PROBING AZULENE-WATER INTERACTIONS AND AZULENE AGGREGATION BY BROADBAND ROTATIONAL SPECTROSCOPY

Noncovalent interactions of aromatic complexes are highly significant in biological systems such as DNA, in materials science and in supramolecular chemistry. Gas phase studies of small aromatic complexes allow the determination of their preferred structural arrangements and of the relative contributions of various intermolecular forces to the interaction energy, laying the foundation for understanding the properties and interactions of larger systems. Azulene is one of the smallest aromatic hydrocarbons with a dipole moment. Here we present the investigation of azulene aggregation and its interactions with water using chirped-pulse Fourier transform microwave spectroscopy. We have observed one and two water molecules complexed with azulene, where water binds to azulene through an O-H$\cdots$$\pi$ hydrogen bond. Azulene dimer shows a stacked configuration where dispersion forces between the $\pi$ electronic densities are predominant. Experimental observations are compared with predictions by various theoretical methods to evaluate their performance

An FPGA-based Timing and Control System for the Dynamic Compression Sector

A field programmable gate array (FPGA) based timing and trigger control system has been developed for the Dynamic Compression Sector (DCS) user facility located at the Advanced Photon Source (APS) at Argonne National Laboratory. The DCS is a first-of-its-kind capability dedicated to dynamic compression science. All components of the DCS laser shock station - x-ray choppers, single-shot shutter, internal laser triggers, and shot diagnostics-must be synchronized with respect to the arrival of x-rays in the hutch. A field-programmable gate array (FPGA) synchronized to the APS storage ring radio frequency (RF) clock (352 MHz) generates trigger signals for each stage of the laser and x-ray shutter system with low jitter. The system is composed of a Zynq FPGA, a debug card, line drivers and power supply. The delay and offsets of trigger signals can be adjusted using a user-friendly graphical user interface (GUI) with high precision. The details of the system architecture, timing requirements, firmware, and software implementation along with the performance evaluation are presented in this paper. The system offers low timing jitter (15.5 ps r.m.s.) with respect to APS 352 MHz clock, suitable for the 50 ps r.m.s. x-ray bunch duration at the APS

Computational investigation of thallium interactions with functionalized multi-walled carbon nanotubes for electrochemical sensing applications

Thallium (Tl) is a heavy toxic element which can cause several health issues. WHO and EPA have set a maximum permissible limit for thallium in drinking water above which it is hazardous, so its determination in our environment becomes crucial. Multi-walled carbon nanotubes (MWCNTs) are preferred for use in thallium sensing due to their large surface area and high conductivity, which allow them to be readily functionalized to selective groups. Previous experimental results showed that Tl selectively interacted with the MWCNTs functionalized with 3-amino-1,2,4-triazole-5-thiol (T-MWCNTs) with a limit of detection of 1.29 μg L−1 and linear range 10–100 μg L−1 by using voltammetry under optimized conditions. In actual water samples, the electrochemical sensor fabricated with the above-mentioned functionalized MWCNTs nanocomposite demonstrated high reproducibility and recovery. Molecular recognition and the outcomes of chemical and biological processes are shaped by non-covalent interactions among molecules. It is essential to investigate how these interactions impact binding preferences to enhance our understanding of these events. Here, we examine the structures of complexes of Tl and T-MWCNTs using quantum chemical calculations. Our results show that the most favourable complex of Tl-T-MWCNTs involve strong interaction of Tl with the nitrogen lone pair and additional stabilising interaction provided by the oxygen lone pair of amide linkage of T-MWCNTs. Moreover, we observed that the thiol group within T-MWCNTs readily undergoes deprotonation due to its acidic nature. Non-covalent interactions among molecules influence chemical and biological processes and molecular recognition. To improve our knowledge of these events, it is important to explore the ways in which these interactions affect binding preferences The negative value of adsorption energy (−1.53 eV) of this structure suggested that the interaction process between Tl and T-MWCNTs is spontaneous

Fully Unsupervised Machine Translation Using Context-Aware Word Translation and Denoising Autoencoder

Learning machine translation by using only monolingual data sets is a complex task as there are many possible ways to connect or associate target sentences with source sentences. The monolingual word embeddings are linearly mapped on a common shared space through robust learning or adversarial training in an unsupervised way, but these learning techniques have fundamental limitations in translating sentences. In this paper, a simple yet effective method has been proposed for fully unsupervised machine translation that is based on cross-lingual sense to word embedding instead of cross-lingual word embedding and language model. We have utilized word sense disambiguation to incorporate the source language context in order to select the sense of a word more appropriately. A language model for considering target language context in lexical choices and denoising autoencoder for language insertion, deletion, and reordering are integrated. The proposed approach eliminates the problem of noisy target language context due to erroneous word translations. This work takes into account the challenge of homonyms and polysemous words in the case of morphologically rich languages. The experiments performed on English-Hindi and Hindi-English using different evaluation metrics show an improvement of +3 points in BLEU and METEOR-Hindi over the baseline system

Conformational Panorama of Cycloundecanone:A Rotational Spectroscopy Study

[Image: see text] The conformational landscape of the medium-size cyclic ketone cycloundecanone has been investigated using chirped-pulse Fourier transform microwave spectroscopy and computational calculations. Nine conformations were observed in the rotational spectrum and identified from the comparison of experimental and theoretical rotational constants as well as the observed and predicted types of rotational transitions. All singly substituted (13)C isotopologues were observed for the most abundant conformer, which allowed the determination of partial substitution and effective structures. The most abundant conformer dominates the rotational spectrum and is almost 40 times more abundant than the least abundant conformer. Conformational preferences are governed by the combination of transannular H···H and eclipsed HCCH interactions