The present work evaluates the water oxidation catalytic activity of a Mn-based metal–organic framework (MOF), which we envisioned to reduce the oxygen evolution reaction (OER) overpotential because ...of its high electrical conductivity, facilitated by solvent-encapsulated structural features. The presence of Mn centers induces interesting magnetic features in the MOF, which exhibits impressive cryogenic magnetic refrigeration with a ΔS M value of 29.94 J kg–1 K–1 for a field change of ΔH = 5T at 2.3 K. To the best of our knowledge, the ΔS M value of the current system ranked the highest position among the published examples. The crystal structure aligns perfectly with the thematic expectations and features as many as ten metal-coordinated water molecules, forming an extensive web of a hydrogen-bonded network while facing toward the porous channel filled with another set of much-anticipated entrapped lattice water molecules. Such structural features are expected to manifest high proton conductivity, and detailed investigation indeed yields the best value for the system at 1.57 × 10–4 S/cm at 95% humidity and 85 °C. In order to evaluate the thematic notion of a one-to-one relationship between OER and improved electrical conductivity, extensive electrocatalytic water splitting (WS) investigations were carried out. The final results show highly encouraging WS ability of the Mn-MOF, showing the electrocatalytic surface area value of the active species as 0.0686 F/g with a turnover frequency value of 0.043 (mol. O2) (mol. Mn-MOF)−1 s–1. Another fascinating aspect of the current communication is the excellent synergy observed between the experimental WS outcomes and the corresponding theoretical data calculated using density functional theory (DFT). Consequently, a plausible mechanism of the overall OER and the role of the Mn-MOF as a water oxidation catalyst, along with the importance of water molecules, have also been derived from the theoretical calculations using DFT.
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IJS, KILJ, NUK, PNG, UL, UM
The synthesis of nitrogen-doped carbon dots (N@CDs) was accomplished by a hydrothermal process using meta- phenylenediamine as a source of carbon and nitrogen. As prepared N@CDs exhibited bright blue ...color fluorescence emission (λex = 340 nm and λem = 420 nm) with a quantum yield of 12%. Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were eradicated by N@CDs with a minimum inhibition concentration (MIC) of 1 and 0.75 mg/mL, respectively. The N@CDs were also proven as nanovesicles for drug molecules where the drug release displayed a sustained time-dependent profile at the physiological condition. The release of ciprofloxacin as a model drug was governed by the Korsmeyer-Peppas model, indicating ∼60% of its release from the N@CD conjugated drug system at the physiological pH. Selective analysis of trinitrophenol (TNP), a popular explosive, was achieved by fluorescence quenching of N@CDs, compared favorably with other nitrophenols. An estimated detection limit of TNP was 2.45 μM with a linear response spanning from 1 to 75 μM.
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•Morphological and biochemical parameter study of 15 lablab purpureus genotypes.•Antioxidant activity study showed highest IC50 value of 27.36 µg/mL.•HPLC depicted presence of trans-cinnamic acid and ...p-coumaric acid in most genotypes.•GC–MS identified 58 volatile compounds with 4 having important biological properties.
Morphological parameters study, phytochemical analysis including volatile compounds profiling, and antioxidant activity studies of fifteen phenotypically distinct genotypes of Lablab purpureus L. were carried out. It revealed wide variation in morphological parameters among the genotypes. Biochemically, genotype DCP 11 possessed the highest amounts of protein (32.33±0.50 g/100 g), phenol (3.77±0.12 g/100 g) and flavonoids (8.32±0.05 mg/100 g) as well as exhibited the highest antioxidant activity (IC50 value 27.36±0.61 µg/mL), and DCP 12 had the highest iron (15.24±0.10 mg/100 g) and zinc (5.54±0.04 mg/100 g) and lowest tannin (0.59±0.02 g/100 g) content. High performance liquid chromatography (HPLC) analysis identified ten phenolic constituents of which trans-cinnamic acid and p-coumaric acid were present in thirteen genotypes. Out of fifty-eight volatile compounds detected by gas chromatography-mass spectrometry (GC–MS) analysis, three compounds exhibited interesting biological activities like pheromone activity, sleep-inducing activity, signaling activity, neuroactive and analgesic activity, and one used as component of cosmetic products.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
494.
Voronoi game on graphs Bandyapadhyay, Sayan; Banik, Aritra; Das, Sandip ...
Theoretical computer science,
2015, Volume:
562
Journal Article
Peer reviewed
Open access
Voronoi game is a geometric model of competitive facility location problem played between two players. Users are generally modeled as points uniformly distributed on a given underlying space. Each ...player chooses a set of points in the underlying space to place their facilities. Each user avails service from its nearest facility. Service zone of a facility consists of the set of users which are closer to it than any other facility. Payoff of each player is defined by the quantity of users served by all of its facilities. The objective of each player is to maximize their respective payoff. In this paper we consider the two player Voronoi game where the underlying space is a road network modeled by a graph. In this framework we consider the problem of finding k optimal facility locations of Player 2 given any placement of m facilities by Player 1. Our main result is a dynamic programming based polynomial time algorithm for this problem on tree network. On the other hand, we show that the problem is strongly NP-complete for graphs. This proves that finding a winning strategy of P2 is NP-complete. Consequently, we design a 1−1e factor approximation algorithm, where e≈2.718.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Hybrid layered double perovskites (HLDPs), representing the two‐dimensional manifestation of halide double perovskites, have elicited considerable interest owing to their intricate chemical ...bonding hierarchy and structural diversity. This intensified interest stems from the diverse options available for selecting alternating octahedral coordinated trivalent M(III) and monovalent metal centers M(I), along with the distinctive nature of the cationic organic amine located between the layers. Here, we have synthesized three new compounds with general formula (R′/R′′) 4/2 M(III)M(I)Cl 8 ; where R′=C 3 H 7 NH 3 (i.e. 3N) and R′′=NH 3 C 4 H 8 NH 3 (i.e. 4N4); M(III)=In 3+ or Ru 3+ ; M(I)=Cu + by simple solution‐based acid precipitation method. The structural analysis reveals that (4N4) 2 CuInCl 8 and (4N4) 2 CuRuCl 8 adopt the layered Dion Jacobson (DJ) structure, whereas (3N) 4 CuInCl 8 exhibits layered Ruddlesden Popper (RP) structure. The alternative octahedra within the inorganic layer display distortions and tilting. Three compounds show temperature‐dependent structural phase transitions where changes in the staking of inorganic layer, extent of octahedral tilting and reorientation of organic spacers with temperature have been noticed. We have achieved ultralow lattice thermal conductivity (κ L ) in the HLDPs in the 2 to 300 K range, marking a distinctive feature within the realm of HLDP systems. The RP‐HLDP compound, (3N) 4 CuInCl 8 , demonstrates anisotropy in κ L while measured parallel and perpendicular to layer stacking, showcasing ultralow κ L of 0.15 Wm −1 K −1 at room temperature, which is one of the lowest values obtained among Pb‐free metal halide perovskite. The observed ultralow κ L in three new HLDPs is attributed to significant lattice anharmonicity arising from the chemical bonding heterogeneity and soft crystal structure, which resulted in low‐energy localized optical phonon modes that suppress heat‐carrying acoustic phonons.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This paper reports development of self‐healable thermoplastic polyurethane (TPU) compound through the mixing of masterbatches of TPU and EVA (poly ethylene‐co‐vinyl acetate) (EVA) having various mole ...compositions. The aim was to promote a limited chemical interaction between TPU and EVA in the pristine compound that can enhance viscoelastic flow across the cut surface for autonomic healing. The healing was externally stimulated through microwave irradiation and the healing efficiency was determined from changes in tensile properties and complemented by image analysis. Infrared spectroscopy was used to detect TPU‐EVA crosslinking in the TPU compound, which was further delineated from viscoelastic and swelling results. Tensile properties demonstrated a drop in tensile modulus, strength, and elongation at break than original TPU on increasing EVA concentration, but those, at the same time, were retained until the fifth healing cycles with higher EVA concentration in the masterbatch. The healing mechanism was attributed to the destruction of the hard domain in TPU leading to a marked increase in viscoelastic mobility at the interface of the cut section. The pristine TPU modified with higher amount of EVA in the masterbatch exhibited the highest range of healing efficiency (sample CC0‐93%, sample BB0‐97%, respectively)), reinstated the hypothesis of mixing a higher amount of EVA to promote autonomic healing. EVA based TPU compounds with superior self‐healing property makes them an ideal candidate for applications in cable insulation and shape‐memory devices.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The article presents the design of a compact narrowband microstrip cross-coupled bandpass filter with improved selectivity and a wide stopband. The proposed fourth-order quasi-elliptic filter is ...designed at 2.5 GHz with a fractional bandwidth of 4% suitable for WLAN applications. At first, doubly-folded half-wavelength hairpin lines have been arranged symmetrically in a cross-coupled configuration combining the electric, magnetic, and mixed coupling. Accordingly, a size reduction of 17% over the folded inline hairpin-line filter with the same specifications has been achieved. Moreover, the selectivity has been improved greatly by the introduction of two deep transmission zeros with an attenuation level of 48 dB at the edges of the passband. However, the presence of the spurious harmonics with an attenuation level of 10 dB limits the performance of the filter related to the stopband rejection. As a remedy, conventional and meander spurlines have been incorporated in each hybrid coupled section of adjacent cross-coupled cells for achieving the modal phase velocity compensation. Accordingly, an extended stopband with a rejection level of 38 dB up to 4 f 0 has been recorded by using a meander spurline and an overall size reduction of 33% has been achieved.
A unique brush coating technique was adopted to prepare high microwave absorbing super‐hydrophobic bactericidal fabrics. 3D micro‐CT, field emission scanning electron microscopy (FE‐SEM) and high ...resolution transmission electron microscopy (HR‐TEM) analyses were employed to establish the composite morphology. X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the embedded silver nanoparticles in the cotton fabrics. The developed thin wearable coated fabrics hold the lowest resistivity of 8 ohm‐cm−2 (lighten up series of LEDs) and electromagnetic interference (EMI) shielding effectiveness (SE) of 30.07 dB at 0.3 mm coating thickness within the X‐band frequency range. These thin coated fabrics can be the used in the flexible electronic devices along with extreme bactericidal feature against E. coli.
Our recent approach of coated textile fabrication has been accomplished by means of exclusive brush coating technique using industrial based silver paint. The fabric was characterized by both 2D and 3D morphological analysis for developing potentially high EMI shielding materials. Side by side, the thin, wearable and super‐hydrophobic brush coated fabric was capable enough to lighten up the series of LEDs and also performed antibacterial property via destroying the cell membrane with blocking the respiratory system of the E. coli bacteria.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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