The Al-Zr system is used to form a thermally stable strengthening phase in high temperature aluminum-base casting alloys. These alloys have good strength at elevated temperature due to the precipitation of coherent metastable Al3Zr particles upon decomposition of the supersaturated Al-Zr solid solution by a carefully designed heat treatment. Formation of the Al3Zr particles occurs by a peritectic reaction, which decrees that once formed, the particles cannot be dissolved by a solid-state homogenization process. Accordingly, melting the alloy must serve as the homogenization step of the precipitation hardening process; and solidification during casting must serve as the quenching step. Unfortunately, a prohibitively fast solidification rate is necessary to obtain a solid solution with as little as 0.4% Zr in Al. It is found that adding Cr to Al-0.4wt%Zr binary alloy makes it easier to form the supersaturated solid solution, and the ternary Al-0.4wt%Zr- 0.8wt%Cr alloy has better room and elevated temperature tensile properties than the binary Al- 0.4wt%Zr alloy. Various one-step and two-step isothermal aging cycles were investigated in order to arrive at the optimum aging schedule for the Al-0.4wt%Zr-0.8wt%Cr. It is found that soaking the alloy at 400C for 24 hours is optimum; and employing a two-step aging schedule reduces the aging time without sacrificing strength. The two- step aging schedule includes soaking the alloy at 375C for 3 hours and then at 425C for an additional 12 hours. Examination of the precipitates that form in the Al-0.4wt%Zr-0.8wt%Cr with High Resolution Transmission Electron Microscopy (HRTEM) shows that they have the L12 crystal structure. Energy Dispersive Spectrometry (EDS) shows that the particles contain only aluminum and zirconium whereas the matrix is a solid solution of chromium in aluminum. Hence, it is suggested that zirconium strengthens the Al- 0.4wt%Zr-0.8wt%Cr alloy by a precipitation hardening mechanism and chromium further enhances the strength by solid solution strengthening.

Mechanotransduction is a process by which cells sense and convert mechanical loads into biochemical signals and transcriptional changes. This process is particularly critical in bone, a metabolically active tissue that continously remodels and adapts to mechanical loads in its local environment. Osteocytes are the most prevalent bone cell type and are responsible for coordinating skeletal adaptation. Recently, the loss of primary cilia, nonmotile antenna-like cellular structures, has been attributed to causing defects in skeletal development and loading-induced bone formation. While primary cilia have been implicated in osteocyte mechanotransduction, the molecular mechanism associated with this process is not understood. In this thesis, we demonstrate that the osteocyte primary cilium forms a microdomain that mediates osteogenic responses to mechanical loads. In the first study, we build a genetically encoded primary cilium-localized calcium biosensor and characterize ciliary calcium mobilization in response to mechanical loading with unprecedented sensitivity. Next, we apply similar techniques to monitor levels of another second messenger, cyclic AMP (cAMP), and are the first to demonstrate that the primary cilium segregates ciliary cAMP from the cytosol. In the third study, we link loading-induced bone formation in vivo to adenylyl cyclase 6 enzyme function, a component of the primary cilium-mediated mechanotransduction mechanism. Collectively, this thesis elucidates how osteocyte primary cilia convert mechanical stimuli into osteogenic responses at the molecular and tissue levels and characterizes the primary cilium as a microdomain that serves as a biochemical and mechanical signaling nexus. Improvements in our understanding of primary cilia-regulated mechanotransduction will advance research efforts in the bone, tissue engineering, and mechanobiology communities.

Osteoporosis is a major metabolic bone disease that causes reduced bone mass, deteriorated bone microstructural and increased fracture risk. In clinical practice, the gold standard to examine bone quality and evaluate fracture risk is using dual energy X-ray absorptiometry through measurements of areal bone mineral density (aBMD). However, it has been well accepted that in addition to aBMD, bone geometry, microstructure and material properties also play important roles in determining overall bone mechanical competence, which is directly related to fracture risk. High-resolution peripheral quantitative computed tomography (HR-pQCT) has the capability to image three-dimensional (3D) bone microstructures in vivo and provide quantitative measurements of bone mineral density as well as cortical and trabecular microstructure. Based on the HR-pQCT images, micro finite element (µFE) models can be constructed to directly estimate bone strength. HR-pQCT has become a widely used imaging tool in clinical research to evaluate the effect of aging, drug treatment, and metabolic bone disease on bone quality. The work in this thesis focuses on evaluating the accuracy and capability of HR-pQCT in quantifying microstructural properties of human radius and tibia bone, exploring its prediction power of whole bone strength and discussing potential applications in clinical studies. In this thesis, we quantified the accuracy of the standard HR-pQCT microstructural measurements of human distal radius and tibia through comparisons with gold standard µCT-based morphological measures. The results showed that the BV/TVd, Tb.N*, Tb.Th and Tb.Sp from HR-pQCT were significantly and highly correlated with those from gold-standard µCT measurements. Strong correlations between the HR-pQCT µFE predictions and direct mechanical testing measures suggest that HR-pQCT µFE is a robust method to determine bone mechanical properties. In a clinical setting, standard HR-pQCT scans are performed on the non-dominant wrist (usually the left) and the corresponding tibia. However, the contralateral side is selected for scanned when there is a fracture the non-dominant wrist. It remains unclear whether the dominant side is representative of the non-dominant side and how much error it will bring into a study where subjects include mixed scans of both sides. In this thesis, we applied HR-pQCT and µCT based morphological and mechanical measurements to characterize the symmetric nature of distal radius and tibia. We found that the right radius tend to be larger than the left radius. However, at the tibia, the bone size was found to be similar between left and right. By micro computed tomography (µCT), microstructural parameters such as BV/TV were also found to be larger at the right radius, while no difference was found at the tibia. Trabecular number, trabecular thickness, trabecular separation and cortical thickness were not different between left and right radius. µFE analyses demonstrated that stiffness and strength of right radius were significantly higher than left radius, while there was no difference at the tibia. The standard clinical region of interest HR-pQCT is recommended by the manufacturer; however, it is not clear whether a segment HR-pQCT scan is representative of whole bone mechanical properties. Therefore we quantified the associations of microstructural and mechanical measurements of the radius and tibia segments with whole bone stiffness and examined if we can improve the correlation when we select a different region. The microstructural and mechanical measurements at the two regions next to the standard HR-pQCT segment (proximal and distal) were also examined. The results showed that the bone microstructure from proximal and distal sections is highly correlated to standard region at both distal radius and tibia. The mechanical properties of the three segments were strongly correlated with overall bone mechanical properties. The microstructural measurements at the most distal section were correlated with whole bone stiffness better compared to those from standard and proximal regions. DXA is incapable of discriminating patients with wrist fracture from those without. In this study, we examined the microstructural and mechanical properties in patients with and without wrist fracture through HR-pQCT based analyses. We demonstrated that wrist fracture patients had lower plate and rod bone volume fraction, less plate and rod trabecular number, thinner cortex and lower whole bone stiffness and strength, compared to healthy controls. Failure analyses also depicted significantly lower trabecular plate compression and tension failure fraction in wrist fracture patients.

The plasticity of cells in a multicellular organism is progressively lost during differentiation. This loss is reflected in studies involving the ectopic misexpression of fate-specifying or terminal selector transcription factors (TFs). These TFs can efficiently activate target genes in undifferentiated cells, but lose this ability as cells differentiate. While this phenomenon of cell fate restriction is widely observed, the mechanisms orchestrating it are poorly understood. In this thesis, I have used the ubiquitous overexpression of Zn-finger-TF CHE-1 as a tool to understand the mechanisms that restrict cell fate in Caenorhabditis elegans. When CHE-1 is ubiquitously expressed at embryonic stages, it activates target gene expression in many cell types, while in adults it can only act in a few neurons. To uncover factors that inhibit plasticity of all other adult cells, I first performed an RNAi screen against chromatin-associated factors. Using this approach I found that the removal of either the PRC2 complex, which deposits the H3K27me3 mark, or loss of proteins that indirectly regulate domains of H3K27me3, allows CHE-1 and two other terminal selector TFs to activate target genes in the germline. These data show that the correct distribution of H3K27me3 is crucial for the restriction of germ cell fate. I next took a candidate approach to identify genes that regulate fate restriction in other cell types. We hypothesized that terminal selector TFs themselves, in addition to specifying cellular identity by controlling large gene sets, may also act to inhibit plasticity. To test this, I first assayed the activity of CHE-1 in mutants of COE-TF unc-3, the terminal selector for a subset of cholinergic motor neurons (MNs). I found that in contrast to wildtype MNs, unc-3 mutant MNs remain plastic as CHE-1 can induce expression of target genes in these cells even at the adult stage. This phenotype is also observed in four of six additional terminal selector mutants tested. I further found that the removal of met-2, a protein required for H3K9 methylation, or mes-2, a PRC2 component, also makes differentiated cholinergic MNs amenable to the activity of CHE-1. Preliminary evidence suggests that met-2 may act in the same pathway as unc-3. These results raise the exciting possibility that selector TFs play a role in restricting cell fate by organizing the heterochromatin domains in differentiated cells. Overall, in this work I provide functional evidence to show that specific chromatin-modifying enzymes restrict the fate of germ cells and that both fate-specifying TFs and chromatin-modifying enzymes are required for the fate restriction in neurons.

A madeira pode ser renovável, de fácil obtenção e custo competitivo, tornou-se com o decorrer do tempo, um dos materiais pioneiros na contrução civil. Porém, no Brasil, o emprego indiscriminado e descontrolado ao longo dos anos, principalmente na construção civil, proporcionou uma redução drástica das florestas nativas das regiões Sul/Sudeste. Conseqüentemente, passou a ser necessária a utilização de madeiras alternativas, e, entre elas, pode-se citar as espécies do gênero Eucalytpus e Pinus. Sabendo-se que tais espécies são altamente susceptíveis à demanda biológica, é indispensável a adoção de medidas preventivas visando melhorar a sua durabilidade. Dentre algumas medidas possíveis, a preservação através da introdução de produtos químicos por processos industriais é a mais eficaz. Uma das questões levantadas a respeito do citado procedimento reporta à sua influência no comportamento intrínseco da madeira, no tocante às suas propriedades mecânicas. Portanto, a partir daí, este projeto tem o objetivo de verificar a influência da preservação química (processo e produto) sob vácuo-pressão contra a demanda biológica, por meio de preservativos hidrossolúveis (tipo CCA e CCB), nas propriedades de resistência e de elasticidade das espécies de Eucalipto Grandis (Eucalyptus grandis) e Pinus Elliottii (Pinus elliottii). Usando apenas o produto CCA, quatro espécies nativas: Angelim (Vatárea sp), Ipê (Tabebuia sp), Copaíba (Copaifera sp) e Jatobá (Hymenaea sp). Como subproduto da pesquisa, foram obtidas algumas relações entre os valores da resistência característica à compressão e ao cisalhamento paralelo às fibras, bem como entre os valores da resistência característica à compressão e a tração paralela às fibras. Também foi objeto de estudo , em uma fase preliminar, a análise da possível variação, ao longo do comprimento da peça, da propriedade de resistência e de rigidez (elasticidade) ) à compressão paralela às fibras, uma vez mantida fixa a posição nos rios. No final, foram obtidos alguns resultados relevantes para a relação entre os valores de compressão paralela da madeira sem preservação e a tratada quimicamente, principalmente referente ao Pinus Elliottii. Nesta espécie, para o tratamento realizado com o CCA, o acréscimo foi de 17% (retenção de 10 kg/m3), enquanto o CCB (retenção em torno de 40 kg/m3) levou a um aumento de 55% em média. Outros resultados passíveis de comentários, referem-se às relações entre propriedades características de cisalhamento e compressão (preservados e sem preservação) para todas as espécies estudadas. Da maneira geral, os valores foram bem superiores àqueles estabelecidos pela NBR 7190/97, alcançando patamares em torno de 50% para as espécies de reflorestamento e 90% para as espécies nativas (exceto para o Ipê). De forma sucinta, pode-se concluir que a preservação química industrial é de extrema relevância, principalmente por não reduzir e, em alguns casos até aumentar os valores das propriedades mecânicas estudadas, além de ser um método comprovado e eficaz contra a biodeterioração. / As time goes bye, wood had been one of the main materials in building construction, because it\'s renovation, easy obtainment ans competitive cost. In Brazil, indiscriminate employing during last decades, particularly in South and Southwest regions, reduced drastically the native species offer. The use of alternative species, as those from Pinus and Eucalyptus genera, became necessary. As the cited species are so susceptible to biological demand, to take prevent procedures to increase natural durability in indispensable. Among these procedures, chemical preservation under pressure in industrial plans can be considered very efficient. One of the questions related to chemical preservation is its influence in mechanical behavior of treated wood. So, the aim of the work is to determine the influence of chemical preservation under pressure (with preservative substances as CCA and CCB) in strength and stiffness properties of Eucalipto Grandis (Eucalyptus grandis) and Pinus Elliottii (Pinus elliottii). The influence do CCA preservative was studied to four tropical essences: Angelim (Vatairea sp), Ipê (Tabebuia sp), Copaíba (Copaifera sp) and Jatobá (Hymenaea sp). At least, comparative values of mechanical properties of natural and preserved wood are presented.

The final stage of the cell cycle is cell division by cytokinesis, when the cell physically separates into two daughter cells. Improper timing or location of the division site results in incorrect segregation of chromosomes and thus genetically unstable aneuploid cells, which is associated with tumorigenesis. Cytokinesis in animal, fungal and amoeboid cells occurs through the assembly and constriction of an actomyosin contractile ring, a mechanism that dates back about one billion years in the common ancestor of these organisms. However, it is not well understood how the ring generates tension or how the rate of ring constriction is set. Long ago a sliding filament mechanism similar to skeletal muscle was proposed, but definitive evidence for muscle-like sarcomeric order in the ring is lacking. Here we build mathematical models of cytokinesis in the fission yeast Schizosaccharomyces pombe, where the most complete inventory of more than 150 cytokinesis genes have been documented. The models explicitly represent proteins in the contractile ring such as formin, myosin, actin, α-actinin, etc. and implements their quantities, biomechanical properties and organizations from the best available experimental information. At the same time, the models adopt coarse-grain approaches that are able to describe the collective behaviors of thousands of ring components, which include tension production, constriction, and disassembly of the ring. In the first part of this thesis, we modeled the extraordinarily rapid constriction of the partially unanchored ring in fission yeast cell ghosts. Experiments on isolated fission yeast rings showed sections of ring unanchoring from the membrane and shortening ~30-fold faster than normal (1). We demonstrated that anchoring of actin to the plasma membrane generates tension in the fission yeast cytokinetic ring by showing (1) unanchored segments in these experiments were tensionless, and (2) only a barbed-end anchoring of actin can generate tension in the normally anchored ring, and can explain the extraordinary behavior of unanchored segments. Molecularly explicit simulations accurately reproduced experimental constriction rates, and showed a novel non-contractile reeling-in mechanism by which the unanchored segment shortens, despite being tensionless. In the second part of this thesis, we built a highly coarse-grained model to study how ring tension is generated and how structural stability is maintained. Recently, a super-resolution microscopy study of the fission yeast ring revealed that myosins and formins that nucleate actin filaments colocalize in plasma membrane-anchored complexes called nodes in the constricting ring (2). The nodes move bidirectionally around the ring. Here we construct and analyze a coarse-grained mathematical model of the fission yeast ring to explore essential consequences of the recently discovered ring ultrastructure. The model reproduces experimentally measured values of ring tension, explains why nodes move bidirectionally and shows that tension is generated by myosin pulling on barbed-end-anchored actin filaments in a stochastic sliding-filament mechanism. This mechanism is not based on an ordered sarcomeric organization. We show that the ring is vulnerable to intrinsic contractile instabilities, and protection from these instabilities and organizational homeostasis require both component turnover and anchoring of components to the plasma membrane. In the third part of this thesis, we measured ring tension in fission yeast protoplasts. We found ~650 pN tension in wild type cells, ~65% the normal tension in myp2 deletion mutants and ~40% normal tension in myo2-E1 mutant cells with negligible ATPase activity and reduced actin binding. To understand the relation between organization and tension, we developed a molecularly explicit simulation of the fission yeast ring with the above organization. Our simulations revealed a clear division of labor between the 2 myosin-II isoforms, which maintains organization and maximal tension. (1) Myo2 anchors the ring to the plasma membrane, and transmits ring tension to the membrane. (2) Myo2, extending ~100 nm away from the membrane, bundles half (~25) of the actin filaments in the cross-section due to filament packing constraints, as only ~25 filaments are within reach. (3) To increase tension requires that the ring be thickened, as tensions in the ~25 membrane-proximal filaments are close to fracture. (4) Unanchored Myp2 indeed enables thickening, by bundling an additional ~25 filaments and doubling tension. Anchoring of these filaments to the membrane is indirect, via filaments shared with the anchored Myo2. (5) In simulated myo2-E1 rings ~20% of the actin filaments peeled away from the ring and formed Myp2-dressed bridges, as observed experimentally in myo2-E1 cells. (6) The organization in simulated Δmyp2 rings was highly disrupted, with ~ 50% of the actin filaments unbundled. Therefore, beyond their widely recognized job to pull actin and generate tension, myosin-II isoforms are vital crosslinking organizational elements of the ring. Two isoforms in the ring cooperate to organize the ring for maximal actomyosin interaction and tension.

The random nature of the micro-structural attributes in materials in general and composite material systems in particular requires expansion of material modeling in a way that will incorporate their inherent uncertainty and predict its impact on material properties and mechanical response in multiple scales. Despite the importance of capturing and modeling material randomness, there are numerous challenges in structural characterization that are yet to be addressed. The work presented in this essay takes a few steps towards an improved material modeling approach which encompasses structural randomness in order to produce a more realistic representation of material systems. For this end a computational framework was developed to generate a realistic representative volume element which reflects the inherent structural randomness. First stochastic structural elements were identified and registered from imaging data and parameters were assigned to represent those elements. Statistical characterization of the random attributes was followed by the construction of a representative volume element which shared the same structural statistical characteristics with the original material system. The resultant statistical equivalent representative volume element (SERVE) was then used in finite element simulations which provided homogenized properties and mechanical response predictions. The suggested framework was developed and then implemented on 3 different material systems. Image processing and analysis in one of the material systems extended the original scope of this work to solving a machine vision and learning problem. Object segmentation for the purpose object and pattern recognition has been a long standing subject of interest in the field of machine vision. Despite the significant attention given to the development of segmentation and recognition methods, the critical challenge of separating merged objects did not share the spotlight. A simple yet original approach to overcome this hurdle was developed using unsupervised classification and separation of objects in 3D. Lower dimensionality classifiers were joined to provide a powerful higher dimensionality classification tool. The robustness of this approach is illustrated through its implementation on two case studies of merged objects. Applications of this methodology can further extend from structural classification to general problems of clustering and classification in various fields.

This thesis deals with metal foam, a relatively new material whose tremendous potential has been identified early on. The material is an excellent shock absorber and also has a very high strength-to-weight ratio, properties that are highly desirable particularly within the aerospace and automotive industries. Despite the material’s immense potential, hardly any metal foam products have made it past the prototype stage. The reason is that the material is difficult to manufacture in the shapes required in industrial applications. Oftentimes, applications require sheets to be bent into specific shapes, yet bending is not possible with conventional methods. Laser forming is currently the only method that shows promise to bend metal foam panels to a range of shapes. In this thesis, the analysis of laser forming of metal foam was taken far beyond the experimental work that has been delivered thus far. A thorough analysis was performed of the thermo-mechanical bending mechanism that governs the deformation of metal foam during laser forming. This knowledge was then used to explain the effect of the process condition on the bending efficiency and the bending limit. Additionally, the impact of laser forming on the metal foam properties was explored. Experimental results were complemented by numerical results that were validated both thermally (using infrared imaging) as well as mechanically (using digital image correlation). Numerical models with different levels of geometrical complexities were used, and the effect of the model geometry on the predictive accuracy was explored. In the second half of the thesis, the aforementioned effort was extended to metal foam sandwich panels, in which metal foam is sandwiched between two sheets of solid metal. The material again has a high strength-to-weight ratio and excellent shock absorption capacity, while also being stiff and core-protective. Just like metal foam alone, metal foam sandwich panels are typically manufactured in flat sheets, and failure-free bending can only be achieved using lasers. The analysis was again initiated with the bending mechanism. It was revisited whether the foam core still follows the same bending mechanism, and how its deformation is affected by the interaction with the solid facesheets. This insight was then used to elucidate the bending efficiency and limit at different process conditions, as well as the impact of the process on the material performance. Additionally, the effect of the sandwich panel manufacturing method on the process outcome was investigated. This was achieved by contrasting two sandwich panel types with a different foam core structure, foam core composition, facesheet composition and facesheet attachment method. Lastly, three-dimensional deformation of metal foam sandwich panels into typical non-Euclidean shapes such as bowl and saddle shapes was explored. It was shown that a significant amount of 3D deformation can be induced. At the same time, it was discussed that the achievable deformation is limited to moderate curvatures, since only a limited amount of in-plane strains may be induced using laser forming. The aforementioned experimental efforts were again accompanied by numerical efforts. Sandwich panel models with different levels of geometrical complexity were used to study all aspects pertaining to the process, and the properties to the facesheet/foam core interface were discussed. Overall, the work in this thesis demonstrated that laser forming is capable of bending metal foam panels and metal foam sandwich panels up to large bending angles without causing failures, while maintaining the favorable properties of the material. Conceptual, experimental and numerical groundwork was laid towards a successful implementation of the material in industrial applications.

In this research, the degradation of carbon fiber/vinylester composites in marine environments was experimentally investigated. Additionally, two types of carbon fiber surface treatments, namely Polyhedral Oligomeric Silsesquioxane (POSS) and the industrial surface treatment F0E, were evaluated to determine their effectiveness in creating a fiber/matrix (F/M) interface for use in the marine environment. Electrochemical Impedance Spectroscopy (EIS) was explored as a new application of an existing technique for use in measuring the amount of water at the F/M interface in carbon fiber/vinylester composites. EIS spectra were used to determine equivalent electric circuit models that allow for the prediction of water at the interface. The location of water within the composite was determined through Positron Annihilation Lifetime Spectroscopy (PALS). Interlaminar shear strength and transverse tensile tests were carried out for dry conditions and after hygrothermal exposure of the composites to study the influence of the integrity of the F/M interface on the macroscopic response of the composite. / by Chris J. Vinci. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

by Cheng Kai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references. / by Cheng Kai. / Acknowledgments --- p.i / Abstract --- p.ii / Table of content --- p.iv / Chapter Chapter One --- Introduction / Chapter 1.1 --- Barkhausen emission --- p.1 / Chapter 1.2 --- Methods of measurements --- p.3 / Chapter 1.2.1 --- Magnetization of a sample --- p.4 / Chapter 1.2.2 --- Signal detection --- p.5 / Chapter 1.2.3 --- Signal processing --- p.5 / Chapter 1.3 --- Instrumentation --- p.6 / Chapter 1.3.1 --- Instron loading machine --- p.6 / Chapter 1.3.2 --- Optical microscopy --- p.7 / Chapter 1.3.3 --- Vicker's hardness tester --- p.7 / Chapter 1.3.4 --- Ceramic furnace --- p.8 / References --- p.9 / Chapter Chapter Two --- Domain Theory / Chapter 2.1 --- The postulate of domain --- p.16 / Chapter 2.2 --- Domain energy --- p.18 / Chapter 2.3 --- The magnetization process --- p.20 / Chapter 2.4 --- Effect of applied stress --- p.22 / Chapter 2.5 --- Hindrances to wall motion by inclusions --- p.23 / References --- p.24 / Chapter Chapter Three --- Steels / Chapter 3.1 --- The making of steel --- p.28 / Chapter 3.2 --- The iron-iron carbide phase diagram --- p.29 / Chapter 3.3 --- Heat treatment of plain-carbon steels --- p.29 / Chapter 3.3.1 --- Slow cooling of plain-carbon steels --- p.29 / Chapter 3.3.2 --- Rapid cooling of plain-carbon steels --- p.30 / Chapter 3.3.3 --- Annealing --- p.31 / References --- p.32 / Chapter Chapter Four --- Effects of carbon on Barkhausen emission in plain carbon steel / Chapter 4.1 --- introduction --- p.35 / Chapter 4.2 --- Experiments --- p.36 / Chapter 4.2.1 --- Samples --- p.36 / Chapter 4.3 --- Results and discussions --- p.37 / Chapter 4.4 --- Conclusions --- p.39 / References --- p.40 / Chapter Chapter Five --- Magnetization process in a steel plate/bar subjected to an increasing tensile load / Chapter 5.1 --- Introduction --- p.45 / Chapter 5.2 --- Experiments --- p.47 / Chapter 5.3 --- Results and discussions for the zinc-coated steel plate --- p.47 / Chapter 5.4 --- Results and discussions for mild steel --- p.50 / Chapter 5.5 --- A comparison between steel plate and steel bar --- p.52 / Chapter 5.6 --- Conclusions --- p.53 / References --- p.54 / Chapter Chapter Six --- Evaluation of residual stress in bent steel bars subjected to different heat treatment by Barkhausen emission / Chapter 6.1 --- Introduction --- p.60 / Chapter 6.2 --- Experiments --- p.60 / Chapter 6.3 --- Results and discussions --- p.61 / Chapter 6.4 --- Conclusions --- p.64 / References --- p.65 / Chapter Chapter Seven --- Effects of heat treatment on electrolytic zinc-coated steel plates by Barkhausen emission / Chapter 7.1 --- Introduction --- p.72 / Chapter 7.2 --- Experiments --- p.72 / Chapter 7.3 --- Results and discussions --- p.73 / Chapter 7.4 --- Conclusions --- p.75 / References --- p.76 / Chapter Chapter Eight --- Effects of demagnetizing and stray fields on Barkhausen emission / Chapter 8.1 --- Introduction --- p.80 / Chapter 8.2 --- Experiments --- p.80 / Chapter 8.3 --- Results and discussions --- p.81 / Chapter 8.4 --- Conclusions --- p.85 / References --- p.85 / Chapter Chapter Nine --- Conclusions and suggestions for further studies --- p.90