Robert Kupfer, Juliane Troschitz, Maik Gude, and Alexander Brosius. "A Method for Characterization of Geometric Deviations in Clinch Points with Computed Tomography and Transient Dynamic Analysis." Key Engineering Materials 883 (April 2021): 89–96. http://dx.doi.org/10.4028/www.scientific.net/kem.883.89.

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When joining lightweight parts of various materials, clinching is a cost efficient solution. In a production line, the quality of a clinch point is primarily controlled by measurement of dimensions, which are accessible from outside. However, methods such as visual testing and measuring the bottom thickness as well as the outer diameter are not able to deliver any information about the most significant geometrical characteristic of the clinch point, neck thickness and undercut. Furthermore, ex-situ destructive methods such as microsectioning cannot detect elastic deformations and cracks that close after unloading. In order to exceed the current limits, a new non-destructive in-situ testing method for the clinching process is necessary. This work proposes a concept to characterize clinch points in-situ by combining two complementary non-destructive methods, namely, computed tomography (CT) and ultrasonic testing. Firstly, clinch points with different geometrical characteristics are analysed experimentally using ex-situ CT to get a highly spatially resolved 3D-image of the object. In this context, highly X-ray attenuating materials enhancing the visibility of the sheet-sheet interface are investigated. Secondly, the test specimens are modelled using finite element method (FEM) and a transient dynamic analysis (TDA) is conducted to study the effect of the geometrical differences on the deformation energy and to qualify the TDA as a fast in-situ non-destructive method for characterizing clinch points at high temporal resolution.

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Marieb, T., J. C. Bravman, P. Flinn, D. Gardner, and M. Madden. "In situ observations of electromigration induced void behavior." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 244–45. http://dx.doi.org/10.1017/s0424820100137598.

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Electromigration and stress voiding have been active areas of research in the microelectronics industry for many years. While accelerated testing of these phenomena has been performed for the last 25 years[1-2], only recently has the introduction of high voltage scanning electron microscopy (HVSEM) made possible in situ testing of realistic, passivated, full thickness samples at high resolution.With a combination of in situ HVSEM and post-testing transmission electron microscopy (TEM) , electromigration void nucleation sites in both normal polycrystalline and near-bamboo pure Al were investigated. The effect of the microstructure of the lines on the void motion was also studied.The HVSEM used was a slightly modified JEOL 1200 EX II scanning TEM with a backscatter electron detector placed above the sample[3]. To observe electromigration in situ the sample was heated and the line had current supplied to it to accelerate the voiding process. After testing lines were prepared for TEM by employing the plan-view wedge technique [6].

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Sadeghi Alavijeh, A., S. V. Venkatesan, R. M. H. Khorasany, W. H. J. Kim, and E. Kjeang. "Ex-situ tensile fatigue-creep testing: A powerful tool to simulate in-situ mechanical degradation in fuel cells." Journal of Power Sources 312 (April 2016): 123–27. http://dx.doi.org/10.1016/j.jpowsour.2016.02.053.

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Jung, A., J. Luksch, S. Diebels, F. Schäfer, and C. Motz. "In-situ and ex-situ microtensile testing of individual struts of Al foams and Ni/Al hybrid foams." Materials & Design 153 (September 2018): 104–19. http://dx.doi.org/10.1016/j.matdes.2018.04.075.

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Satyanti, Annisa, Adrienne B. Nicotra, Thomas Merkling, and Lydia K. Guja. "Seed mass and elevation explain variation in seed longevity of Australian alpine species." Seed Science Research 28, no. 4 (March 15, 2018): 319–31. http://dx.doi.org/10.1017/s0960258518000090.

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AbstractConserving alpine ecosystems and the plant communities they contain using ex situ conservation requires an understanding of seed longevity. Knowledge of seed longevity may determine the effectiveness of ex situ seed banking for alpine plant conservation, and may provide insight into plant recruitment in situ. We sought to determine the influence of elevation and climatic variables, as well as plant and seed traits, on the seed longevity of 57 species inhabiting a unique biome, (sub-)alpine regions of mainland Australia. Seed longevity was estimated using controlled accelerated ageing tests to determine the time taken for seed viability to fall by 50%. We found that, across the study species, like alpine seeds elsewhere in the world, Australian alpine seeds are relatively short-lived and overall shorter-lived than Australian plants in general. Seed mass and elevation explained most of the variation in seed longevity among the Australian alpine species considered. Species with larger seed mass, and collections made at higher elevations, were found to have relatively short-lived seeds. Phylogeny, however, explained very little of the variation in longevity. Our results suggest that viability testing for Australian alpine seeds in ex situ seed banks should be conducted with shorter intervals than for the non-alpine flora. This study highlights how seed longevity in the Australian Alps is not dictated primarily by evolutionary lineage but rather by a complex combination of environmental variables and intrinsic seed characteristics. Potential implications for conservation ex situ and in situ in the context of climate change are discussed.

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Li, Xuejie, Peng Zhou, Kevin Ogle, Sebastian Proch, Manas Paliwal, Anna Jansson, and Jörgen Westlinder. "Transient stainless-steel dissolution and its consequences on ex-situ bipolar plate testing procedures." International Journal of Hydrogen Energy 45, no. 1 (January 2020): 984–95. http://dx.doi.org/10.1016/j.ijhydene.2019.10.191.

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Svitasheva, Svetlana. "Ellipsometry as Testing Method of Properties of Nano-Scale Films." Applied Mechanics and Materials 749 (April 2015): 146–54. http://dx.doi.org/10.4028/www.scientific.net/amm.749.146.

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Ellipsometry is power instrument for testing several properties of thin films. Advantage and attractiveness of these optical studies consist in that they are non-destructive and non-disturbing. High sensitivity to surface state allows us to monitoring properties of films beginning from atomic scale as in-situ and as ex situ. Ellipsometry give us information about film thickness, and film composition, and its surface morphology. From analysis of ellipsometric spectra it is possible get data about zone structure of semiconductor materials, such as energy of critical points, absorption edge location, and crystallinity. Speed of data acquisition is sufficient high to test dynamic of film growth. Ellipsometric measurements are quite simple but its interpretation requires special software. In this paper some possibilities of ellipsometric method are demonstrated in examples film polymorphism.

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Slodczyk, Aneta, Oumaya Zaafrani, Matthew Sharp, John Kilner, Bogdan Dabrowski, Olivier Lacroix, and Philippe Colomban. "Testing the Chemical/Structural Stability of Proton Conducting Perovskite Ceramic Membranes by in Situ/ex Situ Autoclave Raman Microscopy." Membranes 3, no. 4 (October 25, 2013): 311–30. http://dx.doi.org/10.3390/membranes3040311.

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Morgan, Quentin, John Pope, and Peter Ramsay. "Concurrent in-situ measurement of flow capacity, gas content and saturation." APPEA Journal 53, no. 1 (2013): 273. http://dx.doi.org/10.1071/aj12023.

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A new core-less testing capability has been developed to provide concurrent measurements of coal seam flow capacity and gas content at in-situ conditions. The fluid-based measurement principles are intended to overcome time constraints, accuracy limitations, and cost implications of discrete measurements attributed to traditional ex-situ measurements on core samples. Details of measurement principles, associated enabling technologies, and generic test procedures have been disclosed in a previous publication. In 2012 a number of field trials were conducted with this new service for both coal mine operators and CSG operators. This peer-reviewed paper will detail pre-job planning, well site execution, and data analysis for one of these trials, which involved testing several seams across two wells, and will illustrate comparison with data acquired using conventional testing techniques from offset wells. This peer-reviewed paper will also highlight key learnings and overall performance, and explain how the learned lessons can be applied to improve testing efficacy and data quality.

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Fan, Xiaowu, Mi-Kyoung Park, Chuanjun Xia, and Rigoberto Advincula. "Surface Structural Characterization and Mechanical Testing by Nanoindentation Measurements of Hybrid Polymer/clay Nanostructured Multilayer Films." Journal of Materials Research 17, no. 7 (July 2002): 1622–33. http://dx.doi.org/10.1557/jmr.2002.0240.

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Nanostructured montmorillonite/poly(diallyldimethylammonium chloride) multilayer thin films were fabricated up to 100 layers thick by stepwise alternating polyelectrolyte and clay deposition from solution. The structure and morphology of the films were characterized by x-ray diffraction, ellipsometry, atomic force microscopy, and quartz crystal microbalance ex situ and in situ measurements. The mechanical properties were tested by nanoindentation. The hardness of the multilayer thin film was 0.46 GPa. The thin film's modulus was correlated to its ordering and anisotropic structure. Both hardness and modulus of this composite film were higher than those of several other types of polymer thin films.

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Taheri, Hossein, Margaret Kilpatrick, Matthew Norvalls, Warren J. Harper, Lucas W. Koester, Timothy Bigelow, and Leonard J. Bond. "Investigation of Nondestructive Testing Methods for Friction Stir Welding." Metals 9, no. 6 (May 29, 2019): 624. http://dx.doi.org/10.3390/met9060624.

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Friction stir welding is a method of materials processing that enables the joining of similar and dissimilar materials. The process, as originally designed by The Welding Institute (TWI), provides a unique approach to manufacturing—where materials can be joined in many designs and still retain mechanical properties that are similar to, or greater than, other forms of welding. This process is not free of defects that can alter, limit, and occasionally render the resulting weld unusable. Most common amongst these defects are kissing bonds, wormholes and cracks that are often hidden from visual inspection. To identify these defects, various nondestructive testing methods are being used. This paper presents background to the process of friction stir welding and identifies major process parameters that affect the weld properties, the origin, and types of defects that can occur, and potential nondestructive methods for ex-situ detection and in-situ identification of these potential defects, which can then allow for corrective action to be taken.

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Young, James L. "(Energy Technology Division Supramaniam Srinivasan Young Investigator Award) Materials and Capability Development in Photo- and Electro-chemical Electrons-to-Molecules (E2M) Device Research." ECS Meeting Abstracts MA2022-01, no. 36 (July 7, 2022): 1567. http://dx.doi.org/10.1149/ma2022-01361567mtgabs.

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In this talk, I will first give an overview of some recent work in photoelectrochemical (PEC) materials and device development as part of the HydroGEN Consortium. Within this consortium, I serve as the NREL lead and a capability expert for the PEC water splitting technology. Our group supports several, university-led seedling projects in developing various PEC materials and plays the central role in a national laboratory collaboration focused on improving PEC device durability. I will highlight the development and demonstration of our flagship capability for PEC device benchmarking and on-sun testing. In the second part of this talk, I will present some efforts in low-temperature electrolysis (LTE) research as part of the H2NEW Consortium and a Technology Commercialization Fund project. My work focuses on ex-situ characterization of membrane electrode assembly (MEA) performance and development of porous transport layer (PTL) materials and surface modifications. The ex-situ characterization approaches are used in concert with in-situ testing to understand and improve LTE materials and interface properties. Finally, I will give an overview of NREL’s recent E2M electrochemical device testbed development for CO2 and N2 reduction research. This includes powerful, inline product analysis systems and custom hardware to study electrocatalyst integration, evaluate cell architectures, and conduct spatial and combinatorial studies.

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van Hintum, Theo, and Rob van Treuren. "Reliability of germination testing of ex situ conserved seeds: a genebank case study on outsourced analyses." Plant Genetic Resources 10, no. 2 (May 11, 2012): 134–36. http://dx.doi.org/10.1017/s1479262112000111.

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Germination tests are performed on a routine basis to determine the viability of genebank accessions. The results determine which accessions have to be rejuvenated. The reliability of the germination test results used by the Centre for Genetic Resources, the Netherlands was determined by the retesting of 641 random samples anonymously, in the same year and by the same testing agency as the original tests. Results showed alarmingly low reliabilities, with error levels much higher than expected based on sampling effects. The result of a germination test of a random sample with a germination of 80% was shown to have a 95% confidence interval from 63 to 97%. The errors differed strongly over crops and testing years, and were larger for crop wild relatives than for crop species.

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Li, Jing-Jian, Xin Liu, Bo Zhao, and Wen-Lan Li. "NPR1 gene transformation as assessed by germ cell in situ transformation pathway into Siraitia grosvenorii." Bangladesh Journal of Botany 44, no. 2 (October 13, 2018): 245–50. http://dx.doi.org/10.3329/bjb.v44i2.38513.

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NPR1 gene was transformed into Siraitia grosvenorii (Swingle) C. Jeffrey ex. A.M. Lu and Zhi Y. Zhang by germ cell in situ transformation. Ovary injection, cutting chapiter, and chapiter spreading treatments were applied in this study. The transgenic plants were selected using hygromycin screening and confirmed by PCR testing, genome integrated with NPR1 gene in transgenic plants was analyzed by Southern hybridization. Results showed that three treatments could produce transgenic plants. Some of the transgenic plants were selected for tobacco mosaic virus inoculation testing, which showed a higher level of resistance to tobacco mosaic virus than non-transgenic controls.

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van Rooyen, Melody, Thorsten Becker, and Mahmoud Mostafavi. "An Experimental Approach to the Application of Digital Image Correlation to Small Punch Creep Testing." MATEC Web of Conferences 347 (2021): 00026. http://dx.doi.org/10.1051/matecconf/202134700026.

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Deterioration assessment of materials is essential to the continued effective operation of critical components operating, at high temperatures and stresses, in thermal power plants. Within progressive inspection strategies, small punch creep testing (SPCT) presents an effective method for establishing the degree of creep exhaustion of in-service power engineering alloys on account of the small volume of material required (Ø8 mm × 0.5 mm discs). These tests make the application of complex strain fields, analogous to the strain field experienced by the service components, possible. In addition, this work explores the application of a noncontact digital image correlation (DIC) method to the full-field measurement of strains which is not possible through traditional extensometry. The accelerated SPCT tests were performed on 12 % Cr ex-service steels subjected to 600 °C. Experimental methodologies and challenges associated with ex situ DIC-SPCT are discussed including equipment and parameter selection, speckle pattern application, preforming requirements and loading method. It is shown that the developed DIC technique using a stereo microscope, airbrushed speckle patterns, sombrero-preformed discs and interrupted tests can be used to compare surface strain development in various aged forms of the ex-service steel. Such an approach is valuable to understanding strain development in small punch tests and to assist in the comparative damage assessment of ex-service power plant materials.

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Filter, Josefine, Christin Bosinsky, Sefine Oksal Kilinc, Aki Sebastian Ruhl, and Martin Jekel. "In-situ fixed bed denitrification in sequential biofiltration: laboratory testing of solid substrates." Journal of Water Reuse and Desalination 10, no. 4 (May 22, 2020): 394–404. http://dx.doi.org/10.2166/wrd.2020.005.

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Abstract High nitrate concentrations in wastewater treatment plant effluents and aquifers can challenge sequential biofiltration systems in preventing nitrite and gas formation in the sand bed, as well as to achieve the regulated limit value for nitrate in potable water reuse applications. This study investigates the introduction of electron donors in the form of organic fixed bed materials as an in-situ anoxic zone into sequential biofiltration systems. Laboratory batch and column tests with straw, soft wood, peat, polylactic acid (PLA), and polycaprolacton (PCL) revealed incomplete denitrification with a hydraulic retention time below 10 h, high organic carbon leaching, especially during the first three months, and gas accumulation within the filter bed. Therefore, ex-situ denitrification prior to oxic biofilters or in a defined side-stream treatment is recommended. No enhanced transformation of trace organic chemicals was observed under nitrate reducing conditions. Peat revealed a sorption potential for 5-methyl-benzotriazole, carbamazepine, benzotriazole, and metoprolol.

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Fernández Silva, B., J. Kawalko, K. Muszka, M. Jackson, K. Fox, and B. P. Wynne. "Deformation modes investigation during ex-situ dwell fatigue testing in a bimodal near-α titanium alloy." International Journal of Fatigue 163 (October 2022): 107098. http://dx.doi.org/10.1016/j.ijfatigue.2022.107098.

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Ahuja, M. R. "Strategies for conservation of germplasm in endemic redwoods in the face of climate change: a review." Plant Genetic Resources 9, no. 3 (February 4, 2011): 411–22. http://dx.doi.org/10.1017/s1479262111000153.

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This study reviews the various conservation strategies applied to the four redwood species, namely coast redwood (Sequoia sempervirens), Sierra redwood or giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides) and South American redwood or alerce (Fitzroya cupressoides), which are endemic in the USA, China and South America, respectively. All four redwood genera belong to the family Cupressaceae; they are monospecific, share a number of common phenotypic traits, including red wood, and are threatened in their native ranges due to human activity and a changing climate. Therefore, the management objective should be to conserve representative populations of the native species with as much genetic diversity as possible for their future survival. Those representative populations exhibiting relatively high levels of genetic diversity should be selected for germplasm preservation and monitored during the conservation phase by using molecular markers. In situ and ex situ strategies for the preservation of germplasm of the redwoods are discussed in this study. A holistic in situ gene conservation strategy calls for the regeneration of a large number of diverse redwood genotypes that exhibit adequate levels of neutral and adaptive genetic variability, by generative and vegetative methods for their preservation and maintenance in their endemic locations. At the same time, it would be desirable to conserve the redwoods in new ex situ reserves, away from their endemic locations with similar as well as different environmental conditions for testing their growth and survival capacities. In addition, other ex situ strategies involving biotechnological approaches for preservation of seeds, tissues, pollen and DNA in genebanks should also be fully exploited in the face of global climate change.

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Quinn, R. M., L. H. Zhang, M. J. Cox, D. Townsend, T. Cartwright, G. Aldrich-Smith, P. A. Hooper, and J. P. Dear. "Development and Validation of a Hopkinson Bar for Hazardous Materials." Experimental Mechanics 60, no. 9 (August 18, 2020): 1275–88. http://dx.doi.org/10.1007/s11340-020-00638-w.

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Abstract Background There are a variety of approaches that can be employed for Hopkinson bar compression testing and there is no standard procedure. Objectives A Split-Hopkinson pressure bar (SHPB) testing technique is presented which has been specifically developed for the characterisation of hazardous materials such as radioactive metals. This new SHPB technique is validated and a comparison is made with results obtained at another laboratory. Methods Compression SHPB tests are performed on identical copper specimens using the new SHPB procedures at Imperial College London and confirmatory measurements are performed using the well-established configuration at the University of Oxford. The experiments are performed at a temperature of 20 ∘C and 200 ∘C. Imperial heat the specimens externally before being inserted into the test position (ex-situ heating) and Oxford heat the specimens whilst in contact with the pressure bars (in-situ heating). For the ex-situ case, specimen temperature homogeneity is investigated both experimentally and by simulation. Results Stress-strain curves were generally consistent at both laboratories but sometimes discrepancies fell outside of the inherent measurement uncertainty range of the equipment, with differences mainly attributed to friction, loading pulse shapes and pulse alignment techniques. Small metallic specimens are found to be thermally homogenous even during contact with the pressure bars. Conclusion A newly developed Hopkinson bar for hazardous materials is shown to be effective for characterising metals under both ambient and elevated temperature conditions.

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Cokendolpher, James C. "Tropical Pitcher Plant (Nepenthes: Nepenthaceae) Pollen Germinability and Storage: Conservation Implications." Carnivorous Plant Newsletter 35, no. 1 (March 1, 2006): 23–29. http://dx.doi.org/10.55360/cpn351.jc560.

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In order to better understand options available for ex situ production of seeds, studies were undertaken to better define methods for collection and viability testing of pollen of Nepenthes ampullaria, N. tentaculata, and N. ventricosa. Methods for storage of pollen of a model species N. ventricosa were compared. Although the results discussed are preliminary, they give us a glimpse of what is possible and some recommendations for prolonged storage are made.

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Taran, Yu V., Jürgen Schreiber, Mark R. Daymond, and E. C. Oliver. "Fatigue Degradation and Martensitic Transformation of Austenitic Stainless Steel AlSi 321: New Results and Prospects." Materials Science Forum 524-525 (September 2006): 899–904. http://dx.doi.org/10.4028/www.scientific.net/msf.524-525.899.

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On ECRS-6 [1], we have presented first results of the researches of fatigue degradation and martensitic transformation of austenitic stainless steel AISI 321 by neutron diffraction stress analysis. A series of samples preliminary ex-situ cyclically fatigued at the frequency of 5 and 0.5 Hz was in-situ tested on the stress rig of the ENGIN instrument. In the high cycle fatigued (HCF) samples, the applied stress-elastic strain responses of austenite and martensite phases were find out to be strongly different as compared to the low cycle fatigued (LCF) samples, in which they are close. Moreover, the martensite Poisson ratio in the HCF-samples is almost twice to that of observed 0.28-0.30 in austenite and in both phases of the LCF-samples. With the purpose to search the reason of such unusual behavior of the martensite phase, one of the HCF-samples has been anew in-situ tested on the stress rig of the ENGIN-X in: 1) a LCF-mode at the frequency of 0.1 Hz to increase the fatigue level, and 2) a quasistatic mode to measure the applied stress-elastic strain responses of both phases. Also, two of the LCF-samples have been subjected to the ex-situ secondary HCF-testing at the frequency of 5 Hz and again in-situ measured on the ENGIN-X stress rig. Results of the mechanical characterization of phases in the twice fatigued austenitic stainless steel are presented and discussed.

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Ziółkowski, Grzegorz, Konrad Gruber, Emilia Tokarczyk, Robert Roszak, and Matthias Ziegenhorn. "X-ray Computed Tomography for the ex-situ mechanical testing and simulation of additively manufactured IN718 samples." Additive Manufacturing 45 (September 2021): 102070. http://dx.doi.org/10.1016/j.addma.2021.102070.

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Ringler, Eva. "The use of cross-species testing of microsatellite markers and sibship analysis in ex situ population management." Conservation Genetics Resources 4, no. 3 (April 18, 2012): 815–19. http://dx.doi.org/10.1007/s12686-012-9642-5.

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Eissa, Essam M., Mohammed H. Elkomy, Hussein M. Eid, Adel A. Ali, Mohammed A. S. Abourehab, Amal M. Alsubaiyel, Ibrahim A. Naguib, Izzeddin Alsalahat, and Amira H. Hassan. "Intranasal Delivery of Granisetron to the Brain via Nanostructured Cubosomes-Based In Situ Gel for Improved Management of Chemotherapy-Induced Emesis." Pharmaceutics 14, no. 7 (June 29, 2022): 1374. http://dx.doi.org/10.3390/pharmaceutics14071374.

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This research aimed to boost granisetron (GS) delivery to the brain via the intranasal route to better manage chemotherapy-induced emesis. Glycerol monooleate (GMO), Poloxamer 407 (P 407) and Tween 80 (T 80) were used to formulate GS-loaded cubosomes (GS-CBS) utilizing a melt dispersion-emulsification technique. GS-CBS were characterized by testing particle diameter, surface charge and entrapment efficiency. The formulations were optimized using a Box–Behnken statistical design, and the optimum formula (including GMO with a concentration of 4.9%, P 407 with a concentration of 10%, and T 80 with a concentration of 1%) was investigated for morphology, release behavior, ex vivo permeation through the nasal mucosa, and physical stability. Moreover, the optimal formula was incorporated into a thermosensitive gel and subjected to histopathological and in vivo biodistribution experiments. It demonstrated sustained release characteristics, increased ex vivo permeability and improved physical stability. Moreover, the cubosomal in situ gel was safe and biocompatible when applied to the nasal mucosa. Furthermore, compared to a drug solution, the nose-to-brain pathway enhanced bioavailability and brain distribution. Finally, the cubosomal in situ gel may be a potential nanocarrier for GS delivery to the brain through nose-to-brain pathway.

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Brepols, C., K. Drensla, A. Janot, M. Trimborn, and N. Engelhardt. "Strategies for chemical cleaning in large scale membrane bioreactors." Water Science and Technology 57, no. 3 (February 1, 2008): 457–63. http://dx.doi.org/10.2166/wst.2008.112.

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Systematically testing alternative cleaning agents and cleaning procedures on a large scale municipal membrane bioreactor, the Erftverband optimized the cleaning strategies and refined the original cleaning procedures for the hollow fiber membranes in use. A time-consuming, intensive ex-situ membrane cleaning twice a year was initially the regular routine. By introducing the effective means of cleaning in place in use today, which employs several acidic and oxidative/alkaline cleaning steps, intensive membrane cleaning could be delayed for years. An overview and an assessment of various cleaning strategies for large scale plants are given.

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Shirodker, A., S. Bhangle, and R. Gude. "FORMULATION DEVELOPMENT AND EVALUATION OF AN IN SITU OPHTHALMIC GELLING SYSTEM OF BRIMONIDINE TARTRATE AND TIMOLOL MALEATE FOR THE TREATMENT OF GLAUCOMA." INDIAN DRUGS 54, no. 02 (February 25, 2017): 76–78. http://dx.doi.org/10.53879/id.54.02.10854.

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The present study involved formulation of an in situ gelling system of brimonidine tartrate and timolol maleate for the treatment of glaucoma. Carbopol® 980 NF, xanthum gum and hydroxypropyl methylcellulose K4 M were used as polymers. The prepared in situ gelling systems were evaluated for clarity, appearance, texture analysis, pH, viscosity, rheological properties, in vitro gelation, isotonicity, drug content uniformity, in vitro release studies, microbiological evaluation, ex vivo release studies and stability testing. The results of the attenuated total reflectance spectroscopy and differential scanning calorimetry studies confirmed that there is no incompatibility between the drugs and the excipients. The formulations exhibited pseudoplastic rheology and formulation 3 showed the highest release of both the drugs from the formulation. The stability studies showed that the formulation was stable over the given period of time. Thus, it is evident that the in situ gelling system is a promising drug delivery system for the treatment of glaucoma.

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Kathavate, V. S., K. Eswar Prasad, Mangalampalli S. R. N. Kiran, and Yong Zhu. "Mechanical characterization of piezoelectric materials: A perspective on deformation behavior across different microstructural length scales." Journal of Applied Physics 132, no. 12 (September 28, 2022): 121103. http://dx.doi.org/10.1063/5.0099161.

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Piezoelectric materials (PEMs) find a wide spectrum of applications that include, but are not limited to, sensors, actuators, semiconductors, memory devices, and energy harvesting systems due to their outstanding electromechanical and polarization characteristics. Notably, these PEMs can be employed across several length scales (both intrinsic and extrinsic) ranging from mesoscale (bulk ceramics) to nanoscale (thin films) during their applications. Over the years, progress in probing individual electrical and mechanical properties of PEM has been notable. However, proportional review articles providing the mechanical characterization of PEM are relatively few. The present article aims to give a tutorial on the mechanical testing of PEMs, ranging from the conventional bulk deformation experiments to the most recent small-scale testing techniques from a materials science perspective. The advent of nanotechnology has led materials scientists to develop in situ testing techniques to probe the real-time electromechanical behavior of PEMs. Therefore, this article presents a systematic outlook on ex situ and in situ deformation experiments in mechanical and electromechanical environments, related mechanical behavior, and ferroelectric/elastic distortion during deformation. The first part provides significant insights into the multifunctionality of PEM and various contributing microstructural length scales, followed by a motivation to characterize the mechanical properties from the application's point of view. In the midst, the mechanical behavior of PEM and related mechanical characterization techniques (from mesoscale to nanoscale) are highlighted. The last part summarizes current challenges, future perspectives, and important observations.

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McCallum, Adrian B., Damon Kent, and Denham Lee. "Sugar as an Analogue for Snow in Penetration Testing: A Preliminary Comparison." Powders 1, no. 1 (February 24, 2022): 33–46. http://dx.doi.org/10.3390/powders1010004.

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Snow is a sintered matrix of ice, the strength of which is determined by the number and size of bonds between ice grains. However, because snow is a thermally unstable material, it is problematic to transport and store samples for accurate ex situ testing of mechanical behaviour. As an analogue for snow, we examined the sintering behaviour of different types of granular sugar at different humidities over different temporal periods and then assessed the extent of sintering and resistance to penetration of these samples. Like snow, increased sintering occurs in sugar over time. Sintering extent and rate are affected by the humidity environment and penetration resistance generally increases after increased sintering time. This preliminary examination suggests that in the absence of snow testing facilities, humidity-controlled sintered sugar may serve as a valuable proxy for examining the temporal variation of penetration resistance in snow.

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Ngamkham, Komsan, Satian Niltawach, and Somrerk Chandra-ambhorn. "Development of Tensile Test to Investigate Mechanical Adhesion of Thermal Oxide Scales on Hot-Rolled Steel Strips Produced Using Different Finishing Temperatures." Key Engineering Materials 462-463 (January 2011): 407–12. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.407.

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The objective of this work was to carry out tensile tests to investigate the effect of finishing temperature on mechanical adhesion of thermal oxide scale on hot-rolled low carbon steel strips. Two hot-rolled low carbon steel strips were produced in an industrial hot rolling line by fixing a coiling temperature at 620 °C and varying finishing temperatures at 820 and 910 °C. Two testing methods were conducted. First, each of a number of samples was subjected to a given imposed strain with ex-situ imaging of scale surface after straining. Second, only one sample was strained in a test with ex-situ imaging of scale surface at every 2 mm elongation of the sample. A spallation ratio, an area where scale was spalled out and normalised by the total area observed by microscope, was plotted as a function of the imposed strain. These two methods gave the same tendency of results as follows. At a given strain, the spallation ratio of scale on steel produced using higher finishing temperature was larger. The gradient of spallation ratio with respect to the imposed strain of that scale was also steeper. This reflects the higher susceptibility of scale to spall out with increasing imposed strain. This behaviour might be related to the larger thickness of scale on steel produced using higher finishing temperature. For the second testing method, lowering the magnification of microscope to observe scale spallation from 50x to 20x increased R2 of the curve of spallation ratio versus the imposed strain, as well as improved the reproducibility of the test.

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Frei, Reto, Anthony S. Breitbach, and Helen E. Blackwell. "Expedient construction of small molecule macroarrays via sequential palladium- and copper-mediated reactions and their ex situ biological testing." Chemical Science 3, no. 5 (2012): 1555. http://dx.doi.org/10.1039/c2sc01089e.

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Wang, Wei-Chien, Wei-Hsing Huang, Ming-Yu Lee, Hoang Trung Hieu Duong, and Ya-Hui Chang. "Standardized Procedure of Measuring the pH Value of Cement Matrix Material by Ex-Situ Leaching Method (ESL)." Crystals 11, no. 4 (April 17, 2021): 436. http://dx.doi.org/10.3390/cryst11040436.

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According to the Spanish National Research Council (CSIC) report, the ex-situ leaching method (ESL) is more appropriate and accurate than other methods for measuring pH value in terms of repeatability and reproducibility. In this study, the ESL method was used to measure the pH value of cement matrix materials. The design test process aimed to avoid underestimating the variation in pH during the process of solution stirring and pH measurement without using both argon and nitrogen to block the specimen contact with air, with good repeatability and reproducibility. This study also considered the influence of the dryness of the specimen before crushing, the size of the powder, the air-exposed specimen, the air-exposed solution, the temperature of the solution, etc. After testing and analysis, a standard procedure for detecting the pH value of cement matrix materials was established which is known as the S-ESL method.

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Kohli, Nupur, Prasad Sawadkar, Sonia Ho, Vaibhav Sharma, Martyn Snow, Sean Powell, Maria A. Woodruff, Lilian Hook, and Elena García-Gareta. "Pre-screening the intrinsic angiogenic capacity of biomaterials in an optimised ex ovo chorioallantoic membrane model." Journal of Tissue Engineering 11 (January 2020): 204173142090162. http://dx.doi.org/10.1177/2041731420901621.

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Biomaterial development for clinical applications is currently on the rise. This necessitates adequate in vitro testing, where the structure and composition of biomaterials must be specifically tailored to withstand in situ repair and regeneration responses for a successful clinical outcome. The chorioallantoic membrane of chicken embryos has been previously used to study angiogenesis, a prerequisite for most tissue repair and regeneration. In this study, we report an optimised ex ovo method using a glass-cling film set-up that yields increased embryo survival rates and has an improved protocol for harvesting biomaterials. Furthermore, we used this method to examine the intrinsic angiogenic capacity of a variety of biomaterials categorised as natural, synthetic, natural/synthetic and natural/natural composites with varying porosities. We detected significant differences in biomaterials’ angiogenesis with natural polymers and polymers with a high overall porosity showing a greater vascularisation compared to synthetic polymers. Therefore, our proposed ex ovo chorioallantoic membrane method can be effectively used to pre-screen biomaterials intended for clinical application.

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Zhang, Ruopeng, Shiteng Zhao, Colin Ophus, Yu Deng, Shraddha J. Vachhani, Burak Ozdol, Rachel Traylor, et al. "Direct imaging of short-range order and its impact on deformation in Ti-6Al." Science Advances 5, no. 12 (December 2019): eaax2799. http://dx.doi.org/10.1126/sciadv.aax2799.

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Chemical short-range order (SRO) within a nominally single-phase solid solution is known to affect the mechanical properties of alloys. While SRO has been indirectly related to deformation, direct observation of the SRO domain structure, and its effects on deformation mechanisms at the nanoscale, has remained elusive. Here, we report the direct observation of SRO in relation to deformation using energy-filtered imaging in a transmission electron microscope (TEM). The diffraction contrast is enhanced by reducing the inelastically scattered electrons, revealing subnanometer SRO-enhanced domains. The destruction of these domains by dislocation planar slip is observed after ex situ and in situ TEM mechanical testing. These results confirm the impact of SRO in Ti-Al alloys on the scale of angstroms. The direct confirmation of SRO in relationship to dislocation plasticity in metals can provide insight into how the mechanical behavior of concentrated solid solutions by the material’s thermal history.

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Randall, Nicholas X., Matthieu Vandamme, and Franz-Josef Ulm. "Nanoindentation analysis as a two-dimensional tool for mapping the mechanical properties of complex surfaces." Journal of Materials Research 24, no. 3 (March 2009): 679–90. http://dx.doi.org/10.1557/jmr.2009.0149.

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Instrumented indentation (referred to as nanoindentation at low loads and low depths) has now become established for the single point characterization of hardness and elastic modulus of both bulk and coated materials. This makes it a good technique for measuring mechanical properties of homogeneous materials. However, many composite materials are composed of material phases that cannot be examined in bulk form ex situ (e.g., carbides in a ferrous matrix, calcium silicate hydrates in cements, etc.). The requirement for in situ analysis and characterization of chemically complex phases obviates conventional mechanical testing of large specimens representative of these material components. This paper will focus on new developments in the way that nanoindentation can be used as a two-dimensional mapping tool for examining the properties of constituent phases independently of each other. This approach relies on large arrays of nanoindentations (known as grid indentation) and statistical analysis of the resulting data.

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Lall, Amrita, Paul Bowen, and Afsaneh Rabiei. "A numerical and experimental approach to compare the effect of sample thickness in small in-situ SEM and large ex-situ tensile testing in Alloy 709." Materials Characterization 184 (February 2022): 111614. http://dx.doi.org/10.1016/j.matchar.2021.111614.

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Dong, Hui Min, Xue Feng An, Xiao Su Yi, and Zheng Tao Su. "The Use of Quasi-Static Indentation Testing to Evaluate Low-Velocity Impact Resistance of Ex Situ Toughened Composite." Applied Mechanics and Materials 697 (November 2014): 35–40. http://dx.doi.org/10.4028/www.scientific.net/amm.697.35.

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The aim of this study was to investigate the valuable impact damage parameters from quasi-static indentation testing to access the low-velocity impact behaviour of ex-situ toughened composites by comparing low-velocity impact and quasi-static test results (the same boundary conditions). In terms of the delamination damage threshold load and indentation depth, quasi-static tests predicted the impact damage resistance well. However, only very conservative estimates of maximum load due to the final fibre failure under higher energy level were achieved. This phenomenon is attributed to two factors. First, energy during quasi-static indentation event is completely transformed or absorbed by the laminate, where it is stored elastically in panel bending or absorbed by the creation of damage, without the energy in the form of vibration, heat, inelastic behaviour of the impactor or the supports. Second, strain rate effect may have a remarkable influence on the fibre failure but on undamaged and delaminated damage.

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Rodríguez-Sánchez, Victoria, Lourdes Encina-Encina, Amadora Rodríguez-Ruiz, and Ramona Sánchez-Carmona. "Horizontal target strength of Luciobarbus sp. in ex situ experiments: Testing differences by aspect angle, pulse length and beam position." Fisheries Research 164 (April 2015): 214–22. http://dx.doi.org/10.1016/j.fishres.2014.11.020.

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Nieto-Peroy, Cristóbal, Marco Sabatini, Giovanni Palmerini, and Élcio Jeronimo de Oliveira. "A Concurrent Testing Facility Approach to Validate Small Satellite Combined Operations." Aerospace 8, no. 12 (November 24, 2021): 361. http://dx.doi.org/10.3390/aerospace8120361.

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Federated remote laboratories allow for the execution of experiments ex situ. The coordination of several laboratories can be used to perform concurrent experiments of combined space operations. However, the latency of the communications between facilities is critical to performing adequate real-time experiments. This paper presents an approach for conducting coordinated experiments between floating platforms at two remote laboratories. Two independently designed platforms, one at Luleå University of Technology and the other at La Sapienza University of Rome, were established for this purpose. A synchronization method based on the Simple Network Time Protocol was created, allowing the offset and delay between the agents to be measured.Both platforms exchange data about their measured time and pose through a UDP/IP protocol over the internet. This approach was validated with the execution of simulated operations. A first demonstrative experiment was also performed showing the possibility to realize leader/follower coordinated operations. The results of the simulations and experiments showed communication delays on the order of tens of milliseconds with no significant impact on the control performance. Consequently, the suggested protocol was proven to be adequate for conducting coordinated experiments in real time between remote laboratories.

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Zhang, Lei, and Shaogang Wang. "Correlation of Materials Property and Performance with Internal Structures Evolvement Revealed by Laboratory X-ray Tomography." Materials 11, no. 10 (September 21, 2018): 1795. http://dx.doi.org/10.3390/ma11101795.

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Although X-rays generated from a laboratory-based tube cannot be compared with synchrotron radiation in brilliance and monochromaticity, they are still viable and accessible in-house for ex situ or interrupted in situ X-ray tomography. This review mainly demonstrates recent works using laboratory X-ray tomography coupled with the measurements of properties or performance testing under various conditions, such as thermal, stress, or electric fields. Evolvements of correlated internal structures for some typical materials were uncovered. The damage features in a graded metallic 3D mesh and a metallic glass under mechanical loading were revealed and investigated. Micro-voids with thermal treatment and void healing phenomenon with electropulsing were clearly demonstrated and quantitatively analyzed. The substance transfer around an electrode of a Li-S battery and the protective performance of a Fe-based metallic glass coating on stainless steel were monitored through electrochemical processes. It was shown that in situ studies of the laboratory X-ray tomography were suitable for the investigation of structure change under controlled conditions and environments. An extension of the research for in situ laboratory X-ray tomography can be expected with supplementary novel techniques for internal strain, global 3D grain orientation, and a fast tomography strategy.

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Holloway, Justin, Maria Balart Murria, and Melanie J. Loveridge. "A Study of Stress Evolution and Deformation in Cylindrical Cells, from before Manufacturing to End of Life." ECS Meeting Abstracts MA2022-01, no. 37 (July 7, 2022): 1638. http://dx.doi.org/10.1149/ma2022-01371638mtgabs.

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The mass production of lithium-ion cells involves applying a range of manufacturing processes to a range of materials. These processes inevitably result in residual stresses within the individual materials, which when abetted by operational stresses can cause deformation and fracture of the componentry. This contributes to the degradation of electrochemical properties, device performance, and durability of the cells; leading ultimately to cell failure. This experimental study is concerned with determining the mechanical degradation of componentry within cylindrical cells. Mechanical degradation was evaluated for commercial cells using x-ray tomography, mechanical testing and microscopy. Nanoindentation testing was used to characterise mechanical changes in the foil material in three conditions: before cell manufacture, after cell manufacture and after aging. This work represents a novel ex situ characterisation tool and a new approach to understanding degradation in electrochemical systems. Additionally, we anticipate this work to aide modelling of and controlling degradation within electrochemical systems.

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Cumming, Denis J., Christopher Tumilson, S. F. Rebecca Taylor, Sarayute Chansai, Ann V. Call, Johan Jacquemin, Christopher Hardacre, and Rachael H. Elder. "Development of a diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) cell for the in situ analysis of co-electrolysis in a solid oxide cell." Faraday Discussions 182 (2015): 97–111. http://dx.doi.org/10.1039/c5fd00030k.

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Co-electrolysis of carbon dioxide and steam has been shown to be an efficient way to produce syngas, however further optimisation requires detailed understanding of the complex reactions, transport processes and degradation mechanisms occurring in the solid oxide cell (SOC) during operation. Whilst electrochemical measurements are currently conducted in situ, many analytical techniques can only be used ex situ and may even be destructive to the cell (e.g. SEM imaging of the microstructure). In order to fully understand and characterise co-electrolysis, in situ monitoring of the reactants, products and SOC is necessary. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) is ideal for in situ monitoring of co-electrolysis as both gaseous and adsorbed CO and CO₂ species can be detected, however it has previously not been used for this purpose. The challenges of designing an experimental rig which allows optical access alongside electrochemical measurements at high temperature and operates in a dual atmosphere are discussed. The rig developed has thus far been used for symmetric cell testing at temperatures from 450 °C to 600 °C. Under a CO atmosphere, significant changes in spectra were observed even over a simple Au|10Sc1CeSZ|Au SOC. The changes relate to a combination of CO oxidation, the water gas shift reaction, carbonate formation and decomposition processes, with the dominant process being both potential and temperature dependent.

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Seddon, Jennifer M., Kristen E. Lee, Stephen D. Johnston, Vere N. Nicolson, Michael Pyne, Frank N. Carrick, and William A. H. Ellis. "Testing the regional genetic representativeness of captive koala populations in South-East Queensland." Wildlife Research 41, no. 4 (2014): 277. http://dx.doi.org/10.1071/wr13103.

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Context Captive breeding for release back to the wild is an important component of ex situ conservation but requires genetic diversity that is representative of the wild population and has the ultimate goal of producing ecologically sustainable and resilient populations. However, defining and testing for representativeness of captive populations is difficult. Koalas (Phascolarctos cinereus) are bred for educational and tourism purposes in zoos and wildlife parks in South-East Queensland, but there are drastic declines evident in some wild koala populations in this region. Aim We compared genetic diversity at microsatellite loci and mitochondrial DNA in two captive koala populations with that of the local, wild koalas of South-East Queensland, determining the degree to which genetic diversity of neutral loci had been preserved and was represented in the captive populations. Key results The expected heterozygosity and the allelic richness was significantly greater in one captive colony than one wild South-East Queensland population. There was low but significant differentiation of the captive from wild populations using FST, with greater differentiation described by Jost’s Dest. In contrast, a newly introduced Kullback–Leibler divergence measure, which assesses similarity of allele frequencies, showed no significant divergence of colony and wild populations. The captive koalas lacked many of the mitochondrial haplotypes identified from South-East Queensland koalas and possessed seven other haplotypes. Conclusions Captive colonies of koalas have maintained levels of overall neutral genetic diversity similar to wild populations at microsatellite loci and low but significant differentiation likely resulted from drift and founder effects in small captive colonies or declining wild populations. Mitochondrial DNA suggests that captive founders were from a wider geographic source or that haplotypes have been lost locally. Implications Overall, tested captive koalas maintain sufficient microsatellite diversity to act as an in situ reservoir for neutral genetic diversity of regional populations.

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Liu, Jian, Min Wu, Jian Chen, Zibo Ye, Cheng Lin, Weiping Chen, and Canyi Du. "In-Situ Synthesis, Microstructure, and Mechanical Properties of TiB2-Reinforced Fe-Cr-Mn-Al Steel Matrix Composites Prepared by Spark Plasma Sintering." Materials 14, no. 9 (April 30, 2021): 2346. http://dx.doi.org/10.3390/ma14092346.

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In-situ synthesis, microstructure, and mechanical properties of four TiB2-Reinforced Fe-Cr-Mn-Al Steel Matrix Composites have been researched in this work. The microstructure and phases of the prepared specimens have been characterized by using scanning electron microscopy (SEM), X-ray diffraction technique, and transmission electron microscopy (TEM). The sintered specimens consisted of Fe2AlCr, CrFeB-type boride, and TiB2. The mechanical properties, such as hardness and compression strength at room temperature (RT) and at elevated temperatures (600 °C and 800 °C) have been evaluated. The compressive strength and Vickers hardness of the sintered specimens increase with the volume fraction of TiB2 in the matrix, which are all much higher than those of the ex-situ TiB2/Fe-15Cr-20Mn-8Al composites and the reported TiB2/Fe-Cr composites with the same volume fraction of TiB2. The highest Vickers hardness and compressive strength at room temperature are 1213 ± 35 HV and 3500 ± 20 MPa, respectively. As the testing temperature increases to 600 °C, or even 800 °C, these composites still show relatively high compressive strength. Precipitation strengthening of CrFeB and in-situ synthesis of TiB2 as well as nanocrystalline microstructure produced by the combination of mechanical alloying (MA) and spark plasma sintering (SPS) can account for the high Vickers hardness and compressive strength.

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Duan, Xudong, Huacui Wang, Yikai Jia, Lubing Wang, Binghe Liu, and Jun Xu. "A Multiphysics Understanding of Internal Short Circuit Mechanisms in Lithium-Ion Batteries upon Mechanical Stress Abuse." ECS Meeting Abstracts MA2022-02, no. 5 (October 9, 2022): 558. http://dx.doi.org/10.1149/ma2022-025558mtgabs.

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Lithium-ion batteries (LIBs) have played an increasingly dominant role in the current mobile society. Due to the risky safety testing procedure, ultra-rigorous demands of the testing facility, and complicated multiphysics nature of the safety issues, lack of high-fidelity models to describe the safety behaviors of lithium-ion batteries upon abusive loading has significantly deferred the further application of LIBs. Herein, firstly, mechanical behaviors of the battery component materials are characterized by both in-situ and post-mortem experiments. Then, we reveal the formation process of various internal short circuit (ISC) modes inside batteries upon different abusive loadings with the aid of ex-situ observation using the X-ray Computed Tomography scanning technique and post-mortem characterization of the battery samples. To quantify the stress-driven ISC mode and failure behavior of the component material, numerical models for all component materials are established and applied in a cell model which can reveal the deformation-material failure-material contact-different ISC mode formation process. To further quantify the relationship between electrothermal response and mechanical response of battery, we develop a 2D detailed model with fully coupling of electrochemo-thermal-mechanics governing laws consisting of a 2D mechanical model, 2D ISC model, 2D heat model and Thermal Runaway model. The multiphysics model demonstrates a promising generalization in various SOC and loading situations. Results highlight the power of computational modeling to understand the underlying mechanism of safety issues in energy storage systems in a broader context.

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Journal articles on the topic 'Ex-situ testing'

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