The continuous global production of polyurethane (PU) and its environmental persistence generate negative impacts on ecosystems, driving the search for sustainable handling solutions, specifically the use of enzymes. Therefore, this study seeks to elucidate the understanding of the enzymatic degradation mechanism of polyurethanase esterases A and B (PueA and PueB) applied to PU-MDI (methylene diphenyl diisocyanate). In this sense, previously built structures were used and dockings were carried out for the PueA and PueB complexes. The results indicate binding scores of -10.743 and -9.587 kcal mol-1 for PueA and PueB, respectively. Furthermore, the complexes were then subjected to molecular dynamics simulations (MD) for 500 ns in triplicate, showing a good interaction between the enzymes and the PU-MDI. Finally, a QM/MM (quantum mechanics/molecular mechanics) simulation, starting with an adequate snapshot from classical MD was carried out, and a relaxed scan was performed to obtain the occurrence coordinates, followed by umbrella sampling to obtain the free energy profile of the systems. The results indicate that the PueA and PueB reaction mechanisms occur in two steps, with determining energy barriers of 11.95 and 15.10 kcal mol-1, respectively, indicating that these enzymes may be used to degrade PU. PU (PU ecosystems solutions Therefore PUMDI MDI methylene diisocyanate. diisocyanate . diisocyanate) sense 10.743 10743 10 743 -10.74 9.587 9587 9 587 -9.58 mol1 mol 1 mol- respectively Furthermore (MD 50 triplicate PUMDI. MDI. Finally QMMM QM MM quantum mechanicsmolecular mechanics simulation coordinates systems steps 1195 11 95 11.9 1510 15 15.1 mol1, 1, 10.74 1074 74 -10.7 9.58 958 58 -9.5 5 119 11. 151 15. 10.7 107 7 -10. 9.5 -9. 10. -10 9. -9 -1 -

Abstract U2 and U4 were successfully synthesized from C7H6N2 N-alkylation (general and useful route to quaternary ammonium salts NH4Cl from tertiary amines) with alkyl bromides. The products were further alkylated to the corresponding ILs: U5 and U7. All the synthesized compounds were characterized by spectroscopic techniques, and their compositions were established through elemental analysis. The synthesized compounds were investigated as inhibitors for MS corrosion, using 1 M HCl as a model solution. WL experiments, surface analysis, quantum chemical calculations and MD simulation methods were used for evaluating the inhibitors anticorrosion properties. The results showed that ILs possessed remarkable inhibition properties under the studied conditions. U5 displayed the highest IE of 95.22%, at 200 ppm. ILs corrosion IE(%) was ascribed to their adsorption onto the MS surfaces, which followed the Langmuir’s isotherm. SEM revealed the formation of a barrier film by the inhibitors on the MS surface. Finally, the experimental results were corroborated by theoretical quantum chemical calculations and MD simulation studies. The studied inhibitor molecules interaction energies with the Fe surface followed the order U5 > U7 > U2 > U4, which is consistent with the experimental data.

ABSTRACT The use of mechanistic plant growth models relies on the availability of high-quality inputs to reduce uncertainty in estimates. Measurements of photosynthetically active radiation inside a protected environment are either more expensive to obtain or dependent on assumptions regarding external measurements. This study aimed to reduce the influence of uncertainty in the measurements of low-cost lux meters by using a data assimilation strategy. We first determined, by simulation, the impact of different sensors on the estimates. We then used the Ensemble Kalman Filter to assimilate artificial observations of tomato growth in the Reduced-State Tomgro model, in simulations for which the solar radiation inputs were obtained from a low-cost lux meter. We compared the assimilated estimates to the simulations that used solar radiation obtained with a scientific-grade quantum sensor. For periods of larger radiation intensity, in which the differences in measurements from both instruments are larger, assimilation of observations with low errors lead to estimates that are closer to the ones obtained by scientific grade sensors. These results suggest that low-cost sensors could be used to obtain inputs for growth models in protected environments, provided there are also imperfect observations of the state. highquality high quality lowcost cost strategy determined simulation ReducedState Reduced State model meter scientificgrade sensor intensity environments state

Inspired by the one-hundredth anniversary of the seminal works of Stern and Gerlach, our contribution is a proposal of how to use their famous experiment in a more contemporary perspective. Our main idea is to re-cast the experiment in the modern language of prepare-and-measure scenarios. By doing so, it is possible to connect geometric and algebraic aspects of the space of states with the physical space. We also discuss possible simulations of the SG experiment as well as some experimental properties of the experiment revealed at the statistical level. Merging a more modern perspective with a paradigmatic experiment, we hope this paper can serve as an entry door for quantum information theory and the. onehundredth one hundredth Gerlach recast re cast prepareandmeasure prepare measure scenarios so level

We provide a pedagogical calculation of the first two spacing distribution for a spin-1/2 XX chain in the presence of an external magnetic field. The results obtained from analytical expressions are compared with those from extensive quantum Monte Carlo simulations. The results obtained for the spacing distributions are used to describe the magnetic behavior of the system and contrasted with the standard analysis based on quantities such as the average energy, magnetization, and susceptibility. Finally, the equivalence between the analytical expressions for the spacing distributions provided by the second quantization formalism and those from the inter-particle distribution method is illustrated. As shown, the spacing distributions can be used as pedagogical examples of the use of the second quantization formalism in introductory courses of quantum statistical mechanics. Additionally, these distributions can be calculated easily from quantum Monte Carlo simulation and, therefore, can be used to illustrate this numerical method. spin1/2 spin12 spin 1/2 1 2 spin-1/ field simulations energy magnetization susceptibility Finally interparticle inter particle illustrated shown mechanics Additionally therefore spin1 spin1/ 12 1/ spin-1 spin-

At the 20th century dawn, the understanding of matter on a microscopic scale broke the Classical Physics barriers, giving birth to what we know today as Quantum Physics. The concepts of physical reality needed to be rediscussed, considering the strange dual object on which Quantum Physics was being built and a new structuring formalism needed to be developed. The present work reports the development of a didactic sequence that aims to teach the fundamentals of Quantum Physics in High School and Higher Education. The approach intends to offers means to avoid the nebulous notion of “wave-particle duality”, avoiding the pitfalls created by analogies with classical objects that obscure the understanding of the concept of a quantum object. The approach is developed in multimedia language organized around experiments shown in short videos, images, animations and computational simulations. Teaching by investigation was given, encouraging students to observe and analyze the phenomena and facts presented in an investigative way. For future application, a pilot test was elaborated using the participanty observation of teachers and questionary answered by the students, with a view to obtaining a first evaluation of the didactic sequence. th dawn barriers rediscussed Education waveparticle wave particle duality, duality , duality” videos images simulations given way application

No início do século XX, a compreensão da matéria em escala microscópica demandou romper com paradigmas da Física Clássica, dando origem ao que conhecemos hoje como Física Quântica. Os conceitos de realidade física precisaram ser rediscutidos, considerando o estranho objeto dual sobre o qual a Física Quântica estava sendo erguida e um novo formalismo estruturante precisou ser desenvolvido. O presente trabalho relata o desenvolvimento de uma sequência didática que visa ensinar os fundamentos da Física Quântica no Ensino Médio e Superior. A abordagem utilizada oferece meios para contornar a turva noção de “dualidade onda-partícula”, evitando as armadilhas criadas pelas analogias com os objetos clássicos que obscurecem a compreensão do conceito de objeto quântico. A abordagem é desenvolvida na linguagem multimídia e organizada em torno de experimentos exibidos em vídeos de curta duração, imagens, animações e simulações computacionais. O ensino por investigação foi empregado, estimulando os alunos a observar e analisar de forma investigativa os fenômenos e fatos apresentados. Para aplicação futura, um teste piloto foi elaborado utilizando da observação participativa dos professores e de questionário respondido pelos alunos, com vistas a auferir uma primeira avaliação da sequência didática. XX Clássica rediscutidos desenvolvido Superior dualidade ondapartícula, ondapartícula onda partícula , onda-partícula” quântico duração imagens computacionais empregado apresentados futura onda-partícula

Abstract In this work the self-assembling of InAs quantum dots (QDs) within asymmetric barriers of (Al)GaAs is studied via reflection high energy electron diffraction (RHEED). A comparative study between the AlGaAs/InAs/GaAs interfaces and its mirror-like heterostructure GaAs/InAs/AlGaAs showed significant differences in the self-assembling and capping of the QDs. The critical thickness of InAs QDs was proven to be larger when it is grown on AlGaAs alloys, compared with the deposition on GaAs layers. This change is explained by the reduced mobility of In atoms on the Al-containing surfaces, for which the QDs density is increased. Through the in-situ analysis of diffusion parameters, it is concluded that the mobility of In atoms decreases the mass transport of 2D and 3D precursors that conduces to the self-assembling of the QDs nanoislands, modifying the rate at which the QDs are formed. Further, during the first stages of QDs capping it is observed that the III-V materials intermixing plays a predominant role. The nanoislands are less affected when are covered by AlGaAs in comparison with the GaAs capping, preserving the QDs morphology and avoiding materials alloying. By following the RHEED intensity behavior during the QDs capping, a model was proposed to obtain quantitative parameters for the smoothing process. High-resolution x-ray diffraction (HRXRD) measurements show the composition of sharp interfaces for the AlGaAs/InAs/GaAs heterostructure. Lastly, numerical simulations were performed to evaluate the strain changes using the experimental information as input data.

This study is carried out to find novel active drug candidates which can effectively bind to key residues of main protease (Mpro) of SARS-CoV-2. We performed molecular docking of fifty-seven (57) ligands from two classes: vanillylacetone and its derivatives and beta-hydroxy ketone derivatives against Mpro of SARS-CoV-2. We also docked three antiviral drugs as reference/benchmark drugs including remdesivir (RDV), chloroquine (CQ), and hydroxychloroquine (HCQ) against Mpro for comparison of inhibition tendencies of selected ligands. Binding energies of our reference drugs are as: CQ = -5.1 kcal mol-1 (with predicted inhibition constant (Ki pred) = 177 μmol), HCQ = -5.7 kcal mol-1 (Ki pred = 64.07 μmol) and RDV -6.3 kcal mol-1 (Ki pred = 13.95 μmol). We got remarkable results for our docked ligands as 79% of total ligands indicated binding energies better than CQ, 39 % better than both HCQ and CQ, and 19 % better than all reference drugs. More interestingly interaction analysis of eight best-docked ligands showed that they interacted with desired key residues of Mpro. We further selected the four best-docked ligands L1 = -6.6 kcal mol-1 (Ki pred =13.95 μmol), L6 = -7.0 kcal mol-1 (Ki pred = 7.08 μmol), L34 = -6.0 kcal mol-1 (Ki pred = 38.54 μmol), and L50 = -6.6 kcal mol-1 (Ki pred =13.95 umol) for further analysis by quantum chemical study, molecular dynamic (MD) simulations and ADMET analysis. We have also carried out MD-simulations of six more docked ligand L2, L14, L20, L36, L46 and L48 some of which were showing weak binding affinities and some average binding affinities to check their simulation behavior. Their RMSD, RMSF and binding free energy results were also quite satisfying. We believe the current investigation will evoke the scientific community and highlights the potential of selected compounds for potential use as antiviral compounds against Mpro of SARS-CoV-2.

O presente estudo objetivou analisar os dados de simulações de dois algoritmos quânticos diferentes: Algoritmo de Deutsch e a Transformada de Fourier Quântica. Para tal abordagem foi utilizado o framework Qiskit na realização das simulações dos algoritmos anteriormente apresentados. Tais simulações se deram na máquina local (computador clássico) e nos chips quânticos da International Business Machines (IBM) via nuvem. Na máquina local, os resultados obtidos são os previstos pela teoria. Nos protótipos da IBM, no entanto, pequenas flutuações de erro puderam ser observadas. Todavia, os estados quânticos esperados foram obtidos com ótima probabilidade. Nossos resultados mostram que os computadores quânticos utilizados são robustos para os algoritmos estudados, sendo essa uma maneira bastante intuitiva para o ensino dos conceito de informação e computação quântica para o estudantes do ciclo profissional (técnico) da graduação.

The present study aimed to analyze the simulation data of two different quantum algorithms: Deutsch Algorithm and the Quantum Fourier Transform. In order to execute this, has been used the Qiskit framework to implement the afore mentioned algotihms. Such simulations took place on local machine (classic computer) and on the quantum chips of International Business Machines (IBM) via cloud. On the local machine the results obtained are those predicted by the theory. In IBM prototypes, small error fluctuations have been observed. However, the expected states were obtained with high probability. Our results show that the quantum computers are robust to the studied algorithms, been this an intuitive way to teach the concepts of quantum information and computation to students in the professional (techinical) level of graduation.

The non-toxic anticorrosion properties of nicotinamide have been studied on aluminum in an acidic medium. The techniques included weight loss method, electrochemical measurements, quantum chemical calculations, Monte Carlo simulation, infra-red spectroscopy and scanning electron microscopy. This study gathers information about the inhibitor molecule adsorption onto the surface of metal specimens. Thermodynamic parameters were utilized to predict the adsorption mechanism. The dependence of corrosion inhibition efficiency on various parameters was examined, and it was seen that the increase in the inhibitor concentration and in temperature led to an increase in the inhibition efficiency. The dipole moment and E HOMO-E LUMO influenced the inhibition efficiency, which was observed by quantum chemical studies.

We propose the teaching of wave-particle duality mediated by a software called Virtual Mach-Zehnder Interferometer, developed by our research group. We introduce the Dirac’s formalism contextualized on the Mach-Zehnder Interferometer, constructing explicitly the operators that represent the action of each device on the interferometer, calculating probability amplitudes on screens. Wave-particle complementarity is explored both in the qualitative and quantitative perspective, using computational simulations provided by the software. By studying concepts such as visibility, predictability and distinguishability, we explore the intermediate interference patterns aiming to expand what has not traditionally been found in textbooks and most courses. With the purpose of illustrating the application of the software in the classroom, the paper presents some didactical situations experienced by students of a physics teacher-training course during a quantum physics class, discussing students’ discursive interactions. The didactical approach to quantum interference phenomena carried out with the software, whether qualitative or quantitative, can promote rich and interesting discussions among students, exploring recent topics of quantum physics and allowing them to have a deeper and articulated understanding of the theory.

The present study aimed to evaluate the inhibition effect of an organic compound, namely, (E)-N'-(2-hydroxybenzylidene)isonicotinohydrazide (BIH), for carbon steel corrosion in a 1.0 M HCl solution, by using weight loss (WL), potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Results show that BIH is a good inhibitor, and the percentage of inhibition efficiency increases on its higher concentrations. The maximum inhibition efficiency of 94% was obtained at 5×10-3 M. Polarization studies revealed that the BIH compound acts as a mixed type inhibitor. EIS showed that increasing the concentration of the inhibitor led to an increase in the charge transfer resistance and a decrease in the double layer capacitance. It was found that the adsorption of this compound obeyed the Langmuir adsorption isotherm. The associated activation energies and thermodynamic parameters of the adsorption process were evaluated and discussed. The temperature effect was studied in the range from 303 to 333 K. In addition, quantum chemical calculations based on the density function theory (DFT) and Monte Carlo simulations were done to support the experimental results.

ABSTRACT Aqueous amine solutions are benchmark solvents for CO2 capture and their operational drawbacks are well-known. In order to overcome these problems, the support of amines on solid materials appears as an option for CO2 capture. Cellulose is a versatile and low-cost material that can be used as a support. This study reports chemical modification of cellulose fibers extracted from rice husk with different amines and their potential for CO2 capture. The obtained compounds were characterized by different techniques. The CO2 sorption capacity was gravimetrically assessed in a Magnetic Suspension Balance. Quantum mechanical simulations and experimental results revealed that -NH- and -NH2 represent major working sites of the employed compounds. The best result for CO2 sorption was attained for the amine-modified cellulose CL-D-400 with a sorption capacity of 409 µmol CO2/g at 1 bar and 1091 µmol CO2/g at 10 bar with amine concentrations as low as 2 × 10- 6 mol/mg.

One of the ways to improve and accelerate osseointegration of a surgical implant with bone is application of biocompatible coatings, in particular, hydroxyapatite (HAp). Since the cases of delamination of the coating take place in dental practice, it is very important to estimate the adhesive strength of HAp with the implant. A measure of the coating-to-substrate bond strength is the energy of this bond. In this research, quantum chemistry is used to calculate the binding energy of functional groups (anions) of hydroxyapatite and titanium 2+, which is a standard implant material. First, using Density Functional Theory with Becke three-parameter Lee-Yang-Parr hybrid exchange-correlation functional, the lowest potential energy surface is calculated. Then, by ab initio molecular dynamics, the reaction path, the reaction products, frequencies of oscillations, the activation energies and binding energies between various combinations of component anions of HAp and Ti(II) are calculated.

Abstract The greatest obstacle in simulating processes involving essential oils is the small number of thermo-physical properties and experimental data available in the literature. In this work, thermodynamic models are investigated in order to predict such properties, which are requisites for the modelling and simulation of the Eucalyptus essential oil batch distillation processes. A group contribution method was used to predict the vapor pressure (CSGC-PVR) when experimental data were unavailable. Regarding the activity coefficients, a fully predictive model based on quantum calculations (COSMO-SAC) is used. Moreover, this work also uses those predicted properties in a dynamic model, capable of describing the fractionation process by batch distillation. The simulations were performed in the equation-oriented simulator EMSO to demonstrate the feasibility of the proposed method. The proposed method suggests a simulated recovery of a 98.89% eucalyptol fraction from E. globulus and a 98.53% citronellal fraction from E. citriodora.