Dissertations / Theses on the topic 'Mechanical properties of material'
To see the other types of publications on this topic, follow the link: Mechanical properties of material.
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 'Mechanical properties of material.'
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
Robertson, Alec 1974. "Material properties of actin filament bundles." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/46628.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Includes bibliographical references (p. 119-127).
Actin is an ubiquitous structural protein fundamental to such biological processes as cell motility and muscle contraction. Our model system is the acrosomal process of the Limulus sperm which extends a 60 ýtm long actin bundle during reproduction. It is an example of a biological spring where the force of elongation derives from twist energy stored within the bundle during spermatogenesis. In addition to actin the acrosome comprises only one other protein: scruin, an actin-binding protein specific to Limulus that decorates and crosslinks actin filaments into a crystalline bundle. Our goal is to reconstitute the structure of the acrosome using these two proteins in order to further elucidate the role of scruin in actin bundle crosslinking.A multi-scale approach is presented wherein the bending rigidity of scruin bundles and their constituent filaments are probed individually, then inter-related by simple mechanical models. Material properties of filaments and bundles are measured using a combination of optical tweezers, electron and fluorescence microscopy. We find that scruin bundles reconstituted from acrosome fragments display an ordered structure, with a bending rigidity orders of magnitude higher than their individual filaments. Actin bundles formed by depletion exhibit similar behavior, revealing an intrinsic regime of coupled actin bundle formation. Bundle elastic moduli are eight orders of magnitude stiffer than reconstituted networks and an order of magnitude softer than the native acrosome, highlighting scruin's ability to dictate a wide range of material properties depending on the formation conditions.
by Alec P. Robertson.
Ph.D.
2
Wiedenman, Nathan Scott. "Towards programmable materials : tunable material properties through feedback control of conducting polymers." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45889.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 159-168).
Mammalian skeletal muscle is an amazing actuation technology that can controllably modify its force and position outputs as well as its material properties such as stiffness. Unlike muscle, current engineering materials are limited by their intrinsic properties, dictated at the molecular level.This work is focused on developing an integrated device, called a programmable material, which mirrors the capabilities of natural co-fabricated controlled actuation systems such as muscle. While such a device may have the external appearance of a homogeneous material, it can possess unique properties not existing in any currently manufactured material. When actuation, sensing, and control capabilities are integrated within a closed-loop system, the mechanical properties of the system such as stiffness, viscosity, and inertia will arise from the dynamics of the feedback loop rather than from any inherent mechanical properties of the materials from which the device was fabricated. Moreover, these properties may be 'tuned' by altering the feedback parameters embedded in the material system. With this approach properties such as negative stiffness may be generated which do not exist in bulk materials.The most promising of the existing artificial muscle technologies is actuation with conducting polymer. Additionally, conducting polymer has been used to fabricate the position sensor and control electronics. Creating these components from a single type of material has made it possible to co-fabricate the system into an integrated device. This is the first research to attempt to create a co-fabricated, fully integrated conducting polymer feedback device. This work establishes the feasibility of building the device and answers many of the questions of fabrication and design.
by Nathan Scott Wiedenman.
Ph.D.
3
Kappiyoor, Ravi. "Mechanical Properties of Elastomeric Proteins." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/54563.
Full textAbstract:
When we stretch and contract a rubber band a hundred times, we expect the rubber band to fail. Yet our heart stretches and contracts the same amount every two minutes, and does not fail. Why is that? What causes the significantly higher elasticity of certain molecules and the rigidity of others? Equally importantly, can we use this information to design materials for precise mechanical tasks? It is the aim of this dissertation to illuminate key aspects of the answer to these questions, while detailing the work that remains to be done.
In this dissertation, particular emphasis is placed on the nanoscale properties of elastomeric proteins. By better understanding the fundamental characteristics of these proteins at the nanoscale, we can better design synthetic rubbers to provide the same desired mechanical properties.Ph. D.
4
Salahshoor, Pirsoltan Hossein. "Nanoscale structure and mechanical properties of a Soft Material." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-theses/924.
Full textAbstract:
"Recently, hydrogel have found to be promising biomaterials since their porous structure and hydrophilicity enables them to absorb a large amount of water. In this study the role of water on the mechanical properties of hydrogel are studied using ab-initio molecular dynamics (MD) and coarse-grained simulations. Condensed-Phased Optimized Molecular Potential (COMPASS) and MARTINI force fields are used in the all-atom atomistic models and coarse-grained simulations, respectively. The crosslinking process is modeled using a novel approach by cyclic NPT and NVT simulations starting from a high temperature, cooling down to a lower temperature to model the curing process. Radial distribution functions for different water contents (20%, 40%, 60% and 80%) have shown the crosslinks atoms are more hydrophilic than the other atoms. Diffusion coefficients are quantified in different water contents and the effect of crosslinking density on the water diffusion is studied. Elasticity parameters are computed by constant strain energy minimization in mechanical deformation simulations. It is shown that an increase in the water content results in a decrease in the elastic. Finally, continuum hyper elastic model of contact lens is studied for three different loading scenarios using Finite Element Model. "
5
Dimas, Leon Sokratis Scheie. "Effective mechanical Properties of material models with random heterogeneities." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103706.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 191-198).
In this thesis we obtain analytical approximations to the probability distribution of the elastic tensor and fracture strengths of material models with random heterogeneities. We start by investigating the effective elastic properties of one-, two-, and three-dimensional rectangular blocks whose Young's modulus varies spatially as a lognormal random field. We decompose the spatial fluctuations of the Young's log-modulus F = In E into first- and higher-order terms and find the joint distribution of the effective elastic tensor by multiplicatively combining the term-specific effects. Through parametric analysis of the analytical solutions, we gain insight into the effective elastic properties of this class of heterogeneous materials. Building on this analysis we find analytical approximations to the probability distribution of fracture properties of one-dimensional rods and thin two-dimensional plates for systems in which: only the Young's modulus varies spatially as an isotropic lognormal field and more generally, both the Young's modulus and the local material strength vary spatially as possibly correlated lognormal fields. The properties considered are the elongation, strength, and toughness modulus at fracture initiation and at ultimate failure. For all quantities at fracture initiation our approach is analytical in I D and semi-analytical in 2D. For ultimate failure, we quantify the random effects of fracture propagation and crack arrest by fitting regression models to simulation data and combine the regressions with the distributions at fracture initiation. Through parametric analysis, we gain insight into the strengthening/weakening roles of the Euclidean dimension, size of the specimen, and the correlation, variance and correlation function of the random fields. Finally, we extend the approach to investigate the elasticity of non-lognormal random heterogeneous materials. First we investigate the elastic bulk stiffness of two-dimensional checkerboard specimens in which square tiles are randomly assigned to one of two component phases. This is a model system for multi-phase polycrystalline materials such as granitic rocks and many ceramics. We study how the bulk stiffness is affected by different characteristics of the specimen and obtain analytical approximations to the probability distribution of the effective stiffness. In particular we examine the role of percolation of the soft and stiff phases. In small specimens, we find that the onset of percolation causes significant discontinuities in the effective modulus, whereas in large specimens the influence of percolation is smaller and gradual. Secondly we study the effective stiffness of multi-phase composite systems in which the Young's modulus varies as a filtered Poisson point process and find that the homogenization approach initially developed for lognormal systems produces accurate results also for this class of non-lognormal systems.
by Leon Sokratis Scheie Dimas.
Ph. D.
6
Engman, Alexander. "Mechanical properties of bulk alloys and cemented carbides." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230897.
Full textAbstract:
The usage of cobalt (Co) as binder phase material in cemented carbides has been questioned becauseof the potential health hazards associated with cobalt particle inhalation. Cobalt is used because ofits excellent adhesive and wetting properties, combined with adequate mechanical properties. Thepurpose of this work is to investigate the mechanical properties of Fe-Ni bulk alloys and WC-Cocemented carbides using Integrated Computational Materials Engineering (ICME) methods com-bined with FEM data. The report investigates the mechanical properties of several bulk alloys inthe Fe-Ni system as a function of void size and fraction. FEM indentation and FEM fracture datais interpolated and used to model the hardnessHand fracture toughnessKIc. A precipitationhardening model based on the Ashby-Orowan’s equation is implemented to predict the e↵ect on theyield strength from precipitated particles. A model for solid solution hardening is also implemented.Existing models are used to simulate the properties of WC-Co cemented carbides together with thesolid solution hardening model. Results show that the simulated properties of the Fe-Ni bulk alloysare comparable to those of cobalt. However, the results could not be confirmed due to a lack ofexperimental data. The properties of WC-Co cemented carbides are in reasonable agreement withexisting experimental data, with an average deviation of the hardness by 11.5% and of the fracturetoughness by 24.8%. The conclusions are that experimental data for di↵erent Fe-Ni bulk alloys isneeded to verify the presented models and that it is possible to accurately model the properties ofcemented carbides.Anv¨andandet av kobolt (Co) som bindefas-material i h°ardmetall har blivit ifr°agasatt som en f¨oljdav av de potentiella h¨alsoriskerna associerade med inhalering av koboltpartiklar. Kobolt anv¨ands p°agrund av dess utm¨arkta vidh¨aftande och v¨atande egenskaper, kombinerat med tillr¨ackliga mekaniskaegenskaper. Syftet med detta arbete ¨ar att unders¨oka de mekaniska egenskaperna hos Fe-Ni bulklegeringarochWC-Co h°ardmetall genom att anv¨anda Integrated Computational Materials Engineering(ICME) metoder kombinerat med FEM-data. Rapporten unders¨oker de mekaniska egenskapernahos flera bulklegeringar i Fe-Ni systemet. FEM-indentering och FEM-fraktur data interpoleras ochanv¨ands f¨or att modellera h°ardheten H och brottsegheten KIc. En modell f¨or utskiljningsh¨ardningbaserad p°a Ashby-Orowans ekvation implementeras f¨or att f¨oruts¨aga e↵ekten p°a brottgr¨ansen av utskiljdapartiklar. ¨Aven en modell f¨or l¨osningsh¨ardning implementeras. Existerande modeller anv¨andsf¨or att simulera egenskaperna hos WC-Co h°ardmetall tillsammans med modellen f¨or l¨osningsh¨ardning.Resultaten visar att de simulerade egenskaperna hos Fe-Ni bulklegeringar ¨ar j¨amf¨orbara medde f¨or kobolt. Dock kan de inte bekr¨aftas p°a grund av avsaknad av experimentell data. Egenskapernahos WC-Co h°ardmetall st¨ammer rimligt ¨overens med existerande experimentell data, meden genomsnittlig avvikelse av h°ardheten med 11.5% och av brottsegheten med 24.8%. Slutsatserna¨ar att det beh¨ovs experimentell data f¨or Fe-Ni bulklegeringar f¨or att kunna verifiera modellernasnoggrannhet och att det ¨ar m¨ojligt att f¨oruts¨aga egenskaperna hos h°ardmetall.
7
Parenti, Cristina. "VARIATION OF THE LOCAL MATERIAL PROPERTIES OF AORTA." Master's thesis, Temple University Libraries, 2010. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/70843.
Full textAbstract:
Mechanical EngineeringM.S.E.
Understanding the aortic wall deformation and failure during traumatic aortic rupture (TAR), which is a leading cause of fatality in motor vehicle accidents is of great concern. The specific objective of the present study is to develop a material model that can describe the multi layer nature of the aortic wall. Fundamentally, the aortic wall is composed mainly of three layers, tunica intima, media and adventitia, and they are known to have different structures. Understanding the material properties of these layers is essential in order to study the local mechanisms of deformation, force transmission, and failure. The hypothesis of this study is that the tissue's instantaneous shear modulus grows along the radial direction while moving from the intima toward the adventitia. The higher compliance of the tissue near the intima, which is partly due to the concentration of the smooth muscle cells and partly due to the arrangement of collagen and elastin fibers, can explain the nature of aorta failure which is primarily generated from the inside towards the outer layers. A combination of micro- and nano-indentation tests were used to measure the local material properties of porcine aorta at the length scales of 160 µm and 40 µm respectively. The material properties of aorta were investigated in the lateral (left) region in several longitudinal locations of the descending aorta and the observed viscoelastic behavior was summarized in the form of instantaneous shear moduli and reduced relaxation functions. The instantaneous shear modulus was found to generally increase along the radial direction to about 0.6 normalized radial distance and then became almost constant but with higher variability. The reduced relaxation functions were generally independent of the location and test method. Comparing the mechanical results with the histological results obtained through Van-Guisen staining showed that the material properties are partly related to the distribution of smooth muscle cells. The results of this study can be used to explain the mechanisms of failure in aorta and contribute to improve the computational modeling of aorta's deformation which is valuable in a variety of applications including automotive accidents, endovascular grafts, and angioplasty.
Temple University--Theses
8
Kylström, Sanna. "The Effect of Twinning on the Mechanical Properties of Alloy 825." Thesis, KTH, Materialvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254760.
Full textAbstract:
Twinning is a known phenomenon in material science, but how is it connected with grain size and yield strength? Investigations are made on alloy 825 with light optical microscopy for 19 samples to calculate the twin fraction and grain size. Afterwards, the results are compared to yield strength throughout tensile tests. The samples have different reduction of dimension by hot rolling and have been annealed for different time intervals. It turns out that twinning makes alloy 825 slightly softer and more ductile on a smaller scale, since the twin fraction increases when the yield strength decreases. However, the grain size also slightly increases when the yield strength decreases, which is important to have in mind for the connection with the three of them.Tvillingbildning är ett känt fenomen inom materialvetenskap, men hur hör tvillingar, kornstorlek och sträckgräns ihop? Finns det ett samband? Undersökningar utförs med ett ljusoptiskt mikroskop för legering 825 på 19 prover, för att räkna ut tvillingfraktionen och kornstorleken. Detta jämförs sedan med sträckgränsen som man tillhandahåller från dragprov. Proverna har olika reduktion av sin dimension genom valsning och har glödgats olika tider. Det visar sig att tvillingbildning gör legering 825 något mjukare och mer duktil på en mindre skala, eftersom tvillingfraktionen ökar då sträckgränsen sjunker. Dock ökar även kornstorleken när sträckgränsen minskar, vilket är viktigt att tänka på när det kommer till sambandet mellan kornstorlek, tvillingar och sträckgräns.
9
Uberti, Megan E. "Exploring the material properties of small scale folded structures." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/83750.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (page 21).
make robotics more readily available to the average person. Although designs for a number of successful printable robots have already been produced, there has been little formal exploration into the materials properties of these structures. Three point bending tests were performed on beams made of the materials and cross-sectional geometries of current designs to determine the bending stiffness of the printable beams currently found in printable robots, particularly the printable quad-rotor frame. As expected the composite acrylic and PEEK triangular beam had the highest bending stiffness El at 4.15 ± 1.67 N*m2. The lowest El was the triangular PEEK beam in its weak configuration at 0.02 ± 0.005 N*m2. 3D printed ABS beams had an unreliable result, with El in the range of 11.7 ± 8.05 N*m2. Overall our experimentally calculated values for El were generally consistent with the theoretically calculated values, providing useful information to inform future design choices and understanding the limitations of printable robot structures.
by Megan E. Uberti.
S.B.
10
HASSAN, INAMUL. "Effects of Austempering Process on Mechanical Behavior Properties of Compacted Graphite Iron." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Material och tillverkning, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-45645.
Full textAbstract:
The thesis paper here focuses on the effects of the austempering temperature (TA) and the austempering time (tA) on the unalloyed fully ferrite Compacted Graphite Iron (CGI), to obtain improve in mechanical properties and the study of the microstructure. The unalloyed CGI samples were austenitised at 850oC for 60 and 90 min and were then heat treated at 275, 325 and 375oC with different holding times at 30,60,90, and 120 mins. Mechanical properties like the tensile strength, yield strength, young’s modulus, Brinell and Vickers harness were conducted to perform the analysis on the samples. LOM was used for the study of the microstructure and SEM was used for the study of fractography of the fractured tensile bar.
11
Xavier, Angela Marie. "Determination of the Material Properties of the Pediatric Rib." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392019115.
Full text
12
Harris, Trudy Katherine. "The mechanical properties of ultrahard materials at elevated temperatures." Thesis, University of Hull, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363188.
Full text
13
Eshetu, Tefera Zegeye. "Impact Acoustic Testing for Classification of CGI Mechanical and Material properties." Thesis, KTH, Industriell produktion, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-140320.
Full textAbstract:
Automotive industries have been putting extensive effort into producing engine materials considering resistance and weight of the engine material. This material should withstand higher combustion pressure and in the meantime should be lighter. Compacted Graphite Iron (CGI) is a material that could allow achieving these design requirements. But the variation of the CGI material and mechanical properties are very high within the given specifications. The thesis is focused on classifying CGI according to its material and mechanical properties. Impact Acoustic Testing method is a Non Destructive Testing method which is fast and might be able to classify the CGI materials based on its properties. The method can measure the structural response of a part. Its volumetric approach tests the whole part providing objective and quantitative results. The result was that the method could able to distinguish between gray iron and CGI, and could distinguish partly among CGI. Keywords: Non Destructive Testing, Impact Acoustic Testing, Compacted Graphite Iron
14
Blackwell, Bryan E. (Bryan Ellis). "A framework for determining the mechanical properties of dissimilar material joints." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/11245.
Full text
15
Zhao, Jingyi Zhao. "Relating Grain Boundaries to the Mechanical Properties of Polycrystalline Material: Gradient Nanocrystalline Material and Electro-Plasticity." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron153296020243128.
Full text
16
Venugopal, Vysakh. "Design of Multi-Material Lattice Structures with Tailorable Material Properties using Density-Based Topology Optimization." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1553252070840125.
Full text
17
Yeh, Chih-chiang. "Evaluation of material properties and friction data in metalforming." Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182179682.
Full text
18
Park, Christina Soyeun 1980. "Characterizing the material properties of polymer-based microelectrode arrays for retinal prosthesis." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89907.
Full text
19
Valero, Diana (Diana E. ). "Compression testing and measurement of material properties of a double network hydrogel." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98758.
Full textAbstract:
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (page 26).
Double network hydrogel samples were synthesized and manufactured out of polyacrylamide (PAAm) and alginate solutions. They were casted into cube molds with each side measuring 20 mm. Samples were tested under compressive loads in cyclic compression tests and stress relaxation tests. A viscoelastic model was applied and material properties were calculated using the experimental data. The elastic modulus of these PAAm-alginate gels was found to be 35kPa, while the viscosity, [eta], was found to be 1.43 kPa-s. The viscous response was found to have a dependency on the strain rate by an exponential factor of 0.26. Using the applied theoretical model and the experimentally determined material properties, you can then characterize the mechanical response of the PAAm-alginate hydrogel when it undergoes small strains.
by Diana Valero.
S.B.
20
Bhanbhro, Riaz. "Mechanical Properties of Tailings : Basic Description of a Tailings Material from Sweden." Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16952.
Full textAbstract:
Tailings dams are constructed to store waste material from mining industry and usually these dams are raised with time depending upon production rate. Tailings material is sometimes used in construction of tailings dams. Tailings are artificial material and the behavior of tailings material upon loading is different compared to natural soil materials. The mechanical properties of tailings have influence on the performance of a tailing dam. Since the tailings dams are constructed to withstand for long times, it is essential to understand tailings materials in depth in order to assure safe existence of the dams in short term as well as in long term perspective. This licentiate thesis describes the present work carried out on sulphide rich tailings from one mine in Sweden. The material presented is based upon material from three different papers. The first paper describes the basic characteristics of tailings which includes; specific gravity, phase relationships, particle size, particle shape and direct shear behavior. The second paper discusses direct shear tests carried out on tailings from one Swedish mine. Shear strength parameters are evaluated and results from 27 tests (15 drained and 12 undrained tests) are discussed. This paper also describes the vertical height reductions observed during direct shear tests. The third paper focuses on the laboratory results from triaxial tests conducted on tailings materials. This paper shows the drained behavior of tailings under application of different consolidation pressures.The results from particle analysis showed that smaller particles were very angular and bigger particles were sub angular. The material was classified as silt and silty sand. The average particle density (ρs) is 2.83t/m3. The dry density and void ratios were found to be 1.18–1.65 t/m3 and 0.72–1.41 respectively. During direct shear tests vertical height reductions were observed with slight increment in pore pressures. The strain hardening behavior was observed in both drained and undrained conditions in direct shear tests. The strength parameters determined in triaxial test were higher than of those calculated in direct shear tests. Friction angle ϕ' in triaxial tests were found to be 39 to 41degrees and it did not showed any effect with relation to depth. The cohesion and friction angle in direct shear test at 0.15radian, in drained tests were found as in range of 9.7-33.7kPa and 12.5-18.3 degrees respectively. The same parameters for undrained tests were found as 7.1-16.1 kPa and 16.0-20.4 degrees for cohesion and friction angle respectively.Godkänd; 2014; 20140818 (riabha); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Riaz Bhanbhro Ämne: Geoteknik/Soil Mechanics and Foundation Engineering Uppsats: Mechanical Properties of Tailings Basic Description of a Tailings Material from Sweden Examinator: Professor Sven Knutsson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Adjungerande professor Peter Viklander, Vattenfall AB, Luleå Tid: Torsdag den 18 septemebr 2014 kl 10.00 Plats: F1031, Luleå tekniska universitet
21
Yoon, Se-Young. "Bonding Material Coated Clay for Improving Paper Properties." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14540.
Full textAbstract:
The paper industry utilizes fillers either to reduce the cost or to provide desired functional or end-use properties of paper products. However, there are disadvantages associated with higher filler loadings beyond a certain level, which reduces paper strength. The present study focused on improving the physical property of filled papers. Three methods of structuring fillers were designed; precipitation with starch, complexation with starch and fatty acid, and regeneration with cellulose. Because cellulose and starch have hydroxyl groups on the chemical structure, the hydrogen bonding between fillers and wood fibers is assumed to be occurred by structuring fillers.
For starch application, we used two different approaches; salt precipitation and fatty acid complexation. The cooked starch can be precipitated by certain salt solutions such as (NH4)2SO4. Also, the cooked starch can be complexed with fatty acid to produce an insoluble crystalline structure. When starch composites with clay made by both methods were put into the furnish as fillers, dramatic strength improvement was achieved such as 100-200% gains in tensile strength. This is due to the strong bonding between clay fillers and wood fibers, which is determined by Z-directional tensile strength. One of advantages is that using the starch-fatty acid complex has an inherent water repellent property, sizing effect.
For cellulose as a bonding material, N-methylmorpholine-N-oxide was used as a solvent to dissolve the cellulose. The advantage of using this method is that we can use the low grade cellulose. The physical properties of the cellulose coated clay handsheets were significantly improved, but optical properties such as brightness and opacity were inferior to the hadnsheets filled with starch-clay composites due to relatively large particle size.
In order to model the strength improvement by the composite filler, BDT theory, which is a modified Pages Equation, was used. After calculating the factors such as surface area and specific bond strength, the model matched well with the experimental results. Using this model, the tensile strength improvement could be predicted in terms of the change of bond strength and composite size.
22
Khan, Saadika B. "Mechanical and handling properties of light-cured acrylic resin custom tray material." Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_4268_1227009157.
Full textAbstract:
Both light-cured (LC) and chemically-cured (CC) acrylic resin custom tray materials are used at the Oral Health Centre, Faculty of Dentistry, University of the Western Cape. At present, the CC acrylic is the standard for formal undergraduate teaching and training. The LC material is not part of routine didactic teaching as little evidence-based scientific information is available with regards to its properties and its usage in the clinical environment. Negative effects have caused researchers to focus on alternatives and to research for other materials with more advantageous properties. The objectives of this study was to determine the linear dimensional shrinkage and fracture toughness of light-cured acrylic custom tray materials and compare it to the chemically-cured type. Also to evaluate the acceptance of light-cured acrylic resin custom trays by undergraduate students.
23
Agbisit, Roderick Nazario Malcaba. "Relationships between material properties and microstructure-mechanical attributes of extruded biopolymeric foams." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/334.
Full text
24
Daniel, Geoffrey Morrall. "Evaluation of material properties of mechanically alloyed SUS304L with Zr addition." Kyoto University, 2019. http://hdl.handle.net/2433/242327.
Full text
25
Forskitt, M. "A computer modelling of some mechanical properties of perforated and porous materials." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381214.
Full text
26
Hemmasizadeh, Ali. "Characterization of Heterogeneous Material Properties of Aorta Using Nanoindentation." Diss., Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/240046.
Full textAbstract:
Mechanical EngineeringPh.D.
Arterial mechanical properties have received increasing attention in the past few decades due to their vast effect on predicting cardiovascular diseases and injuries. The heterogeneity of thoracic aortic tissue was characterized in terms of viscoelastic material properties and correlations were obtained between these properties and tissue morphology. Additionally, the effect of material preservation on the material properties was determined. Changes in the mechanical properties of porcine thoracic aorta wall in the radial direction were characterized using a quasi-linear viscoelastic modeling of nanoindentaiton tests. Two layers of equal thickness were mechanically distinguishable in descending aorta based on the radial variations in the instantaneous Young's modulus E and reduced relaxation function G(t). Overall, comparison of E and Ginf of the outer half (70.27±2.47 kPa and 0.35±0.01) versus the inner half (60.32±1.65 kPa and 0.33±0.01) revealed that the outer half was stiffer and showed less relaxation. The results were used to explain local mechanisms of deformation, force transmission, tear propagation and failure in arteries. A multimodal and multidisciplinary approach was adopted to characterize the transmural morphological properties of aorta. The utilized methods included histology and multi-photon microscopy for describing the wall micro-architecture in the circumferential-radial plane, and Fourier-Transform infrared imaging spectroscopy for determining structural protein, and total protein content. The distributions of these quantified properties across the wall thickness of the porcine descending thoracic aorta were characterized and their relationship with the mechanical properties was determined. It was revealed that there is an increasing trend in mechanical stiffness, Elastic lamella Density (ELD), Structural Protein (SPR), Total Protein (TPR), and Elastin and Collagen Circumferential Percentage (ECP and CCP) from inner layers toward the outer ones. Finally two larger regions with equal thickness (inner and outer halves) were determined based on cluster analysis results of ELD which were in agreement with the cluster analysis of instantaneous Young's modulus. Changes to the local viscoelastic properties of fresh porcine thoracic aorta wall due to three common storage temperatures (+4 oC, -20 oC and -80 oC) within 24 hours, 48 hours, 1 week and 3 weeks were characterized. The changes to both elastic and relaxation behaviors were investigated considering the multilayer, heterogeneous nature of the aortic wall. For +4 oC storage samples, the average instantaneous Young's modulus (E) decreased while their permanent average relaxation amplitude (Ginf) increased and after 48 hours these changes became significant (10%, 13% for E, Ginf respectively). Generally, in freezer storage, E increased and Ginf showed no significant change. In prolonged preservation (> 1 week), the results of +20 oC storage showed significant increase in E (20% after 3 weeks) while this increase for -80 oC was not significant, making it a better choice for tissue cold storage applications. Results from this dissertation present a substantial step toward the anatomical characterization of the aortic wall building blocks and establishing a foundation for understanding the role of microstructural components on the functionality of blood vessels. A better understanding of these relationships would provide novel therapeutic targets and strategies for the prevention of human vascular disease.
Temple University--Theses
27
Zander, Johan. "Modelling mechanical properties by analysing datasets of commercial alloys." Licentiate thesis, Stockholm : Industriell teknik och management, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4527.
Full text
28
Eriksson, Daniel. "Wood - an anatomical structure in the tree and an engineering material in industry : prediction of material properties in managed Scots pine stands in the forest /." Umeå : Dept. of Forest Ecology and Management, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200873.pdf.
Full text
29
Vara, Amit Rashiklal. "Determination of material properties of mild steel at different temperatures and strain rates." Master's thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/5458.
Full textAbstract:
Includes abstract.Includes bibliographical references.
Quantification of material properties through physical experiments is of significant importance. Test data from such experiments aid in the understanding of the material behaviour when exposed to a variety of loading conditions. Such data also help in the formulation of empirical and constitutive relations that can be applied in numerical simulations. This project dealt with the determination of the variation of the yield stress of mild steel with temperature and strain rate. This was achieved by carrying out high temperature tensile tests at different strain rates on mild steel specimens. These experiments also helped set a methodology for carrying out high temperature tensile tests using a servohydraulic universal tester. Results from the tests indicated that increases in temperature tended to decrease the yield stress, whereas increases in strain rate had the opposite effect. This was found to be consistent with data found in literature. It was also noted that the temperature effect was more dominant than the strain rate effect over quasi-static strain rates.
30
Chopra, Prateek. "Effective mechanical properties of lattice materials." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/39436.
Full textAbstract:
Lattice materials possess a spatially repeating porous microstructure or unit cell. Their usefulness lies in their multi-functionality in terms of providing high specific stiffness, thermal conductivity, energy absorption and vibration control by attenuating forcing frequencies falling within the band gap region. Analytical expressions
have been proposed in the past to predict cell geometry dependent effective material properties by considering a lattice as a network of beams in the high porosity limit. Applying these analytical techniques to complex cell geometries is cumbersome. This precludes the use of analytical methods in conducting a comparative study involving complex lattice topologies. A numerical method based on the method of long wavelengths and Bloch theory is developed here and applied to a chosen set of lattice geometries in order to compare effective material properties of infinite lattices. The proposed method requires implementation of Floquet-bloch transformation in conjunction with a Finite Element (FE) scheme. Elastic boundary layers emerge from surfaces and interfaces in a finite lattice, or an infinite lattice with defects such as cracks. Boundary layers can degrade effective
material properties. A semi-analytical formulation is developed and applied to a chosen set of topologies and the topologies with deep boundary layers are identified. The methods developed in this dissertation facilitate rapid design calculation and selection of appropriate core topologies in multifunctional design of sandwich
structures employing a lattice core.
31
Lawson, Nathaniel C. "Mechanical properties of dental impression materials." Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2008r/lawson.pdf.
Full text
32
Ajwani, Anita. "Mechanical properties of bio-absorbable materials." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-12042009-020133/.
Full text
33
Sparnins, Edgars. "Mechanical properties of flax fibers and their composites." Doctoral thesis, Luleå, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26640.
Full textAbstract:
Flax fibers, along with a number of other natural fibers, are being considered as an environmentally friendlier alternative of synthetic fibers in fiber-reinforced polymer composites. A common feature of natural fibers is a much higher variability of mechanical properties. This necessitates study of the flax fiber strength distribution and efficient experimental methods for its determination. Elementary flax fibers of different gauge lengths are tested by single fiber tension in order to obtain the stress-strain response and strength and failure strain distributions. The applicability of single fiber fragmentation test for flax fiber failure strain and strength characterization is considered. It is shown that fiber fragmentation test can be used to determine the fiber length effect on mean fiber strength and limit strain. The effect of mechanical damage in the form of kink bands and of diameter variability on the strength of elementary flax fibers is considered. Stiffness and strength under uniaxial tension of flax fiber composites with thermoset and thermoplastic polymer matrices are studied. The applicability of rule of mixtures and orientational averaging based models, developed for short fiber composites, to flax reinforced polymers are evaluated. Both the quasi-static and time dependent mechanical properties of flax fiber/thermoplastic starch based composites are analyzed. The effect of temperature and relative humidity is investigated. It is found that microdamage accumulation in this type of composites is not significant. Results show that the composite elastic modulus and failure stress are linearly related to the maximum stress reached by the matrix in tensile tests. Simple material models are suggested to account for the observed nonlinear viscoelasticity and viscoplasticity.Godkänd; 2009; 20091029 (edgspa); DISPUTATION Ämnesområde: Polymera konstruktionsmaterial/Polymeric Composite Materials Opponent: Docent Kristofer Gamstedt, Kungliga Tekniska Högskolan, Stockholm Ordförande: Docent Roberts Joffe, Luleå tekniska universitet Tid: Onsdag den 9 december 2009, kl 10.00 Plats: E 231, Luleå tekniska universitet
34
Wang, Zhixin. "Polydimethylsiloxane Mechanical Properties Measured by Macroscopic Compression and Nanoindentation Techniques." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3402.
Full textAbstract:
In this thesis, the relationship between the elastic modulus of PDMS and the base/agent ratio (the amount of crosslinking) is studied. Reliable macroscopic compression test instrument was developed. Preload method was applied for the nanoindentation flat punch test to develop full contact.
In chapter 2, an easy instrument setup for macroscopic compression test is described. A series of PDMS samples with different base/agent ratios were tested using the macroscopic compression method. The relationship between PDMS elastic modulus and its base/agent ratio was established.
In chapter 3, PDMS nanoindentation DMA tests provide stable data with different test control models. The storage modulus collected using nanoindenting DMA tests is comparable with elastic modulus collected in PDMS compression test in chapter 2. Nanoindentation experiments with flat punch were also done to test the elastic modulus of PDMS network 5:1. The adhesion force tests with different nanoindentation tips, which are Berkovich tip, conical tip and cube corner tip, show that PDMS's adhesion force is related to the sample's base/agent ratio, the nanoindentating depth and the tip's geometrical shape.
35
Zadhoush, Ali. "The influence of defects on the mechanical properties of short fibre reinforced thermoplastics." Thesis, Brunel University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.255673.
Full text
36
Johansson, Frida, and Johanna Klarin. "Mechanical properties of trabecular structures produced by SLM, as a function of the trabecular morphology." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Produktutveckling, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-36593.
Full textAbstract:
Eurocoating, Italy, is a company that works in the biomedical sector. They have for a long time created prostheses from CAD files achieved from customers, and now they want to build their own expertise about the design. The thesis work was a part of a three year long collaborative research project between Eurocoating and University of Trento that was aiming to investigate the prostheses with open-porous surface and trabecular structure, created by Selective Laser Melting. The purpose of the thesis was to investigate and characterize 30 different trabecular structures of Ti-6Al-4V, fabricated by Selective Laser Melting. That includes investigation the effect on the morphology and porosity fraction caused by the manufacturing and the effect on mechanical and physical properties due to the different characterizations of the structures. The thesis work had its foundation in literature studies to receive deep knowledge about the subject. Practical tests were performed to investigate mechanical behaviour under compressive and tensile loading, static friction and wear resistance. The findings from these tests were compared to the porosity fraction and the morphological characterizations. The result stated that the porosity fraction was lower than the designed porosity, and that is was strongly influenced by size of the voids and struts. The strut thickness was higher than the design values, especially on the lateral surface, while the voids size were approximately as designed. Result from the compression test showed a trend of decreasing stiffness and strength with increasing porosity fraction. Also structures with same porosity fraction could have a wide range in mechanical properties which indicates high dependence on the morphological geometry i.e. pore size and shape, strut size and pore distribution. Comparisons between tensile and compression behaviour stated that the structures had a lower strength but a significant higher stiffness in tensile load. All structures from the wear test showed a good resistance while the results from the friction test needs further investigation to be fully understood. The physical and mechanical properties of the trabecular structures was found to be close to those of cortical and trabecular bone in porosity, stiffness and strength. There is a range of variations leading to possibilities to adopt the application depending on customer. Thus, these can be considered as promising structures used biomedical application to optimize osseointegration and secondary long term fixation.
37
Appelsved, Peter. "Investigation of Mechanical Properties of Thermoplastics with Implementations of LS-DYNA Material Models." Thesis, KTH, Hållfasthetslära (Inst.), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103790.
Full textAbstract:
The increased use of thermoplastics in load carrying components, especially in the automotive industry, drives the needs for a better understanding of its complex mechanical properties. In this thesis work for a master degree in solid mechanics, the mechanical properties of a PA 6/66 resin with and without reinforcement of glass fibers experimentally been investigated. Topics of interest have been the dependency of fiber orientation, residual strains at unloading and compression relative tension properties. The experimental investigation was followed by simulations implementing existing and available constitutive models in the commercial finite element code LS-DYNA. The experimental findings showed that the orientation of the fibers significantly affects the mechanical properties. The ultimate tensile strength differed approximately 50% between along and cross flow direction and the cross-flow properties are closer to the ones of the unfilled resin, i.e. the matrix material. An elastic-plastic model with Hill’s yield criterion was used to capture the anisotropy in a simulation of the tensile test. Residual strains were measured during strain recovery from different load levels and the experimental findings were implemented in an elastic-plastic damage model to predict the permanent strains after unloading. Compression tests showed that a stiffer response is obtained for strains above 3% in comparison to tension. The increased stiffness in compression is although too small to significantly influence a simulation of a 3 point bend test using a material model dependent of the hydrostatic stress.
38
Albakri, Isra Abdelkarim Moh'd. "Fluoride release, mechanical properties and biological interaction of a modified denture base material." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/12855.
Full textAbstract:
The aim of the present study was to evaluate the effect of modifying the polymethylmethacrylate (PMMA) denture resin with fluoridated glass fillers on the fluoride release ability, mechanical and surface properties, and the effect on bacterial and candidal adhesion on the denture surface. Specimens of PMMA loaded with different concentration of fluoridated glass fillers (0, 1, 2.5, 5, and 10% wt) were prepared and aged in deionized water and lactic acid. Fluoride release and re-release, and mechanical properties including; flexural properties, nanohardness, surface topography, surface roughness and surface free energy were assesed. The effect on the adhesion of S. mutans and C. albicans, to the PMMA was also quantified. The findings showed the ability of modified PMMA to release and re-release fluoride in both ageing media. Flexural properties’ deterioration was correlated to the filler loading but complied generally with the ISO specifications. The incorporation of fluoridated glass fillers did not influence neither the surface hardness nor the surface free energy (P >0.05). Surface roughness (Ra) has increased and the surface topography aligned with the Ra values. The incorporation of fluoridated glass fillers and the saliva coating reduced the adhesion of S.mutans and C. albicans to the surface of PMMA (P<0.05).
39
Sánchez, Vivas Lorena. "Bamboo as a Sustainable Engineering Material: Mechanical Properties, Safety Factors, and Experimental Testing." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7925.
Full textAbstract:
With exponential global population growth occurring and associated environmentally destructive consumption of natural resources, alternative materials that are fast growing and sustainable are being sought out to satisfy human needs. One material that is fast growing and sustainable that can be used to meet most basic needs of humans (i.e. shelter, food, tools) is the plant bamboo, of the grass family Poaceae. Bamboo was used in the past by native peoples who lived in the environment where bamboo natively grows (all continents except Europe and Antarctica) with proven success for uses such as shelter, piping, tools, wells, food, fencing, baskets and much more. These practices were mostly abandoned and deemed obsolete due to the introduction of long lasting ‘modern’ building materials of steel and concrete which gained popularity in the 1800s. Now, in the current century with much advancement in science, technology, and education, humanity is reconsidering many practices and returning to more ancient practices and ways that are better for human health, the environment, and overall sustainability.
These environmental considerations are drivers of this research, which focuses on how to use bamboo for engineering applications. First, in order to use a material for engineering and design applications, a material must be destructively tested to attain material property values. Therefore, a critical examination of the bamboo mechanical property values published literature was performed. It was found that although many scientists all over the world have been working on mechanical property testing of bamboo, their results have been published in different journals, in different languages, and had not yet been aggregated and compared. This led to the first study in this work that analyzed mechanical property data from 43 bamboo peer-reviewed publications written in English, Spanish, and Portuguese (the three main languages in which bamboo literature is published). This study focused on aggregating mechanical property values, establishing a range of values for each property as well as an average, and correlating the difference in property values to bamboo variables stated in bamboo literature (age, bamboo species, density, moisture content, post-harvest treatment, and testing standard employed). The five mechanical properties reviewed were: shear strength, compressive strength, tensile strength, bending strength / modulus of rupture (MOR), and modulus of elasticity (MOE) and their average values were 9 MPa, 52 MPa, 159 MPa, 120 MPa, and 16 GPa, respectively. Although a thorough graphical set of analyses were performed attempting to correlate the difference in mechanical property values to the previously listed variables, and only main variables found to influence strength values were moisture content and specific testing standard employed.
The results of the high range of mechanical property values with no variable with which to separate the results to lower the range, led to the second part of the research. It incorporated the high range of values reported in the literature but was able to establish safety factors and reduction factors alongside corresponding failure rates. This work allows for a designer to use bamboo culms choosing a failure rate he/she deems appropriate for structural bamboo construction. The analyses in this work were performed using Allowable Stress Design (ASD) and Load and Resistance Factor Design (LRFD) equations applied to bamboo as well as Monte Carlo statistical analyses for verification. The raw data and statistically analyzed data of 25 publications were used for this analysis, yielding 3806 strength test values (shear strength, compressive strength, bending strength / modulus of rupture, and tensile strength). Shear strength safety factors ranged from 1.38-3.58 for failure ratios from 1:6-1:25000; compressive strength from 1.30-2.79; bending strength from 1.43-4.03; tensile strength from 1.66-7.43. No singular safety factor is suggested for design as that is due to the judgment of the designer of what failure ratio he/she deems appropriate for the specific application.
Although many compression tests have been performed on bamboo, there are no known tests which destructively test bamboo after an extended period of time after harvesting (more than ~3 months). This experiment conducted a field experiment to test the functionality of using bamboo for the application of installing bamboo wells to provide groundwater. The bamboo tested in the third part of the study was of two species, Dendrocalamus giganteus and Dendrocalamus asper half of which were 1) air-dried in a laboratory for 3.5 years and the other half of which was 2) inserted in the ground as bamboo wells. The bamboo culms (or poles) had been separately treated in three different ways right after cutting: 1/3 with a borax and boric acid solution (most conventional treatment in the industry), 1/3 with coconut oil (experimental treatment in the literature), and 1/3 air-dried, a non-treated control. Bamboo wells are said to be used in ancient times as well as in more recent applications in the 1990s in India by small scale farmers. The publication of bamboo well studies have been very few and nearly no scientific analyses had been performed on them. Therefore, six bamboo wells were assembled and installed at the University of South Florida Geopark, the first of their kind in the U.S. These wells were half of species D. giganteus and half of species D. asper and also treated individually using the three different treatments described above. The wells were monitored for pH and presence of leached boron for a 3.5-year monitoring period and then removed. Upon removal, the bamboo well casings were examined for molds present as well as by mechanical compression testing to assess degradation in comparison to each other (of different treatments) and to air-dried control samples maintained in the laboratory for 3.5 years. The mold fc. Acrodictys was observed to cover the entire inner portion of the bamboo (inner diameter), from the surface level up to the water table. The lab air-dried control samples had compression strength and compressive modulus of elasticity values correlating to those found in the literature, 44-90 MPa (72 MPa average) and 15-31 GPa, respectively. Removed well samples exhibited compressive strengths and compressive modulus of elasticity values of 22-61 MPa (39 MPa average) and 7-25 GPa, respectively. This study revealed that bamboo wells were feasible and although their compressive strengths lowered by around a half after being in the ground for 3.5 years, their compressive strength and compressive modulus of elasticity values were still in the range of bamboo tested in the literature.
40
Romanov, Vasily Vladimirovich. "MATERIAL PROPERTIES OF AORTA FROM BIAXIAL OSCILLATORY TESTS." Master's thesis, Temple University Libraries, 2010. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/117228.
Full textAbstract:
Mechanical EngineeringM.S.E.
This project addresses characterization of the material properties of aortic tissue. Understanding of these properties is important for a variety of studies including tissue engineering, effects of aging and diseases, stents engineering, and traumatic aorta rupture. The goal of the presented research was to characterize the stress-strain relationship of aorta in dynamic oscillatory biaxial loading. A setup was developed that supplied pressure loading from the physiological to sub-failure levels (between 7 and 76 kPa) to porcine aorta at frequencies ranging from 0.50Hz to 5.00Hz. Samples tested were constrained at both ends while the deformation and the pressure were recorded. Volumetric strain versus pressure was used to characterize the structural behavior of the material which showed frequency dependency and hysteresis indicating viscoelastic response. An offset method was developed to account for drifting behavior exhibited by some of the samples. The structural behavior of aorta was modeled using a quasi-linear viscoelastic (QLV) creep theory. The QLV model included a logarithmic steady state elastic function v = 0.663 +/- 0.040 + 0.241 +/- 0.011 ln(P) for pressure in kPa, and a Prony series creep function ( J0 = 0.472 +/- 0.021, J2 = 0.109 +/- 0.060, J3 = 0.419 +/- 0.056). Modeling results were then used to determine the relationships between the circumferential and longitudinal stresses and strains of the material. The results exhibited that the stress in the transverse direction was about 1.5 times larger than in the axial direction. However, in the axial direction material was stiffer and the deformation was 30% less. The relaxation function of the material was determined by linearizing the non-linear component of the QLV model and applying to it the linear viscoelastic theory. Furthermore, literature comparison revealed that aorta's creep function, as well as its elastic modulus, is within the range of what has been reported in the literature. In conclusion, an experimental model was developed that can be used to predict the behavior of porcine aorta under physiological and sub-failure conditions at quasi-static and dynamic loading.
Temple University--Theses
41
Wang, Shuyue. "Material Properties of Adhesive Joint." Thesis, KTH, Hållfasthetslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277865.
Full textAbstract:
The development of the commercial 5G network with high-frequency mmWave requires tighter base station grid, which increases the demand for smaller and more unobtrusive products. One way to connect materials of different properties and keeping the product size small is to use adhesive joints instead of screw joints. The thesis project is about understanding the material behaviour of adhesive joint and determining the material model. Adhesive joints can be described as a highly temperature-dependent material, including both hyperelastic and viscoelastic material behaviours. A relaxation test was carried out to evaluate the joint behaviour and its temperature dependence. The results showed that the Neo Hookean material model and the Generalized Maxwell model can be used to describe the basic joint properties. Additionally, the adhesive joint exhibited a softening behaviour under cyclic loading, in which the softening in the first load cycle was captured by the Mullins effect. A cyclic loading test was carried out to evaluate the joint damage. The results showed that when the joint thickness was equal to the applied displacement, no visible joint damage will occur. However, if the joint thickness is less than the applied displacement, total joint failure can be captured by small reaction force and discontinuities in the force-displacement curve.Utvecklingen av den kommersiella 5G-nätverk med högfrekvent signaler sätter krav för en tätare basstationsnät, vilket i sin tur behöver mindre och mer diskreta produkter. Ett sätt att combinera material med olika egenskaper och samtidigt försöka minimera produktsstorleken är att ersätta skruvförband med limförband. Detta masterexamensarbete handlar om att undersöka materialbeteende hos limfog och att bestämma dess materialmodell. Limfogd kan beskrivas som ett temperaturberoende material med både hyperelastiskt och viscoelastiskt materialbeteende. En relaxationstest genomfördes för att utvärdera limfogens beteende och dess temperaturberoende egenskaper. Testresultaten visade att Neo Hookean och Generalized Maxwell material modellen kan användas för att beskriva de grundläggande materialegenskaperna hos limfogen. Under cyklisk last initierades skadan i limfog där materialets styvhet minskades med antal ökade lastcykel. Minskningen av styvheten vid den första lastcykel kan beskrivas med Mullins effekt. När limfogens tjocklek är lika med den applicerade förskjutning, visades ingen synlig skada. Däremot om tjockleken är mindre än den applicerade förskjutning, kan total brott i limfogen identifieras med små reaktionskraft och diskontinuitet i kraftförskjutningskurvan.
42
Root, Samuel E. "Mechanical Properties of Semiconducting Polymers." Thesis, University of California, San Diego, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10745535.
Full textAbstract:
Mechanical softness and deformability underpin most of the advantages offered by semiconducting polymers. A detailed understanding of the mechanical properties of these materials is crucial for the design and manufacturing of robust, thin-film devices such as solar cells, displays, and sensors. The mechanical behavior of polymers is a complex function of many interrelated factors that span multiple scales, ranging from molecular structure, to microstructural morphology, and device geometry. This thesis builds a comprehensive understanding of the thermomechanical properties of polymeric semiconductors through the development and experimental-validation of computational methods for mechanical simulation. A predictive computational methodology is designed and encapsulated into open-sourced software for automating molecular dynamics simulations on modern supercomputing hardware. These simulations are used to explore the role of molecular structure/weight and processing conditions on solid-state morphology and thermomechanical behavior. Experimental characterization is employed to test these predictions—including the development of simple, new techniques for rigorously characterizing thermal transitions and fracture mechanics of thin films.
43
Gustafsson, Jesper, and Mikael Landberg. "Production of bio-plastic materials from apple pomace : A new application for the waste material." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-21216.
Full textAbstract:
Extensive quantities of apple pomace are generated annually but disposal of this waste is still much disputed. In EU alone, 500 000 tons are produced every year. Without further treatment, the acidic character of apples with their high sugar and low protein content makes the pomace unsuitable for landfilling and animal feedstock. However, further treatment is usually not economically feasible. This study addresses this issue by introducing a new approach for the apple pomace to produce sustainable materials. The high content of sugars in apple pomace which can be reshaped and reformed at higher temperatures makes the waste material suitable for plastic production. Other components found in apple pomace are 5 % proteins and 1.5 % fats. Fibers are abundant, dietary fibers amounts for more than half (55 %) the original apple pomace weight. Phenols, sorbitol and acids can be found in minor mount, 2 % or less. The apple pomace itself is a mixture of mostly pulp and peel which corresponds to 9/10 of the total mass. Whereas seeds, seed core and stalk are the remaining 1/10. The possibilities of utilizing apple pomace to produce biofilms and 3D shapes have been investigated. The effects of introducing orange pomace, another waste material produced in extensive quantities, to apple pomace samples has also been studied. Two methods were used to produce bioplastic materials; solution casting and compression molding. Glycerol was used as a plasticizer. Apple pomace, either washed or not washed, was oven-dried and milled into a fine powder. Using compression molding, plates or cups of the two powders with different amounts of glycerol were prepared. Mixtures of apple pomace and orange pomace, with or without glycerol, were prepared in the same way. The apple pomace was also used in a film casting method to produce plastic films. Applying laser cutting to the plates and plastic films, dog-bone specimens were created whose mechanical properties were analysed using a universal testing machine. Highest values in terms of tensile strength and elongation at max was reached with bioplastics produced from solution casting where the values varied in the range 3.3 – 16 MPa and 11 – 55 % respectively. The compression molding approach resulted in tensile strength values in the range 0.94 – 5.9 MPa whereas the elongation at max was in the range 0.30 – 1.9 %. A possible application for this material could be disposable tableware which does not require high mechanical strength. It was shown that it is possible to produce 3D structures and plastic films from apple pomace. Washed apple pomace with glycerol has similar properties as not washed apple pomace without the plasticizer. Adding orange pomace to apple pomace samples increases the tensile strength at the expense of the elongation at max. The pressing conditions and powder size greatly effects the mechanical properties, where a larger powder size lower the values for the mechanical properties. This new approach paves the way for a new utilization of apple pomace to replace some petroleum-based materials and at the same time solve the disposal problem of apple pomace.
44
Gernhardt, Marvin. "Multi-material microstructures with novel stimuli-responsive properties." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/210195/1/Marvin_Gernhardt_Thesis.pdf.
Full textAbstract:
This thesis presents the development of two novel materials that undergo drastic changes when exposed to a certain trigger. One of them becomes harder and stiffer when exposed to visible light of a certain wavelength and one of them degrades when exposed to a certain enzyme. The properties of the materials were investigated thoroughly. The advanced 3D printing technique direct laser writing was used to fabricate microscopic structures from both materials. Such microstructures possessing highly adaptable properties could be used as scaffold materials for cells in order to study their development as a response to the triggered changes.
45
Park, Jin Young. "Pultruded composite materials under shear loading." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/32865.
Full text
46
Bertolla, Luca. "Mechanical Reinforcement of Bioglass®-Based Scaffolds." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-234586.
Full textAbstract:
Bioactive glasses exhibit unique characteristics as a material for bone tissue engineering. Unfortunately, their extensive application for the repair of load-bearing bone defects is still limited by low mechanical strength and fracture toughness. The main aim of this work was two-fold: the reinforcement of brittle Bioglass®-based porous scaffolds and the production of bulk Bioglass® samples exhibiting enhanced mechanical properties. For the first task, scaffolds were coated by composite coating constituted by polyvinyl alcohol (PVA) and microfibrillated cellulose (MFC). The addition of PVA/MFC coating led to a 10 fold increase of compressive strength and a 20 fold increase of tensile strength in comparison with non-coated scaffolds. SEM observations of broken struts surfaces proved the reinforcing and toughening mechanism of the composite coating which was ascribed to crack bridging and fracture of cellulose fibrils. The mechanical properties of the coating material were investigated by tensile testing of PVA/MFC stand–alone specimens. The stirring time of the PVA/MFC solution came out as a crucial parameter in order to achieve a more homogeneous dispersion of the fibres and consequently enhanced strength and stiffness. Numerical simulation of a PVA coated Bioglass® strut revealed the infiltration depth of the coating until the crack tip as the most effective criterion for the struts strengthening. Contact angle and linear viscosity measurements of PVA/MFC solutions showed that MFC causes a reduction in contact angle and a drastic increase in viscosity, indicating that a balance between these opposing effects must be achieved. Concerning the production of bulk samples, conventional furnace and spark plasma sintering technique was used. Spark plasma sintering performed without the assistance of mechanical pressure and at heating rates ranging from 100 to 300°C /min led to a material having density close to theoretical one and fracture toughness nearly 4 times higher in comparison with conventional sintering. Fractographic analysis revealed the crack deflection as the main toughening mechanisms acting in the bulk Bioglass®. Time–dependent crack healing process was also observed. The further investigation on the non-equilibrium phases crystallized is required. All obtained results are discussed in detail and general recommendations for scaffolds with enhanced mechanical resistance are served.
47
Nährström, Elin. "Relation between microstructure features, cooling curves and mechanical properties in CGI-cylinder block." Thesis, KTH, Materialvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-160819.
Full textAbstract:
The purpose of this master thesis was to evaluate variations in solidification and cooling rate in compacted graphite iron prototype cylinder blocks and for each position relate this to the microstructure and also relate the microstructure to mechanical properties. This has been done to increase the knowledge to predict mechanical properties in cast iron components. There were three sample categories; reference-, tensile test- and thermocouple samples. The investigation included analysis of cooling curves, SinterCast parameters, image analysis, measured hardness and tensile strength. Thermocouples of type N were used at interesting positions for observation of the cooling behaviour and the image analysis was carried out by the software Axio Vision SE64 by Carl Zeiss GmbH. The hardness was measured according to Brinell HBW 5/750 and tensile testing was performed according to standard SS-EN ISO 6892-1:2009. It is concluded that the microstructure depend on many parameters, one of them is the position in the cylinder block. A relation between solidification time and the microstructure features; secondary dendrite arm spacing and eutectic cell size was observed. Because of dissimilarity in microstructure between the tensile test samples and thermocouple samples it is believed that the thermocouples have contributed with a cooling and/or nucleation effect. Considering the mechanical properties there is not solely the nodularity, eutectic cell size or secondary dendrite arm spacing that are the controlling microstructure feature, more research needs to be made.
48
Singaraju, Aditya Bharadwaj. "Crystallographic and spectroscopic assessment of pharmaceutical material mechanics." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6643.
Full textAbstract:
Despite the advent of alternative dosage forms, solid dosage forms constitute a major proportion of dosage forms not only on the market, but also in many pharmaceutical companies’ pipelines. This is because of their superior stability and ease of manufacturing relative to other dosage forms. Although solid dosage forms have been the topic of discussion for decades, the process of compaction of these dosage forms is considered an art rather than science because of the empiricism that exists in this area. With the introduction of Quality by Design (QbD), it is imperative that the drug development process is guided by structured scientific principles. It has been hypothesized that crystal structure of organic solids plays a pivotal role in understanding the properties, processing and eventually performance of solids. In this regard, the intermolecular interactions within a solid play a paramount role in dictating the materials response to stress. One important parameter that is weakly addressed in the literature is the concept of strength of intermolecular interactions. In the current work, we utilize the concept of elasticity as a metric for strength of intermolecular interactions. We introduce powder Brillouin light scattering; an inelastic light scattering technique to measure the elasticity of organic solids and try to correlate the mechanical moduli extracted from the spectra to the compaction performance of solids. We hypothesize that any redistribution of intermolecular interactions would be reflected in the BLS spectrum of these materials and the material properties can be used to explain the differences in compaction performance. Before we tested our hypothesis, we validated our powder BLS technique using aspirin as model system. We then applied the same analysis to four model systems that involved different ways of reorganizing the intermolecular interactions upon subtle modifications to the molecular structure.
In Chapter 4, we investigated the effect of alkyl chain length and crystal structure on the mechanical properties and compaction performance of p-aminobenzoic acid (PABA) and its esters. For the entire ester series, a similar hydrogen bonding pattern was observed with strong N-H…O (carbonyl) and supportive N-H…N interactions. While the ethyl and butyl esters exhibited a layered structure, the methyl ester displayed a 3-D isotropic structure. The crystal structure for PABA exhibited a three-dimensional, quasi-isotropic distribution of the hydrogen-bonding interactions that connected the PABA dimers. The powder BLS spectra for these materials revealed low velocity shear modes for the layered structures and a spectrum consistent with an isotropic structure for Me-PABA and PABA. This was in good agreement with the compressibility behavior under load, with Et-PABA and Bu-PABA more compressible than PABA. However, due to greater particle-particle adhesion, PABA compacts showed greater tensile strength at higher pressures. The moduli calculated also showed that both Et-PABA and Bu-PABA had lower shear and Young’s modulus relative to the other materials. Attachment energies corroborated the above results. These studies showed that weak dispersive forces play an important role in understanding material properties.
In Chapter 5, a series of nitrobenzoic derivatives were used to study the effect of secondary interactions on the crystal reorganization and material properties. The materials used in the study include p-nitrobenzoic acid (4-NBA), m-nitrobenzoic acid (3-NBA, 4-chloro-3-nitrobenzoic acid (Cl-NBA), 4-bromo-3-nitrobenzoic acid (Br-NBA), and 4-methyl-3-nitrobenzoic acid (Me-NBA). Crystal structures of the materials revealed different organization of C-H…O interactions. Two types of C-H…O interactions were prevalent namely C-H…O (nitro) and C-H…O (carboxy). The reorganization of these two types of interactions led to different packing motifs and different mechanical behavior. These structural features were reflected in their mechanical properties assessed by powder Brillouin light scattering. Cl-NBA and Br-NBA displayed an isotropic spectrum similar to polystyrene and aspirin. 3-NBA, 4-NBA and Me-NBA displayed different spectra from Cl-NBA and Br-NBA with high frequency tailing in the longitudinal mode distribution indicating a specific direction of extended molecular interactions. The Young’s modulus and shear modulus followed the order: 3-NBA < Me-NBA< 4-NBA < Cl-NBA < Br-NBA. The maximum longitudinal modulus Mmax was the highest for 3-NBA and was significantly greater than rest of the materials. From the compaction studies, it was observed that the tabletability followed the rank order 3-NBA > 4-NBA > Me-NBA ≈ Br-NBA ≈ Cl-NBA which is the same order as Mmax. 3-NBA by virtue of its low shear and Young’s modulus to be the most compressible material, but the compressibility rank order was 4-NBA > Me-NBA ≈ 3-NBA > Cl-NBA > Br-NBA. However, 3-NBA by virtue of its greater particle-particle adhesion was the most compactable material. The yield pressures obtained from Heckel plots revealed that 4-NBA and Me-NBA were relatively more plastic when compared to the other materials. This study demonstrated that subtle changes to the molecular structure can result in drastically different crystal packing which in turn would influence the mechanical properties and the compaction performance of organic solids.
In Chapter 6, we investigated the effect of cocrystallization on the compaction performance of caffeine(CAF). The series of halo-nitrobenzoic acids (F-NBA, Cl-NBA and 3-NBA) were used as coformers. The cocrystals CAF: F-NBA, CAF: Cl-NBA and CAF: NBA Form 1 adopted a flat layered structure that can undergo deformation with ease. This increased the compressibility of the cocrystals relative to CAF. In addition to the improved compressibility, by virtue of increased particle-particle contacts, the cocrystals also displayed superior tabletability. In contrast to the layered structures adopted by the three cocrystals, the CAF: NBA Form 2 displayed a columnar structure that exhibited resistance to stress. The compressibility and the tabletability of CAF: NBA Form 2 was significantly compromised when compared to that of Form1. All the compaction characteristics of the cocrystals were in good agreement with moduli and parameters obtained from powder BLS spectra. The layered materials showed the presence of low velocity shear modes corroborating the earlier studies. There was a clear difference in the spectra of the polymorphs, indicating that powder BLS can be used for mechanical screening of polymorphs.
In Chapter 7, we examined the effects of crystal structure and coformer functionality on the compaction performance of theophylline (THY). The coformers employed include 4-fluoro-3-nitrobenzoic acid (FNBA), acetaminophen (APAP), and p-aminobenzoic acid (PABA). While THY-APAP and THY-FNBA exhibited layered structures, the THY-PABA displayed a interdigitated columnar structure. Powder BLS spectra showed the presence of low frequency shear modes relative to THY for all the three cocrystals. However, the order of frequencies followed: THY-FNBA < THY-APAP < THY-PABA. The shear modulus calculated followed the order THY-APAP≈ THY-FNBA < THY < THY-PABA which is in agreement with the crystal structures discussed. The Young’s modulus followed the order THY-FNBA < THY-APAP < THY < THY-PABA. The two layered structures (THY-APAP, THY-FNBA) showed distinct compaction performance (similar compressibility but different compactability and tabletability). The layered structures were more compressible than THY which is hypothesized to undergo deformation through multiple mechanisms. THY-PABA showed poor compaction properties. This highlights the fact that although the coformer (PABA) is molecularly similar to FNBA, the resultant cocrystals are structurally and mechanically distinct. These observations were well supported by the moduli calculated from powder BLS studies. The order of yield pressures obtained from Heckel analysis followed the same order as shear modulus. The tensile strength of the compacts of the cocrystals level off at around 150 MPa but the tensile strength of THY compacts continues to increase. From a manufacturing perspective the cocrystals can prove to be a better option as they as more compactable at higher porosities or they possess greater tabletability at low compaction pressures.
Overall, we have used model systems to demonstrate that the redistribution of intermolecular forces upon point substitution or cocrystallization have a dramatic effect on the material properties. It is also worth noting that elasticity along with plasticity can provide important information about the strength of interactions which would help in understanding the role of weak intermolecular forces in the performance of organic materials. To gain a better perspective of the compaction process and move towards a QbD approach, it is also imperative to understand the link between crystal structures, intermolecular interactions which is possible with the help of novel characterization techniques (BLS, AFM).
49
Horn, Etienne. "The calibration of material properties for use in discrete element models." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20088.
Full textAbstract:
Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: One of the main challenges in using the Discrete Element Method (DEM) is to specify the correct input parameter values. In general, the models are sensitive to the input parameter values and accurate results can only be achieved if the correct values are specified. For the linear contact model, micro parameters such as the particle density, stiffness, coefficient of friction, as well as the particle size and shape distributions are required. Thus, there is a need for a procedure to accurately calibrate these parameters before any attempt can be made to accurately model a complete bulk materials handling system. Since the DEM is often used to model applications in the mining and quarrying industries, a calibration procedure was developed for materials that consist of relatively large (up to 40 mm in size) particles. A coarse crushed aggregate was used as the test material. Using a specially designed large scale shear box, the confined Young’s Modulus and internal friction angle of the material were measured by means of the confined compression test and the direct shear test respectively. The bulk (macro) density and porosity were also measured. The particle size distribution was measured while visual inspection was used to identify the different particle shapes. DEM models of the experimental set-up were developed and the input parameter values were varied iteratively until a close correlation between the experimental and numerical results was achieved. The resulting set of input parameter values were then verified through a series of anchor pull-out and angle of repose experiments and simulations. A good correlation between the experimental and numerical results was observed. In a study, independent of the calibration process, a half fraction factorial design was implemented to quantify the effect of the input parameter values on the bulk properties and to construct multiple linear regression models that relate the parameters to the bulk properties. The results were found to be in accordance with expected bulk behaviour, and can be used to develop advanced DEM calibration strategies. Based on the project outcomes, it was concluded that the developed calibration procedure performed satisfactorily and that the calibrated input parameters allow for the accurate modelling of the coarse aggregate.
AFRIKAANSE OPSOMMING: Een van die groot uitdagings in die gebruik van die Diskreet Element Metode (DEM) is om die korrekte invoer parameterwaardes te spesifiseer. Die modelle is in die algemeen sensitief vir die invoer parameterwaardes, en akkurate resultate kan slegs verkry word indien die korrekte waardes gespesifiseer word. Mikroparameters soos partikeldigtheid, styfheid, wrywingskoëffisiënt, die partikelgrootte verspreiding asook die partikelvorm verspreiding, word benodig vir die lineêre kontakmodel. ’n Prosedure word dus benodig om hierdie parameters akkuraat te kalibreer alvorens ’n volledige korrelagte materiaalhanteringstelsel akkuraat gemodelleer kan word. Aangesien die DEM gereeld in die modellering van myn- en gruisgroefbedryf toepassings gebruik word, is ’n kalibrasieprosedure ontwikkel vir materiaal wat bestaan uit relatief groot (tot 40 mm in grootte) partikels. Grofgebreekte klippe is as toetsmateriaal gebruik. Deur gebruik te maak van ’n spesiaal ontwerpte grootskaal-skuifboks is die ingeperkte Young se Modulus en die interne wrywingshoek van die materiaal gemeet deur middel van die ingeperkte kompressietoets en die direkte skuiftoets onderskeidelik. Die makro-digtheid en poreusheid is ook gemeet. Die partikelgrootte verspreiding is gemeet terwyl visuele inspeksie gebruik is om die verskillende partikelvorms te identifiseer. DEM modelle van die eksperimentele opstelling is ontwikkel en die invoer parameterwaardes is herhaaldelik gewysig totdat ’n goeie korrelasie verkry is tussen die eksperimentele en numeriese resultate. Die gevolglike stel invoer parameterwaardes is daarna geverifieer deur ’n reeks ankeruittrek- en natuurlike helling eksperimente en simulasies. In ’n studie, onafhanklik van die kalibrasieproses, is die half-fraksie faktoriaalontwerp geïmplementeer om die invoer parameterwaardes se effek op die makro eienskappe te kwantifiseer en om meervoudige lineêre regressiemodelle te ontwikkel wat die parameters met die makro eienskappe verbind. Die resultate was in ooreenstemming met die verwagte makro gedrag en kan gebruik word om gevorderde DEM kalibrasie-strategieë te ontwikkel. Daar is tot die gevolg gekom dat, gebaseer op die projekresultate, die ontwikkelde kalibrasieprosedure bevredigend presteer en dat die gekalibreerde invoer parameters die akkurate modellering van die grofgebreekte klippe toelaat.
50
Koch, Timothy David. "Device for selecting lightwave ranges via computer control for studying building material properties via goniophotometer." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40440.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007."June 2007."
Includes bibliographical references (p. 21).
To enable the fast and accurate cataloging of material samples, I designed a filtration device for selecting specific visible and near-infrared light wavelengths related to the red, green, and blue sensitivity peaks of a visible detection camera and the pixel response for a near-infrared camera. This filter device functions in conjunction with the Department of Architecture's Daylighting Laboratory goniophotometer to profile the complete reflection and transmission properties for sample building materials. The resulting data is used in computer simulations and material optimization. The goniophotometer uses two types of detection cameras, color and infrared, to measure the light that is transmitted or reflected off a sample of material. The spectral sensitivity variances of the cameras create inaccuracies in the resulting data when full-spectrum light is used. To remove these inaccuracies, the light is filtered into smaller sections of the full spectrum and the data is recombined by software, to remove these inaccuracies. The device to filter the light is the subject of this thesis. The final filter design uses a geneva drive to index wheels containing pairs of high-pass and low-pass filters into the light path between the light source and the test specimen.
(cont.) The device satisfies the design specifications dictated by the usability, function and spatial constraints. This design should prove to be very reliable and flexible through its continued use in studying building materials. As the project is advanced, future work includes installation of the control system and integration into the software used to coordinate the goniophotometer components.
by Timothy David Koch.
S.B.