Several exiting bridges were not designed to withstand earthquake loads effectively. Therefore, there is a pressing need to estimate the seismic losses and mitigate the earthquake risk of these critical structures. This study aims to verify the modeling approach of Reinforced concrete (RC) bridge substructures by predicting the dynamic response of an as-built bridge bent. Multi-column bridge bent previously tested in another study using large-scale experiments and quasi-static cyclic loading is chosen for the numerical modeling verification. A detailed fiber-based model of the bridge bent is developed and subjected to the loading protocol used in the experiments. Evaluations of the dynamic response obtained from the previous testing and those of the developed fiber-based model verified the adopted numerical model and enabled utilizing this idealization approach in the seismic assessment of other RC bridges in the UAE.
Drought is a natural phenomenon that occurs due to low precipitation conditions, it has negative effects on various fields such as agriculture, environment, economy, and society. In this study, drought conditions in the northern United Arab Emirates (UAE) were assessed using the Standardized Precipitation Index (SPI) and Aridity Index (AI) for annual time span. Monthly observed rainfall and temperatures data was used for a period of 10 years (2010-2019) for multiple stations. SPI and AI had similar behaviors where both showed very similar trends of drought. The trend displayed an increasing in the values that indicates wetter conditions in the future. However, some parts of UAE still having hyper arid conditions, therefore, indicating the need for appropriate drought management and monitoring.
The impact of lockdown due to COVID- 19 on air quality in Abu Dhabi Emirate was evaluated. The study investigated the changes in concentrations of PM10, PM2.5, SO2 and NO2 before and during the lockdown period. To avoid the spread of the COVID-19 pandemic in Abu Dhabi Emirates, regional lockdown procedures were taken between March 23 and June 22, 2020. The daily average level of PM10 increased by 17.5 % while PM2.5, SO2 and NO2 decreased by 12.9 %, 4.16 % and 22.76 %, respectively. The study outcomes indicated that air quality in Abu Dhabi Emirates was improved during the lockdown due to limited human activities such as transportation of people and goods
Life cycle cost (LCC) of buildings in the construction sector is an integrated method commonly used to estimate building cost through their life cycle. The building LCC is an economic decision analysis process, which assists designers in investments in new construction. Design decisions made at early stages are determining the whole life effectiveness of the building. Locally, concrete is the most used construction material with about 25% of the construction cost. The research aims to develop a cost model for three different concrete mixtures, include all cost elements from cradle to grave. The concrete mixtures considered are standard concrete, concrete with ground granulated blast furnace slag composition, and concrete with fly ash composition. The LCC allows for enhancing the overall performance of buildings, especially in the early stages. To conclude, LCC analysis will track cost performance over the economic lifespan, monitor design progress within the capital, and operating cost budgets.
Microorganisms have a significant impact on upstream operations and ultimate recovery. These microbes possess diverse metabolic functions which can be beneficial or detrimental to upstream operators, which are obligatory to be fully aware of to enhance the quality and the quantity of the produced oil. Moreover, the UAE's onshore hydrocarbon reservoirs have not been explored from the microbial perspective. Obtaining data related to UAE reservoirs would aid in proactive decision making for preventing or controlling the existing issues such as souring, formation damage, and MIC in the upstream sector. Molecular microbiological methods, including flow cytometry, metagenomic sequencing and bioinformatics will be used to generate a map of the resident microbial communities at onshore field sites. These community datasets will be contextualized in light of site metadata (from SCADA systems and water chemistry measurements) to relate the microbiology with these environmental niches.
Foam flooding is designed to solve the high heterogeneity occurred in reservoirs and improve sweep efficiency. However, high temperature and high salinity in the Middle East reservoirs with high permeability contrast after secondary recovery poses a serious problem to foam stability. Four surfactants, including two amphoteric surfactants (B-1235 and LME-50) and two nonionic surfactants (Ethomeen C/12 and Duomeen TTM), were applied to generate foams under harsh conditions in this work. Surfactant screening is based on foam capacity and foam stability. Here, we identified that only B-1235 had excellent foaming ability and the foams generated by this amphoteric surfactant kept good foam stability. The impact of oil on foam stability was also checked. Foam stability with different foam quality under high pressure and high temperature in the foam cell was evaluated to choose the optimal foam quality.
In the Claus process, polycyclic aromatic hydrocarbons (PAHs) are the main precursors for soot particle formation, which reduce the efficiency of the process. Therefore, the formation of PAHs must be minimized. The aim of this work is to study different reaction pathways that may lead to PAH formation through quantum chemical and kinetics calculations. Three pathways were studied in this work, where phenanthrene formation from naphthalene was studied in Pathways 1 and 2, and Pathway 3 explored the development of phenanthrene from naphthalene by H and C2H2 additions. It was found from an ethylene flame simulation that our mechanism corresponds to 61% increase in phenanthrene formation. Furthermore, Claus furnace simulation showed that the conditions used in industries are not suitable for large PAH destruction, and their optimization using detailed reaction mechanism could help in finding suitable conditions for aromatics destruction in the furnace.
Initial studies were conducted using HT-HP filter press and Filter papers as porous media for visual inspection of polymer cake dissolution efficiency. Final conclusions were drawn from the simulated coreflooding studies, wherein the injection and production return permeabilities were investigated on post-fractured and enzyme treated cores .The breaker was mixed with the frac fluid, where as in the second, the breaker treatment was applied once the frac fluid is in place. It is also seen from comparative performance studies that the breaking ability enhances when the breaker is in second phase treatment instead of being mixed with the frac fluid. The simulated core flood runs conducted indicated a filter cake deposition due to frac fluid leak off. leading to reduction of permeability from 95 md to 0.3 md simulating formation damage in most cases. The results illustrated a restoration of up to 95% of the production and injection permeability.
Wettability of shale oil rocks is a sensitive petrophysical factor for EOR from shale oil reservoirs. The recent literature showed that the shale rocks exhibit a mixed-wetting behavior which is composed of organic matter (oil-wet) and inorganic matter (water-wet). Moreover, current studies have found that nanofluids has the potential to increase the oil recovery up to 17 %. However, there is a lack of mechanistic understanding associated with the wettability alteration potential of shale rocks upon modification with nanofluids. Thus, the objective of this study is to experimentally quantify the shale wettability pre and post aging in silica nanofluid. The contact angle measurement is used to quantitatively assess the wettability of shale. Furthermore, the imaging analysis techniques (i.e., SEM and AFM) are utilized to provide insights into micro-scale mechanisms for wettability alteration.
In this paper, we propose a novel viscoelastic model to analyze the polymer rheological behavior in porous media. The main advantage of our model is its ability to capture the polymer mechanical degradation at ultimate shear rates primarily observed near wellbores. Furthermore, the fitting parameters used in the model have been correlated to the rock and polymer properties, significantly reducing the need for expensive and time-consuming coreflooding tests for future polymer screening works. Finally, the proposed model is implemented in the MATLAB Reservoir Simulation Toolbox (MRST) to evaluate polymer flooding at a field scale and quantify additional oil recovery.
