Study of fluid flow in unconventional reservoir rocks : assessing flow regimes, geomechanics and capillary end effects

Unconventional resources have received significant attentions as recent advances in technology has made it possible to economically produce from these reservoirs. While the economical production from these reservoirs have been initiated, the impact of the mentioned mechanisms on fluid flow are not well understood. In this thesis, to study the effects of flow regimes and geomechanical stress on fluid flow in shale matrix, several experiments were performed at different pore pressure and net stress conditions. It was aimed to obtain a reliable model for prediction of matrix permeability during the production period when the pore pressure is decreasing and the net stress is increasing with time. For this purpose, the matrix permeability of several shale rock samples were measured at different conditions. In addition, the results of TOC, Helium porosimetry, XRD analysis, contact angle measurements, MICP test and SEM image analysis were used to characterize the shale sample under study. In line with the experimental measurements, the corresponding flow equations were derived using Navier-Stokes (NS) equations with slip boundary conditions. The derived flow equations and the experimental results were used to obtain appropriate slip coefficients. Then the geo-mechanical effects on matrix permeability were considered. The experimental data were used to develop a model for permeability prediction at different pore pressure and net stress values. The proposed model was also validated using a set of experimental data in the literate. Furthermore, the gas flow in micro and nanoscale systems was simulated using the Lattice Boltzmann method (LBM). After validation, the simulation results were compared with the scaled experimental data. From the comparison, Tangential Momentum Accommodation Coefficient (TMAC) for LBM simulation of gas flow in shale rocks was determined. Results obtained in this study are essential for using the LBM as a simulation technique for fluid flow modelling in shale rocks. In addition to single phase flow studies, two-phase relative permeability of unconventional rocks were measured. It is shown that the Capillary End Effect (CEE) caused as result of ultra-high capillary pressure in shale formations, is the main artefacts that makes these measurements unreliable. In this thesis, a model is developed to correct the CEE during the steady-state relative permeability measurements. The proposed model was also evaluated by a set of artificially generated data and the experimental SS-kr data measured in the lab

Canal Transportation and Centering Ability of Twisted File and Reciproc: A Cone-Beam Computed Tomography Assessment

Introduction: The purpose of this in vitro study was to compare the canal transportation and centering ability of Twisted File (TF) to that of Reciproc system. Methods and Materials: Forty noncalcified roots with mature apices, minimum length of 19 mm and an apical curvature of 15-30 degrees (according to Schneider’s method), from freshly extracted mandibular and maxillary teeth, were selected for this study. Samples were randomly divided into two groups (n=20) and canal preparation with either TF or Reciproc was performed according to manufacturers' instruction. Pre- and post-instrumentation cone-beam computed tomography (CBCT) images were captured and the extent of canal transportation and centering ability of the files were calculated, using the NNT Viewer software and Photoshop CS5, at levels of 3, 4, and 5 mm from the apex. The Mann-Whitney U test was used to analyze the statistical significance between the two groups. Results: One fracture occurred in the TF group. TF produced more transportation than Reciproc in both mesiodistal and buccolingual directions; however, the difference between the two systems were not statistically significant except for the TF group at 5-mm distance from the working length, where the difference was significant(P>0.05). Conclusion: Both file systems were able keep the original curvature of the canal and thus can be considered safe for clinical application

Deepfake Detection of Occluded Images Using a Patch-based Approach

DeepFake involves the use of deep learning and artificial intelligence techniques to produce or change video and image contents typically generated by GANs. Moreover, it can be misused and leads to fictitious news, ethical and financial crimes, and also affects the performance of facial recognition systems. Thus, detection of real or fake images is significant specially to authenticate originality of people's images or videos. One of the most important challenges in this topic is obstruction that decreases the system precision. In this study, we present a deep learning approach using the entire face and face patches to distinguish real/fake images in the presence of obstruction with a three-path decision: first entire-face reasoning, second a decision based on the concatenation of feature vectors of face patches, and third a majority vote decision based on these features. To test our approach, new datasets including real and fake images are created. For producing fake images, StyleGAN and StyleGAN2 are trained by FFHQ images and also StarGAN and PGGAN are trained by CelebA images. The CelebA and FFHQ datasets are used as real images. The proposed approach reaches higher results in early epochs than other methods and increases the SoTA results by 0.4\%-7.9\% in the different built data-sets. Also, we have shown in experimental results that weighing the patches may improve accuracy

SOCIAL STATUS OF PHYSICAL EDUCATION TEACHERS

The aim of this study was to investigate the social status of physical education teachers in Hamedan province, Iran. Data gathering done by means of a researcher made questionnaire. After approving the validity by experts, the reliability approved by 11 professors through Chronbakh alpha equal to 0.87. Research society was all physical education teacher of Hamedan province consist of 800 people. The sample was estimated using Morgan table and the total number of 235 questionnaires returned and analyzed. After detecting the normal distribution of data using kolmogorov-smirnov test, independent t test and one way ANOVA were applied to test the hypothesis. A significant difference found among the mean of job interest and economic factor in samples compare to the society. In other words, teacher’s interest was higher than the average and also, the economic factors are not the main reason to choose their job. Also, significant difference found between the mean of social status of chosen jobs in sample compare to the mean of society. it means that based on respondents ideas, the social status of jobs such as seller, barber, waiter and taxi driver is lower than physical education teacher and this status is higher for physician, employee and non- physical education teacher. Totally, no matter the social status of other jobs, the credibility and status of the job of physical education teachers recognized high by respondents

A Novel Hybrid Framework for Co-Optimization of Power and Natural Gas Networks Integrated With Emerging Technologies

In a power system with high penetration of renewable power sources, gas-fired units can be considered as a back-up option to improve the balance between generation and consumption in short-term scheduling. Therefore, closer coordination between power and natural gas systems is anticipated. This article presents a novel hybrid information gap decision theory (IGDT)-stochastic cooptimization problem for integrating electricity and natural gas networks to minimize total operation cost with the penetration of wind energy. The proposed model considers not only the uncertainties regarding electrical load demand and wind power output, but also the uncertainties of gas load demands for the residential consumers. The uncertainties of electric load and wind power are handled through a scenario-based approach, and residential gas load uncertainty is handled via IGDT approach with no need for the probability density function. The introduced hybrid model enables the system operator to consider the advantages of both approaches simultaneously. The impact of gas load uncertainty associated with the residential consumers is more significant on the power dispatch of gas-fired plants and power system operation cost since residential gas load demands are prior than gas load demands of gas-fired units. The proposed framework is a bilevel problem that can be reduced to a one-level problem. Also, it can be solved by the implementation of a simple concept without the need for Karush–Kuhn–Tucker conditions. Moreover, emerging flexible energy sources such as the power to gas technology and demand response program are considered in the proposed model for increasing the wind power dispatch, decreasing the total operation cost of the integrated network as well as reducing the effect of system uncertainties on the total operating cost. Numerical results indicate the applicability and effectiveness of the proposed model under different working conditions

An In vitro Comparison of Apically Extruded Debris Using Reciproc, ProTaper Universal, Neolix and Hyflex in Curved Canals

Introduction: As a consequence of root canal preparation, dentinal chips, irrigants and pulp remnants are extruded into preradicular space. This phenomenon may lead to post endodontic flare-ups. The purpose of this study was to compare the amount of extruded debris with four endodontic NiTi engine-driven systems. Methods and Materials: Sixty mesiobuccal roots of maxillary molars with 15-30˚ curvature were divided randomly into four groups (n=15). Each group was instrumented up to apical size of 25 using Reciproc, ProTaper Universal, Neolix and Hyflex. Bidistilled water was used as irrigant and extruded debris was collected in pre-weighted Eppendorf tubes. Tubes were stored in incubator for drying the debris. Extruded debris were weighted in electronic microbalance with accuracy of 0.0001 g. The raw data was analyzed with one way analysis of variance (ANOVA) and Tukey’s HSD post hoc test. Level of significance was set at 0.05. Results: The debris extrusion with Reciproc files was significantly higher than the other groups (P<0.05). Hyflex significantly extruded less debris than other files (P<0.05). There was no significant difference between ProTaper Universal and Neolix regarding the amount of extruded debris (P=0.98). Conclusion: All systems extruded debris during the instrumentation. Reciproc system significantly extruded more debris. Caution should be taken when interpreting the results of this study and applying it to the real clinical situation.Keywords: Controlled Memory; Debris Extrusion; Reciprocating; Root Canal Preparation; Rotary Instrumentatio