Passive cooling systems, such as wind towers, can help to reduce energy consumption in buildings and at the same time reduce greenhouse gas (GHG) emissions. Wind towers can naturally ventilate buildings and also can create enhanced thermal comfort for occupants during the warm months. This study proposes a modern wind tower design with a moistened pad. The new design includes a fixed column, a rotating and movable head, an air opening with a screen, and two windows at the end of the column. The wind tower can be installed on roof-tops to take advantage of ambient airflow. The wind tower’s head can be controlled manually or automatically to capture optimum wind velocity based on desired thermal condition. To maximize its performance, a small pump was considered to circulate and spray water on an evaporative cooling pad. A computational fluid dynamics (CFD) simulation of airflow around and inside the proposed wind tower is conducted to analyze the ventilation performance of this new design of wind tower. Thereby, the velocity, total pressure, and pressure coefficient distributions around and within the wind tower for different wind velocities are examined. The simulation results illustrate that the new wind tower design with a moistened pad can be a reasonable solution to improve naturally the thermal comfort of buildings in hot and dry climates.

The cold, remote, northern regions of Canada constitute a challenging environment for the provision of reliable energy and food supply to communities. A transition from fossil fuels to renewables-based sources of energy is one positive step in reducing the greenhouse gases from the energy supply system, which currently requires long-distance transport of diesel for electricity and heating needs. Geothermal energy can not only displace diesel for part of this energy need, it can provide a base-load source of local energy to support food production and mitigate adverse impacts of food insecurity on communities. In this proof-of-concept study, we highlight some potential benefits of using geothermal energy to serve Canada’s northern communities. Specifically, we focus on food security and evaluate the technical and economic feasibility of producing vegetables in a “controlled environment”, using ground sources of heat for energy requirements at three remote locations—Resolute Bay, Nunavut, as well as Moosonee and Pagwa in Ontario. The system is designed for geothermal district heating combined with efficient use of nutrients, water, and heat to yield a diverse crop of vegetables at an average cost up to 50% lower than the current cost of these vegetables delivered to Resolute Bay. The estimates of thermal energy requirements vary by location (e.g., they are in the range of 41 to 44 kW of thermal energy for a single greenhouse in Resolute Bay). To attain adequate system size to support the operation of such greenhouses, it is expected that up to 15% of the annually recommended servings of vegetables can be provided. Our comparative analysis of geothermal system capital costs shows significantly lower capital costs in Southern Ontario compared to Northern Canada—lower by one-third. Notwithstanding high capital costs, our study demonstrates the technical and economic feasibility of producing vegetables cost-effectively in the cold northern climate. This suggests that geothermal energy systems can supply the heat needed for greenhouse applications in remote northern regions, supplying a reliable and robust source of cost-competitive sustainable energy over the long-term and providing a basis for improved food security and economic empowerment of communities.

Renewable and sustainable energy sources can play an important role in meeting the world’s energy needs and also in addressing environmental challenges such as global warming and climate change. Geothermal well-doublet systems can produce both electrical and thermal energy through extracting heat from hot-water aquifers. In this paper, we examine some potential challenges associated with the operation of well-doublet systems, including heat conductivity, chemical, and mechanical issues. In these systems, geomechanics issues such as thermal short-circuiting and induced seismicity arise from temperature and pressure change impacts on the stress state in stiff rocks and fluid flow in fractured rock masses. Coupled chemical processes also can cause fluid channeling or formation and tubular goods plugging (scaling) with precipitates. Mechanical and chemical disequilibrium conditions lead to increased production uncertainties; hence risk, and therefore coupled geo-risk assessments and optimization analyses are needed for comparative commercialization evaluations among different sites. The challenges related to heat transfer processes are also examined. These studies can help better understand the issues that may arise during the operation of geothermal well-doublet systems and improve their effectiveness, subsequently reducing associated costs and risks.

Despite holding a significant proportion of the known hydrocarbon reserves by the carbonates, enough studies have not been conducted to understand their geomechanical parameters and their predictability, especially in Iran. The present paper introduces a novel approach for obtaining geomechanical parameters of carbonate rocks through investigating the relationship between geomechanical parameters and Archie’s coefficients in one of the Iranian fractured carbonate reservoirs. The geomechanical parameters here included Young’s modulus, bulk modulus, and shear modulus, while Archie’s coefficients were the cementation factor and formation resistivity factor. For this purpose, 14 representative limestone core plugs were chosen and Archie’s coefficients were determined and the effect of increasing confining pressure on these parameters was investigated. Then, through numerical simulations using Particle Flow Code (PFC3D), the geomechanical parameters of the reservoir, including Young’s modulus (E), (dynamic and static), bulk and shear modulus, and Poisson’s ratio were obtained. The numerical results were verified by the laboratory tests and wireline logs’ data and showed a satisfying matching. Finally, the empirical relations between geomechanical parameters and Archie’s coefficients were determined for the target reservoir. According to the obtained results, the average correlation between Young’s modulus and both the cementation factor and formation resistivity factor was about 95%, which is a satisfying accuracy. As expected, shear modulus and bulk modulus had a stronger relationship with E being respectively about 99% and 98%. Moreover, lab-measured porosity and Young’s modulus had a correlation coefficient of about 95%. The obtained results of the present study provide new insights into the simultaneous evolution of the reservoir’s mechanical and petrophysical characteristics.

This study focuses on determining the orientation and constraining the magnitude of present-day stresses in the Dezful Embayment in Iran’s Zagros Fold and Thrust Belt. Two datasets are used: the first includes petrophysical data from 25 wells (3 to 4 km deep), and the second contains 108 earthquake focal mechanisms, mostly occurring in blind active basement faults (5 to 20 km deep). Formal stress inversion analysis of the focal mechanisms demonstrates that there is currently a compressional stress state ($A_{\phi }=2.0–2.2)$ in the basement. The seismologically determined S_Hmax direction is 37° ± 10°, nearly perpendicular to the strike of most faults in the region. However, borehole geomechanics analysis using rock strength and drilling evidence leads to the counterintuitive result that the shallow state of stress is a normal/strike-slip regime. These results are consistent with the low seismicity level in the sedimentary cover in the Dezful Embayment, and may be evidence of stress decoupling due to the existence of salt layers. The stress state situation in the field was used to identify the optimally oriented fault planes and the fault friction coefficient. This finding also aligns with the prediction Coulomb faulting theory in that the N-S strike-slip basement Kazerun Fault System has an unfavorable orientation for slip in a reverse fault regime with an average SW-NE S_Hmax orientation. These results are useful for determining the origin of seismic activity in the basin and better assessing fault-associated seismic hazards in the area.

Defects in steel reinforcement are critical factors in the evaluation of the service life of reinforced concrete (RC). Steel reinforcement (bar) defects or deterioration may lead to crack propagation and strength decrease in RC structural members. Deterioration also changes the steel magnetic properties; the evaluation of these changes can be investigated by an indirect passive and non-invasive method to locate and quantify defect in RC structures. Herein, a passive magnetic inspection (PMI) method is modified and used to examine its potential as a non-destructive testing (NDT) method for condition assessment of steel reinforcement. The passive magnetic flux density of steel bar with three small holes in three different positions and locations along the bar is measured in the laboratory. A signal processing methodology based on frequency spectrum analysis and filtering is applied to the experimental data, and the results are compared with the numerical simulation. The processed data from the experimental test shows the potential of PMI method to detect, locate and evaluate bar condition. Both experimental results (after signal processing) and simulation results show a good similarity for top and bottom holes. Cross-correlation of numerical simulation with experimental data was necessary to reveal detection of the side hole.