This study presents a novel method for predicting the undrained shear strength (c_u) using artificial intelligence technology. The c_u value is critical in geotechnical applications and difficult to directly determine without laboratory tests. The group method of data handling (GMDH)-type neural network (NN) was utilized for the prediction of c_u. The GMDH-type NN models were designed with various combinations of input parameters. In the prediction, the effective stress (σ_v’), standard penetration test result (N_SPT), liquid limit (LL), plastic limit (PL), and plasticity index (PI) were used as input parameters in the design of the prediction models. In addition, the GMDH-type NN models were compared with the most commonly used method (i.e., linear regression) and other regression models such as random forest (RF) and support vector regression (SVR) models as comparative methods. In order to evaluate each model, the correlation coefficient (R²), mean absolute error (MAE), and root mean square error (RMSE) were calculated for different input parameter combinations. The most effective model, the GMDH-type NN with input parameters (e.g., σ_v’, N_SPT, LL, PL, PI), had a higher correlation coefficient (R² = 0.83) and lower error rates (MAE = 14.64 and RMSE = 22.74) than other methods used in the prediction of c_u value. Furthermore, the impact of input variables on the model output was investigated using the SHAP (SHApley Additive ExPlanations) technique based on the extreme gradient boosting (XGBoost) ensemble learning algorithm. The results demonstrated that using the GMDH-type NN is an efficient method in obtaining a new empirical mathematical model to provide a reliable prediction of the undrained shear strength of soils.

The conformal fractional derivative (CFD) has become a hot research topic since it has a physical interpretation and is easier to grasp and apply to problems compared with other fractional derivatives. Its application to heat transfer, diffusion, diffusion-advection, and wave propagation problems can be found in the literature. Fractional diffusion equations have received great attention recently due to their applicability in physical, chemical, and biological processes and engineering. The diffusion of the pollutants within the ground, which is an important environmental problem, can be modeled with a diffusion equation. Diffusion in some porous materials or soil can be modeled more accurately with fractional derivatives or the conformal fractional derivative. In this study, the diffusion problem of a spilled pollutant leaking into the ground modeled with the conformal fractional time derivative in spherical coordinates has been solved analytically using the Fourier series for a constant mass flow rate and complete symmetry under the assumptions of homogeneous and isotropic soil, constant soil temperature, and constant permeability. The solutions have been simulated spatially and in time. A parametric analysis of the problem has been performed for several values of the CFD order. The simulation results are interpreted. It has also been suggested how to find the parameters of the soil to see whether the CFD can be used to model the soil or not. The approach described here can also be used for modeling pollution problems involving different boundary conditions.

Tr en Türk Çimento Sektörü, endüstriyel ve evsel nitelikli atıkları lisanslı tesislerinde alternatif yakıt veya hammadde olarak kullanabilmektedir. Alternatif yakıt ve hammadde kullanımının artması çevre kirliliğinin önlenmesi, doğal kaynakların ve enerjinin tasarruf edilmesi açısından oldukça önemlidir. Alternatif yakıtlar genel olarak arıtma çamuru, atık yağ, ömrünü tamamlamış lastikler, solvent ve boya grupları altında toplanabilir. Alternatif hammaddeler ise maden atıkları, ısıl işlem atıkları, inşaat atıkları grupları altında değerlendirilebilir. Bu çalışmanın amacı, alternatif hammadde ve alternatif yakıt kullanımının ve çevresel yararlarının değerlendirilmesidir. Bu amaçla, örnek olarak seçilen bir çimento tesisinde, 2013-2015 yıllarında kabul edilen atıklar, kabul öncesi yapılan analizler, kullanılan alternatif hammaddelerin ve yakıtların miktarları ve maliyete olan etkileri incelenmiştir. Çimento fabrikasında alternatif hammadde olarak demir koku, grid, döküm kumu ve fosfojips, kalite parametrelerine uyumlu bir şekilde geri kazanılmaktadır. Alternatif hammadde kullanımı maliyet olarak tesise toplamda 7.031.998 TL kazanç sağlamıştır. Alternatif yakıt olarak arıtma çamuru kullanılmaktadır. Arıtma çamuru kullanımının maliyet olarak tesise kazancı 200.514.450 TL olmuştur. Turkish Cement Sector uses industrial and domestic wastes as alternative fuels or raw materials in licensed facilities. Increasing use of alternative fuels and raw materials is very important in terms of eliminating environmental pollution, saving natural material resources and energy. Alternative fuels can generally be gathered under the groups of sewage sludge, waste oil, worn out tires, solvent and paints. As for alternative raw materials, they can be evaluated undermine waste, heat treatment waste, construction waste groups. The aim of this study is to evaluate the use of alternative raw materials and fuels and their environmental benefits. For this purpose, in a cement plant selected as a case study, wastes accepted between 2013 and 2015, pre-acceptance analyzes, quantities of alternative raw materials and fuels used, and their financial impacts are examined. Iron scent, grid, casting sand and phosphogypsum are recycled as an alternative raw material in the cement plant in accordance with quality parameters. The use of alternative raw materials resulted in savings totaling 7.031.998 TL for the plant. As alternative fuel, sewage sludge is used. The financial benefit of sewage sludge usage to the plant is 200.514.450 TL.

This study investigates the application of conformable fractional derivatives (CFD) for modeling groundwater flow dynamics. Fractional derivatives offer a powerful alternative to overcome the limitations of traditional models in groundwater management, a critical challenge due to increasing population demands and diminishing water resources. In this context, the conformable fractional time derivative was integrated into the groundwater flow equation to enable more precise and accurate calculations of complex flow dynamics in aquifer systems. The analytical solution of the developed CFD-based groundwater flow equation was established and compared with both the classical Theis solution and experimental data. The proposed solution incorporated the well-known Theis equation, modified to include the fractional-order derivative parameter α, which allowed for greater flexibility in representing the temporal evolution of drawdown. When α = 1, the solution reverted to the classical Theis equation. Especially, the CFD-based solution with α = 0.9 exhibited superior alignment with experimental results, outperforming the classical Theis model. Performance evaluation metrics confirmed the enhanced predictive capabilities of the CFD-based model, with the coefficient of determination value of 0.9806 compared to 0.8781 for the classical model, and reductions in mean absolute error, mean squared error, and root mean squared error by 37%, 45%, and 48%, respectively. These findings highlight the potential of the proposed approach in improving groundwater management and aquifer characterization by accurately modeling storage effects and non-local behaviors in groundwater systems.

Günümüzün en acil çevresel sorunlarından biri, atıkların bertarafı, özellikle de düzenli depolama ile ilgilidir. Yanlış depolama yöntemleri nedeniyle yeraltı sularının kalitesi ciddi şekilde tehlikeye girmiştir. Vahşi depolama sahalarında insan sağlığı ve çevre kirliliğiyle ilgili problemler daha yaygındır. Bu düzensiz depolama sahaları birçok dezavantaja ve ciddi sağlık sorunlarına yol açmaktadır. Bu sebeple, daha önce depolama sahalarında meydana gelen şev göçmelerine neden olan vakalar incelenmiştir. Bu çalışmada, atık stabilitesinin değerlendirilmesine odaklanarak katı atık depolama alanlarıyla ilgili stabilite sorunları araştırılmaktadır. Çalışma, Hekimbaşı, Dona Juana, Gnojna Grora, Hiriya, Payatas ve Xerolakka gibi çeşitli düzenli depolama sahalarındaki şev göçmesi vakalarının analizini içermektedir. Plaxis 2D yazılımı kullanılarak, bu analizlerden elde edilen veriler titizlikle değerlendirilmiş ve en uygun düzenli depolama sahası yönetim stratejilerinin belirlenmesi amaçlanmıştır. Düzenli depolama sahalarındaki şev göçmeleri genellikle uygun olmayan depolama sahası tasarımı, günlük örtü serme ve atık sıkıştırma eksikliği, yetersiz atık ayrıştırma, yetersiz sızıntı suyu drenajı ve gaz tahliyesi ile aşırı şev açısı ve yüksekliğinden kaynaklanmaktadır. Bu koşullardan bir veya daha fazlasının varlığı saha stabilitesinde kayba neden olabilir. Mühendislik kontrollerinin yetersiz olduğu bu sahalarda duraysızlıklar yaşanmaktadır.

It is very important to analyze the polluted water that streams transfer around them by diffusion. Dirty water leaking from streams like this causes soil and water pollution. The protection of surface and underground water resources is very important given the decreasing water resources. How deep a pollutant has infiltrated can be found by solving the diffusion equation. In this study, the concentration amount of the pollutant passing from a long-polluted stream to the soil was investigated by the finite difference method. Instead of using expensive packet programs, a widespread program Matlab used by engineers and scientists to analyze data, develop algorithms, solve problems analytically and numerically, and create models is preferred in this study. The cross-section of the stream is rectangular and its length is considered to be quite long. Therefore, the problem has been examined in two dimensions. First, the necessary finite difference equations are derived and this problem is analyzed using appropriate boundary conditions. A numerical solution has been obtained for two cases in which the bottom of the stream is permeable and it is not. The mass flow rate of both of the cases was calculated and it is found that the mass flow rate in the first case in which the bottom of the stream is permeable is almost double of the second case. The flow velocities on the boundaries have been found to be less in the case in which the bottom of the stream is impermeable.