Computer Calculations Research Articles

Formation and characterization of charge transfer complex between alectinib and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone: Application to development of microwell spectrophotometric method

Alectinib (ALC) is a novel highly selective anaplastic lymphoma kinase (ALK) inhibitor that is effective in the treatment of patients with advanced ALK-positive non-small cell lung cancer and lymphomas. This study, describes, for the first time, the formation of a charge transfer complex (CTC) between ALC with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The CTC was characterized using different spectrophotometric and computational techniques. UV–visible spectrophotometry ascertained the formation of the CTC in methanol via the formation of a new broad absorption band with a maximum absorption peak (λmax) at 505 nm. The molar absorptivity (ε) of the complex was 2.72 × 103 L mol−1 cm−1 and its band gap energy was 1.94 eV. The stoichiometric ratio of ALC:DDQ was found to be 1:1. The association constant of the complex was 9.6 × 102 L mol−1, and its standard free energy was −16.98 J mol−1. Computational calculations were conducted using different calculation tools. The computed geometrical parameters, specifically bond lengths, exhibited variations in the CTC compared to the individual reactants (ALC and DDQ). The Mulliken atomic charge analysis indicated increased values for DDQ (the acceptor) and decreased values for ALC (the donor) in the CTC, confirming the formation of a CTC. The reaction was employed as a basis for a novel microwell spectrophotometric method for the quantification of ALC in its bulk form, capsule content, and uniformity testing. This greenness and high throughput of the method was documented. The method represents a valuable tool for routine use in quality control laboratories for analysis of ALC's bulk form and capsules.

Influence of Temperature on Rotational Dynamics of 3B7D2HC-2-one Molecule in Non-polar, Polar, and Polar Aprotic Solvents.

Rotational dynamics of 3-(3H-2l4-benzo[c]isothiazol-2-yl)-7-(diethylamino)-2H-chromen-2-one (3B7D2HC-2-one) is studied using steady-state fluorescence depolarization and time-resolved fluorescence techniques in non-polar, polar and polar aprotic solvents by varying temperatures. Computational calculations are performed using Gaussian 09 software. Over the general solvatochromic method, an advanced thermochromic shift method is used to estimate dipole moments. Experiment rotational diffusion of 3B7D2HC-2-one in methanol indicates slow rotation over the other two solvents. Further, experiment rotational diffusion is analyzed using hydrodynamic and Quasi-hydrodynamic theories. The observed reorientation time follows the trend as predicted by quasi-hydrodynamic models.

A novel conceptual design approach for autonomous underwater helicopter based on multidisciplinary collaborative optimization

Autonomous underwater helicopters (AUHs) are complex electromechanical systems consisting of multiple interconnected sub-disciplines, posing a significant challenge for traditional sequential design strategies in managing their interactions. To address this challenge, a multidisciplinary collaborative optimization (MCO) strategy is proposed, integrating structural, hydrodynamic, and energy disciplines to enhance AUH cruising range. Additionally, a novel approximation model is introduced, combining the Logistic-Tent chaos sparrow search algorithm (LTC-SSA) with the backpropagation neural network (BPNN) algorithm. This method aims to replace costly computational fluid dynamics (CFD) and structural mechanics calculations, thus reducing AUH optimization costs. The laminate design of the composite pressure hull follows classic lamination theory (CLT) and the Tsai-Wu failure criterion. Results demonstrate that the multidisciplinary co-design strategy significantly reduces optimization time costs of AUH, from several months to several days. Furthermore, the proposed LTC-SSA-BPNN algorithm accurately evaluates sailing resistance and Tsai-Wu failure index, with maximum errors of 1.64% and 9.32% respectively. Additionally, the composite pressure shell achieves a 30.4% weight reduction and a 4.1% reduction in sailing resistance while maintaining structural stability. Moreover, the maximum cruising range increases by 34.4%. This strategy offers theoretical support for AUH conceptual design and promises performance enhancement in practical engineering applications.

A C3‐Symmetric Amino Organocatalyst for Asymmetric Synthesis of Warfarin and Analogues: Mechanistic Insight from ESI‐MS Spectrometry and Computational Calculations

AbstractA novel C3‐symmetric multi–amino catalyst was synthesized and evaluated in the asymmetric Michael addition to produce warfarin and its analogues. The multi–amino catalyst turned out to be efficient up to 1 % molar without the use of acidic additives providing the desired product in 82 % yield and maintaining good level of enantioselectivity. ESI‐MS experiments together with data supplied by theoretical models allowed us the understand the operating mechanism of the catalyst, clarifying the role of the amine functions and confirming the catalyst's multifunctionality. The presence of three active catalytic sites makes it easy its anchoring to silica as solid support for applications in heterogeneous phase catalysis.

Exploration of Choline Chloride Based Type II and Type III Deep Eutectic Solvents: A Computational and Experimental Approach

AbstractDeep eutectic solvents (DESs) of choline chloride with citric acid (CACC), Maleic acid (MACC) and Magnesium chloride hexahydrate (MAGCC) were synthesized in 1 : 1 molar ratio and investigated experimentally and computationally. For the computational study, density functional theory (DFT) calculation with B3LYP/6‐31 (+, +) G (d,p) level of theory for MACC and CACC and at B3LYP/SDD basis set for MAGCC was employed and the FT‐IR spectroscopy was used for experimental evaluation. For understanding the orientation of bonds and hydrogen bonding present in DESs geometrically optimized structures were used. Through frontier molecular orbital (FMO) theory and HOMO−LUMO values and various quantum chemical parameters, viz., ionization potential (IP), electron affinities (EA), electro negativity (χ), chemical potential (μ), global softness (σ) and hardness (η), electrophilicity index (ω) were calculated for all DESs. These computational values made it clear that MAGCC is the most stable among the three DESs due to the high value of global hardness (η) (3.291 eV) and HOMO−LUMO energy gap (Egap) (6.582 eV) and lowest value of softness (σ) (0.152 eV), CACC shows the moderate values (η=2.452, Egap=4.905 and σ=0.204 eV). While MACC is found to be the least stable and most reactive among three DESs with values of η, Egap and σ, 1.970, 3.940 and 0.254 eV, respectively. Furthermore, MESP analysis gives an idea about the electrophilic and nucleophilic surface region of DESs. This study will give valuable information for a better understanding of DESs and the applicability of computational calculations in the future.

Adsorption and Inhibition Mechanisms of New Pyrazole Derivatives for Carbon Steel Corrosion in Hydrochloric Acid Solutions Based on Experimental, Computational, and Theoretical Calculations.

The study aims to synthesize two green pyrazole compounds, N-((1H-pyrazol-1-yl)methyl)-4-nitroaniline (L4) and ethyl 5-methyl-1-(((4-nitrophenyl)amino)methyl)-1H-pyrazole-3-carboxylate (L6), and test their action as corrosion inhibitors for carbon steel (CS) in a 1 M HCl solution. Both chemical and electrochemical methods, namely, gravimetric measurements (WL), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS), were used to assess the efficiency of the investigated molecules. DFT calculations at B3LYP/6-31++G (d, p) and molecular dynamics simulation were used to carry out quantum chemical calculations in order to link their electronic characteristics with the findings of experiments. The organic products exhibited good anticorrosion ability, with maximum inhibition efficiencies (IE %) of 91.8 and 90.8% for 10-3 M L6 and L4, respectively. In accordance with PDP outcomes, L6 and L4 inhibitors act as mixed-type inhibitors. Assessment of the temperature influence evinces that both L4 and L6 are chemisorbed on CS. The adsorption of L4 and L6 on CS appears to follow the Langmuir isotherm. Scanning electron microscopy and UV-visible disclose the constitution of a barrier layer, limiting the accessibility of corrosive species to the CS surface. Theoretical studies were performed to support the results derived from experimental techniques (WL, PDP, and EIS).

Exploration of disodium methylenebis naphthalene sulfonatea as a novel depressant for the flotation separation of apatite from dolomite

To address the flotation separation problem between apatite and dolomite, DMNS (disodium methylenebis naphthalene sulfonate) was selected as a depressant in this research. Micro-flotation results showed NaOl exhibited good floatability for dolomite and apatite, with no significant difference in the floatability between these two minerals. The addition of DMNS completely depressed the floatability of dolomite but slightly affected the floatability of apatite. The artificial minerals mixture flotation ensured that DMNS achieved the separation between apatite and dolomite when the NaOl was used. The adsorption measurement illustrated adsorption amount of DMNS on dolomite surface was more than that of it on apatite surface, the Zeta potential results illustrated NaOl still adsorbed on the apatite surface but did not adsorbed on the dolomite surface after conditioning with DMNS. XPS analysis verified that no effective interaction occurred between DMNS and apatite surface, and DMNS chemically adsorbed on the dolomite surface by the interaction between –SO3H groups of DMNS and Ca2+/Mg2+ of the dolomite surface. First-principles calculations further ensured the higher adsorption energy of DMNS on the dolomite surface. The computational calculation also revealed that the interaction of DMNS with the dolomite surface was much stronger than that with the apatite surface.

Integrated Systems of a Solar Thermal Energy Driven Power Plant

Integrated Systems of a Solar Thermal Energy Driven Power Plant

Type Design of Continuous Stirred Tank Reactors (CSTRs) for Bath Bomb Lavender Production

One of the most widely used complimentary bath products is lavender bath bomb, which has a pleasant scent, a foamy feel, and a relaxing effect. This is a chance to expand the production of bath bombs. The manufacture of lavender bath bombs on a large scale (industry) can be done using a continuous stirred tank reactors (CSTRs). This research aims to design a reactor to react the raw materials of lavender bath bomb through mixing reaction. The method used is by conducting computational analysis and calculation of the reactor and its stirrer and mass balance as the basis for calculation using Microsoft Excel. According to the computation results, the examined reactor needs one stirrer with a power of 141 horsepower and a total volume of 7.2334 ft3 with a height of 27.1045 in. These computational and analytical results can describe the production system using the reactor as a learning tool.

Simultaneous identification and enantioseparation of ofloxacin and duloxetine without the single standard and computational calculation of their inclusion complexes.

Given the markedly different pharmacological activities between enantiomeric isomers, it is crucial to encourage the stereoselective determination of chiral drugs in the biological and pharmaceutical fields, and the combination of drugs makes this analysis more complicated and challenging. Herein, a capillary electrophoresis (CE) method for the enantioseparation of ofloxacin and duloxetine was established, enabling the simultaneous identification of four isomers in nonracemic mixtures with enantiomeric excess (ee%) values exceeding 5%. This was achieved through the integration of theoretical simulation and electron circular dichroism (ECD), all without reliance on individual standards. Molecular modeling explained and verified the migration time differences of these isomers in electrophoretic separation. Moreover, the correlation coefficients (R2 ) between the enantiomeric peak area differentials and ee% were both above 0.99. Recovery rates were quantified using bovine serum as the matrix, with results ranging from 93.32% to 101.03% (RSD = 0.030) and 92.69% to 100.52% (RSD = 0.028) for these two chiral drugs at an ee value of 23.1%, respectively.

A Simulation of Hydrazine Molecule’s Potential Energy Surface using Variational Quantum Eigensolver Algorithm

Quantum computing is a technology that utilizes the principles of quantum mechanics to perform complex computational processes. In this work, we use Qiskit Module from IBM to do quantum computational calculation using Variational Quantum Eigensolver (VQE) algorithm. VQE is a hybrid quantum-classical method that combines a quantum computer to measure energies and a classical computer to process the measurement results and update the parameters of the quantum computer. The purpose of VQE is to find the ground state energy of a chemical system. In the previous study, many of the VQE calculations have been done on simple molecules. So, in this study, we would like to use Hydrazine molecule as our object of VQE calculation. Furthermore, these results will be compared with the results from the classical calculation (MP2, CCSD(T), QCISD(T), and CASSCF) methods for testing the effectiveness of VQE using Unitary Coupled-Cluster Single and Double excitations (UCCSD) Ansatz. The quantum algorithm based on the UCCSD Ansatz led to a simplification of the algorithm by reducing the circuit depth. Then, the possibility to use active space approximation, can be used to reduce the quantum gates while trying to keep a good level of accuracy. In this study, we chose (2,2) and (4,4) active spaces. Based on the results, as we increase the size of the active space during the evaluation of the single-point energy, the estimated ground states obtained from the VQE algorithm yield nearly identical values. Conversely, in CASSCF calculations, expanding the active space introduces more energy corrections, thus making it more sensitive. Additionally, when examining potential energy surfaces, VQE demonstrates results that gradually align with CCSD(T) and QCISD(T) methods.

Dioxides transition metal monolayers: A first-principles calculations

We carried out first-principles computational calculations within the framework of density functional theory using the generalized gradient approximation along with the pseudo-potential method, in order to investigate the structural and electronic properties and the energy stability of ternary bidimensional alloys based on TMxV1-xO2 (TM = Cr, Mo, and W) for x = 0.0, 0.25, 0.50, 0.75, and 1.0 transition metal dioxides in the 1H structure (group #187). We found that the values of the lattice constants of the VO2, CrO2, MoO2 and WO2 monolayers are in good agreement with reported results and that the lattice constants of ternary alloys obey Vegard's law, with a maximum deviation of 0.362% (less than 1%) for the alloy W0.25V0.75O2. We found that the values calculated for formation energies are negatives, therefore the ternary monolayers are thermodynamically stable. In addition, we found that the Cr0.25V0.75O2 monolayer has a half-metallic character with a magnetic moment of 1.0 μB/cell, while the Mo0.25V0.75O2 and W0.25V0.75O2 monolayers exhibit a metallic behavior, with magnetic moments of 0.40 μB/cell and 1.16 μB/cell, respectively. These magnetic properties come from the hybridization between the V-d, Cr-d, and O-p orbitals. The TMxV1-xO2 (TM = Cr, Mo, and W, with x = 0.50 and 0.75) alloys exhibit a metallic behavior and do not exhibit magnetic properties. In particular, we carried out a study of the mechanical and dynamic stability of the Cr0.25V0.75O2 monolayer, in view of the fact that it is the system of greatest interest for applications in spintronics, through calculations of the elastic constants (a criterion for mechanical stability) and calculations of the vibrational properties of the lattice (phonons).

Silahlı İnsansız Hava Araçları İçin Namlu Mekanizması Analizi

Silahlı insansız hava araçlarının ve bu araçların gelecekteki farklı nesillerinin tasarım ve imalatına vizyonlu bir bakış açısı sunacak bu çalışmada; özel kuvvetler ve askeri taktik kullanım alanına uygun, mini insansız hava aracı konsept tasarımı yapılmıştır. Söz konusu araç; yatay, dikey ve ara açılarda atış yapabilen, hedefi hareket halinde takip eden, nişan alıp ateşleme yapabilen bir silah sistemine sahip taktik silahlı insansız hava aracıdır (SİHA). Tasarımın, silah sistemine ait matematiksel modellemesi karmaşık sayılar kullanılarak oluşturulmuştur. Yapılan matematiksel modelleme bilgisayar ortamına aktarılmıştır. Elde edilen parametrik veriler, bilgisayar ortamında yapılan simülasyonlar ile doğrulanmıştır.

Insights into the Adsorption of Cr(VI) on Activated Carbon Prepared from Walnut Shells: Combining Response Surface Methodology with Computational Calculation

Walnut shells were used to produce highly microporous activated carbon. The prepared activated walnut shells were found to be an efficient adsorbent for removing Cr(VI). The study used the response surface methodology to investigate four independent variables effect: Cr(VI) concentration, pH, AC-Ws dose, and temperature on the Cr(VI) removal efficiency, which was studied in the concentration range of 0.1 to 0.3 g/L, 4 to 10, 15 to 35 °C and 1 to 5 mg/L, respectively. Through experiments designed, the optimum conditions were determined to be 4, 0.23 g/L, 298 k, and 2 g/L, respectively. At these conditions, the efficiency of removal was found to be 93%. The thermodynamic study of the adsorption process showed a spontaneous and exothermic nature. The kinetic model that explains the experimental data is the pseudo-second-order model. Furthermore, the Langmuir isotherm model was estimated to be an excellent representation of the equilibrium data. Quantum calculations and NCI analyses were also performed to get more light on the adsorption mechanism of the Cr(VI) atom and its complex form on the prepared AC-Ws surface.

Design and Synthesis of Pyridine Bis-Hydrazone Metal Complexes of Co(II), Cu(II), and Hg(II): Spectral, Gaussian, Electrochemical, Biological, Drug-Likeness and Molecular Docking Investigations

A bis-hydrazone ligand (H2DS) was synthesized via condensation of pyridine-2,6-dicarbohydrazide with salicylaldehyde and utilized to prepare a new series of Cu(II), Co(II), and Hg(II) metal chelates. All the prepared chelates were investigated using various assistive spectroscopic and microscopic tools including (1H, 13C -NMR, IR, UV–visible, ESR, XRD, EDX, SEM, and MS), elemental analysis, magnetic susceptibility, and thermal (TG/DTA) analysis. Furthermore, all of the previous structural investigations weresupported with theoretical studies based on DFT theory where the molecular modeling of the geometrically optimized structures was constructed through Gaussian 09 software. Various energy components such as (EBinding, EHOMO, and ELUMO) besides MEP (Molecular electrostatic potential), bond parameters (bond angle and bond length), dipole moment, and molecular chemical parameters were derived from the computational calculations. Moreover, the redox behavior of Cu(II) with/without the ligand (H2DS) was investigated using cyclic voltammetry. This technique is utilized to study the effect of the chelating agent on the attitude of the copper species in the solution universe. The impact of interaction is proved by changing in the potential of reduction/oxidation peaks alongside evaluating of both kinetic and thermodynamic stability. The produced hydrazone and its chelates were screened for antimicrobial activities (Escherichia coli, Staphylococcus aureus, and Candida albicans), antioxidant activities (DPPH and TAC), and cell viability MTT assay. Finally, the degree ofefficiency of the binding that occurs between the different protein receptors and the ligandwas estimated by molecular docking where the results showed a strong relationship with the biological investigations.

Nominal wake field of a ship with moonpool

ABSTRACT To investigate the influence of a moonpool on the nominal wake field of a ship during calm water navigation, computational fluid dynamics calculations are performed using the STAR-CCM + software. The analysis found that the influence of boundary layer separation in the moonpool causes the hull boundary layer thicker, which reduces the average axial velocity of the propeller behind the moonpool and enhances the wake. The uniformity of the axial velocity distribution at the propeller disc is also reduced, worsening the uniformity of the wake field. In addition, the wake field characteristics of rear propellers change periodically with the fluctuation of moonpool. As a result the propeller bearing force and vibration characteristics change periodically with not only blade frequency and multiple blade frequency, but also the fluctuation of moonpool. These phenomena make the performance of propellers on ships with moonpool different from that of normal ships.

Surrogate-Based Uncertainty Analysis for Groundwater Contaminant Transport in a Chromium Residue Site Located in Southern China

Numerical modeling is widely acknowledged as a highly precise method for understanding the dynamics of contaminant transport in groundwater. However, due to the intricate characteristics of environmental systems and the lack of accurate information, the results are susceptible to a significant degree of uncertainty. Numerical models must explicitly consider related uncertainties in parameters to facilitate robust decision-making. In a Chromium Residue Site located in southern China (the study area), this study employed Monte Carlo simulation to assess the impact of variability in key parameters uncertainty on the simulation outcomes. Variogram analysis of response surface (VARS), global sensitivity analysis, and an XGBoost (version 2.0.0)-based surrogate model was employed to overcome the substantial computational cost of Monte Carlo simulation. The results of numerical simulation indicate that the contaminant is spreading downstream towards the northern boundary of contaminated site near Lianshui River, threatening water quality. Furthermore, migration patterns are complex due to both downstream convection and upstream diffusion. Sensitivity analysis identified hydraulic conductivity, recharge rate, and porosity as the most influential model parameters, selected as key parameters. Moreover, uncertainty analysis indicated that the variability in key parameters has a minimal impact on the simulation outcomes at monitoring wells near the contaminant source. In contrast, at wells positioned a considerable distance from the contaminant source, the variability in key parameters significantly influences the simulation outcomes. The surrogate model markedly mitigated computational workload and calculation time, while demonstrating superior precision and effectively capture the non-linear correlations between input and output of the simulation model.

The oxidation of d‐galactose into mucic acid (galactaric acid): experimental and computational insights towards a bio‐based platform chemical

AbstractAldaric acids are becoming valuable platform chemicals in bioeconomy and circular economy approaches. Among them, mucic acid (meso‐galactaric acid) is gaining industrial attention as a bio‐based precursor of adipic acid found in polyamides, and of 2,5‐furan dicarboxylic acid, a valuable substitute for terephthalic acid in polyesters. A combination of detailed experimental protocols and conditions with DFT computational calculations for the synthesis of mucic acid from galactose are herein described. The product is obtained by reaction with diluted aqueous nitric acid as the oxidizing agent and the reaction medium. Optimized reaction conditions require 5 M nitric acid, 95 °C, galactose/HNO3 molar ratio 1 : 9, 100 g/L galactose concentration in the reaction medium. Computational calculations suggest that the oxidation mechanism may involve a contextual oxygen protonation and nitrate nucleophilic attack, leading to the oxidized product. The proposed mechanism requires a stoichiometry of 6 moles of nitric acid per galactose mole, albeit both experimental and computational data evidence that proton excess may be necessary to start the reaction. The reported study gives useful insights for the production of galactaric acid.

Eu(OTf)3‐Catalyzed Formal Dipolar [4π+2σ] Cycloaddition of Bicyclo‐[1.1.0]butanes with Nitrones: Access to Polysubstituted 2‐Oxa‐3‐azabicyclo[3.1.1]heptanes

AbstractHerein, we have synthesized multifunctionalized 2‐oxa‐3‐azabicyclo[3.1.1]heptanes, which are considered potential bioisosteres for meta‐substituted arenes, through Eu(OTf)3‐catalyzed formal dipolar [4π+2σ] cycloaddition of bicyclo[1.1.0]butanes with nitrones. This methodology represents the initial instance of fabricating bicyclo[3.1.1]heptanes adorned with multiple heteroatoms. The protocol exhibits both mild reaction conditions and a good tolerance for various functional groups. Computational density functional theory calculations support that the reaction mechanism likely involves a nucleophilic addition of nitrones to bicyclo[1.1.0]butanes, succeeded by an intramolecular cyclization. The synthetic utility of this novel protocol has been demonstrated in the concise synthesis of the analogue of Rupatadine.

Eu(OTf)3 -Catalyzed Formal Dipolar [4π+2σ] Cycloaddition of Bicyclo-[1.1.0]butanes with Nitrones: Access to Polysubstituted 2-Oxa-3-azabicyclo[3.1.1]heptanes.

Herein, we have synthesized multifunctionalized 2-oxa-3-azabicyclo[3.1.1]heptanes, which are considered potential bioisosteres for meta-substituted arenes, through Eu(OTf)3 -catalyzed formal dipolar [4π+2σ] cycloaddition of bicyclo[1.1.0]butanes with nitrones. This methodology represents the initial instance of fabricating bicyclo[3.1.1]heptanes adorned with multiple heteroatoms. The protocol exhibits both mild reaction conditions and a good tolerance for various functional groups. Computational density functional theory calculations support that the reaction mechanism likely involves a nucleophilic addition of nitrones to bicyclo[1.1.0]butanes, succeeded by an intramolecular cyclization. The synthetic utility of this novel protocol has been demonstrated in the concise synthesis of the analogue of Rupatadine.