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Cemented paste backfill (CPB) has been widely used as local and regional underground support to reduce host rock wall closure in mined-out areas and also to reduce rockfall and rockburst incidents. However, analyzing the rock mass—CPB interactions in the first month after backfill placement must account for the CPB’s time-dependent strength, stiffness, and volume change characteristics during binder hydration. This article presents the first such comprehensive study made for CPB from the Williams mine in Ontario, Canada. Monotonic isotopically consolidated drained compressive triaxial tests were conducted on cured CPB specimens using the lubricated-ends test technique. The specimens had 3.0–7.5% Cement Content (CC); Curing Times (CTs) were from 3 to 28 days; and the confining stress ranged from 25 to 350 kPa. During shearing, all tests exhibited an initial contractive phase leading to a Characteristic State (CHS or point of volumetric strain reversal) followed by dilation with a maximum dilation rate corresponding to peak stress at the Failure State (FS). Both CHS and FS are adequately described by the Mohr–Coulomb criterion and a framework formulation was proposed to predict the evolution of CHS and FS based on CC and CT. Furthermore, the volumetric strains at CHS and FS can be defined as linear functions of the respective axial strains at the CHS and FS. Quantification of the observed behaviors through these functional relationships can help develop future constitutive models that better represent CPB’s transient response to triaxial stress loading while curing, which is essential to understanding as-placed backfill properties and its interaction with surrounding rock mass.

The study of the properties of engineered rocks is of great importance to researchers in engineering sciences such as petroleum, mining, and civil engineering owing to their wide application in these fields. In the present study, a physico-chemical and geomechanical investigation was carried out on the effects of different clay minerals on porous rocks. Various chemical products formed during chemical interactions between cement, clay minerals, and water can change the pore structure and thus the rock characteristics. The results of the current study showed that increasing the clay content could remarkably reduce the porosity and permeability of the rock by an average of 86% and 6.76%, respectively. In this regard, samples containing kaolinite were further influenced due to their new pore structure. Moreover, a power relationship was found between sonic velocity and porosity, which can be used to predict rock properties. Chemical analysis indicated an amplification in quantities of chemical products, particularly calcium silicate hydrate and portlandite, due to an increase in clay content. The impacts of porosity and cementation quality as two main factors on rock strength have also been studied. The outcomes revealed that a reduction in porosity could compensate for detrimental effects of poor bond quality and consequently improved UCS by up to 30% in samples containing kaolinite, while decreasing the degree of cementation prevailed over the porosity reduction in specimens including illite and resulted in a 14% decrease in UCS. The effects of porosity and bond quality on UCS would cancel each other out in samples containing bentonite. It is worth noting that when it comes to changes in geomechanical characteristics, the dominant factor (i.e., porosity reduction or cementation quality) determines the ultimate effect of clay minerals on the properties of engineered porous rocks.

Pore water pressure and effective stress development within cemented paste backfill (as one of the most popular local and regional underground mining supports) depends on rates of change of hydraulic conductivity and stiffness, which in turn are functions of cement hydration and backfilling rates. Previous laboratory studies attempted to investigate these interactions; however, the loading conditions they used are not representative of effective stress paths recorded in field monitoring programs during mine backfilling. In this work, typical effective stress paths occurring in mining operations are characterized in terms of an initial period of zero effective stress ranging from 3 to 48 h, and subsequently developed effective stress rates ranging from 5 to 20 kPa/hr. Servo-controlled consolidation machines apply the prescribed stress paths with adjustments every minute, thereby achieving an essentially continuous stress rate. The stress paths are applied to samples with 3.0%, 5.3% and 7.5% binder contents, and electrical conductivity monitoring on control samples is used to correlate the stress levels to stages of cement hydration. The secant constrained modulus is used to quantify the degree to which different stress paths may damage developing hydration products, resulting in softer backfill. For instance, the secant constrained modulus at 2.5% axial strain of samples with 3.0% binder content and loaded at the fastest rate with 48 h delay time was almost half of the ones loaded at the slowest rate and 12 h delay time after 65 h of curing indicating cement hydration products damage due to faster loading rate. The test samples' void ratios are compared with similar CPB’s in-situ void ratios and stress paths. Void ratios obtained from these experiments were very close to the average in-situ values under similar loading conditions. The test results help interpret the as-placed CPB’s bulk properties and will lead to better sample preparation procedures for other tests intended to determine CPB's engineering properties.

Salt precipitation is a major factor influencing the internal characteristics of concrete during curing. In this study, the impacts of the type and concentration of various salts on the characteristics of porous cementitious materials were investigated using a series of engineered porous concrete specimens. The results indicated that chemical interactions among interparticle cement, clay mineral, calcite, and different salts in aqueous media during 28 days of curing could alter properties such as porosity, permeability, and mechanical strength depending on salt concentration. Among these, concrete permeability was most affected. There was an inverse relationship between the content of monovalent ions and concrete porosity and permeability. In contrast, for divalent ions in the concentration range of 10–30 g/L, an optimum value of 15 g/L resulted in the lowest salt precipitation and highest porosity and permeability values. Furthermore, different salts present during curing led to an increase of up to 16% in compressional wave velocity. Based on the results of ultrasonic and uniaxial compressive strength (UCS) tests, linear and exponential correlations were observed between porosity and compressional/shear wave velocities, while UCS was exponentially related to porosity.

Measuring the volume fraction of each phase in multi-phase flows is an essential problem in petrochemical industries. One of the standard flow regimes is stratified two-phase flow, which occurs when two immiscible fluids are present in a pipeline. In this paper, we performed several experiments on vertical concave, horizontal concave, and double-ring sensors to benchmark obtained simulation results from modeling these sensors in stratified two-phase flow using COMSOL Multiphysics software. The simulation data was confirmed by experimental data. Due to the low number of data in the experimental method in order to extract more data, the mentioned software was used to extract more data and then compare the sensitivity of different directions of concave and double ring sensors. The simulation results show that the overall sensitivity of the concave is higher than the double-ring and the momentary sensitivity of the horizontal concave is higher in higher void fractions, and the vertical one has higher sensitivity in lower void fractions.

One of the most severe problems in power plants, petroleum and petrochemical industries is the accurate determination of phase fractions in two-phase flows. In this paper, we carried out experimental investigations to validate the simulations for water–air, two-phase flow in an annular pattern. To this end, we performed finite element simulations with COMSOL Multiphysics, conducted experimental investigations in concave electrode shape and, finally, compared both results. Our experimental set-up was constructed for water–air, two-phase flow in a vertical tube. Afterwards, the simulated models in the water–air condition were validated against the measurements. Our results show a relatively low relative error between the simulation and experiment indicating the validation of our simulations. Finally, we designed an Artificial Neural Network (ANN) model in order to predict the void fractions in any two-phase flow consisting of petroleum products as the liquid phase in pipelines. In this regard, we simulated a range of various liquid–gas, two-phase flows including crude oil, oil, diesel fuel, gasoline and water using the validated simulation. We developed our ANN model by a multi-layer perceptron (MLP) neural network in MATLAB 9.12.0.188 software. The input parameters of the MLP model were set to the capacitance of the sensor and the liquid phase material, whereas the output parameter was set to the void fraction. The void fraction was predicted with an error of less than 2% for different liquids via our proposed methodology. Using the presented novel metering system, the void fraction of any annular two-phase flow with different liquids can be precisely measured.

Objective This clinical trial was designed and conducted due to the anti-inflammatory potential of Oleoylethanolamide (OEA) to examine the effect of OEA supplement on glycemic status, oxidative stress, inflammatory factors, and anti-Mullerian hormone (AMH) in women with polycystic ovary syndrome (PCOS). Method This study was a randomized clinical trial, double-blinded, placebo-controlled that was carried out on 90 women with PCOS. Patients were divided into two groups: receiving an OEA supplement ( n  = 45) or a placebo ( n  = 45). The intervention group received 125 mg/day OEA and the placebo group received the wheat flour for 8 weeks. Demographic data were collected through questionnaires. Fasting blood sugar (FBS), insulin resistance (IR), total antioxidant capacity (TAC), malondialdehyde (MDA), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and AMH were measured before and after the study. Results Data analysis of food recall and physical activity questionnaires, showed no significant differences between the two groups ( p  > 0.05). Biochemical factors including glycemic status, MDA, inflammatory factors, and AMH decreased significantly ( p  < 0.05). TAC increased remarkably ( p  < 0.05) in comparison between the two groups, after the intervention. Conclusion OEA supplement with anti-inflammatory characteristics could be efficient independent of diet changes and physical activity in improving disrupted biochemical factors, so both supplementation or food resources of this fatty acid could be considered as a compensatory remedy in patients with PCOS. Trial Registration This study was retrospectively (09-01-2022) registered in the Iranian website ( www.irct.ir ) for registration of clinical trials (IRCT20141025019669N20).

In this study, the response of a supercritical round jet to various excitation modes including varicose, helical, flapping, dual varicose/helical and dual varicose/flapping is studied using large eddy simulations. A translation method is proposed to enhance the accuracy of the equation-of-state and transport correlations. Results show that the excitations, especially the dual modes and the varicose mode (when the forcing frequency matches the preferred mode in the potential core), considerably increase the turbulent mixing, the pitch distance and the penetration depth of the coherent structures as compared with the unexcited case. However, the excitations, especially the dual modes, de-energize the coherent structures and reduce the degree of three-dimensionality of the coherent structures. The excitations reduce the potential core length drastically, especially under the flapping and the dual mode excitations. Analyses show that the dual varicose/flapping mode excitations have the highest impacts on the jet development and the cross-section shape as compared with the other modes. Moreover, the dual varicose/flapping excitations have the highest impact on the large-scale turbulent mixing. However, the small-scale turbulent mixing is at the maximum value, when the supercritical jet is stimulated by the dual varicose/flapping mode excitations with the varicose-to-flapping frequency ratio of 2. The cross-correlations between the density fluctuations and the imposed perturbations indicate that the impact of the excitations on the turbulent diffusion is at the maximum value at the potential core breakdown location, while the correlation diminishes at the other locations.

Although cryopreservation of ovarian tissue has advanced greatly, it remains a challenge, and protocols should be optimized to handle the heterogeneous nature of ovarian samples. In an effort to address this factor, the present study evaluated the effects of corpus luteum (CL) and side of ovaries (right versus left) on cellular morphology and viability of vitrified bovine ovarian fragments in a closed system. The ovaries were categorized according to whether they had a CL and which side they were on, and then divided into six groups: 1) CL+ (with CL) group; 2) CL˗ (without CL) group; 3) right ovaries group; 4) left ovaries group; 5) fresh control group (ovaries without vitrification or culture that were not selected for CL or ovarian side) and 6) In vitro culture medium control group (non-vitrified ovaries that were not selected for the presence or absence of CL or side of the ovaries). The current study shows that the CL˗ and right groups had the greatest percentage of follicles with normal morphology compared to other vitrified-warmed groups. Furthermore, the levels of necrosis and tissue damage of the right cultured group were the lowest compared to other groups. It was shown that bovine ovarian tissues derived from right ovaries and ovaries without a corpus luteum can be functionally and morphologically preserved after vitrification. For the first time, the present study suggests that bovine ovarian tissue vitrification can be improved by considering the origin of the ovaries.