Dissertations / Theses on the topic 'In situ testing'
To see the other types of publications on this topic, follow the link: In situ testing.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'In situ testing.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Williams, Valorie Sharron 1960. "In situ microviscoelastic measurements by polarization interferometry." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276691.
Full textAbstract:
A new type of computer-controlled instrument has been developed to measure microviscoelastic properties of thin materials. It can independently control and measure indentation loads and depths in situ revealing information about material creep and relaxation. Sample and indenter positions are measured with a specially designed polarization interferometer. Indenter loadings can be varied between 0.5 and 10 grams and held constant to ±41 mg. The resulting indentation depths can be measured in situ to ±1.2 nm. The load required to maintain constant indentation depths from 0.1 to 5.0 microns can be measured in situ to ±3.3 mg and the depth held constant to ±15 nm.
2
Hagen, Anette Brocks. "In-situ Compession Testing of Nanosized Pillars." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25618.
Full textAbstract:
Applications of nanomechanical testing methods have become increasingly important in all fields of material research. There is a significant interest in obtaining information about material features at small scales, in order to get a detailed characterization of the materials deformation behavior. To meet the needs, various experimental techniques have been developed to explore mechanical properties at micro-and nanoscale. So far, most small-scale mechanical testing methods have been done at room temperature, since it does not require the special modification of equipment. However, engineering materials are often used at temperatures other than room temperature. The oil and gas industry in the arctic areas are on increase and exploration of these fields require high strength materials capable of significantly reducing the probability of failure in the critical extreme environments. Iron alloys along with other metals are by far the most common metals used in the industry due to their great range of desirable properties.In view of the long-standing contradictory statements on the deformation of bcc single crystals and their macroscopic slip planes, recent insights and developments are reported in this thesis. The literatures reveals that the flow stress of Fe have a pronounced dependence of crystal orientation and temperature, mostly due to non-planar spreading of a/2<111> type dislocation cores [1]. They exhibit complex slip modes during deformation and show a severe glide direction sensitivity due to the dislocation core structure. Recently conducted experiments on pure Fe micropillars, shows that slip is activated on both {110} and {112} planes at room temperature. Additionally, slip systems with lower stressed planes are sometimes preferable. However, experimental confrontations of the slip behavior of pure Fe at low temperatures are generally missing in the literature.In the present investigation, attention is focused on constructing and developing a nanomechanical cooling system to study slip behavior of bcc α-Fe at low temperatures. The experimental work included in-situ uniaxial compression tests of Focused Ion Beam (FIB) fabricated pillars with a diameter of 1μm, in the single slip orientations <235> and <149>. Characterization of the crystallographic orientations was done by Electron Backscatter Diffraction (EBSD) analysis, where grains of interest were highlighted. The testing was conducted inside of a Scanning Electron Microscope (SEM) equipped with a PI85 PicoIndenter provided by Hysitron, and the constructed cooling system.From the experimental and analytical work it is concluded that the constructed cooling system has the capability to reduce the sample temperature down to -90°C, whereas the simultaneous cooling of the sample ensure reliable mechanical tests. From the in-situ compression tests at low temperatures, it is seen from slip trace analysis that slip is activated in both {110} and {112} planes, where slip systems with lower Schmid factors are more preferable than the ones with higher stresses, for <235> oriented pillars. Furthermore, it is observed an increased strength with decreasing temperature, by comparing the present results with Rogne and Thalow`s work [2], where Fe pillars of same size were tested at room temperature. The temperature dependency is more prominent for <235> oriented pillars, than for <149> oriented pillars. <235> oriented pillars exhibits 39.8% higher stress at 2.5% strain at -90°C, than <235> oriented pillars obtain at room temperature (1070MPa vs. 644MPa). For <149> oriented pillars a 10.3% higher stress is obtained at -90°C, than <149> oriented pillars obtain at room temperature (710 vs. 637MPa). It is assumed that the subsequent deformation mechanisms are affected of the relative microstructural features of the bcc structure for the different grain orientations. Additionally, activation of secondary slip systems could be aivresult of the breakdown of Schmid`s law as well as small misalignments between indenter tip and pillar top-surface.
3
Crouthamel, David Roger 1963. "In-situ flow testing of borehole plugs." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/291331.
Full textAbstract:
A cement borehole plug and a crushed tuff/bentonite clay mixture borehole plug were tested insitu in highly welded tuff. The hydraulic performance of the cement plug was evaluated through steady-state and transient hydraulic tests with a hydraulic conductivity in the range of 10⁻¹⁰ cm/s. A crushed tuff/bentonite mixture plug was tested through a steady-state flow test with a measured hydraulic conductivity of 10⁻⁹ cm/s. The plug was installed in a fractured borehole which was grouted to reduce the overall rockmass permeability. Installation procedures were evaluated in the laboratory prior to field installation. Installation of the cement seal with a bailer indicated seal degradation with water present in the borehole. Degradation appeared as piping, both internal and along the interface, and mixing of the cement with the water. Tests on the mixture seal indicated the need for homogeneous placement and adequate compaction to resist internal water piping and channelling.
4
Jailin, Clément. "Projection-based in-situ 4D mechanical testing." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLN034/document.
Full textAbstract:
L'analyse quantitative de volumes 3D obtenus par tomographie permet l’identification et la validation de modèles. La séquence d’analyse consiste en trois problèmes inverses successifs : (i) reconstruction des volumes (ii) mesure cinématique par corrélation d'images volumiques (DVC) et (iii) identification. Les très longs temps d’acquisition nécessaires interdisent de capter des phénomènes rapides. Une méthode de mesures, Projection-based Digital Volume Correlation (P-DVC), raccourcit la séquence précédente en identifiant les quantités clés sur les projections. Cette technique réduit jusqu'à 2 le nombre de radiographies utilisées pour le suivi de l’essai au lieu de 500 à 1000. Cette thèse étend cette approche en réduisant la quantité d’informations acquises, rendant ainsi accessibles des phénomènes de plus en plus rapides et repoussant les limites de la résolution temporelle. Deux axes ont ainsi été développés : - d’une part, l'utilisation de différentes régularisations, spatiales et temporelles des champs 4D (espace/temps) mesurés généralise la méthode P-DVC (avec volume de référence) à l'exploitation d’une seule radiographie par étape de chargement. L’essai peut désormais être réalisé de façon continue, en quelques minutes au lieu de plusieurs jours; - d’autre part, la mesure du mouvement peut être utilisée pour corriger le volume reconstruit lui-même. Cette observation conduit à proposer une nouvelle procédure de co-détermination du volume et de sa cinématique (sans prérequis), ce qui ouvre ainsi de nouvelles perspectives pour l’imagerie des matériaux et médicale où parfois le mouvement ne peut pas être interrompu. Le développement de ces deux axes permet d’envisager de nouvelles façons de réaliser les essais, plus rapides et plus centrés sur l’identification de quantités clés. Ces méthodes sont compatibles avec les récents développements « instrumentaux » de la tomographie rapide en synchrotron ou laboratoire, et permettent de réduire de plusieurs ordres de grandeurs les temps d’acquisition et les doses de rayonnementThe quantitative analysis of 3D volumes obtained from tomography allows models to be identified and validated. It consists of a sequence of three successive inverse problems: (i) volume reconstruction (ii) kinematic measurement from Digital Volume Correlation (DVC) and (iii) identification. The required very long acquisition times prevent fast phenomena from being captured.A measurement method, called Projection-based DVC (P-DVC), shortens the previous sequence and identifies the kinematics directly from the projections. The number of radiographs needed for tracking the time evolution of the test is thereby reduced from 500 to 1000 down to 2.This thesis extends this projection-based approach to further reduce the required data, letting faster phenomena be captured and pushing the limits of time resolution. Two main axes were developed:- On the one hand, the use of different spatial and temporal regularizations of the 4D fields (space/time) generalizes the P-DVC approach (with a known reference volume) to the exploitation of a single radiograph per loading step. Thus, the test can be carried out with no interruptions, in a few minutes instead of several days.- On the other hand, the measured motion can be used to correct the reconstructed volume itself. This observation leads to the proposition of a novel procedure for the joint determination of the volume and its kinematics (without prior knowledge) opening up new perspectives for material and medical imaging where sometimes motion cannot be interrupted.end{itemize}The development of these two axes opens up new ways of performing tests, faster and driven to the identification of key quantities of interest. These methods are compatible with the recent ``hardware" developments of fast tomography, both at synchrotron beamlines or laboratory and save several orders of magnitude in acquisition time and radiation dose
5
Greina, Kristine. "IN-SITU FRACTURE MECHANICAL TESTING OF MICROSIZED CANTILEVERS." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25617.
Full textAbstract:
The arctic is an appealing new ventures area for the oil and gas industry. However the climate is extremely demanding, and more technically challenging than any other environment. With design temperatures down to -60°C the ductile to brittle transition temperature (DBTT) is an important concern. The propagation of a brittle fracture in iron and steel requires much less energy than that associated with a ductile fracture. Once a material is cooled below the DBTT, it has a much greater tendency to shatter on impact instead of bending or deforming. The brittle-ductile behavior of BCC crystals has long been an area of intensive study, however the fundamental mechanisms that control the transition have not yet been explained. The rapid development within nanotechnology has made it possible to conduct small scale fracture experiments. The development of innovative nanomechanical testing techniques could lead to a better understanding of fracture properties at low temperatures, quantitative information on local stress requirements for crack propagation and subsequently explain the fundamental mechanisms that control the ductile to brittle transition. Advanced fracture experiments of pure iron at a micron scale have been completed. Electron Backscatter Diffraction analysis were conducted in order to determine the crystal orientation of the surface grains. Micro-cantilevers with dimensions of approximatly 2x2x10 μm were fabricated, in grains with preferred crystal orientation, by means of Focused Ion Beam (FIB) milling. The cantilevers were then loaded in a controlled manner to obtain load displacement data using a Picoinenter. The use of a picoindenter combine with a Scanning Electron Microscope (SEM) has shown to be a valuable tool since it allows events observed in the mechanical data to be correlated directly with the corresponding deformation mechanisms witnessed through the electron microscope. Extensive work has been put in to designing and constructing a cooling system, in order to conduct micro fracture experiments at low temperatures. The developed cooling system consists of a liquid nitrogen tank mounted on an SEM port, which is mechanically connected to the sample through a coldfinger. The thermal conductivity of the cooling system proved be sufficient; after approximately 1,5h a temperature of -90°C was reached, and loading of cantilevers at room temperature, -70°C and -90°C were successfully conducted. All cantilever were plastically deformed during loading, but no fracture occurred. Due to the absence of fracture the critical stress intensity factor, i.e. fracture toughness, could not be determined. However the preliminary stress intensity, (KQ) was calculated using five different methods. The results showed a drop in the preliminary stress intensity values between -70°C and -90°C. The KQ values may indicate the stress causing the first deviation from ideal elastic behavior by dislocation movement and plastic deformation. By this, the stress at which plastic deformation starts, decrease with decreasing temperature. It was not possible to measure the Crack Tip Opening Displacement (CTOD) directly during in-situ experiments, due to low image resolution. However, CTOD was calculated with two different methods: the hinge model and the double gauge model, both relying on the measurements of CMOD during loading. CTOD values for the two different methods were compared, however, they did not correlate. The double gauge model is probably the most accurate method since it is a direct approach and independent of the global behavior, whereas the hinge model relies on accurate values for the rotational center.
6
Akbar, Aziz. "Development of low cost in-situ testing devices." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364801.
Full text
7
Zhao, Yueyang. "In situ soil testing for foundation performance prediction." Thesis, University of Cambridge, 2008. https://www.repository.cam.ac.uk/handle/1810/283842.
Full text
8
Li, Jingyun Evans John L. "Alternate in-situ environmental testing system by matrix design." Auburn, Ala, 2009. http://hdl.handle.net/10415/1619.
Full text
9
Oswald, Louisa Jane, and n/a. "Usefulness of Macroinvertebrates for In Situ Testing of Water Quality." University of Canberra. Institute for Applied Ecology, 2008. http://erl.canberra.edu.au./public/adt-AUC20090107.130047.
Full textAbstract:
For various reasons, existing methods for the assessment of aquatic pollution do not always
adequately address the way in which contaminants affect receiving environments and their
component ecosystems. The main advantage of biological assessment over the measurements
of physical and chemical aspects of water quality is that biota provide an integrated response
to all prevailing influences in their environment. Biological assessment protocols have been
developed for a range of test organisms, from bacteria to mammals using measurement from
molecular biomarkers to indicators at the population or community level of organisation.
Macroinvertebrates in particular have been popular for ecological assessment of habitat and
water quality because they are small and straight forward to sample and identify using
relatively simple and inexpensive equipment and readily available taxonomic keys.
However, various biological assessment techniques also have their limitations. Field-based
assessment of biological communities does not provide direct evidence to determine
underlying causal relationships, while laboratory or mesocosm toxicity tests are criticised for
their limited ability to extrapolate to natural field conditions. To help bridge the gap, this
thesis aims to investigate the efficacy of using caged macroinvertebrates in situ to assess the
ecological condition of aquatic environments, and whether a causal relationship can be
established when macroinvertebrates are deployed in situ at sites known to have impaired
water quality. Endpoints employed in this thesis include survival, measurements of
morphology (as a surrogate for growth) and condition and, for trials assessing sites that
receive mine drainage, the tissue concentration of certain trace metals.
Development of an in situ approach to water quality monitoring and assessment will
potentially provide methods for use by resource managers, community groups and aquatic
researchers that are less expensive and faster to run than existing methods and will
complement other approaches employed in the assessment of water quality.
In situ testing of water quality using macroinvertebrates requires the collection, handling,
caging, deployment and retrieval of test organisms at sites of suspected pollutant impact. As
such procedural factors may affect test organisms and potentially confound their responses, it
is important to consider and understand as many of these factors as possible. Aquatic
macroinvertebrates held in finer mesh cages had larger heads than in coarser mesh cages. This
was likely due to increased substrate available for growth of epilithon and periphyton on
which the caged organisms could graze. Caging density had no effect on amphipod mortality
over the trial period, however, individuals held at higher densities increased in size (as
indicated by longer dorsal lengths) more than those held at lower or intermediate densities.
Temporary storage of test organisms in laboratory aquaria may facilitate the collection of
abundances required for in situ trials, however, tanked individuals were smaller and had lower
biomasses than individuals collected and deployed immediately. While this is likely to result
from differences in feeding during the storage period, it is also possible that tank storage and
the ?double handling? deleteriously affected them, or reduced their tolerance.
The effects of transplanting macroinvertebrates between sites varied considerably depending
on the characteristics of "source" and "transplant" sites. Certain taxa suffered marked
mortality within 24 hours even at their source site, indicating an adverse effect of the caging
itself, or perhaps via the change in food, shelter or microclimate which could potentially
render them unsuitable as test organisms in caging studies. Other taxa did not differ in
survival or body size when relocated between sites, with some evidence of increased growth
at sites dissimilar from their source site. In general, organisms relocated to sites that are
"similar" to their source environment performed less well at the transplant site. However,
organisms transplanted to "dissimilar" sites were found to be bigger than those caged and
deployed back to the source site.
When employed to assess known pollution scenarios in and around Canberra,
macroinvertebrate responses were, in some instances, able to be linked to specific
environmental parameters or combinations thereof. In Case Study 1, findings varied in
relation to the response endpoint being examined, and between test species, although
concentrations of metals were significantly higher in tissue of macroinvertebrates deployed at
the impact site downstream of the abandoned Captains Flat mine and increased with time
exposed. In Case Study 2, freshwater shrimp suffered significant mortality within 24 hours of
deployment at the impact sites, with larger individuals more susceptible at sites receiving
urban stormwater runoff. While various biological effects were most closely correlated with
ammonia concentrations at the site, different body size endpoints were affected in opposite
ways. In Case Study 3, body size endpoints for one test organism varied consistently with
respect to site and time factors, but none of the changes could be linked to any of the
environmental data collected. Response variables for a different test species also indicated
significant effects arising from both deployment site and time, however, each endpoint
responded in a different way to the treatment factors, and aligned with different
combinations of environmental data.
In general, linking of macroinvertebrate responses with environmental data was difficult
because of the high variability in the environmental data. However, it was further complicated
by the mismatch in the level of replication between the two datasets. As a consequence of
this, the macroinvertebrate data had to be collapsed to a lower level for comparison with the
environmental data, resulting in a loss of natural variability and analytical power. Since only
the strongest treatment effects, which could be detected above the background "noise", were
detected and modelled against the environmental data, it is possible that other "cause" and
"effect" relationships may have been overlooked.
From these results, it is clear that many macroinvertebrate taxa are suitable for use as
bioindicators in in situ trials, but that criteria used for selection of test species should
definitely include more than just impact-sensitivity and abundance. However, there are
several aspects associated with the experimental set up of field-based protocols involving
caged macroinvertebrates that may limit their usefulness as a rapid and reliable bioassessment
tool, and need to be considered when designing and undertaking these kinds of trials. It is also
apparent that choice of endpoint can greatly influence conclusions, with detection of treatment
effects reported in this thesis varying greatly depending on which morphological endpoint
was examined.
This study clearly demonstrated that there may be significant difficulties in establishing
causal relationships between environmental data and biotic responses of macroinvertebrates
deployed under field conditions. However, it has also shown that deployment of caged
macroinvertebrates in situ may assist in the determination of biological effects arising from
impaired water quality, which can then serve as the basis for more focussed laboratory or
mesocosm studies in which environmental conditions can be more readily controlled or
monitored.
10
Daniel, Christopher Ryan. "Energy transfer and grain size effects during the Standard Penetration Test (SPT) and Large Penetration Test (LPT)." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/775.
Full textAbstract:
The Standard Penetration Test (SPT) is the most widely used in-situ soil test in the world. "Large Penetration Test" (LPT) is a term used to describe any scaled up version of the SPT. Several types of LPT have been developed around the world for the purpose of characterizing gravel deposits, as SPT blow counts are less reliable in gravels than in sands. Both tests suffer from the lack of a reliable means of determining transferred energy. Further, the use of LPT blow counts is generally limited to calculation of equivalent SPT blow counts using correlation factors measured in sands. Variation of LPT blow counts with grain size is assumed to be negligible.
This research shows that safety hammer energies can be reliably estimated from measurements of hammer impact velocity for both SPT and LPT. This approach to determining transferred energy is relatively simple, and avoids the primary limitation of existing methods, which is the inability to calibrate the instrumentation.
Transferred energies and hammer impact velocities are collected from various sources. These data are used to determine the ratio between the hammer kinetic energy and the transferred energy (energy transfer ratio, ETR), which is found to follow a roughly Normal distribution for the various hammers represented. An assessment of uncertainty is used to demonstrate that an ETR based approach could be superior to existing energy measurement methods.
SPT grain size effects have primarily been characterized as the variation of an empirical relative density correlation factor, (CD)SPT, with mean grain size. In this thesis, equivalent (CD)LPT data are back-calculated from measured SPT-LPT correlation factors (CS/L). Results of a numerical study suggest that SPT and LPT grain size effects should be similar and related to the ratio of the sample size to the mean grain size. Based on this observation, trend-lines with the same shape as the (CD)SPT trend-line are established for the back-calculated (CD)LPT data. A method for generating the grain size effect trend-line for LPT is then proposed. These trend lines provide a rational approach to direct interpretation of LPT data, or to improved prediction of equivalent SPT blow counts.
11
Hess, Jeremy. "In-Situ Testing of Uretek's Injectable Barrier as a Mechanism for Groundwater Control." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6095.
Full textAbstract:
Construction projects involving the installation or repair of subsurface structures or utilities often require dewatering to induce a temporary lowering of the local groundwater elevation to facilitate construction. In the event that a known contaminant plume is present in an adjacent area, this dewatering may inadvertently draw the contaminant into the previously uncontaminated work area. Uretek Holdings, Inc. has developed its Injectable BarrierSM to be installed prior to dewatering exercises to provide a groundwater cut-off by reducing the potential movement of groundwater due to the hydraulic gradient induced by dewatering. A benefit of Injectable BarrierSM as compared to conventional methods of hydraulic control is that excavation is not required prior to its installation and no excess soils are generated through its installation. Injectable BarrierSM is a proprietary process registered with the United States Patent and Trademark Office by Uretek Holdings, Inc.
Since methodical in-situ testing of the effectiveness of the Injectable BarrierSM has not been performed to date, it was the focus of this research to test the performance of the barrier under in-situ conditions utilizing a subsurface environment indicative of a West-Central Florida location. A testing plot to perform this research was selected on Hillsborough County property in Tampa, Florida which provided both a relatively shallow groundwater elevation in addition to a clay confining layer at a relatively shallow depth, making this an ideal location for testing the performance of the Injectable BarrierSM.
After establishing the native conditions through baseline pump testing and repeating the testing procedure following the installation of the Injectable BarrierSM, a quantification of the reduction in hydraulic conductivity was achieved. Pumping tests were performed on the Injectable BarrierSM at its standard spacing as well as modified versions of the barrier with variation in the lateral spacing to include 6 foot, 4 foot, 3 foot, and 2 foot injection patterns to determine if a modified injection process could improve its performance. The 3 foot lateral spacing corresponding to the standard Injectable BarrierSM process indicated a 20% reduction in the hydraulic conductivity following its installation. By performing a small scale excavation following the completion of all pumping tests, it was discovered that the dispersion of the material in the subsurface appeared insufficient to provide the coverage needed to establish a barrier capable of further reducing the local hydraulic conductivity, especially at the shallowest injection depth of 3 feet below land surface (ft bls). It is concluded that modified amounts of injected material, closer lateral injection spacing, and potentially modified injection temperatures and component ratios could increase the effectiveness of the Injectable BarrierSM.
12
Lynch, Alan Gerald. "Trends in back-calculated stiffness of in-situ recycled and stabilised road pavement materials." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85857.
Full textAbstract:
Thesis (MEng)-- Stellenbosch University, 2013.ENGLISH ABSTRACT: Two common methods of road pavement, granular material stabilisation used in road construction throughout South Africa today include Cold in Place Recycling (CIPR) and stabilisation with cement or bitumen and an active filler to create Bitumen Stabilised Materials (BSM). As part of the updating of the South African Pavement Design Method (SAPDM) an experimental section, investigating the structural capacity of cement and lime stabilised and BSM pavement layers, was constructed and will be monitored over a two year period. As part of this study Falling Weight Deflectometer (FWD) measurements were taken on the various experimental stabilised pavement layers constructed. The FWD deflection data, measured at various time intervals over a 360 day period, forms the basis of the study presented here. The objective of this thesis was to identify typical back-calculated layer stiffnesses and their variability over time for the various in-situ recycled and stabilised base layers constructed within the experimental section. Stabiliser type, content and layer thicknesses were varied across experimental sub-sections. Trends in back-calculated stiffness of cement stabilised base layers consistently showed significant reductions in layer stiffness subsequent to construction traffic loading. Subsequent to the initial reduction in stiffness little change in stiffness was noted under normal traffic loads. Observations on the trends in back-calculated stabilised layer stiffness per material type over time indicated that seasonal moisture and temperature fluctuations have an effect on the stiffness of the pavement structure as a whole. BSM materials showed significant variability over time in-line with seasonal variability in the supporting subgrade stiffness in the southbound lane. BSM materials with 1% cement added in the northbound lane show initial stiffness reductions due to direct rainfall application however a significant increase in layer stiffness occurs up to 360 days after construction. BSMs with 2% cement in the northbound lane show significant increases in layer stiffness over the 360 day observation period. No significant difference in stiffness trend was observed between BSM emulsion a BSM foam materials. The BSM emulsion with 0.9% residual bitumen and 1% cement was observed to show rapid reduction in stiffness upon opening to traffic and reverting to stiffness values similar to an unbound material of approximately 350 MPa. Cement and lime stabilised materials showed typical post 28 –day average stiffnesses per sub-section ranging between 600 MPa and 1800 MPa. BSM foam with 1% cement added were observed to have average stiffnesses per sub-section in the range of 400MPa to 2200 MPa and BSM emulsion with 1% cement with stiffnesses between 400 MPa to 1700 MPa over the 360 day period. BSMs with 2% cement added showed stiffness ranges between 900 MPa to 4300 MPa for BSM foam and 900 MPa to 3900 MPa for BSM emulsions over the 360 day period. The spatial variability of back-calculated stiffness per sub-section of a particular stabilisation design was significant and was observed, through the Co-efficient of Variation (COV), to increase over time. The effect of the observed variability when incorporated into a pavement design scenario, requiring a design reliability of 90%, showed 50% of the pavement structure would be overdesigned by a factor of 4. With respect to the current philosophies on the development of stiffness over time of cement and lime stabilised and BSM pavement layers some useful observations were made. Cement stabilised materials correlate well with stiffness development theories predicted by previous studies. Theories relating to the stiffness development of BSMs however did not predict the levels of variability in base layer stiffness observed on the experimental section. The continued observation of the experimental section for another year will give greater insight to the stiffness trends of the stabilised materials discussed above.
13
Richardson, Sarah. "In-Situ Testing of a Carbon/Epoxy IsoTruss Reinforced Concrete Foundation Pile." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1280.pdf.
Full text
14
Davies, Michael Paul. "Predicting axially and laterally loaded pile behaviour using in-situ testing methods." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26689.
Full textAbstract:
The prediction of axial and lateral pile behaviour is a complex engineering problem. Traditional methods of data collection and subsequent analyses are frequently in error when compared to full-scale, load tests. In-situ testing, using advanced electronic tools, provides a means by which representative field data may be obtained. This study investigates the use of such in-situ data in predicting axially loaded pile capacity and laterally
loaded pile load-deflection behaviour.
A total of twelve static axial pile capacity methods were evaluated to predict the results obtained from eight full-scale pile load tests on six different piles. These methods, separated into direct and indirect classes, used data obtained from the cone penetration test. Extensive use of commercially available microcomputer software significantly simplified the analyses. In addition, several dynamic pile capacity predictions are presented including results from in-situ dynamic measurements obtained with a pile driving analyzer during pile emplacement. An attempt has been made, with the use of tell-tales, to differentiate the shaft resistance and end-bearing components of the load test results. These results are then compared to the prediction methods investigated.
Two methods of predicting lateral load-deflection behaviour using in-situ data have been investigated. One method uses pressuremeter test data and the other, a new method proposed in this study, uses full-displacement flat plate dilatometer test data. These predictions are compared with full-scale lateral load tests on three piles of differing size. In both the axial and lateral load cases, the preferred method(s) of analyses are identified. It is shown that excellent agreement can be obtained for predicting measured pile behaviour using several methods. The limitations of this study are noted, and recommendations for further research are proposed.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
15
Briston, Kevin James. "The functional testing of individual nano-objects using in-situ electron miicroscopy." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555646.
Full textAbstract:
Nano-objects, such as nanowires and carbon nanotubes, are very important for the future of the electronics industry due to their potential for creating novel devices and to continue increasing the densities of devices on microchips. In-situ electron microscopy techniques are ideal for performing functional testing of these nanoobjects, since they allow functional properties and behaviour of the nano-objects to be directly related to dynamic observations of their structure. In this work tools and techniques have been developed for the investigation of nano-objects using in-situ electron microscopy. These include the development of a novel micro gripper, made using relatively inexpensive electrochemical and focused ion beam techniques, for the manipulation of micro- and nano-objects; the development of a W filament ).t-heater, for the in-situ heating of microvolumes of material; and the adaption of a transmission electron microscope nanoprobe to allow electrical testing of nano-objects in-situ inside a transmission electron microscope. The tools and techniques developed have been used to perform in-situ investigations of three types of nano-objects. Firstly, individual Fe-filled carbon nanotubes have had their field emission properties tested and compared to unfilled carbon nanotubes in-situ in a scanning electron microscope. Secondly, Sn nanowires under development for welding/joining applications were heated in-situ in a scanning electron microscope. It was found that the behaviour of the nanowires was strongly affected by the presence of an oxide shell, though the oxidation could be prevented using an organic coating. Thirdly, Au nanowires for nanoelectronic systems were electrically tested in-situ in a transmission electron microscope. The presence of carbon contamination on the nanowires resulted in poor contacts and catastrophic failure. However, if the carbon contamination is thick enough, it was found that carbon nanotubes with well-defined inner diameters could be made during nanowire breakdown. In light of these initial functional nano-object tests it is clear that there are many opportunities for future development in this area.
16
Farrington, Robert. "Testing mixed phase cloud parametrizations through confronting models with in-situ observations." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/testing-mixed-phase-cloud-parametrizations-through-confronting-models-with-insitu-observations(e2b7e31b-fa4a-4501-9f30-2ca2452c58fa).html.
Full textAbstract:
Accurate representations of clouds are required in large-scale weather and climate models to make detailed and precise predictions of the Earth's weather and climate. Representations of clouds within these models are limited by the present understanding of the role of aerosols in the microphysical processes responsible for cloud formation and development. As part of a NERC funded CASE studentship with the Met Office, this thesis aims to test new aerosol-dependent mixed-phase cloud parametrizations by obtaining extensive cloud microphysical measurements in-situ and comparing and contrasting them with model simulations. Cloud particle concentrations were measured during the Ice NUcleation Process Investigation And Quantification (INUPIAQ) field campaign at Jungfraujoch in Switzerland. A new probe was used to separate droplet and small ice concentrations by using depolarisation ratio and size thresholds. Whilst the new small ice crystal and droplet number concentrations compared favourably with other instruments, the size and depolarisation ratio thresholds were found to be subjective, and suggested to vary from cloud to cloud. An upwind site was chosen to measure out-of-cloud aerosol particle concentrations during INUPIAQ. During periods where the site was out-of-cloud and upwind of Jungfraujoch, several large-scale model simulations were run using the aerosol concentrations in an aerosol-dependent ice nucleation parametrization. The inclusion of the parametrization failed to increase the simulated ice crystal number concentrations, which were several orders of magnitude below those observed in-situ at Jungfraujoch. Several possible explanations for the high observed ice crystal number concentrations at Jungfraujoch are tested using further model simulations. Further primary ice nucleation was ruled out, as the inclusion of additional ice nucleating particles in the model simulations suppressed the liquid water content, preventing the simulation of the mixed-phase clouds observed during INUPIAQ. The addition of ice crystals produced via the Hallett-Mossop process upwind of Jungfraujoch into the model only infrequently provided enough ice crystals to match the observed concentrations. The inclusion of a simple surface flux of hoar crystals into the model simulations was found to produce ice crystal number concentrations of a similar magnitude to those observed at Jungfraujoch, without depleting the simulated liquid water content. By confronting models with in-situ observations of cloud microphysical process, this thesis highlights interactions between surface ice crystals and mixed-phase clouds, and their potential impact on large-scale models.
17
Kidd, David Alan 1956. "In situ testing of Gila Conglomerate with application to probabilistic slope stability." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277060.
Full textAbstract:
In this study the shear strength parameters for a consolidated, well-cemented boulder conglomerate at the Cyprus Miami Copper Mine are determined by a newly developed field test. The values obtained are used to investigate the probability of failure of pit slopes cut into the conglomerate. Any boulder conglomerate is impossible to test accurately with conventional laboratory techniques due to its large particle sizes and the destruction of cementation by conventional sampling methods. For these reasons a simple in situ test was developed which could be used in conjunction with laboratory techniques and analytical procedures to estimate the in situ strength properties of the Gila Conglomerate. The variability in the testing of the shear strength parameters of Gila Conglomerate make a probabilistic approach to design appropriate.
18
Pavic, Aleksandar. "Vibration serviceability of long-span cast in-situ concrete floors." Thesis, University of Sheffield, 1999. http://etheses.whiterose.ac.uk/3486/.
Full textAbstract:
This thesis describes an investigation into the vibration serviceability of long-span and slender in-situ concrete floors, which are typically post-tensioned. The motivation for the research is the present trend towards increased slenderness of post-tensioned floors supporting open-plan high- quality offices where vibration serviceability may easily become the governing design criterion. The vibration serviceability issue in post-tensioned floors is now also recognised by the UK Concrete Society which proposed, for the first time, guidelines for performing a vibration serviceability check when designing office floors. The guidelines were published in Concrete Society Technical Report 43 (CSTR43) in 1994 and its publication prompted the initialisation of this research project. There were two reasons for this. Firstly, problems were reported with the reliability and practical application of these guidelines, and, secondly, the guidelines were not experimentally verified which is unusual for any design provision related to vibration serviceability. In order to improve understanding of the dynamic performance of a rather specific group of office floors which are long-span and made of cast in-situ concrete, a combined experimental and analytical approach has been adopted. A state-of-the-art facility comprising hardware and software suitable for field modal testing and dynamic response measurements of prototype floor structures was commissioned as a part of this research. The facility is built up around the instrumented sledge hammer, which served as the main excitation source in modal testing, and multi-degree-of-freedom vibration parameter estimation procedures utilising measured floor frequency response functions. The main testing programme consisted of modal testing of four prototype floor structures of varying complexity weighing between 13 and 1000 tonnes. All four slab structures were slender and made of in-situ concrete. These tests were complemented by measurements of the floors' acceleration responses to a single person walking excitation tuned to create as large as realistically possible responses. The modal testing experimental data (measured natural frequencies, mode shapes and modal damping ratios) were used to validate numerical finite element (FE) models representing each floor structure. To do this, advanced FE model correlation and manual updating procedures were employed. Results of these exercises highlighted a number of important issues related to the dynamic behaviour of the concrete floors investigated. Firstly, the bending stiffness of in-situ concrete columns and walls contributed significantly to overall floor bending stiffness and must be considered. Secondly, higher modes of vibration which are close to the fundamental frequency appear in concrete floors, and should not be neglected as they can be easily excited by walking leading to dynamic responses greater than those associated with the fundamental mode. Thirdly, the width of band beams contributes significantly to the lateral stiffness of post-tensioned floors, which, in turn, may be very beneficial for their vibration serviceability. The validated numerical FE models were then used to check the performance of three representative walking excitation models available in the literature. It was shown that, in general, all three models overestimated the measured response to the third harmonic of the walking excitation, which is particularly important for low-frequency office floors. Only one of the models did so in a way which is not overly conservative. This model is recommended for use in vibration serviceability assessment of post-tensioned floors. Finally, gross oversimplification of these important issues is identified as the principal reason for the failure of the current CSTR43 vibration serviceability guidelines to predict reliably vibration response of a wide range of post-tensioned in-situ cast concrete floors.
19
Gray, Jody D. "In situ determination of strength and stiffness of structural lumber and composite products." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=2817.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2003.Title from document title page. Document formatted into pages; contains xi, 154 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 112-122).
20
Evenden, M. P. "Assessment of the cutting characteristics of coal seams by in situ testing methods." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381170.
Full text
21
Ehret, Steven J. "Instrumentation for anodization and in-situ testing of titanium alloys for capacitor anodes." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1311612394.
Full text
22
Arnegard, Matthew E. "Toxicant-releasing substrates : a new method for delivering copper to microbial communities in SITU /." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12162009-020200/.
Full text
23
Ashok, Mahima. "Analysis of HER2 testing in breast cancer." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29711.
Full textAbstract:
Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2010.Committee Chair: Griffin, Paul; Committee Member: Butera, Robert; Committee Member: Halpern, Michael; Committee Member: Nichols, Richard; Committee Member: Vidakovic, Brani. Part of the SMARTech Electronic Thesis and Dissertation Collection.
24
Salsbury, Duane. "In-situ testing of radiation effects on VLSI capacitors using the NPS linear accelerator." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA326761.
Full textAbstract:
Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, December 1996.Thesis advisor(s): Sherif Michael. "December 1996." Includes bibliographical references (p. 95-96). Also Available online.
25
Allan, Peter Gerard. "Development of a self-boring pressuremeter for the in situ testing of weak rocks." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238944.
Full text
26
Ren, Zhe. "Nanomechanics : combining mechanical testing in situ with focused X-ray diffraction on a synchroton beamline." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4387.
Full textAbstract:
Les nanostructures ont des propriétés mécaniques qui diffèrent de celles des matériaux massifs. La compréhension des propriétés mécaniques aux échelles nanométriques requièrent la mise en place d’essais mécaniques combinés à des observations structurales. Au cours de cette thèse nous avons développé un microscope à force atomique (AFM) dédié permettant de solliciter mécaniquement un nano-objet unique sur une ligne de lumière synchrotron. Les possibilités offertes par cette nouvelle approche expérimentale sont démontrées sur deux exemples de sollicitation mécanique in situ: (i) la nanoindentation in situ de cristaux d’or combinée à la diffraction cohérente des rayons X; (ii) la flexion trois points de nanofils d’or associée à la micro-diffraction de Laue. Ces expériences permettent d'accéder au comportement élastique ainsi qu’au comportement plastique du nanomatériau et permettent de déterminer la limite d'élasticité et le type de défauts induits par le chargement mécaniqueNanostructures were found to exhibit different mechanical properties compared to their bulk counterpart. For obtaining further insight into the mechanical behaviour on the nanoscale, mechanical tests are combined with observation techniques allowing for monitoring the structural evolution. Within this thesis a special atomic force microscope has been developed which is compatible with different X-ray diffraction techniques at synchrotron sources for in situ mechanical testing on single nano-objects. The great potential of the new experimental approach is demonstrated on two kinds of in situ mechanical tests: (i) in situ nano-indentation on Au crystals with coherent X-ray diffraction. (ii) In situ three point bending tests on Au nanowires with μLaue diffraction. These experiments give access to the elastic as well as the plastic behavior of the nanomaterial and allows for determining the elastic limit and the type of defects induced by the mechanical loading
27
Ozyurt, Gokhan. "Cataloging And Statistical Evaluation Of Common Mistakes In Geotechnical Investigation Reports For Buildings On Shallow Foundations." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615084/index.pdf.
Full textAbstract:
Information presented in site investigation reports has a strong influence in design, project costs and safety. For this reason, both the quality and the reliability of site investigation reports are important. However in our country, geotechnical engineering is relegated to second place and site investigation studies, especially parcel-basis ground investigation worksdo not receive the attention they deserve. In this study, site investigation reports, that are required for the license of design projects, are examined and the missing/incorrect site investigations, laboratory tests, geotechnical evaluations and geotechnical suggestions that occur in the reports are catalogued. Also, frequency of each mistake is statistically examined
for geotechnical engineers, recommendations and solutions are presented to help them avoid frequent problems.
28
Ren, Zhe. "Nanomechanics : combining mechanical testing in situ with focused X-ray diffraction on a synchroton beamline." Electronic Thesis or Diss., Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4387.
Full textAbstract:
Les nanostructures ont des propriétés mécaniques qui diffèrent de celles des matériaux massifs. La compréhension des propriétés mécaniques aux échelles nanométriques requièrent la mise en place d’essais mécaniques combinés à des observations structurales. Au cours de cette thèse nous avons développé un microscope à force atomique (AFM) dédié permettant de solliciter mécaniquement un nano-objet unique sur une ligne de lumière synchrotron. Les possibilités offertes par cette nouvelle approche expérimentale sont démontrées sur deux exemples de sollicitation mécanique in situ: (i) la nanoindentation in situ de cristaux d’or combinée à la diffraction cohérente des rayons X; (ii) la flexion trois points de nanofils d’or associée à la micro-diffraction de Laue. Ces expériences permettent d'accéder au comportement élastique ainsi qu’au comportement plastique du nanomatériau et permettent de déterminer la limite d'élasticité et le type de défauts induits par le chargement mécaniqueNanostructures were found to exhibit different mechanical properties compared to their bulk counterpart. For obtaining further insight into the mechanical behaviour on the nanoscale, mechanical tests are combined with observation techniques allowing for monitoring the structural evolution. Within this thesis a special atomic force microscope has been developed which is compatible with different X-ray diffraction techniques at synchrotron sources for in situ mechanical testing on single nano-objects. The great potential of the new experimental approach is demonstrated on two kinds of in situ mechanical tests: (i) in situ nano-indentation on Au crystals with coherent X-ray diffraction. (ii) In situ three point bending tests on Au nanowires with μLaue diffraction. These experiments give access to the elastic as well as the plastic behavior of the nanomaterial and allows for determining the elastic limit and the type of defects induced by the mechanical loading
29
Foscan, Tiziana. "Mechanical characterization of double-wythe masonry walls with a view to in-situ testing methods." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
Find full textAbstract:
Unreinforced masonry is one of the most commonly used structure typologies for the construction of residential buildings, which is why the estimation of its mechanical parameters is of primary importance. The main techniques to acquire them are based on destructive methods, however less invasive tests have been studied in the past years in order to obtain the same parameters in-situ: the core testing method is one of those. While monotonic compression tests on single-wythe cores provided good results, tests performed on double-wythe cores have given a significant overestimation of the compressive strength, supposedly due to the excessive stiffness of the high strength mortar cap used to perform the tests, that doesn’t allow the opening of the collar joint. An experimental campaign was conducted at Delft University of Technology in order to identify a new configuration of the cap suitable to use in moderately destructive tests to retrieve the mechanical properties of masonry under compression. An initial Finite Element Analysis is performed to anticipate the behaviour of the different configurations in order to choose the right prototypes. Four different models are developed, and the most significant ones are implemented and tested in the laboratory. In particular, a configuration with high strength mortar cap is tested as a comparison with previous tests on double-wythe cores, while a configuration with a high strength mortar cap separated from the core by a neoprene sheet is chosen in an attempt to reduce the confinement in the direction perpendicular to the collar joint. Finally the results obtained from the monotonic compression tests on cores are compared with the results from destructive tests on companion wallets, which were carried out in a previous experimental campaign on the same masonry.
30
Chapman, Michael James. "Experimental determination of in-situ serviceability of Sitka spruce timber by ultrasonic non-destructive testing." Thesis, University of Ulster, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370087.
Full text
31
Böhm, Jochen. "In situ tensile testing at the limits of X-ray diffraction a new synchrotron-based technique." Stuttgart Max-Planck-Inst. für Metallforschung, 2004. http://deposit.d-nb.de/cgi-bin/dokserv?idn=972182810.
Full text
32
Lingwanda, Mwajuma. "In-situ Penetration as Alternative to Extensive Boreholes and Lab Testing for Exploration in Sandy Soils." Licentiate thesis, KTH, Jord- och bergmekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161217.
Full text
33
Fennessy, Michael Jim. "Development and testing of an instrument to measure estuarine floc size and settling velocity in situ." Thesis, University of Plymouth, 1994. http://hdl.handle.net/10026.1/1836.
Full textAbstract:
An instrument has been developed to observe the settling of individual flocs in turbid water in order to to measure size and settling velocity spectra of estuarine cohesive suspended sediments. INSSEV - IN Situ SEttling Velocity instrument - is bed mounted and comprises a computer controlled decelerator chamber that collects a sample of water from which some of the suspended matter is allowed to enter the top of a settling column. The settling flocs are viewed using a miniature video system. Subsequent analysis of video tapes provides direct measurements of size and settling velocity of individual flocs down to 20 um. From this information floc effective density is estimated. The main feature of the instrument is its ability to video flocs in situ irrespective of the concentration in the estuary, with as little disturbance to their hydrodynamic environment as possible. In addition to size and settling velocity distributions, data analysis developed for the instrument produces spectra of concentration and settling flux with respect to size, settling velocity or effective density. This is the first time that these parameters have been measured in situ. Field testing in the Tamar Estuary, South West England, and the Elbe Estuary, Germany, has given useful results in flow velocities up to 0.6 m s-1 and in concentrations up to 400 mg l-1 INSSEV was used in the 1993 Elbe Intercalibration Experiment where nearly all types of instrumentation for the in situ determination of estuarine floc size and/or settling velocity were deployed over several tidal cycles. From observations in the turbidity maximum of the Tamar Estuary, INSSEV data has shown significant changes in floc population characteristics during the tidal cycle, the most important being changes in floc effective density. A strong relationship between floc effective density and ambient turbulence characteristics is shown.
34
Grippo, Christian P. (Christian Patrick) 1969. "Design and manufacturing of a tensile text machine for in-situ atomic force microscope mechanical testing." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89386.
Full text
35
Evans, John T. IV. "DEVELOPMENT OF A METHOD FOR IN-SITU TESTING OF OXYGEN CONCENTRATIONS IN COMPOST BEDDED PACK BARNS." UKnowledge, 2015. http://uknowledge.uky.edu/bae_etds/30.
Full textAbstract:
Compost bedded pack barns are a relatively new type of dairy housing system that is being implemented in Kentucky. Extensive research has been done on the composting of animal manure, however, little has been done on composting animal manure in place. One of the most concerning challenges is aeration. Improper aeration can cause system failure. The ability to quickly and accurately measure the oxygen concentration would allow researchers the ability to determine which methods of tillage/aeration are most effective in compost bedded pack barns. The research in this thesis focused on the development of a method for simultaneously testing oxygen concentrations at different locations and depth in compost in-situ. A probe was developed that vertically aligned Apogee Instruments oxygen sensors (SO-120) in order to generate an oxygen profile of the compost. The probe was used to test the effect of different tillage/aeration strategies in a composted bedded pack barn. The results indicated the probe was effective at measuring the oxygen concentrations in active compost tested in laboratory conditions and it was determined that there was a significant difference in oxygen concentration with respect to depth. However, when applied in the compost bedded pack barn, large amounts of variation occurred randomly in the data, causing no difference to be detected as a result of varying tillage aeration treatments.
36
Glorian, Heinrich, Viktor Schmalz, Pawel Lochyński, Paul Fremdling, Hilmar Börnick, Eckhard Worch, and Thomas Dittmar. "Portable Analyzer for On-Site Determination of Dissolved Organic Carbon — Development and Field Testing." Molecular Diversity Preservation International (MDPI), 2018. https://tud.qucosa.de/id/qucosa%3A33327.
Full textAbstract:
Dissolved organic carbon (DOC) is a sum parameter that is frequently used in water analytics. Highly resolved and accurate DOC data are necessary, for instance, for water quality monitoring and for the evaluation of the efficiency of treatment processes. The conventional DOC determination methods consist of on-site sampling and subsequent analysis in a stationary device in a laboratory. However, especially in regions where no or only poorly equipped laboratories are available, this method bears the risk of getting erroneous results. For this reason, the objective of the present study was to set up a reliable and portable DOC analyzer for on-site analysis. The presented DOC system is equipped with an electrolysis-based decomposition cell with boron-doped diamond electrodes (BDD) that oxidizes the organic compounds to carbon dioxide. Within this study, the influence of different electrode materials and the composition of the applied electrolytes on the DOC decomposition in an undivided electrolytic cell were systematically investigated. Furthermore, some technical aspects of the portable prototype are discussed. After a detailed validation, the prototype was used in an ongoing monitoring program in Northern India. The limit of detection is 0.1 mg L−1 C with a relative standard deviation of 2.3% in a linear range up to 1000 mg L C−1. The key features of the portable DOC analyzer are: No need for ultra-pure gases, catalysts or burning technology, an analyzing time per sample below 5 min, and a reliable on-site DOC determination.
37
Watring, Dillon S. "Development of Novel, Microscale Fracture Toughness Testing for Adhesives." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3474.
Full textAbstract:
The purpose of this thesis was to develop microscale fracture toughness tests to be performed in situ based off previously used macroscale fracture toughness tests. The thesis also was to use these tests to perform in situ analysis and imaging of reinforced adhesives during crack propagation. Two different fracture toughness tests were developed for this thesis through developing fixtures and sample geometry. A microscale double cantilever beam (DCB) test was developed for mode I fracture (opening mode). A microscale end notch flexure (ENF) test was developed for mode II fracture (sliding mode).
Three different types of materials were used as a reinforcing agent and tested using the micro-DCB and micro-ENF tests. Magnetoelectric nanoparticles (MENs) doped adhesive showed a 12% increase in mode II toughness and 33% increase in total fracture energy for micro-DCB. Similarly, the graphene foam (GrF) doped adhesive showed an approximate 34% increase in mode II toughness and a 71% increase in total fracture energy for mode I. In situ imaging provided real time imaging of crack propagation for all three reinforcing agents that allowed for a novel analysis of the crack propagation and general fracture.
38
de, Vaulx Thomas. "Determination of the first damage criterion of a glass/epoxy composite material using an in-situ test system." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/17608.
Full text
39
Barrett, Anthony R. "Dynamic Testing of In-Situ Composite Floors and Evaluation of Vibration Serviceability Using the Finite Element Method." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28879.
Full textAbstract:
The presented research examined three areas: best practices in high quality dynamic testing of in-situ floor systems, extensive dynamic testing of three bare (non-fit out) in-situ multi-bay steel composite floors to estimate their dynamic parameters/response and to identify trends in dynamic behavior, and development of a set of fundamental finite element (FE) modeling techniques to adequately represent the dynamic response of steel composite floors for the purpose of evaluating vibration serviceability. The measurement, analysis, and computation of a floor's accelerance frequency response function (FRF) is the core premise linking all areas of the presented research.
The burst chirp signal using an electrodynamic shaker is recommended as the most accurate and consistent source of excitation for acquiring high quality measurements suitable for use in parameter estimation, operating deflection shape animation, and calibration/validation of FE models. A reduced mid-bay testing scheme is recommended as a time-saving alternative to modal testing over a full coverage area, provided the only desired estimated parameters are frequencies, damping, and mid-bay acceleration response.
Accelerance FRFs were measured with an electrodynamic shaker located within 23 unique bays on the three tested floors. Dominant frequencies ranged from 4.85 Hz to 9 Hz and measured estimates of damping varied considerably, ranging from 0.44% to 2.4% of critical (0.5%-1.15% was typical). Testing showed several mode shapes were localized to just a few bays and not all modes were adequately excited by forcing at a single location. The quality of the estimated mode shapes was significantly improved using multi-reference modal testing.
FE models for the tested floors were developed based on high quality measured data and were shown to provide adequate representations of measured floor behavior. Fundamental techniques are presented for modeling mass, stiffness, boundary conditions, and performing dynamic analysis. A method of evaluating vibration serviceability was proposed using the FE model's computed accelerance FRF for comparison with a design accelerance curve that represents an acceleration response threshold in the frequency domain. An example design accelerance curve is presented based on current serviceability guidelines for acceleration tolerance and effective harmonic forces due to human activities such as walking.Ph. D.
40
Vennapusa, Pavana Kumar Reddy. "Investigation of roller-integrated compaction monitoring and in-situ testing technologies for characterization of pavement foundation layers." [Ames, Iowa : Iowa State University], 2008.
Find full text
41
Mehmannavaz, Reza. "A laboratory study on the development and testing of a bioaugmentation system for contaminated soils." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0028/NQ50221.pdf.
Full text
42
Kemerling, Brandon L. "Development of a Weldability Testing Strategy for Laser Powder-Bed Fusion Applications." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu152380570674288.
Full text
43
Butler, Joseph Edmund. "In-situ Fiber Strength Distribution in NextelTM 610 Reinforced Aluminum Composites." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/32433.
Full textAbstract:
MetPreg, a composite developed by Touchstone Research Laboratories (Tridelphia, WV), is an aluminum metal matrix composite reinforced by continuous NextelTM 610 alumina fibers. The question is, after processing, are the NextelTM fibers affected in any way that their strengthening contribution to the composite is reduced? From experimentation and statistical analysis, a strength distribution of pre-processed NextelTM 610 fibers is formed and an empirical correlation is developed relating strength to the observed flaw size on the failed single fibers. This correlation is then independently applied to flaw size information gathered from fibers on the fracture surface of MetPreg samples to develop a separate strength distribution of post-processed NextelTM 610 fibers. The pre- and post-processed distributions are compared to one another to determine the effect, if any, that composite processing has on the strength of NextelTM 610 fibers. The results indicate that the in-situ strength distribution of fibers was increased by composite processing.Master of Science
44
Meijer, Gerrit Johannes. "New methods for in situ measurement of mechanical root-reinforcement on slopes." Thesis, University of Dundee, 2016. https://discovery.dundee.ac.uk/en/studentTheses/c8857b54-36cb-4e68-83b1-cf1e78df30d9.
Full textAbstract:
Vegetation can increase the resistance of slopes against landsliding. The mechanical contribution of roots to the shear strength of the soil is however difficult to measure in situ. Existing methodologies are time-consuming and therefore not suitable to quantify spatial variability on the slope. Furthermore, some existing methods, for example large in situ shear box testing, can be difficult to apply on remote sites with difficult access, e.g. steep slopes. Therefore in this thesis novel, simple and portable methods to quantify mechanical root-reinforcement in the field were developed. The ‘blade penetrometer method’, one of these new methods, was based on standard penetrometer testing but used an adapted tip shape to increase sensitivity to roots. Root depths and diameters could be quantified based on characteristics of the depth–resistance trace, both in the laboratory and in the field. Several new analytical interpretive models were developed to predict the force–displacement behaviour of roots loaded under various conditions: one assuming roots broke in tension and another assuming roots broke in pure bending. Both methods did take root–soil interaction into account. Based on these models, some roots were shown to have broken in bending and others in tension, depending on plant species and root diameter. Two new methods were developed to measure the root-reinforced soil strength directly. The ‘pin vane’ was an adaptation of a standard field shear vane, replacing the cruciform blades of the latter by prongs to minimise the effects of soil disturbance and root breakage during installation. This was one of the main problems encountered when using standard vanes in rooted soil. This ‘pin vane’ method was qualitatively shown to be able to measure the reinforcing effects of both fine and thick roots (or root analogues), both in the laboratory and the field. This method will be most useful when the strength of densely rooted surface layers is to be analysed, e.g. for erosion resistance purposes. Another newly developed shear device was the ‘corkscrew’. Rotational installation of the screw ensured minimal soil and root disturbance. During vertical extraction the root-reinforced shear strength was mobilised along the interface of the soil plug caught within the screw. The measured extraction force could be related to the reinforced soil strength. This method underestimated the strength in surface layers (especially at 0–125 mm and less so at 125–250 mm depth) but functioned well in deeper soil layers important for landsliding. Although laboratory results were promising, during in situ testing in deeper layers ( > 125 mm) local variation in soil stress, gravel content and water content, combined with low root volumes, made it difficult to accurately quantify the effect of the roots. Where the effect of roots was pronounced, e.g. in more heavily rooted surface layers (0–125 mm), significant positive trends between the measured soil strength and root strength and quantity were found. Measured reinforcements were small compared with various root-reinforcement model predictions but comparable to direct shear tests on rooted soil reported by others. These new methods, although still in the early stages of development, showed promising results for practical use in field conditions. The equipment was simple to use and portable, enabling measurements on sites with difficult accessibility. However, more work is required to validate the interpretive models developed and to calibrate these methods for a wider range of soil and root conditions.
45
Swett, Lauren J. "Seasonal Variations of Pavement Layer Moduli Determined Using In Situ Measurements of Pavement Stress and Strain." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/SwettLJ2007.pdf.
Full text
46
Hinterman, Eric Daniel. "System modeling, graphical user interface development, and sensors testing for the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE)." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/119301.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 79-80).
The Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) represents the first time that NASA is demonstrating In-Situ Resource Utilization (ISRU) on the surface of another planetary body. MOXIE will produce oxygen from atmospheric CO 2 on Mars. It is being developed for NASA's 2020 Mars Rover and will produce greater than 99.6% pure oxygen through solid oxide electrolysis. MOXIE is roughly 0.5% of the scale that would be necessary to produce oxygen for breathing and use as a propellant for a human Mars mission. Tests are being performed on MOXIE in the laboratory at NASA's Jet Propulsion Laboratory (JPL) and the Massachusetts Institute of Technology (MIT). At the same time, a model is being developed to simulate and predict the performance of MOXIE. The ability to predict the performance of MOXIE on Mars is a critical step in preparation for surface operations. Without the ability to estimate inefficient or unsafe operating conditions, MOXIE operations on Mars run a spectrum of risk ranging from loss of efficiency to the loss of the entire mission. Therefore, to predict performance and thus avoid subjecting flight hardware to unsafe conditions, a dynamic model has been developed that simulates MOXIE's operation. Simulink, a package contained within the MATLAB programming language, was chosen as a convenient way to build a dynamic representation of MOXIE. The model was built as a combination of theoretical and empirical values regarding the gas flows, thermal transfers, electrochemistry, and control loops that are representative of the true MOXIE system. The results of this model have been validated against data from JPL's MOXIE testbed laboratory. Continued model validation will occur as JPL acquires new data throughout 2018. This thesis gives an overview of how MOXIE works and how it has been modeled. MOXIE is the first instrument of its kind to leave the Earth, and the modeling of this instrument is similarly unique. As the dynamic model continues to evolve with new data, it becomes a fast and inexpensive way to test MOXIE without subjecting expensive hardware to hazardous conditions. In addition, this thesis covers the development of a Graphical User Interface (GUI) that allows users to easily control the model and view its outputs. Finally, the design and results of construction of a vacuum chamber for testing of MOXIE components are presented. These tests will help to further validate the model and will pave the way for extensibility studies of the MOXIE system.
Supported with the NASA Space Technology Research Fellowship
by Eric Daniel Hinterman.
S.M.
47
Ali, Arfan. "System modelling and testing of a magnetic susceptibility device and effect of downhole in-situ temperatures on magnetic susceptibility." Thesis, Heriot-Watt University, 2009. http://hdl.handle.net/10399/2232.
Full textAbstract:
Magnetic techniques have so far been under exploited in the petroleum industry. Recently scientists have published some results on laboratory based magnetic susceptibility data for reservoir rock minerals which show strong correlations with key petrophysical parameters including permeability. However, such laboratory based experiments are not representative of in-situ reservoir conditions. Part of this thesis investigates the in-situ magnetic properties of reservoir rocks and minerals at reservoir temperatures via laboratory experiments to model downhole conditions. The shapes of hysteresis curves at various temperatures and the shapes of temperature dependent susceptibility (TDS) curves for individual minerals (paramagnetic, diamagnetic, ferromagnetic) were used to identify the type of magnetic minerals present, their concentrations, phase transitions and changes in mineralogy. For paramagnetic minerals, magnetic susceptibility decreases with an increase in temperature, whereas diamagnetic susceptibility is shown to be independent of temperature. Ferromagnetic substances can show a variety of thermomagnetic changes depending on the type of ferromagnetic minerals present. Changes in the domain state of ferromagnetic carriers with temperature were also observed, which either resulted from the formation of new ferromagnetic components and/or variations in grain size. Theoretical and experimental data on the thermomagnetic properties of reservoir rock minerals are also presented. A downhole sonde capable of taking magnetic susceptibility measurements in-situ downhole has been designed and tested in this thesis. Since the laboratory based methods have demonstrated correlations between the magnetically derived mineral contents and petrophysical parameters, the downhole magnetic susceptibility sonde can potentially provide in-situ predictions of these parameters. Model boreholes were prepared in the laboratory using powder samples and by drilling through solid blocks of rock. Tests were performed on these model boreholes using the magnetic susceptibility sonde.
48
Renner, Axel, Uwe Marschner, and Wolf-Joachim Fischer. "A new imaging approach for in situ and ex situ inspections of conductive fiber–reinforced composites by magnetic induction tomography." Sage, 2014. https://tud.qucosa.de/id/qucosa%3A35619.
Full textAbstract:
Fiber-reinforced plastics for industrial applications face constantly increasing demands regarding efficiency, reliability, and economy. Furthermore, it was shown that fiber-reinforced plastics with tailored reinforcements are superior to metallic or monolithic materials. However, a trustworthy description of the load-specific failure behavior and damage evolution of composite structures can hardly be given, because these processes are very complex and are still not entirely understood. Among other things, several research groups have shown that material damages like fiber fracture, delamination, matrix cracking, or flaws can be discovered by analyzing the electrical properties of conductive composites, for example, carbon fiber–reinforced plastics. Furthermore, it was shown that this method could be used for structural health monitoring or nondestructive evaluation. Within this study, magnetic induction tomography, which is a new imaging approach, is introduced in the topic of nondestructive evaluation of carbon fiber–reinforced plastics. This non-contacting imaging method gains the inner spatial distribution of conductivity of a specimen and depicts material inhomogeneity, like damages, not only in two-dimensional images but also in three-dimensional images. Numerical and experimental investigations are presented, which give a first impression of the performance of this technique. It is demonstrated that magnetic induction tomography is a promising approach for nondestructive evaluation. Potentially, it can be used for fabrication quality control of conductive fiber–reinforced plastics and as a structural health monitoring system using an integrated or superficially applied magnetic induction tomography setup.
49
Brewer, Michael D., and Michael D. Brewer. "Column Leaching Experiments and Mass Balance Modeling Simulating In-Situ Leaching within the Oxide Zone of the Florence Porphyry Copper Deposit, Pinal County, Arizona." Thesis, The University of Arizona, 1998. http://hdl.handle.net/10150/191367.
Full textAbstract:
Column leaching experiments were conducted to simulate in-situ leaching processes and to provide information on the mechanisms and extent of copper recovery, acid consumption, and chemical composition of recycled raffinate. Two 1.52-meter by 0.30-meter columns, each loaded with approximately 150 kilograms of copper oxide ore from the Florence porphyry copper deposit, were leached with a dilute sulfuric acid solution for 84 days. Computer simulation of the saturation state and aqueous mass transfer of predominant elements during the column tests was performed using EQ3NR, an aqueous solution speciation-solubility modeling code and the geochemical mass balance modeling code NETPATH. These modeling codes were used to quantify the amount of minerals dissolved and precipitated in the columns during the column leaching experiments. NETPATH mass balance models containing Cu-montmorillonite and chrysocolla as sources of copper match observations of pre-leach material. Cu-montmorillonite contributed 55% and 34% of the dissolved copper in the columns effluent.
50
Brashear, Kyle Thomas. "The Assessment of Sonic Waves and Tracer Gases as Non-Destructive Testing (NDT) Methods for In-Situ Underground Mine Seals." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/50519.
Full textAbstract:
Since the MINER Act of 2006, the minimum static load of in-situ underground mine seals has been increased from 20-psi to either 50-psi if monitoring is conducted or 120-psi if left unmonitored. These minimum strength requirements in seals must be designed, built, and maintained throughout the lifetime of the seal. Due to this, it has become necessary to assess the effectiveness of non-destructive testing (NDT) technologies to determine seal integrity, which in this case, are explored using sonic waves and tracer gases. Through both small and large scale testing, two NDT methods were evaluated on their abilities to determine integrity of the seal. A sonic wave technique to observe a change in wave velocity to identify faults within the seal material. As a NDT method, tracer gases may be used as a potential indicator of a connection between both sides of the seal material through a series of faults and cracks within the material itself. This paper reviews the history of underground mine seals and discusses the overall assessment of sonic waves and tracer gases to serve as NDT methods for estimating the integrity of these seals.Master of Science