Semiempirical Calculation Method Research Articles

A new semi-empirical bearing capacity calculation method for geocell reinforcement in foundations

This study introduces a novel semi-empirical method that conceptualizes the geocell layer as an additional surcharge and expanding the effective footing width. This method integrates reinforcement mechanisms, including confinement, stress dispersion, and the membrane effects, to calculate the ultimate bearing capacity of foundations reinforced with geocells. An extensive analysis on the angle of load dispersion was conducted, drawing upon numerous studies from the literature and considering various influencing parameters. The proposed calculation method for both drained and undrained conditions was validated using 130 small- and large-scale experimental results. The effectiveness of the proposed method is assessed across different failure modes, soil relative densities, geocell characteristics, load eccentricities, and footing shapes. The study revealed that the calculated bearing capacities generally aligned with the point where the pressure-settlement curve transitions to a steep and relatively straight tangent, which has been identified by various researchers as the ultimate load. Furthermore, existing methods for calculating the bearing capacity of geocell-reinforced soil inadequately capture the pressure-settlement responses, mainly due to differing failure modes between unreinforced and reinforced soils. In contrast, the proposed method, which does not necessitate unreinforced test results, proves effective in determining the ultimate bearing capacity of reinforced soil within acceptable settlement limits.

Impact of semi-empirical methods implemented in heat, air, and moisture (HAM) models on predicted wind-driven rain (WDR) loads and hygrothermal responses

The amount, duration, and intensity of wind-driven rain (WDR) are instrumental to the durability and sustainability of building components. Semi-empirical methods implemented in heat, air, and moisture (HAM) models have proved to be a practical and efficient approach to quantify WDR exposure of building components and to examine WDR's influence on hygrothermal responses of building envelopes. However, specific assumptions and simplifications in the implementations can cause discrepancies in WDR calculations and hygrothermal responses. While measured datasets or computational fluid dynamics (CFD) predictions are employed to validate WDR calculations in previous studies, few address the further influence on hygrothermal responses, particularly confronted with full-scale experimental datasets. This paper starts with a general formulation of semi-empirical methods for WDR calculation and elaborates the ASHRAE and ISO standards implemented in two representative HAM models, WUFI and DELPHIN. In the first phase of simulations, two full-scale experimental datasets at Leuven (Belgium) and Eindhoven (the Netherlands) are reproduced by the two models to compare predicted WDR loads. In the second phase, the predicted and measured WDR loads are imposed as boundary conditions of different scenarios of one benchmark case to further analyze the influence on the hygrothermal responses. The results indicate that both models roughly reproduce the semi-empirical methods. Because of disparity in algorithms and implementations and differences in weather and building conditions, the simulated WDR loads show similar trends with deviations to the measured datasets. The predicted hygrothermal responses show deviations to different extents, presumably due to disparity in WDR load predictions during certain periods.

Unveiling reversible hydrogen storage mechanism for the 2D penta-SiCN material

The promise of using 2D materials for hydrogen storage has broad prospects, ascribe to their significant specific surface area and lightweight properties. In this work, the hydrogen storage capability and reversible storage mechanism of 2D penta-SiCN material are investigated based on the first-principles computational method. Thermal stability of penta-SiCN is calculated by the ab-initio molecular dynamics (AIMD) simulation and root-mean-square displacement (RMSD) algorithm. It has been found that penta-SiCN is thermodynamically stable even after adsorbing hydrogen molecules. Taking into account the benchmarks of average and continuous adsorption energies of the adsorption systems, a pristine 2 × 2 × 1 penta-SiCN substrate has the ability to adsorb up to 26H2 molecules, which results in a maximum hydrogen storage capacity of 10.80 wt%. According to the semi-empirical calculation method that based on the thermodynamic analysis, the penta-SiCN adsorption system has a high reversible hydrogen storage capacity of 9.57 wt% within the adsorption and desorption application working conditions. The results proposed in this study demonstrates that penta-SiCN exhibits considerable promise for hydrogen storage with its substantial hydrogen storage capacity, exceptional reversibility, and eco-friendly characteristics.

A simple indicator displacement assay ensemble for rapid and selective determination and naked-eye detection of Cu2+ and citrate through a novel diazo-based colorimetric chemosensor

ABSTRACT Citrate as a naturally occurring ion with important biological roles, especially in metabolic cycles, and as an important biomarker in the early diagnosis of many diseases, including prostate cancer, has received special attention. In the present study, a novel, sensitive, fast and simple colorimetric bisazo-based chemosensor was developed for sequential determination and naked-eye detection of Cu2+ and citrate. UV-Vis spectroscopic studies showed that Reactive Red 141 (RR141) exhibits high selectivity and sensitivity towards Cu2+ in the presence of many other cations in deionised water (10 mmol L−1 MES(2-(N-morpholino)ethanesulfonic acid)/NaOH buffer solution, pH 6.0) and complex real samples as well. The obvious colorimetric response while interaction with copper and citrate is due to complexation between RR141 and Cu2+, and then the citrate detection occurred through metal transfer from the RR141-Cu2+ towards the citrate anion releasing RR141 via an indicator displacement route. The mechanism of detection has been carefully investigated using the semi-empirical calculation method of MM2 molecular mechanics. The proposed detection method for citrate ion has a detection limit of 0.15 µmol L−1 and a satisfactory linear range of 1.92–45.96 µmol L−1, which is consistent with the desired average diagnostic concentration in prostate cancer (less than 2 mmol L−1). Our studies’ results indicate the high capability of the developed chemical sensor for quantitative and qualitative citrate detection in various complex media, including biological and clinical real samples.

Reversible hydrogen storage and release mechanism of a B2N monolayer: a first-principles insight.

It was found the physical adsorption could be an efficient strategy for high capacity, high efficiency and high safety in hydrogen storage. In this research, a systematic investigation into the potential of the B2N monolayer as an excellent physical adsorption hydrogen storage material is conducted by utilizing the first-principles calculation method. The findings of the investigation demonstrate that the B2N monolayer has a planar lattice and excellent structural stability. It is possible for H2 molecules to adsorb onto the B2N monolayer spontaneously. Both the individual adsorption and saturation adsorption corresponded to average adsorption energies ranging from -0.221 to -0.194 eV, fulfilling the physical adsorption criteria. In the case of saturation adsorption, a 1 × 2 × 1 B2N supercell can store a total of 24 H2 molecules, with the hydrogen gravimetric density up to 14.511 wt% and volumetric density up to 138 g L-1. A semi-empirical calculation method is used to research the performance of the system in terms of adsorption and desorption with actual temperature and pressure conditions. Under the actual conditions with adsorption carried out at 30 atm/233 K and desorption carried out at 3 atm/358 K, the maximal reversible hydrogen storage capacity of the hydrogen storage system based on the B2N monolayer can still reach 12.157 wt%, which is superior to that of many other boron-nitrogen compounds and metal-free functionalized hydrogen storage materials. The findings of this work indicate that the pristine B2N monolayer is one of the promising physical adsorption materials which could achieve excellent reversible hydrogen storage under defined conditions.

Quantitative Structure-Activity Relationship of 3-Thiocyanate-1H-Indoles Derived Compounds as Antileukemia by AM1, PM3, and RM1 Methods

Cancer is a disease with fatal consequences; thus, searching for innovative compounds with anticancer properties remains an active pursuit. One of the highly promising candidates is a compound derived from 3-thiocyanato-1H-indoles. However, the number of derivative compounds is currently limited. A quantitative structure and activity relationship (QSAR) study was conducted on derivate compounds 3-thiocyanato-1H-indoles to establish equations that predict the anticancer activity of more effective derivatives. This study aims to compare the effectiveness of the AM1 (Austin Model 1), PM3 (Parameterized Model 3), and RM1 (Recife Model 1) semiempirical methods, which are new techniques implemented in the Hyperchem version 8.0. Twenty experimental data were used, 16 derivatives of 3-thiocyanate-1H-indoles as regression compounds (fitting) and four derivates as test compounds. QSAR analysis was performed based on multiple linear regression calculations on 3-thiocyanate-1H-indoles derivative compounds by plotting IC50 (µM) as the dependent variable and descriptors as the independent variable. The best QSAR equation was obtained from the AM1 semiempirical calculation method with the following equation: IC50 = -1.705 + 0.511(Delta) + 0.346(Dipol) + 18.287(qC9) – 0.645(Log P) + 13.952(qC6), with n =20; r =0.814; r2 =0.662; The standard error (SE) =1.044; Fcount/Ftable =1.851; PRESS =15.219.

Обоснование применимости полуэмпирического метода расчета гидродинамических профилей для прогнозирования отрывных и переходных явлений

Целью работы является тестирование разработанного ранее полуэмпирического метода расчета характеристик гидродинамических профилей в части моделирования ламинарно-турбулентного перехода и отрыва пограничного слоя. Полуэмпирический метод основан на расчете потенциального обтекания профиля с помощью метода граничных интегральных уравнений и моделировании пограничного слоя интегральным методом. В качестве эталонного решения используются результаты CFD расчета обтекания профиля NACA0018 с помощью RANSметода в пакете OpenFOAM. Дано описание способа построения сетки, проведена проверка сеточной сходимости. С помощью указанных методов проведены сопоставительные расчеты коэффициентов подъемной силы и сопротивления профиля в диапазоне докритических углов атаки при двух значениях числа Рейнольдса, показано их хорошее согласование. Далее проведено сопоставление величин толщины потери импульса, положения точки ламинарно-турбулентного перехода в пограничном слое на профиле и положение точки отрыва пограничного слоя. Подтверждена хорошая точность прогнозирования этих характеристик с помощью полуэмпирического расчетного метода. The aim of the work is to test the previously developed semi-empirical method for calculating the characteristics of hydrofoil sections in terms of modeling the laminar-turbulent transition and boundary layer separation. The semi-empirical method is based on the calculation of the potential flow around the hydrofoil section using the boundary integral equations method and modeling of the boundary layer by the integral method. As a reference solution, the results of CFD calculation of flow around the NACA0018 hydrofoil sections using the RANS method in the OpenFOAM package are used. The description of the grid construction method is given, the grid convergence is checked. Comparative calculations of the hydrofoil section lift and drag coefficients in the range of subcritical angles of attack at two values of the Reynolds number were carried out by these methods. The good agreement of the results was shown. Further, the values of the momentum loss thickness, the position of the laminar-turbulent transition point in the boundary layer on the hydrofoil section and the position of the boundary layer separation point were compared. The good accuracy of predicting these characteristics using a semi-empirical calculation method has been confirmed.

High-temperature mass spectrometric study of thermodynamic properties in the TiO2 -Al2 O3 -SiO2 system and modeling.

The TiO2 -Al2 O3 -SiO2 system is the base for various glass-ceramic materials, which have great practical value for a large number of modern technologies. Many TiO2 -Al2 O3 -SiO2 materials are synthesized or applied at high temperatures, which justifies the relevance of the present study. The samples in the TiO2 -Al2 O3 -SiO2 system were synthesized using the method of induction melting in a cold crucible. The thermodynamic properties of the TiO2 -Al2 O3 -SiO2 system were studied using the Knudsen effusion mass spectrometric method. The derived thermodynamic functions were optimized within the generalized lattice theory of associated solutions (GLTAS) approach and compared with the results of calculation using the semiempirical Kohler, Muggianu, Toop, Redlich-Kister, and Wilson methods based on the corresponding data in the binary systems. The SiO2 selective vaporization from the samples under study was shown at temperatures above 1940 K. The thermodynamic properties in the TiO2 -Al2 O3 -SiO2 system, including the TiO2 -SiO2 system, were obtained in the temperature range 1965-2012 K and were optimized using GLTAS to obtain the consistent concentration dependences of the component activities and excess Gibbs energies. Positive deviations from the ideal behavior were observed in the TiO2 -Al2 O3 -SiO2 system at high temperatures. Comparison of these values with the results of the modeling based on the GLTAS approach allowed the recommendations regarding the optimal semiempirical methods for the excess Gibbs energy calculation in different concentration ranges to be made.

Silicon Prismanes: Calculation and Comparison of Heats of Formation

Background: The objects of this work are silicon prismanes - new highenergy materials that can be used in various electronic, optoelectronic, thermoelectric, and biological fields and compete with traditional chemical energy carriers. However, only compounds with hexasilacubane and octasilacubane have been synthesized to date. Synthesis of other silapismanes, and even more so polysilaprismanes, has not yet been achieved. Therefore, both the “simplest” and the highest silaprismanes are studied mainly theoretically, including by quantum chemistry methods. Objective and Methods: To expand information about the enthalpies of formation of "simple" (n = 2) and multilayer (n = 3-7) silicon prismanes using semiempirical calculation methods; bond lengths Si-Si and Si-H; compare them with the results of ab initio calculations already available in the literature. Results: The geometry was optimized by semiempirical methods, the enthalpies of formation, Si-Si and Si-H bond lengths, and the bond angles of the bilayer (m = 3-12) and some multilayer (n = 3-8 and m = 3-9) silaprismanes were determined. Comparison with the enthalpies of formation obtained using ab initio calculations shows that the enthalpies of formation obtained by the MINDO/3 method (Modified Intermediate Neglect of Differential Overlap, version 3) are closest to the results of ab initio calculations of two-layer silicon prismanes; and for multilayers - by the AM1 method (Austin Model 1). Large differences in the lengths of Si-H bonds determined ab initio and semi-empirically by both methods are not observed. As for the Si-Si bonds, the results of semi-empirical methods indicate the presence of the so-called auxetic effect in multilayer silaprismanes. Conclusion: We believe that in the future, the calculations carried out in this work and a comparative assessment of the enthalpies of formation obtained by calculation methods will help to overcome the problems associated with the synthesis of silicon prismanes.

A theoretical insight to understand the structures and dynamics of thiazole derivatives

Quantum chemical analysis of some Thiazole derivatives, namely (2-Chlorobenzothiazole; 5-acetyl-2,4dimethylthiazole; 2-Chlorobenzothiazole; Phthalylsulfathaizole; 2,4,5 Trimethyl thiazole) was performed by using Gaussian 9 software with semi-empirical calculation method such as density functional theory (DFT) and the basis sets used were the DFT/B3LYP methods using 6-311G (d, p). Various quantum chemical parameters such as electronic density, highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and the energy difference between highest and lowest unoccupied molecular orbitals (ELUMO-EHOMO), etc. were calculated. High EHOMO values suggests that the molecule can contribute the electrons towards bond formation; however, the lower values of ELUMO indicate that the molecule can easily accept the electrons. Besides that, the low value of the energy bandgap (ΔE) confirms the excellent inhibition efficiencies of the derivatives. Furthermore, by using these frontier orbital energies, different parameters like ionization energy, electron affinity, global hardness, electronegativity were also calculated. In this article, a theoretical study was performed only to determine the correlation between various parameters related to the electronic structure of Thiazole derivatives and their competence to mitigate the corrosion process.

Особенности дисмутации арилдихлорфосфитов

The paper considers the spontaneous rearrangement, i.e., dismutation, of phosphorous acid dichlorides (aryl dichlorophosphites) into acid chlorides (diaryl chlorophosphites) with separation of phosphorus trichloride. The starting materials contained phenyl, 1- and 2-naphthols as aromatic radicals. The main patterns of dismutation of aryldichlorophosphites were revealed and the basic factors influencing the process time were determined. The dismutation parameters of aryldichlorophosphites were compared with the regularities revealed earlier for a similar process with the participation of diamidoesters of phosphorous acid containing phenyl and naphthyl substituents as an ether component. Calculations of thermodynamic functions of state, i.e., standard enthalpies of ΔfH0298 formation and S0298 entropies, for the dismutation participants, standard values of the Gibbs energy of ΔrG0298 reactions, were calculated. Calculations were carried out without taking into account the influence of the solvent and for the case of standard conditions, as well as for similar systems --- diamidoesters of phosphorous acid. The calculations allowed us to show the thermodynamic possibility of implementing dismutation of aryl dichlorophosphites at relatively low temperatures. The semi-empirical calculation method (RM1) made it possible to establish the lowest-energy conformations of diaryl chlorophosphites formed as a result of dismutation and show their fundamental difference

Semi-empirical determination of radiative parameters for metastable Sc II levels

We present a semi-empirical parametrization method for calculation of spontaneous radiative decay rates of forbidden transitions on an example of analysis of experimental data for Sc II. The values of transition probabilities and radiative lifetimes of metastable levels are in perfect agreement with experimental ones. The obtained results are compared with other calculated data available. The predicted values of radiative parameters for all Sc II metastable levels are presented.

Alkane/Water Partition Coefficient Calculation Based on the Modified AM1 Method and Internal Hydrogen Bonding Sampling Using COSMO-RS.

We introduce a physics-based model for calculating partition coefficients of solutes between water and alkanes, using a combination of a semi-empirical method for COSMO charge density calculation and statistical sampling of internal hydrogen bonds (IHBs). We validate the model on the experimental partition data (∼3500 molecules) of small organics, drug-like molecules, and statistical assessment of modeling of proteins and ligand drugs. The model combines two novel algorithms: a bond-correction method for improving the calculation of COSMO charge density from AM1 calculations and a sampling method to deal with IHBs. From a comparison of simulated and experimental partition coefficients, we find a root-mean-square deviation of roughly one log 10 unit. From IHB analysis, we know that IHBs can be present in two states: open (in water) and closed (in apolar solvent). The difference can lead to a shift of as much as two log 10 units per IHB; not taking this effect into account can lead to substantial errors. The method takes a few minutes of calculation time on a single core, per molecule. Although this is still much slower than quantitative structure–activity relationship, it is much faster than molecular simulations and can be readily incorporated into any screening method.

Modelling of aerodynamical interaction of the wing and propellers of a distributed propulsion system

The paper describes a study of a distributed electric propulsion system impact on the aerodynamic performance of an aircraft wing. A semi-empirical method and CFD calculation method for prop blown wing influence on take-off and landing characteristic were considered and compared. Results of these methods are compared. Optimal location of a prop with leading edge of an airfoil in terms of maximize lift coefficient was obtained through the CFD method.

МОДЕЛЮВАННЯ ВЗАЄМОДІЇ КРИЛЕВОГО ПРОФІЛЮ З ДОЩОВИМ ПОТОКОМ

The subject of the study is the analysis of the multilateral impact of rainfall on the flight of a modern aircraft. When considering various factors of this impact, it was found that the main negative consequences of the interaction of the aircraft with the rain flow are the formation of a thin layer of water on its surface, which under the influence of drops and surface tension forces changes the configuration of the wing profile, causing loss of load-bearing properties and an increase in frontal aircraft resistance. The influence of rain flowing around the bearing surfaces can be reduced to taking into account changes in the characteristics of the surface and the flow of the airflow. The goal is to develop a model for the interaction of modern wing profiles with rain flow. The task is to determine the amount of water deposited on the surface of the wing profile, calculate the parameters of the water film formed on its surface, and as a result of this, change the tangential stress at the liquid-air interface. The semi-empirical calculation method used reveals a significant dependence of the amount of precipitated rain water on the surface of modern wing profiles on their geometry and the conditions of interaction with the stream of raindrops. The result of this work is the resulting model, which allows you to simulate the flow conditions around the wing profile in the rain stream and evaluate the relationship of rain intensity with the parameters of the water film that forms on the profile. Conclusions. An analysis of the features of the rain film flow over the surface of the wing profile and its effect on the parameters of the boundary layer shows the negative nature of the effect of rainfall on the aerodynamics of the aircraft. The results obtained allow us to judge the reliability of using the adopted model to calculate the effect of rain on the aerodynamic characteristics of wing profiles, and the possibility of using the results to determine the dependence of the aerodynamic characteristics of wing profiles on the conditions of rainfall molasses.

Процеси утворення позитивних іонів при взаємодії електронів з молекулами тиміну

The work is aimed to solve the key problems of modern biophysics related to the study of fundamental mechanisms of interaction of ionizing radiation on living cells and stability of biological systems to its influence. The obtained data and their generalizations create a basis for understanding the interaction mechanisms and stability of biological systems to its influence. Investigation is aimed on the obtaining the new priority data about the characteristics of the life important biological molecules, establishing the mechanisms and features of dissociative capture, excitation and ionization under the slow electrons; the study of the influence of intermolecular interactions on these processes and solution of some applications concerning the definition of physical stability of biomolecules in different states of aggregation. The AM1 method that was used in research is a semi-empirical method for the quantum calculation of molecular electronic structure in computational chemistry. It is based on the neglect of differential diatomic overlap integral approximation and investigates the processes of formation of positive ions, which are formed during the interaction of thymine molecules with slow electrons. Fragmentation model of thymine molecules under electron ipmpact is proposed. Six most likely bond breaks in the cyclic structure of thymine molecular ion are identified. The obtained results are in good agreement with experimental data.

Surface Modifications of the Biodegradable Magnesium Based Implants with Self-Assembled Monolayers Formed by T-BAG Method

In this paper, magnesium based materials (Mg and Mg-alloy (AZ91D)) were surface modified using various organic acids (carboxylic and phosphonic), in order to improve corrosion resistance and enhance theirs biocompatibility. Formations of surface layer were performed by tethering by aggregation and growth (T-BAG) method. Organization and bond mode of these layers were examined by Fourier transform infrared spectroscopy (FTIR). Additionally, semiempirical quantum molecular modeling calculation methods were used for getting insight into their structural and electronic properties, as also as corrosion resistance in the physiological solution (Hanks' solution). Corrosion resistance of modified materials were investigated by electrochemical impedance spectroscopy (EIS) in the physiological solution (Hanks' solution) and obtained results reveal a beneficial effect of the modification by forming organic acids self-assembled monolayer (SAM) on the corrosion properties of magnesium based materials, especially layers of octadecylphosphonic acid. The maximum corrosion inhibition efficiency of 87% for magnesium and of 93% for Mg-alloy (AZ91D) are achieved by the formation of octadecylphosphonic acid (ODPA) SAM.

A new technique for permeability calculation of core samples from unconventional gas reservoirs

Unconventional reservoirs and their outstanding characteristics have introduced a new field of research in reservoir engineering. The main challenge arises from the fact that in tight formations pore-throat size lays in the range of a few nanometers to a few dozens of nanometers, which makes the estimation of permeability a difficult task. When developing a permeability model for shale media, it is very important to accommodate for surface adsorption and transient flow effects, in addition to slippage effect and Knudsen diffusion, in order to achieve an accurate model. Prediction of fluid flow inside shale rock needs development of new models that take into account not only the diffusive flow but also the effect of high amount of gas adsorbed to the surface of the pores. In this work, we have proposed a new semi-empirical method for calculation of gas permeability inside tight formations. The method uses experimental data obtained from core plugs (canister data) and an analytical solution of continuity equation coupled with gas desorption in tight porous media. By matching the production data from core plugs, we have been able to calculate gas permeability by solving the analytical equation. We have been able to capture the effect of pore pressure on permeability by using production data at various core saturation pressures. We also compared our model with two previously proposed models. The results of this study show that the permeability calculated using our model is closer to experimental measurements of similar rock samples and comparable with other models.

Synthesis and characterization of a palladium(0) complex with cyclophosphazene bearing two diphenylphosphine ligands and application in Suzuki-Miyaura cross-coupling

This paper describes the synthesis of a cyclophosphazene-based diphenylphosphine ligand and a new Pd(0) complex. Infrared spectroscopy (ATR-IR), ESI+-MS, 31P, 1H and 13C NMR, Raman, WD-XRF, ICP-OES and TGA analysis show the coordination of two palladium atoms per unit of cyclophosphazene. A semiempirical calculation method was employed to find the lowest energy structure among the possible ones and Density Functional Theory (DFT) was used to optimize the found structure and obtain its bond angles, dihedral angles, bond lengths, atomic distances, and to calculate the vibrational spectrum (PBE/def2-TZVP(-f)). The new Pd complex showed activity in Suzuki-Miyaura cross-coupling reactions with halobenzenes and phenylboronic acid, tolerating different functional groups.

Atmospheric Cosmic-Ray Variation and Ambient Dose Equivalent Assessments Considering Ground Level Enhancement Thanks to Coupled Anisotropic Solar Cosmic Ray and Extensive Air Shower Modeling.

This work investigates the impact of Forbush decrease (FD) and ground-level enhancement (GLE) in the atmosphere, based on solar and galactic cosmic-ray models and the extensive air shower simulations. This approach gives the possibility to investigate both the dynamic behavior of neutron monitors (NM) (using response function) and the flight dose. The ambient dose equivalent during quiet solar activity and solar events (i.e., FDs and GLEs) were investigated for realistic flight plans issued from the Eurocontrol Demand Data Repository. The calculated ambient dose equivalents were compared with flight measurements in quiet solar conditions; comparisons are relevant and demonstrate the ability to estimate the dose level. The GLE model was validated for the GLEs 5 and 69 using the cosmic-ray variation recorded by NMs. The GLE model was applied to flight dose calculations. All of these results show that dose values vary drastically with the route path (latitude, longitude and altitude) and with the delay between the flight departure and the solar event occurrence. Doses induced by extreme GLE events were investigated specifically for London to New York flights, and resulting additional doses are a few hundred or 1,000 μSv, impacting significantly the annual effective dose. This highlights the importance of monitoring extreme solar events and using realistic semi-empirical and particle transport methods for reliable calculation of dose levels.