Hydromagnetic boundary layer micropolar fluid flow over a stretching surface embedded in a non-darcian porous medium with radiation

We have studied the effects of radiation on the boundary layer flow and heat transfer of an electrically conducting micropolar fluid over a continuously moving stretching surface embedded in a non-Darcian porous medium with a uniform magnetic field. The transformed coupled nonlinear ordinary differential equations are solved numerically. The velocity, the angular velocity, and the temperature are shown graphically. The numerical values of the skin friction coefficient, the wall couple stress, and the wall heat transfer rate are computed and discussed for various values of parameters

Properties of Cement Composites Utilizing of Bentonite: A Review

The use of bentonite clay slurries in civil and geotechnical engineering dates back to Veder\u27s pioneering work in 1953. Since then, bentonite has been used for various applications such as the construction of bored piles and diaphragm walls. Plastic concrete walls also require sufficient strength and modulus to adapt to the surrounding environment, and the characteristics and different forms of bentonite commercially available were reviewed in this paper.This paper reviews the properties and applications of bentonite, including its use in cement-bentonite composites for remedial cut-off wall construction. Cement-bentonite grouts offer advantages over bentonite grouts in terms of ease of use and adjustability of strength.Cement-bentonite composites were found to be promising materials for remedial cut-off wall construction due to their ability to meet requirements for strength, stiffness, and permeability. By regulating the mix proportions, the strength of the set grout can be adjusted to match that of the surrounding ground. Cement-bentonite grouts also offer advantages over traditional bentonite grouts, as they are easier to use, offer a longer working period before setting, and can be forgiving if the user deviates from the design formula or the mixing technique. This paper provides useful information for those working with bentonite and cement-bentonite composites in civil and geotechnical engineering applications

Properties of Cement Composites Utilizing of Bentonite: A Review

The use of bentonite clay slurries in civil and geotechnical engineering dates back to Veder\u27s pioneering work in 1953. Since then, bentonite has been used for various applications such as the construction of bored piles and diaphragm walls. Plastic concrete walls also require sufficient strength and modulus to adapt to the surrounding environment, and the characteristics and different forms of bentonite commercially available were reviewed in this paper.This paper reviews the properties and applications of bentonite, including its use in cement-bentonite composites for remedial cut-off wall construction. Cement-bentonite grouts offer advantages over bentonite grouts in terms of ease of use and adjustability of strength.Cement-bentonite composites were found to be promising materials for remedial cut-off wall construction due to their ability to meet requirements for strength, stiffness, and permeability. By regulating the mix proportions, the strength of the set grout can be adjusted to match that of the surrounding ground. Cement-bentonite grouts also offer advantages over traditional bentonite grouts, as they are easier to use, offer a longer working period before setting, and can be forgiving if the user deviates from the design formula or the mixing technique. This paper provides useful information for those working with bentonite and cement-bentonite composites in civil and geotechnical engineering applications

Mechanical Properties of HPC Incorporating Fly Ash and Ground Granulated Blast Furnace Slag After Exposure to High Temperatures

The behavior of concrete structures after being exposed to elevated temperatures is considered one of the great vital concerns in Civil Engineering. Moreover, as elevated temperature have adverse effects on the mechanical properties of concrete members, it’s important to find solutions to improve these properties at elevated temperature. This study aims to investigate the effect of supplementary cementitious materials (SCM) on the high performance concrete (HPC) compressive, tensile, and flexural strengths after exposure to different temperatures of 200 °C, 400 °C, 600 °C, and 800 °C. In preparing HPC, different parameters were considered including SCM type, fly ash (FA) or ground granulated blast furnace slag (GGBFS), adding 0.5% (by volume fraction) steel fiber (SF), polypropylene fiber (PP) and hybrid fibers. The results were compared with those for high strength concrete (HSC) and normal strength concrete (NSC). The results showed that using FA and GGBFS, SF, and hybrid fibers can significantly improve the residual mechanical properties of HPC, while using PP fiber has an adverse effect on the residual mechanical properties of HPC especially residual tensile and flexural strengths. The standard code curves underestimate the residual mechanical properties of HPC after 200 °C

Assessment of riverbank filtration performance for climatic change and a growing population

Data availability statement The original contributions presented in the study are included in the article/Supplementary Material; further inquiries can be directed to the corresponding authors.Copyright © 2023 Abd-Elaty, Kuriqi, Ganayem, Ahmed, Saleh and Garrote. Riverbank filtration (RBF) consists of green drinking water production in many regions and is used as a pre-treatment phase. This study investigates the performance of the RBF in the Nile delta, Egypt, for climate change and population growth scenarios of 2030, 2040, and 2050. This study presents a new method for predicting the sharing of riverbanks considering three cases: i) the river stage controlling the water levels in the river, ii) increasing RBF pumping, and iii) changing the groundwater levels. This last scenario is achieved by changing the general head in the MODFLOW model. The results showed that RBF sharing (RBFS) is a proportion of the river leakage inflow, in which the decrease of the river stage due to the influence of climate change reduced the river leakage inflow and RBFS. In addition, increasing RBF pumping, decreasing RBF pumping, and lowering the groundwater levels due to the increase in the future drinking water pumping for the population growth increased the river leakage inflow and RBFS. Finally, combining the three cases decreased RBFS in the coming years of 2030, 2040, and 2050, respectively, due to more groundwater sharing than the river inflow. The results show that the water budget is a good tool to investigate RBFS compared with MT3D results. This technique can reduce the cost of water quality collection and analysis; moreover, it will help with the estimation of RBF and save time compared with solute transport modeling.AK is grateful for the Foundation for Science and Technology’s support through funding UIDB/04625/2020 from the research unit CERIS

Hazards of sea level rise and dams built on the River Nile on water budget and salinity of the Nile Delta aquifer

Data availability: No data was used for the research described in the article.Code availability: Upon request.Supplementary material is available online at: https://www.sciencedirect.com/science/article/pii/S2214581823002872#sec0135 .Copyright © 2023 The Authors. Study region: The Nile Delta region consists of flat, low-lying areas, where most areas are used for agriculture. It covers an area of 22,000 km2, which is 2.20% of the total area of Egypt. Study focus: This study evaluates the water budget and the salinity due to the Sea Level Rise (SLR) and the reduction in the river water flow caused by the Grand Ethiopian Renaissance Dam (GERD) using the numerical code SEAWAT. Three filling scenarios were considered for the GERD reservoir at elevations 600 m, 621 m, and 645 m above mean sea level (AMSL) for the storage volumes of 17 billion cubic meters (BCM) (scenarios #1), 37.30 BCM (scenarios #2), and 74 BCM (scenarios #3). The impact of these fillings scenarios was combined with SLR of 25 cm, and increasing the abstraction rates from the Nile Delta aquifer by 25%, 50%, and 100%, respectively. New hydrological insights for the region: The study findings indicated that the SLR and the GERD reservoir filling with increasing pumping rates, especially during the filling periods, would influence the groundwater resources in the Nile Delta. The GERD reservoir filling could alter the freshwater, in which the aquifer salinity increased by 4.47%, 11.48%, and 29.99% for the three scenarios, respectively. The methodology and findings presented in this study might be useful for investing and comparing the impact of SLR and upstream dam projects on the downstream water budget and salinity at other coastal regions.Alban Kuriqi is grateful for the Foundation for Science and Technology's support through funding UIDB/04625/2020 from the research unit CERIS

Managing coastal aquifer salinity under sea level rise using rice cultivation recharge for sustainable land cover

Data Availability: No data was used for the research described in the article.Code availability: Upon request.Supplementary material is available online at https://www.sciencedirect.com/science/article/pii/S2214581823001532#sec0095 .Copyright © 2023 The Authors. Study region: The coastal aquifer of Nile Delta, Egypt is used to develop the current study. Study focus: Excess water from rice irrigation is a source of incidental recharge to mitigate seawater intrusion. This paper numerically explores the optimal location of rice cultivations by subdividing the delta domain into three distinct recharging regions (north, central and south). Additionally, SEAWAT code was simulated under a combination of rice cultivation relocation and sea level rise (SLR). New hydrological insights for the region: The study findings revealed significant variations in salt volume reduction depending on the location of rice cultivation in the delta. Placing rice cultivation in the northern region resulted in the highest reduction of salt volume (19 %). In contrast, locating the recharge in the central region yielded a salt volume reduction of 0.50 %, while rice cultivation in the southern region produced a 15 % increase. Considering the projected SLR of 61 cm by 2100, there was an overall salt volume increment of 3 %. However, when accounting for both SLR and rice cultivation recharge in the northern region, a substantial salt volume reduction of 17 % was observed. The results demonstrated that incidental recharge by rice cultivation in coastal aquifers is an effective method for enhancing saltwater intrusion control. Moreover, this study improves our understanding of hydrological processes and expected responses in the delta under future climate scenarios

Assessment of riverbank filtration performance for climatic change and a growing population

Riverbank filtration (RBF) consists of green drinking water production in many regions and is used as a pre-treatment phase. This study investigates the performance of the RBF in the Nile delta, Egypt, for climate change and population growth scenarios of 2030, 2040, and 2050. This study presents a new method for predicting the sharing of riverbanks considering three cases: i) the river stage controlling the water levels in the river, ii) increasing RBF pumping, and iii) changing the groundwater levels. This last scenario is achieved by changing the general head in the MODFLOW model. The results showed that RBF sharing (RBFS) is a proportion of the river leakage inflow, in which the decrease of the river stage due to the influence of climate change reduced the river leakage inflow and RBFS. In addition, increasing RBF pumping, decreasing RBF pumping, and lowering the groundwater levels due to the increase in the future drinking water pumping for the population growth increased the river leakage inflow and RBFS. Finally, combining the three cases decreased RBFS in the coming years of 2030, 2040, and 2050, respectively, due to more groundwater sharing than the river inflow. The results show that the water budget is a good tool to investigate RBFS compared with MT3D results. This technique can reduce the cost of water quality collection and analysis; moreover, it will help with the estimation of RBF and save time compared with solute transport modeling

Enhancing Parkinson's disease diagnosis accuracy through speech signal algorithm modeling

Parkinson's disease (PD), one of whose symptoms is dysphonia, is a prevalent neurodegenerative disease. The use of outdated diagnosis techniques, which yield inaccurate and unreliable results, continues to represent an obstacle in early-stage detection and diagnosis for clinical professionals in the medical field. To solve this issue, the study proposes using machine learning and deep learning models to analyze processed speech signals of patients' voice recordings. Datasets of these processed speech signals were obtained and experimented on by random forest and logistic regression classifiers. Results were highly successful, with 90% accuracy produced by the random forest classifier and 81.5% by the logistic regression classifier. Furthermore, a deep neural network was implemented to investigate if such variation in method could add to the findings. It proved to be effective, as the neural network yielded an accuracy of nearly 92%. Such results suggest that it is possible to accurately diagnose early-stage PD through merely testing patients' voices. This research calls for a revolutionary diagnostic approach in decision support systems, and is the first step in a market-wide implementation of healthcare software dedicated to the aid of clinicians in early diagnosis of PD

Compressive strength prediction of Portland cement concrete with age using a new model

Based on the existing experimental data for compressive strength values of different concrete mixes, a statistical analysis for the gathered data was conducted. The analysis revealed a model for predicting the compressive strength of concrete mixes at any age with the help of two constants (A) and (B) that are considered as a characteristic property for a concrete mix. The constant (A) is introduced as a rate of strength gain constant whereas, (B) is introduced as grade of strength constant. Once the values of constants (A) and (B) are defined for a concrete mix, the compressive strength at any age could be simply predicted without collecting data at that age. The values of (A) and (B) could be determined by one of two methods. Solving two simultaneous equations at two different ages while performing either design or trial concrete mix is a method that could be used to define the two constants. Other method is based on concrete strength at 28-day age. The proposed model was studied for different concrete mixes. The study covered some parameters including the influence of, mineral admixtures as a partial replacement of cement, metakaolin, nano silica fume, curing in water or lime and the effect of curing temperature. The analysis reveals that mixes containing no admixtures, mixes containing silica fume and cured at normal temperature, mixes containing nano silica and cured in water are following with high accuracy the proposed model