Two- and three-phase flow functions for numerical simulation of EOR processes

The understanding of governing mechanisms of multi-phase (oil, water, and gas) flow in porous media is of keen interest in petroleum and environmental engineering. In the petroleum engineering context, three-phase flow occurs in several important processes including in enhanced oil recovery (EOR). Recovery of a significant amount of the residual oil in reservoirs after primary recovery and secondary recovery (waterflooding) is important in order to tackle the increasing demand for the energy. EOR methods mainly involve two and three-phase flow in the reservoir. Relative permeability (kr) and capillary pressure (Pc) are two important parameters in multiphase flow which describe the interaction of each fluid in porous media. The importance of these flow functions will be even more significant for three-phase flow systems. This thesis attempts to address three key issues. (i) Improved determination of multi-phase flow functions (kr and Pc). (ii) The impact of parameters affecting flow functions. (iii) Prediction of multi-phase flow functions. Relative permeability (kr) can be measured in the laboratory using steady-state and unsteady-state methods, or estimated by mathematical correlations and pore-network models. As multi-phase flow experiments and in particular steady-state measurements are very time consuming and expensive, more often the unsteady-state method is used for multi-phase kr measurements. In this thesis, a methodology has been devised for calculating kr values and in particular three-phase kr from unsteady-state experiments. The effort was extended to simultaneously calculating Pc from the same coreflood experiment. There are different physical parameters which can affect flow functions. The effect of gas/oil interfacial tension (IFTg/o) on two and three-phase kr and also on residual saturation during alternative water and gas injections has also been studied. Finally, two-phase kr have been estimated for rock and fluid conditions where there is no previous data. This has been achieved by taking data from different conditions under which measurements were made

A Study of Shearing Resistance in Asphaltic Concrete by Multi-stage Triaxial Testing

The current demands for increasing the structural performance of flexible pavement are forcing highway engineers to depart from empirical design methods and develop design procedures based on the basic properties of the materials used. The empirical design methods were considered adequate for many years in view of the requirements for a low load carrying capacity and the high cost of the technological refinements required for a rational design approach. The rational design approach has been precluded by the lack of design data regarding basic material properties of asphaltic concrete. The empirical testing procedures that have been used extensively in the past have produced very little in the way of basic material properties and design data. Even though the triaxial test has not been used extensively in the past, it is recognized as the most reliable testing procedure for revealing the basic strength properties of asphaltic concrete

Accessing Calcified Teeth Using Dynamic Guidance System

Introduction: one of the most common challenging scenarios that a clinician faces on a regular basis is the treatment of a calcified tooth. Using CBCT to identify canals is becoming the standard of care and a tremendous help to clinicians. More recently, Dynamic guidance is becoming a popular among clinicians for dealing with challenging cases such as calcification. Objective: The aim of this study was to evaluate the accuracy of endodontic access of calcified anterior mandibular and maxillary teeth using dynamic guidance. Material and Method: 42 extracted calcified human mandibular and maxillary anterior teeth were selected. Rubber model former mold was used to mount the extracted teeth in the proper position to mimic the human jaw, and CBCT images were captured. Preoperative CBCT scans were transferred to the Dynamic Guidance system software for planning of endodontic access. To simulate a clinical scenario, the dentoforms were mounted to a manikin and placed on an operatory chair. Post-removal burs were used to gain access to the canal after calibration was completed. Once the proper depth was reached, the software prompted the operator to stop. The procedure was terminated at this point, regardless of the success of the operator to locate the canals or not. After completion, the access was evaluated by the passive placement of a #6 C file in the canal to ensure access/patency of the canal. A post-operative CBCT with and without the file in the access was taken. The teeth were then decoronated at the cementoenamel junction to remove any obstruction that would potentially deflect the file, and a file was placed in the canal and a CBCT was taken with the file. All images were assessed for access deviation and accuracy, followed by comparative statistics. Results: Of the 32 included in this study, 28 (87.5%) canals were successfully located. The angular deviation was calculated after superimposing the pre-op CBCT over the post-op CBCT by measuring the angle between the file and the natural path of the physical canal. The average angular deviation was 4.69 degrees, the average platform buccolingual deviation was 0.38 mm, the average platform mesiodistal direction was 0.23 mm, the average of non-depth deviation (deviation in any direction other than apico-coronally) was 0.99 mm, and the average of apical non-depth deviation at the apical extent of the file trajectory was 0.70 mm Conclusion: Calcified canals were located by an inexperienced operator in 87.5% of the time with an angular deviation of 4.69 degrees which confirms that dynamic guide syste

Authentication of newly established human esophageal squamous cell carcinoma cell line (YM-1) using short tandem repeat (STR) profiling method

Cross-contamination during or early after establishment of a new cell line could result in the worldwide spread of a misidentified cell line. Therefore, newly established cell lines need to be authenticated by a reference standard method. This study was conducted to investigate the authenticity of a newly established epithelial cell line of human esophageal squamous cell carcinoma (ESCC) called YM-1 using short tandem repeat (STR) DNA profiling method. Primary human ESCC epithelial cells were cultured from the fresh tumor tissue of an adult female patient. Growth characteristics and epithelial originality of YM-1 cells were studied. Genomic DNA was isolated from YM-1 cells harvested at passage 22 and ESCC donor tumor sample on two different days to prevent probable DNA contamination. STR profiling was performed using AmpFℓSTR® Identifiler® Plus PCR Amplification Kit. To address whether YM-1 cells undergo genetic alteration as the passage number increases, STR profiling was performed again on harvested cells at passage 51. YM-1 cells grew as a monolayer with a population doubling time of 40.66Â h. Epithelial originality of YM-1 cells was confirmed using ICC/IF staining of cytokeratins AE1/AE3. The STR profile of the ESCC donor tumor sample was the same with YM-1 cells at passage 22. However, STR profile of the donor tumor sample showed an off-ladder (OL) allele in their D7S820 locus. Also, re-profiling of YM-1 cells at passage 51 showed a loss of heterozygosity (LOH) at D18S51 locus. This suggests that long-term culture of cell lines may alter their DNA profile. Comparison of the DNA fingerprinting results in DSMZ, and ATCC STR profiling databases confirmed unique identity of YM-1 cell line. This study provides an easy, fast, and reliable procedure for authentication of newly established cell lines, which helps in preventing the spread of misidentified cells and improving the reproducibility and validity of experiments, consequently. © 2015, International Society of Oncology and BioMarkers (ISOBM)

Do Spousal Intimate Relationships Affect Fertility Intentions and Preferences?

The fertility influence of spousal intimate relationships is unknown. Drawing on the Giddens’s theory of transformation of intimacy, this study proposed a hypothesis that couples supporting egalitarian intimate relationships, with a greater risk profile attached to the relationship, and having less attachments to the external normative pressures shaping marital relations, are more likely to have low-fertility intentions and preferences. Using data from a self-administered pilot survey (n = 375 prospective grooms and brides) designed by the authors, and employing multivariate regression models, we found that the lower attachment to external social forces in mate selection was associated with the lower ideal number of children, and those with a greater spousal relational egalitarianism and a higher risk profile attached to their relationships preferred lower number of children and were less likely to intend to have children after marriage. The study sheds new light on the determinants of low fertility.Social Sciences and Humanities Research Council of Canadahttps://doi.org/10.13039/501100000155Nipissing Universityhttps://doi.org/10.13039/100009369Peer Reviewe

HIV/AIDS Knowledge and attitudes of Southern Iranian students

This study aimed to explore Iranian primary school students’ attitudes and knowledge about HIV/AIDS. The knowledge and attitudes of 597 primary school students from all areas of Ahwaz were assessed by anonymous questionnaires in November 2007. None of the students answered all the knowledge questions correctly, and results indicated that there were many misconceptions about the routes of transmission. Sneezing and coughing, contaminated food, water or hands were incorrectly identified as routes of transmission. The knowledge increased with age (P<0.001). The sources of pupils’ information primarily included: Television (66.8%), family members (20.2%), friends (10.6%) and school teachers (2.4%). Also some pupils believed that there was some treatment (38.3%) or an effective vaccine (63.4%) for HIV/AIDS. The result of this study revealed that most primary school students in Ahvaz had a lack of proper knowledge about HIV/AIDS. There is a need to promote an AIDS education in Ahvaz and also all Iranian schools, to improve socio-cultural factors in next years