Development and experimental investigation of a Quadrotor’s robust generalized dynamic inversion control system

Nonlinear Dynamics - The development of a two-loops Quadrotor’s robust generalized dynamic inversion (RGDI)-based control system is presented. The outer (position) loop utilizes PD position...     

Molecular Design Approach Managing Molecular Orbital Superposition for High Efficiency without Color Shift in Thermally Activated Delayed Fluorescent Organic Light-Emitting Diodes

Molecular design principles of thermally activated delayed fluorescent (TADF) emitters having a high quantum efficiency and a color tuning capability was investigated by synthesizing three TADF emitters with donors at different positions of a benzonitrile acceptor. The position rendering a large overlap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) enhances the quantum efficiency of the TADF emitter. Regarding the orbital overlap, donor attachments at 2- and 6-positions of the benzonitrile were more beneficial than 3- and 5-substitutions. Moreover, an additional attachment of a weak donor at the 4-position further increased the quantum efficiency without decreasing the emission energy. Therefore, the molecular design strategy of substituting strong donors at the positions allowing a large molecular orbital overlap and an extra weak donor is a good approach to achieve both high quantum efficiency and a slightly increased emission energy.     

Synthesis of nanomagnetic supported thiourea–copper(I) catalyst and its application in the synthesis of triazoles and benzamides

A novel nanomagnetic supported thiourea–copper(I) complex and inorganic–organic Takemoto‐like hybrid nanomagnetic catalyst was designed, and synthesized. The prepared naomagnetic catalyst was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, energy‐dispersive X‐ray analysis, transmission and scanning electron microscopies, thermogravimetry, nitrogen adsorption/desorption, zeta potential and vibrating sample magnetometry. Furthermore, the fabricated dual‐role inorganic–organic hybrid catalyst shows a striking and robust catalytic activity for the synthesis of triazoles and benzamides through click and coupling reactions, respectively, under mild and eco‐friendly reaction conditions.     

A metal-free visible light promoted three-component facile synthesis of 4-oxo-tetrahydroindoles in ethanol–water

A mild and efficient visible light–mediated one-pot multicomponent tandem approach to construct 4-oxo-tetrahydroindoles in ethanol–water medium at room temperature has been described. The characteristics of reported methodology are the utilization of visible light, an ideal source of energy to generate C C and C N bonds from commercially available substrates namely dimedone, phenacyl bromides, and amines. The presented protocol is highly compatible for developing 4-oxo-tetrahydroindole derivatives with improved selectivity and high yields. Moreover, metal-free synthesis, environmental friendly solvent, easy workup process, high atom economy, cost-effectiveness, short reaction time, and broad substratescope are the major advantages of reported protocol.     

Effects of Essential Oils of Elettaria cardamomum Grown in India and Guatemala on Gram-Negative Bacteria and Gastrointestinal Disorders

The present study examined the chemical composition and antimicrobial and gastrointestinal activity of the essential oils of Elettaria cardamomum (L.) Maton harvested in India (EC-I) and Guatemala (EC-G). Monoterpenes were present in higher concentration in EC-I (83.24%) than in EC-G (73.03%), whereas sesquiterpenes were present in a higher concentration in EC-G (18.35%) than in EC-I (9.27%). Minimum inhibitory concentrations (MICs) of 0.5 and 0.25 mg/mL were demonstrated against Pseudomonas aeruginosa in EC-G and EC-I, respectively, whereas MICs of 1 and 0.5 mg/mL were demonstrated against Escherichia coli in EC-G and EC-I, respectively. The treatment with control had the highest kill-time potential, whereas the treatment with oils had shorter kill-time. EC-I was observed to be more potent in the castor oil-induced diarrhea model than EC-G. At 100 and 200 mg/kg, P.O., EC-I exhibited 40% and 80% protection, respectively, and EC-G exhibited 20% and 60% protection, respectively, in mice, whereas loperamide (10 mg/kg, i.p., positive control) exhibited 100% protection. In the in vitro experiments, EC-I inhibited both carbachol (CCh, 1 µM) and high K⁺ (80 mM)-induced contractions at significantly lower concentrations than EC-G. Thus, EC-I significantly inhibited P. aeruginosa and E. coli and exhibited more potent antidiarrheal and antispasmodic effects than EC-G.     

Quinoline Carbonitriles as Novel Inhibitors for N80 Steel Corrosion in Oil-Well Acidizing: Experimental and Computational Insights

Russian Journal of Electrochemistry - Three quinoline derivatives as corrosion inhibitors for N80 steel 15% HCl solutions. Influence of the –H, –OCH3 groups and the introduction of...     

Synthesis and in vitro anti-Toxoplasma gondii activity of a new series of aryloxyacetophenone thiosemicarbazones

Molecular Diversity - A new series of aryloxyacetophenone thiosemicarbazones 4a–q have been synthesized as anti-Toxoplasma gondii agents. All compounds showed significant inhibitory activity...     

Ultrasensitive NOX Detection in Simulated Exhaled Air: Enhanced Sensing via Alumina Modification of In‐Situ Grown WO3 Nanoblocks

Seedless growth of vertically aligned nanostructures, which can induce smoother transport and minimize Ohmic contact between substrate and semiconductor, can be fabricated by in situ growth utilizing modified hydrothermal methods. Such devices can be useful in designing non‐invasive ultrasensitive hand‐held sensors for diagnostic identification of volatile organic compounds (VOCs) in exhaled air, offering pain‐free and easier detection of long‐term diseases such as asthma. In the present work, WO₃ nanoblocks, with a high surface area and porosity, have been grown directly over transparent conducting oxide to minimize Ohmic resistance, facilitating smoother electron transfer and enhanced current response. Further modification with porous alumina (γ‐Al₂O₃), by electrodeposition, resulted in the selective and ultrasensitive detection of NO_X in simulated exhaled air. Crystal phase purity of as‐fabricated pristine as well modified samples is validated with X‐ray diffraction analysis. Morphological and microstructural analyses reveal the successful deposition of porous alumina over the surface of WO₃. Improved surface area and porosity is presented by porous alumina in the modified WO₃ device, suggesting more active sites for the gas molecules to get adsorbed and diffuse through the pores. Oxygen vacancies, which are detrimental in the transport phenomenon in the presented sensors, have been studied using X‐ray photoelectron spectroscopic (XPS) analysis. Gas sensing studies have been performed by fabricating chemiresistor devices based on bare WO₃ and Al₂O₃‐modified WO₃. The higher sensitivity for NO_X gas in case of γ‐Al₂O₃‐modified WO₃ based devices, as compared to bare WO₃‐based devices, is attributed to the better surface area and charge transport kinetics. The presented device strategy offers crucial understanding in the design and development of non‐invasive, hand‐held devices for NO gas present in the human breath, with potential application in medical diagnostics.     

Catalytic activity of Fe(II) and Cu(II) PNP pincer complexes for Suzuki coupling reaction

Iron and copper PNP pincer complexes of the type [Fe(L)SO₄] and [Cu(L)OCOCH₃] are reported and represented as C‐1 and C‐2 catalyst. Both the complexes were synthesized using bis(diphenylphosphino)pyridine‐2,6‐diamine [L], and salts of ‘Fe’ and ‘Cu’ by direct coordination method. The as synthesized complexes were characterized using FTIR, UV–Vis, mass analysis and TGA. The effect of reaction time, catalyst load, solvent and base on the reaction between phenylboronic acid and para substituted bromobenzenes in the presence of the catalysts were investigated for evaluating the catalytic efficiency of the complexes. The results obtained highlight the enhanced C‐C coupling reactions with the use of 0.4 mol% of the catalyst C‐1 in 14 h and 0.6 mol% of C‐2 in 16 h respectively with Cs₂CO₃ base and ACN as solvent media. Of the two complexes reported, C‐1 with iron as catalytically active metal is more stable and active towards coupling which is reflected in its better coupling yields in lesser reaction time compared to copper bearing C‐2 complex.