591 research outputs found

    Conformational search, structural analysis, vibrational properties, reactivity study and affinity towards DNA of the novel insecticide flonicamid

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    This work deals with the study of structural properties, vibrational analysis, and reactivity of the novel insecticide flonicamid. Eight different minimum energy conformers were found during a conformational search and subsequent geometry optimizations at different levels of theory. The analysis of the PES leads to eight zones of minimum energy due to the scan of selected dihedral angles, which agrees with the structure of the eight most stable conformers found in the conformational search. The vibrational analysis and a complete assignment of the vibrational modes were performed, evidencing a good correlation with the experimental reported data. Furthermore, to predict the reactivity of flonicamid, different descriptors were analyzed. Finally, results obtained from docking analysis suggested that due to the molecular interaction with a sequence of DNA, the possible carcinogenic effects of flonicamid and three of its most important metabolites must be evaluated experimentally.Fil: Corregidor, Pablo Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Zígolo, María Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Ottavianelli, Emilce Ethel. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Informática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin

    Elucidating the vibrational fingerprint of the flexible metal-organic framework MIL-53(Al) using a combined experimental/computational approach

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    In this work, mid-infrared (mid-IR), far-IR, and Raman spectra are presented for the distinct (meta)stable phases of the flexible metal-organic framework MIL-53(Al). Static density functional theory (DFT) simulations are performed, allowing for the identification of all IR-active modes, which is unprecedented in the low-frequency region. A unique vibrational fingerprint is revealed, resulting from aluminum-oxide backbone stretching modes, which can be used to clearly distinguish the IR spectra of the closed- and large-pore phases. Furthermore, molecular dynamics simulations based on a DFT description of the potential energy surface enable determination of the theoretical Raman spectrum of the closed-and large-pore phases for the first time. An excellent correspondence between theory and experiment is observed. Both the low-frequency IR and Raman spectra show major differences in vibrational modes between the closed-and large-pore phases, indicating changes in lattice dynamics between the two structures. In addition, several collective modes related to the breathing mechanism in MIL-53(Al) are identified. In particular, we rationalize the importance of the trampoline-like motion of the linker for the phase transition

    Vibrational Spectroscopies and Chemometry for Nondestructive Identification and Differentiation of Painting Binders

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    A comprehensive dataset of vibrational spectra of different natural organic binding media is presented and discussed. The binding media were applied on a glass substrate and analyzed after three months of natural ageing. The combination of Raman and FT-NIR spectroscopies allows for an improved identification of these materials as Raman technique is more informative about the skeletal vibrations, while FT-NIR spectroscopy is more sensitive to the substituents and polar groups. The experimental results are initially discussed in the framework of current spectral assignment. Then, multivariate analysis (PCA) is applied leading to differentiation among the samples. The two major principal components allow for a complete separation of the different classes of organic materials. Further differentiation within the same class is possible thanks to the secondary components. The loadings obtained from PCA are discussed on the basis of the spectral assignment leading to clear understanding of the physical basis of this differentiation process

    Visual and Chemosensory Pathways Associated With Male Courtship Decisions in Drosophila melanogaster

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    Successful mating in diverse animal species often depends on ritualistic sequences of spatially and temporally coordinated behavioral elements. Yet, the sensory cues and neural circuits that mediate optimal mating display patterns are largely unknown. The courtship ritual in Drosophila melanogaster consists of a well-studied sequence of behavioral elements — including orienting, chasing, tapping, singing, and licking — that are known to depend on several sensory modalities, including both vision and chemosensation. However, the specific sensory inputs utilized by males to direct the spatial and temporal transitions between different elements of the courtship ritual are not well understood. In this thesis, I therefore first develop a new computational tool to quantitatively characterize male courtship behaviors with a high spatial and temporal resolution. Subsequently, I use this tool, in conjunction with genetic and microscopy approaches to map the visual and chemosensory neural pathways that drive some of the patterned behavioral elements of the male courtship ritual. I demonstrate that whereas visual circuits are important for mediating both spatial and temporal components of male mating behaviors, chemosensory circuits are mostly required for enhancing the duration and intensity of courtship bouts. Further, I identify a male-specific axonal architecture present in subpopulations of foreleg chemosensory neurons which is important for helping to sustain mating behaviors. This thesis examines the inputs, processing centers, and neural architectures required for the proper organization of innate mating behaviors and should provide insight into understanding how animals transform sensory stimuli into complex behavioral outputs, which is a major goal in modern neuroscience

    Automatic Toll Collection Using OCR Technique

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    Toll Collection in India is a matter of concern as the toll checkpoints are hotbeds of corruption. The purpose of this project is to propose a technique where collection of tolls can be done electronically using image processing technique where we can detect the vehicle and thereby deduct the toll amount. Using this technique we can make an attempt to eradicate corruption from toll checkpoints in India. The current scenario is that the vehicle needs to slow down at the toll collection area in order to pay the amount which leads to traffic problem and sometimes the toll collector doesn�t collect the toll fee from the owner. So the proposed technique will maintain all the records of the toll collected as there is no physical cash involved in this technique

    A novel license plate character segmentation method for different types of vehicle license plates.

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    License plate character segmentation (LPCS) is a very important part of vehicle license plate recognition (LPR) system. The accuracy of LPR system widely depends on two parts; namely license plate detection (LPD) and LPCS. Different country has different types and shapes of LPs are available. Based on character position on LP, we can find two types of LPs over the world, single row (SR) and double rows (DR) LP. Most of the LPCS methods are generally used for SRLP. This paper proposed a novel LPCS method for SR and DR types of LPs. Experimental results shows the real-time effectiveness of our proposed method. The accuracy of our proposed LPCS method is 99.05% and the average computational time is 27ms which is higher than other existing methods

    Synthesis, spectral analysis and study of antimicrobial activity of 2,5-diformyl-1H-pyrrole bis(methan-1-yl-1-ylidene)dimalonohydrazone

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    AbstractWe have synthesized 2,5-diformyl-1H-pyrrole bis(methan-1-yl-1-ylidene)dimalonohydrazone (DPBMD) and characterized by elemental analysis, FT-IR, UV–Vis, Mass, 1H and 13C NMR spectroscopy. Theoretical calculations were performed by ab initio RHF and density functional theory (DFT)/B3LYP method, 6-31G(d,p) and 6-311++G(d,p) basis sets. The calculated scaled vibrational frequency values have been compared with experimental FT-IR spectrum. The calculated result shows excellent agreement between experimental and calculated frequencies at B3LYP method and 6-311++G(d,p) basis set. The thermodynamics properties, NBO, nonlinear optical properties and mulliken charges of DPBMD have also been analyzed. Involvement of nitrogen [N8/N18] and [N14/N24] lone pairs of electron with [π∗(C9–O10), π∗(C6–N7)/π∗(C16–N17), π∗(C19–O20)] and [(π∗(C12–O13)/π∗(C22–O23)] leads to an enormous stabilization of 84.6/84.6 and 64.1/64.1kcal/mol of the molecule. A combined experimental and theoretical stretching wavenumber symmetric (3003, 3332cm−1) and asymmetric (3276, 3398cm−1) analysis confirms free NH2 groups in DPBMD. The calculated first hyperpolarizability (β0=5.80×10−30esu) at B3LYP method and 6-311++G(d,p) basis sets indicates that DPBMD can be used as an attractive material for non-linear optical. The electronic descriptor analysis indicates that DPBMD is a good precursor for heterocyclic synthesis and as ligand for metal complex formation. The preliminary bioassay suggested that the DPBMD compound exhibits relatively good antibacterial and fungicidal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, and Aspergillus niger
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