Surface deformations and gravity changes caused by pressurized finite ellipsoidal cavities

We develop quasi-analytical solutions for the surface deformation field and gravity changes due to the pressurization of a finite (triaxial) ellipsoidal cavity in a half-space. The solution is in the form of a non-uniform distribution of triaxial point sources within the cavity. The point sources have the same aspect ratio, determined by the cavity shape, while their strengths and spacing are determined in an adaptive manner, such that the net point-source potency per unit volume is uniform. We validate and compare our solution with analytical and numerical solutions. We provide computationally efficient MATLAB codes tailored for source inversions. This solution opens the possibility of exploring the geometry of shallow magma chambers for potential deviations from axial symmetry

Measurement of genetic parameters within and between breeder flocks of Arian broiler lines using randomly amplified polymorphic DNA (RAPD) markers

The present study was carried out in an attempt to detect the genetic variation within and between four populations of commercial broiler lines using RAPD markers. Thirteen out of twenty random markers which were amplified and generating stable and reproducible bands were selected for genotyping of birds in each broiler lines. The average number of diagnostic bands per primer was 8.08 with an average number of 6.96 polymorphic bands across all breed groups. The highest (94%) and the lowest (73.5%) percentage of polymorphic bands were found within sampled birds of Arian C and D lines, respectively. Among the studied broiler lines, the highest genetic uniformity was found in line A, while the greatest within population genetic diversity was found in line C. Estimation of polymorphic loci, Nei’s gene diversity and intra-population uniformity indices suggested that genetic diversities within Arian commercial lines is high. The four strains of broiler lines clustered into two main groups using UPGMA procedure. In the first main group, the closest genetic distance was found between A and B strains, which were first clustered together and then with birds of C strain. The second main group includes birds from D strain. The mean coefficient of gene differentiation (Gst = 0.368) value reflected a high level of population differences. In total, sixty three RAPD bands were found to be strain dependent specific. Therefore, in order to design new diagnostic primers more effective in genetic discrimination among studied lines, unique bands should be cloned and sequenced.Key words: Genetic variation, broiler lines, polymorphism, random amplified polymorphic DNA markers

Squeeze Flow of Highly Concentrated Suspensions

In this thesis we investigated through experiment and model, the anomalous normal stress distribution during constant-force squeeze flow of highly concentrated suspensions. Using pressure-sensitive films the normal stress distribution is measured in suspensions of glass spheres in a Newtonian liquid undergoing constant-force squeeze flow. At volume fractions of solids up to 0.55, the normal stress distribution is independent of volume fraction and almost identical to the parabolic pressure distribution expected for Newtonian fluids. However, at higher volume fractions, the normal stresses become an order of magnitude larger near the center and very low beyond that region. At these high volume fractions, the normal stresses decrease in the outer regions and increase in the inner regions as the squeezing proceeds. The normal stress distribution that results when the glass spheres without any fluid are subjected to squeeze flow is very similar to that for suspensions with volume fractions above 0.55, suggesting that the cause for the drastic changes in the normal stress distribution is the jamming of the particles in the suspension. The drastic changes in the normal stress distribution are explained in terms of the radial flow migration of the liquid phase away from the center of the sample and of the jamming that results from it. Experimental measurements show that changes in the volume fraction of solids due to liquid-phase migration are found to depend on the initial volume fraction of solids, the viscosity of the suspending fluid, and the size of the particles. Under some conditions, the volume fraction of solids remains essentially constant during the squeeze test, indicating that liquid-phase migration does not take place to any significant degree; however, under other conditions, the volume fraction of solids increases throughout the sample as the squeezing proceeds and liquid is expelled from the test region in preference to the solids. In these latter cases the concentration increases are largest toward the center of the samples. Criteria for the occurrence of liquid-phase migration in suspensions undergoing squeeze flow are discussed in terms of dimensionless groups. Liquid-phase migration is modeled numerically by taking into account the time and position dependence of the rheological properties of the material due to the change in the volume fraction of solids. This is done by coupling the equation of motion for a non-Newtonian material that approximates a Bingham plastic with a continuity equation that includes diffusive flux. The developed model is first validated with experimental data and then used to study the effect of various parameters on pressure-induced phase separation. Changes in the volume fraction of solids within the squeezed suspensions due to liquid-phase migration were found to depend on the degree of slip at the surfaces and on the applied force as well as on the material properties

Negotiating Boundaries, The Veil: The Appearance of the Invisible

The chador is more than a matter of taste in clothing or a religious regulation; it is the incarnation of a belief, a culture, and a tradition. Intermingled with it are the profound emotions of the women who have been either voluntarily or forcibly practicing the wearing of the veil. The intention of this thesis is to allow one to see the chador as an extended threshold that both invites and rejects. By concealing the body of the woman, the veil establishes a complex relationship, repelling the external world while simultaneously drawing attention to itself. In passing through this threshold, one will begin to see the invasion of colors, - blue as sacredness, white as peace, and red as rebellion gradually dispersing into the air and onto its monotonous black surface. In this in-between space, brightness battles with darkness, as it tries to trickle in through the minimal openings. One may begin to wonder if a woman is protected as if in her house, or bounded as if in a cage. One will thus find herself with a sense of uncertainty - whether to stay or to leave. This thesis aims to explore the chador and the space between it and the body of the woman. The chador has been constantly questioned from both cultural and religious perspectives. It creates a specific space that, from an architect’s point of view, requires an investigation as an externally imposed zone. As a physical manifestation of the chador, this thesis proposes a theatre in which the journey from the entrance, vestibules, and galleries, through the stage, and into the house will allow one to experience and assimilate the senses buried within the veil and the body of the woman

Fault detection in trajectory tracking of wheeled mobile robots

The problem of fault detection in nonlinear systems with application to trajectory tracking of nonholonomic wheeled mobile robots (WMRs) is addressed in this thesis. For the considered application, a nonholonomic wheeled mobile robot--having nonlinear kinematics--is required to follow a predefined smooth trajectory (in the absence of obstacles in the environment). This goal has to be accomplished despite the presence of faults that may occur in two of its major subsystems which are vital for navigation, namely the driving subsystem and the steering subsystem. These faults are assumed to be caused by actuator faults in either of these two subsystems. The problem addressed here is to detect the presence of faults and to determine the subsystem which has been affected by these faults. Toward this end, two different fault detection approaches are proposed and investigated. The first approach is based on system identification through Extended Kalman Filters (EKF) whereas the second one is based on system identification via artificial neural networks. In the former approach a novel method for residual generation is proposed while in the latter by utilizing the neural network's formal stability properties the desired performance can be guaranteed. Each of the proposed fault detection methods is studied subject to two different kinds of controllers (namely a dynamic linear controller and a dynamic feedback linearization based controller) and two different types of actuator faults (namely the Loss-of-Effectiveness fault and Locked-In-Place fault). In this way, the impact of the controller strategy on the fault detection approach is also investigated and evaluated

Resonance of a rectangular plate influenced by sequential moving masses

In this work, an improved semi-analytical technique is adopted to track the dynamic response of thin rectangular plates excited by sequential traveling masses. This technique exploits a so-called indirect definition of inertial interaction between the moving masses and the plate and leads to a reduction, in the equations of motion, of the number of time-varying coefficients linked to the changing position of the masses. By employing this optimized method, the resonance of the plate can be obtained according to a parametric study of relevant maximum dynamic amplification factor. For the case of evenly spaced, equal masses travelling along a straight line, the resonance velocity of the masses themselves is also approximately predicted via a fast methodology based on the fundamental frequency of the system only

The Impact of Near-Duplicate Documents on Information Retrieval Evaluation

Near-duplicate documents can adversely affect the efficiency and effectiveness of search engines. Due to the pairwise nature of the comparisons required for near-duplicate detection, this process is extremely costly in terms of the time and processing power it requires. Despite the ubiquitous presence of near-duplicate detection algorithms in commercial search engines, their application and impact in research environments is not fully explored. The implementation of near-duplicate detection algorithms forces trade-offs between efficiency and effectiveness, entailing careful testing and measurement to ensure acceptable performance. In this thesis, we describe and evaluate a scalable implementation of a near-duplicate detection algorithm, based on standard shingling techniques, running under a MapReduce framework. We explore two different shingle sampling techniques and analyze their impact on the near-duplicate document detection process. In addition, we investigate the prevalence of near-duplicate documents in the runs submitted to the adhoc task of TREC 2009 web track

Overexpression of epithelial cell adhesion molecule (EpCAM) in gastric cancer and its correlation with overall survival of the patients

BACKGROUND: Epithelial cell adhesion molecule (EpCAM) is an adhesion molecule which is expressed on the epithelial cells and primarily identified as a tumor marker for carcinoma. In this study, the expression of EpCAM in precancerous and cancerous gastric lesions was investigated and then, the association of EpCAM expression with the overall survival of patient suffering from gastric carcinoma was evaluated.METHODS: 12 gastric carcinoma, 3 dysplasia, and 8 intestinal metaplasia (IM) subjects were taken from the department of pathology of Tohid Hospital, Sanandaj, Iran. The diagnosis was made by the expert pathologist. Then, the subjects were stained for EpCAM by immunohistochemistry (IHC) and analyzed by the pathologist.RESULTS: The data showed that EpCAM was expressed in all of the precancerous and cancerous samples. However, 76.4% of carcinoma cells were positive for EpCAM while it was 62.5% and 51.3% for dysplasia and IM, respectively. Importantly, it was observed that the expression of EpCAM on gastric cancer was negatively correlated with the overall survival of the patients.CONCLUSION: In conclusion, it was demonstrated in this study that EpCAM is expressed in gastric carcinoma and its expression is negatively correlated with the overall survival of the patients with gastric cancer

The influence of over-distraction on biomechanical response of cervical spine post anterior interbody fusion: a comprehensive finite element study

Introduction: Anterior cervical discectomy and fusion (ACDF) has been considered as the gold standard surgical treatment for cervical degenerative pathologies. Some surgeons tend to use larger-sized interbody cages during ACDF to restore the index intervertebral disc height, hence, this study evaluated the effect of larger-sized interbody cages on the cervical spine with ACDF under both static and cyclic loading.Method: Twenty pre-operative personalized poro-hyperelastic finite element (FE) models were developed. ACDF post-operative models were then constructed and four clinical scenarios (i.e., 1) No-distraction; 2) 1 mm distraction; 3) 2 mm distraction; and 4) 3 mm distraction) were predicted for each patient. The biomechanical responses at adjacent spinal levels were studied subject to static and cyclic loading. Non-parametric Friedman statistical comparative tests were performed and the p values less than 0.05 were reflected as significant.Results: The calculated intersegmental range of motion (ROM) and intradiscal pressure (IDP) from 20 pre-operative FE models were within the overall ranges compared to the available data from literature. Under static loading, greater ROM, IDP, facet joint force (FJF) values were detected post ACDF, as compared with pre-op. Over-distraction induced significantly higher IDP and FJF in both upper and lower adjacent levels in extension. Higher annulus fibrosus stress and strain values, and increased disc height and fluid loss at the adjacent levels were observed in ACDF group which significantly increased for over-distraction groups.Discussion: it was concluded that using larger-sized interbody cages (the height of ≥2 mm of the index disc height) can result in remarkable variations in biomechanical responses of adjacent levels, which may indicate as risk factor for adjacent segment disease. The results of this comprehensive FE investigation using personalized modeling technique highlight the importance of selecting the appropriate height of interbody cage in ACDF surgery

Estimation of seismic response parameters and capacity of irregular tunnel-form buildings

Insufficient information about the seismic performance of tunnel-form buildings and limited relevant design codes and standards are the main barriers towards application of these systems in seismically active areas. Vertical and horizontal irregularity of typical tunnel-form buildings is another cumbersome challenge restricting the application of these systems. To address these issues, this study aims to evaluate the seismic behaviour of tunnel-form buildings with horizontal irregularity and develop appropriate design methodologies. Based on the results of 3, 5, 7 and 10-storey buildings, new response modification factors are proposed as a function of seismic demand and expected performance level. Fragility curves are also derived for various levels of intensity, and simple equations are introduced to estimate uncoupled frequency ratios. The results, in general, demonstrate the flexible torsional behaviour of irregular tunnel-form structures and their adequate seismic resistance capacity. The buildings studied herein, managed to satisfy the immediate occupancy performance requirements under design-basis earthquake, which implies that the plan regularity requirement for tunnel-form buildings in seismic codes may be too conservative. Moreover, it is concluded that using response modification factor equal to 5 can generally result in sufficient stability and adequate performance level under both design basis and maximum considered earthquake scenarios