Showing papers by "Jadavpur University published in 2014"
TL;DR: In this article, an efficient and sustainable route of AgNP preparation from 1mM aqueous AgNO3 using leaf extracts of three plants, Musa balbisiana (banana), Azadirachta indica (neem) and Ocimum tenuiflorum (black tulsi), well adorned for their wide availability and medicinal property.
Abstract: In recent years, green synthesis of silver nanoparticles (AgNPs) has gained much interest from chemists and researchers. In this concern, Indian flora has yet to divulge innumerable sources of cost-effective non-hazardous reducing and stabilizing compounds utilized in preparing AgNPs. This study investigates an efficient and sustainable route of AgNP preparation from 1 mM aqueous AgNO3 using leaf extracts of three plants, Musa balbisiana (banana), Azadirachta indica (neem) and Ocimum tenuiflorum (black tulsi), well adorned for their wide availability and medicinal property. AgNPs were prepared by the reaction of 1 mM silver nitrate and 5% leaf extract of each type of plant separately. the AgNPs were duely characterized and tested for their antibacterial activity and toxicity. The AgNPs were characterized by UV-visible (vis) spectrophotometer, particle size analyzer (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS). Fourier transform infrared spectrometer (FTIR) analysis was carried out to determine the nature of the capping agents in each of these leaf extracts. AgNPs obtained showed significantly higher antimicrobial activities against Escherichia coli (E. coli) and Bacillus sp. in comparison to both AgNO3 and raw plant extracts. Additionally, a toxicity evaluation of these AgNP containing solutions was carried out on seeds of Moong Bean (Vigna radiata) and Chickpea (Cicer arietinum). Results showed that seeds treated with AgNP solutions exhibited better rates of germination and oxidative stress enzyme activity nearing control levels, though detailed mechanism of uptake and translocation are yet to be analyzed. In totality, the AgNPs prepared are safe to be discharged in the environment and possibly utilized in processes of pollution remediation. AgNPs may also be efficiently utilized in agricultural research to obtain better health of crop plants as shown by our study.
506 citations
TL;DR: This two-part paper has surveyed different multiobjective evolutionary algorithms for clustering, association rule mining, and several other data mining tasks, and provided a general discussion on the scopes for future research in this domain.
Abstract: The aim of any data mining technique is to build an efficient predictive or descriptive model of a large amount of data. Applications of evolutionary algorithms have been found to be particularly useful for automatic processing of large quantities of raw noisy data for optimal parameter setting and to discover significant and meaningful information. Many real-life data mining problems involve multiple conflicting measures of performance, or objectives, which need to be optimized simultaneously. Under this context, multiobjective evolutionary algorithms are gradually finding more and more applications in the domain of data mining since the beginning of the last decade. In this two-part paper, we have made a comprehensive survey on the recent developments of multiobjective evolutionary algorithms for data mining problems. In this paper, Part I, some basic concepts related to multiobjective optimization and data mining are provided. Subsequently, various multiobjective evolutionary approaches for two major data mining tasks, namely feature selection and classification, are surveyed. In Part II of this paper, we have surveyed different multiobjective evolutionary algorithms for clustering, association rule mining, and several other data mining tasks, and provided a general discussion on the scopes for future research in this domain.
406 citations
Posted Content•
TL;DR: A new approach for multi-attribute group decision-making problems is proposed by extending the technique for order preference by similarity to ideal solution to single-valued neutrosophic environment.
Abstract: A single-valued neutrosophic set is a special case of neutrosophic set. It has been proposed as a generalization of crisp sets, fuzzy sets, and intuitionistic fuzzy sets in order to deal with incomplete information. In this paper, a new approach for multi-attribute group decision making problems is.
342 citations
TL;DR: Now a days sugar free food are very much popular because of their less calorie content, so food industry uses various artificial sweeteners which are low in calorie content instead of high calorie sugar.
Abstract: Now a days sugar free food are very much popular because of their less calorie content. So food industry uses various artificial sweeteners which are low in calorie content instead of high calorie sugar. U.S. Food and Drug Administration has approved aspartame, acesulfame-k, neotame, cyclamate and alitame for use as per acceptable daily intake (ADI) value. But till date, breakdown products of these sweeteners have controversial health and metabolic effects. On the other hand, rare sugars are monosaccharides and have no known health effects because it does not metabolize in our body, but shows same sweet taste and bulk property as sugar. Rare sugars have no such ADI value and are mainly produced by using bioreactor and so inspite of high demand, rare sugars cannot be produced in the desired quantities.
338 citations
01 Dec 2014
TL;DR: In this paper, the authors make the argument that optimum surfaces need to address the specificities of phase change heat transfer in the way that a key matches its lock, which calls for the design and fabrication of adaptive surfaces with multiscale textures and non-uniform wettability.
Abstract: Owing to advances in micro- and nanofabrication methods over the last two decades, the degree of sophistication with which solid surfaces can be engineered today has caused a resurgence of interest in the topic of engineering surfaces for phase change heat transfer. This review aims at bridging the gap between the material sciences and heat transfer communities. It makes the argument that optimum surfaces need to address the specificities of phase change heat transfer in the way that a key matches its lock. This calls for the design and fabrication of adaptive surfaces with multiscale textures and non-uniform wettability. Among numerous challenges to meet the rising global energy demand in a sustainable manner, improving phase change heat transfer has been at the forefront of engineering research for decades. The high heat transfer rates associated with phase change heat transfer are essential to energy and industry applications; but phase change is also inherently associated with poor thermodynamic efficiency at low heat flux, and violent instabilities at high heat flux. Engineers have tried since the 1930s to fabricate solid surfaces that improve phase change heat transfer. The development of micro and nanotechnologies has made feasible the high-resolution control of surface texture and chemistry over length scales ranging from molecular levels to centimeters. This paper reviews the fabrication techniques available for metallic and silicon-based surfaces, considering sintered and polymeric coatings. The influence of such surfaces in multiphase processes of high practical interest, e.g., boiling, condensation, freezing, and the associated physical phenomena are reviewed. The case is made that while engineers are in principle able to manufacture surfaces with optimum nucleation or thermofluid transport characteristics, more theoretical and experimental efforts are needed to guide the design and cost-effective fabrication of surfaces that not only satisfy the existing technological needs, but also catalyze new discoveries.
287 citations
TL;DR: A facile wettability patterning method is used to produce open microfluidic tracks that are capable of transporting a wide range of liquid volumes on-chip, overcoming viscous and other opposing forces at the pertinent length scales.
Abstract: Surface tension driven transport of liquids on open substrates offers an enabling tool for open micro total analysis systems that are becoming increasingly popular for low-cost biomedical diagnostic devices. The present study uses a facile wettability patterning method to produce open microfluidic tracks that – due to their shape, surface texture and chemistry – are capable of transporting a wide range of liquid volumes (~1–500 μL) on-chip, overcoming viscous and other opposing forces (e.g., gravity) at the pertinent length scales. Small volumes are handled as individual droplets, while larger volumes require repeated droplet transport. The concept is developed and demonstrated with coatings based on TiO2 filler particles, which, when present in adequate (~80 wt.%) quantities within a hydrophobic fluoroacrylic polymer matrix, form composites that are intrinsically superhydrophobic. Such composite coatings become superhydrophilic upon exposure to UV light (390 nm). A commercial laser printer-based photo-masking approach is used on the coating for spatially selective wettability conversion from superhydrophobic to superhydrophilic. Carefully designed wedge-patterned surface tension confined tracks on the open-air devices move liquid on them without power input, even when acting against gravity. Simple designs of wettability patterning are used on versatile substrates (e.g., metals, polymers, paper) to demonstrate complex droplet handling tasks, e.g., merging, splitting and metered dispensing, some of which occur in 3-D geometries. Fluid transport rates of up to 350 μL s−1 are attained. Applicability of the design on metal substrates allows these devices to be used also for other microscale engineering applications, e.g., water management in fuel cells.
281 citations
TL;DR: In this paper, an experimental program has been taken up on low calcium fly ash geopolymer mortar having three molar concentrations (8,M, 10,M and 12,M) of activator liquids along with different percentage of nano silica addition (0, 4, 6, 8% and 10% of fly ash).
249 citations
TL;DR: In this article, the authors deal with the technical aspects of co-combustion with emphasis on the fundamentals of devolatilization, ignition, burnout and ash deposition behavior along with the constraints and uncertainties associated with the use of different types of biomass of diverse characteristics and the likely impact of partial replacement of coal by biomass on the emission of CO2, SOx, NOx.
Abstract: The energy sector in the global scenario faces a major challenge of providing energy at an affordable cost and simultaneously protecting the environment. The energy mix globally is primarily dominated by fossil fuels, coal being the major contributor. Increasing concerns on the adverse effect of the emissions arising from coal conversion technologies on the environment and the gradual depletion of the fossil fuel reserves had led to global initiatives on using renewables and other opportunity resources to meet the future energy demands in a sustainable manner. Use of coal with biomass as a supplementary fuel in the combustion or gasification based processes is a viable technological option for reducing the harmful emissions. Co-combustion of coal with biomass for electricity generation is gradually gaining ground in spite of the fact that their combustion behavior differ widely due to wide variations in their physical and chemical properties. This article deals with the technical aspects of co-combustion with emphasis on the fundamentals of devolatilization, ignition, burnout and ash deposition behavior along with the constraints and uncertainties associated with the use of different types of biomass of diverse characteristics and the likely impact of partial replacement of coal by biomass on the emission of CO2, SOx, NOx. Other issues of no less importance like sustained availability of biomass, transportation and storage, effect on biodiversity, etc., are left out in the study. The investigations reported in the study reflect the potential of biomass as co-fuel, and the scope of maximizing its proportion in the blend in the coal based power plants and the derived benefits.
248 citations
TL;DR: The bioinspired interdigitated pattern is found to outperform the straight hydrophilic-superhydrophilic pattern design, particularly under higher humidity conditions in the presence of noncondensable gases (NCG), a condition that is more challenging for maintaining sustained DWC.
Abstract: Dropwise condensation (DWC) heat transfer depends strongly on the maximum diameter (Dmax) of condensate droplets departing from the condenser surface. This study presents a facile technique implemented to gain control of Dmax in DWC within vapor/air atmospheres. We demonstrate how this approach can enhance the corresponding heat transfer rate by harnessing the capillary forces in the removal of the condensate from the surface. We examine various hydrophilic-superhydrophilic patterns, which, respectively, sustain and combine DWC and filmwise condensation on the substrate. The material system uses laser-patterned masking and chemical etching to achieve the desired wettability contrast and does not employ any hydrophobizing agent. By applying alternating straight parallel strips of hydrophilic (contact angle ∼78°) mirror-finish aluminum and superhydrophilic regions (etched aluminum) on the condensing surface, we show that the average maximum droplet size on the less-wettable domains is nearly 42% of the width of the corresponding strips. An overall improvement in the condensate collection rate, up to 19% (as compared to the control case of DWC on mirror-finish aluminum) was achieved by using an interdigitated superhydrophilic track pattern (on the mirror-finish hydrophilic surface) inspired by the vein network of plant leaves. The bioinspired interdigitated pattern is found to outperform the straight hydrophilic-superhydrophilic pattern design, particularly under higher humidity conditions in the presence of noncondensable gases (NCG), a condition that is more challenging for maintaining sustained DWC.
238 citations
TL;DR: Comprehensive theoretical and experimental analysis revealed that newly created energy levels can exist as an interband within the energy gap in functionalized graphene quantum structures yielding excitation dependent tunable PL for optoelectronic applications.
Abstract: Graphene quantum dots are known to exhibit tunable photoluminescence (PL) through manipulation of edge functionality under various synthesis conditions. Here, we report observation of excitation dependent anomalous m-n type fingerprint PL transition in synthesized amino functionalized graphene quantum dots (5-7 nm). The effect of band-to-band π*-π and interstate to band n-π induced transitions led to effective multicolor emission under changeable excitation wavelength in the functionalized system. A reasonable assertion that equi-coupling of π*-π and n-π transitions activated the heterogeneous dual mode cyan emission was made upon observation of the PL spectra. Furthermore, investigation of incremented dimensional scaling through facile synthesis of amino functionalized quantum graphene flakes (20-30 nm) revealed it had negligible effect on the modulated PL pattern. Moreover, an effort was made to trace the origin of excitation dependent tunable heterogeneous photoluminescence through the framework of energy band diagram hypothesis and first principles analysis. Ab initio results suggested formation of an interband state as a manifestation of p orbital hybridization between C-N atoms at the edge sites. Therefore comprehensive theoretical and experimental analysis revealed that newly created energy levels can exist as an interband within the energy gap in functionalized graphene quantum structures yielding excitation dependent tunable PL for optoelectronic applications.
235 citations
TL;DR: In this article, the synthesis and detailed investigation on ZnO-SnO 2 composite type hydrogen sensor prototype was reported, which was structurally and morphologically characterized by X-ray diffraction technique and scanning electron microscopy, respectively.
Abstract: This work reports the synthesis and detailed investigation on ZnO–SnO 2 composite type hydrogen sensor prototype. The sensor material was structurally and morphologically characterized by X-ray diffraction technique and scanning electron microscopy, respectively. The gas sensing behaviour of the fabricated sensor prototype was investigated for varied concentration of test gases at different temperature. The cross-response of this sensor to other gases, viz. methane and carbon mono-oxide was also investigated, which showed good selectivity, excellent response and reproducibility to hydrogen at 150 °C.
TL;DR: A new surface-tension-driven, gravity-assisted, one-step, oil-water separation method is presented for sustained filtration and collection of oil from a floating spill, and shows high stability and functionality over repeated use, and can be easily scaled for efficient cleanup of large oil spills on seawater.
Abstract: Marine oil spills seriously endanger sea ecosystems and coastal environments, resulting in a loss of energy resources Environmental and economic demands emphasize the need for new methods of effectively separating oil–water mixtures, while collecting oil content at the same time A new surface-tension-driven, gravity-assisted, one-step, oil–water separation method is presented for sustained filtration and collection of oil from a floating spill A benchtop prototype oil collection device uses selective-wettability (superhydrophobic and superoleophilic) stainless steel mesh that attracts the floating oil, simultaneously separating it from water and collecting it in a container, requiring no preseparation pumping or pouring The collection efficiencies for oils with wide ranging kinematic viscosities (032–704 cSt at 40 °C) are above 94%, including motor oil and heavy mineral oil The prototype device showed high stability and functionality over repeated use, and can be easily scaled for efficient cleanup
TL;DR: Knowing is updated about the diverse therapeutic application of different plant products against various pharmacological targets including cancer, human brain, cardiovascular function, microbial infection, inflammation, pain, and many more are updated.
Abstract: Biodiversity contributes significantly towards human livelihood and development and thus plays a predominant role in the well being of the global population. According to WHO reports, around 80 % of the global population still relies on botanical drugs; today several medicines owe their origin to medicinal plants. Natural substances have long served as sources of therapeutic drugs, where drugs including digitalis (from foxglove), ergotamine (from contaminated rye), quinine (from cinchona), and salicylates (willow bark) can be cited as some classical examples.Drug discovery from natural sources involve a multifaceted approach combining botanical, phytochemical, biological, and molecular techniques. Accordingly, medicinal-plant-based drug discovery still remains an important area, hitherto unexplored, where a systematic search may definitely provide important leads against various pharmacological targets.Ironically, the potential benefits of plant-based medicines have led to unscientific exploitation of the natural resources, a phenomenon that is being observed globally. This decline in biodiversity is largely the result of the rise in the global population, rapid and sometimes unplanned industrialization, indiscriminate deforestation, overexploitation of natural resources, pollution, and finally global climate change.Therefore, it is of utmost importance that plant biodiversity be preserved, to provide future structural diversity and lead compounds for the sustainable development of human civilization at large. This becomes even more important for developing nations, where well-planned bioprospecting coupled with nondestructive commercialization could help in the conservation of biodiversity, ultimately benefiting mankind in the long run.Based on these findings, the present review is an attempt to update our knowledge about the diverse therapeutic application of different plant products against various pharmacological targets including cancer, human brain, cardiovascular function, microbial infection, inflammation, pain, and many more.
TL;DR: It is concluded that the oral nanoemulsion of paclitaxel has got encouraging advantages over the presently available formulations of this injectable chemotherapeutic drug.
TL;DR: In this paper, the grey relational analysis method is applied to multi-attribute decision making problem with single-valued neutrosophic attribute values, where the rating of all alternatives is expressed with a singlevalued set, which is characterised by truth-membership degree, indeterminacy-memberships degree, and falsity-Membership degree.
Abstract: In this paper we investigate multi-attribute decision making problem with single-valued neutrosophic attribute values. Crisp values are inadequate to model real life situation due to imprecise information frequently used in decision making process. Neutrosophic set is one such tool that can handle these situations. The rating of all alternatives is expressed with single-valued neutrosophic set which is characterised by truth-membership degree, indeterminacy-membership degree, and falsity-membership degree. Weight of each attribute is completely unknown to decision maker. We extend the grey relational analysis method to neutrosophic environment and apply it to multi-attribute decision making problem. Information entropy method is used to determine the unknown attribute weights. Neutrosophic grey relational coefficient is determined by using Hamming distance between each alternative to ideal neutrosophic estimates reliability solution and the ideal neutrosophic estimates un-reliability solution. Then neutrosophic relational degree is defined to determine the ranking order of all alternatives. Finally, an example is provided to illustrate the application of the proposed method.
TL;DR: The modified grey relational analysis method is proposed to find out the best alternative for multi-attribute decision- making problem under neutrosophic environment and establishes a deviation based optimization model based on the ideal alternative to determine attribute weight in which the information about attribute weights is incompletely known.
Abstract: In this paper, we present multi-attribute decision-making problem with neutrosophic assessment. We assume that the information about attribute weights is incompletely known or completely unknown. The ratings of alternatives with respect to each attributes are considered as single-valued neutrosophic set to catch up imprecise or vague information. Neutrosophic set is characterized by three independent degrees namely truth- membership degree (T), indeterminacy-membership degree (I), and falsity-membership degree (F). The modified grey relational analysis method is proposed to find out the best alternative for multi-attribute decision- making problem under neutrosophic environment. We establish a deviation based optimization model based on the ideal alternative to determine attribute weight in which the information about attribute weights is incompletely known. Again, we solve an optimization model with the help of Lagrange functions to find out the completely unknown attributes weight. By using these attributes weight we calculate the grey relational coefficient of each alternative from ideal alternative for ranking the alternatives. Finally, an illustrative example is provided in order to demonstrate its applicability and effectiveness of the proposed approach.
TL;DR: The effects of nano-Al2O3 addition on the early-age microstructural properties of cement paste is reported in this article, which is limited to evaluation of properties of Cement paste hydrated up to an age of 7 days.
TL;DR: The gel material shows a highly selective visual response to a commonly used nitroexplosive, picric acid among a set of 19 congeners and the preferred selectivity has been mechanistically interpreted with density functional theory-based calculations.
Abstract: Thiourea (TU), a commercially available laboratory chemical, has been discovered to introduce metallogelation when reacted with copper(II) chloride in aqueous medium. The chemistry involves the reduction of Cu(II) to Cu(I) with concomitant oxidation of thiourea to dithiobisformamidinium dichloride. The gel formation is triggered through metal–ligand complexation, i.e., Cu(I)-TU coordination and extensive hydrogen bonding interactions involving thiourea, the disulfide product, water, and chloride ions. Entangled network morphology of the gel selectively develops in water, maybe for its superior hydrogen-bonding ability, as accounted from Kamlet–Taft solvent parameters. Complete and systematic chemical analyses demonstrate the importance of both Cu(I) and chloride ions as the key ingredients in the metal–organic coordination gel framework. The gel is highly fluorescent. Again, exclusive presence of Cu(I) metal centers in the gel structure makes the gel redox-responsive and therefore it shows reversible gel–...
TL;DR: In this article, a solution-casting method was used to investigate the electroactive β-phase formation mechanism and the dielectric properties of the clay polymer nanocomposite (CPN) films.
TL;DR: In this article, the authors presented LA-CPMS U-Pb zircon and U-Th-pb monazite ages and geochemical data for felsic orthogneisses and granites from the Southern Granulite Terrane of India, a key area for reconstructing the evolution of the late Neoproterozoic Gondwana supercontinent.
TL;DR: It has been found that the yield of the piezoelectric phase is increased by the addition of silver nanoparticles and defects in the P(VDF-HFP) electrospun fibers are removed resulting in a significant enhancement in the output power of the PNG.
Abstract: We report on the electrospinning of poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)] nanofibers doped with silver nanoparticles for the preparation of a polymer based nanogenerator (PNG). It has been found that the yield of the piezoelectric phase is increased by the addition of silver nanoparticles. Furthermore, defects in the P(VDF-HFP) electrospun fibers are removed resulting in a significant enhancement in the output power of the PNG. A maximum generated PNG output voltage of 3 V with a current density of 0.9 μA cm(-2) is achieved.
TL;DR: A comprehensive world coal Hg stable isotope database including 108 new coal samples from major coal-producing deposits in South Africa, China, Europe, India, Indonesia, Mongolia, former USSR, and the U.S. is presented.
Abstract: Mercury (Hg) emissions from coal combustion contribute approximately half of anthropogenic Hg emissions to the atmosphere. With the implementation of the first legally binding UNEP treaty aimed at reducing anthropogenic Hg emissions, the identification and traceability of Hg emissions from different countries/regions are critically important. Here, we present a comprehensive world coal Hg stable isotope database including 108 new coal samples from major coal-producing deposits in South Africa, China, Europe, India, Indonesia, Mongolia, former USSR, and the U.S. A 4.7‰ range in δ202Hg (−3.9 to 0.8‰) and a 1‰ range in Δ199Hg (−0.6 to 0.4‰) are observed. Fourteen (p < 0.05) to 17 (p < 0.1) of the 28 pairwise comparisons between eight global regions are statistically distinguishable on the basis of δ202Hg, Δ199Hg or both, highlighting the potential application of Hg isotope signatures to coal Hg emissions tracing. A revised coal combustion Hg isotope fractionation model is presented, and suggests that gaseous...
TL;DR: Investigating the findings of the present investigations indicated that the nanoemulsion of OM (OMF6) could significantly enhance the oral bioavailability of relatively insoluble OM contributing to improved clinical application.
TL;DR: It is suggested that a multi-species probiotic supplementation in equal proportions for 60 days can effectively improve growth and immunity of L. rohita.
Abstract: Labeo rohita fingerlings were fed for 60 days with basal diet (BD) or one of the following experimental diets: DI (BD + B. subtilis); DII (BD + B. subtilis + L. plantarum); DIII (BD + B. subtilis + P. aeruginosa) and DIV (BD + B. subtilis + P. aeruginosa + L. plantarum). Various growth and immune parameters were examined at 30 and 60 days postfeeding. The fish group fed DIV diet had better improvement (P < 0.05) in weight gain, specific growth rate (SGR) and feed conversion ratio (FCR) than the control and other treatment groups. The serum lysozyme activities, alternative complement pathway activity, phagocytic activity and respiratory burst activity in head kidney macrophages of L. rohita increased significantly in the experimental groups throughout the trial period. Superoxide dismutase increased significantly in the experimental groups, except DI fed group, after 60 days of feeding. A significant improvement in serum IgM level was observed in the treatment groups at 30 days of feeding only. Further, fish fed the DIV diet had highest (P < 0.05) postchallenge survival rate (86.6%), followed by DII (73.3%) and DIII (66.6%) against A. hydrophila infection. Considering these promising results, we suggest that a multi-species probiotic supplementation in equal proportions for 60 days can effectively improve growth and immunity of L. rohita.
TL;DR: This study indicates that CuO NPs are a potent inducer of autophagy which may be a cellular defense against the CuO NP mediated toxicity and inhibition of Autophagy switches the cellular response into apoptosis.
TL;DR: In this article, a dual-band rectangular microstrip antenna (RMSA) is realized by two different single-slotted single-band RF antennas with slotted ground plane.
Abstract: A compact dual-band rectangular microstrip antenna (RMSA) is realized by two different single-slotted single-band rectangular microstrip antennas with slotted ground plane. Each open-ended slot in the single-slotted antenna is responsible to generate a wide impedance band that is shifted to lower frequencies by the effect of the ground slot. The length and position of each open-ended slot is varied to operate the antenna in a suitable resonant band (5.15-5.35 and 5.725-5.825 GHz). The proposed antenna meets the required impedance bandwidth, necessary for dual-band IEEE 802.11a WLAN application (5.125-5.395 and 5.725-5.985 GHz). The dimension of the antenna (12 × 8 × 1.5875 mm3) shows an average compactness of about 53.73% with respect to a conventional unslotted rectangular microstrip patch antenna.
TL;DR: In this paper, the authors used noncovalent interactions between the charged and neutral aromatic rings and with anions to design the solid-state assembly of triply protonated PTPH3 (PTP = 4′-(4-pyridyl)-3,2′:6′,3″-terpyridine) with H2O and three ClO4−, which is synthesized and characterized by single-crystal X-ray diffraction analysis.
Abstract: The novel noncovalent interactions between the charged and neutral aromatic rings and with anions are utilized to design the solid-state assembly of triply protonated PTPH3 (PTP = 4′-(4-pyridyl)-3,2′:6′,3″-terpyridine) with H2O and three ClO4–, which is synthesized and characterized by single-crystal X-ray diffraction analysis. Crystallography reveals that the π+–π+, π+–π, and various anion···π interactions are the major driving forces in the stabilization of the self-assembled structure. In the title complex, a layered assembly is formed through the mutual influence of π+–π+ and π+–π interactions. The anions are interacting with the charged π-acceptors, which are again stabilized through π+–π interactions. Therefore, the overall stabilization is governed through π+–π/π–π+, (π+–π+)n, and anion···π+/π+–π/π–π+ networks in the solid state. The interaction energies of the main driving forces observed in the crystal structure have been calculated using density functional theory. In addition, the short O···O co...
TL;DR: A niching scheme integrated with DE is suggested for achieving a stable and efficient nICHing behavior by combining the newly proposed parent-centric mutation operator with synchronous crowding replacement rule.
Abstract: In real life, we often need to find multiple optimally sustainable solutions of an optimization problem Evolutionary multimodal optimization algorithms can be very helpful in such cases They detect and maintain multiple optimal solutions during the run by incorporating specialized niching operations in their actual framework Differential evolution (DE) is a powerful evolutionary algorithm (EA) well-known for its ability and efficiency as a single peak global optimizer for continuous spaces This article suggests a niching scheme integrated with DE for achieving a stable and efficient niching behavior by combining the newly proposed parent-centric mutation operator with synchronous crowding replacement rule The proposed approach is designed by considering the difficulties associated with the problem dependent niching parameters (like niche radius) and does not make use of such control parameter The mutation operator helps to maintain the population diversity at an optimum level by using well-defined local neighborhoods Based on a comparative study involving 13 well-known state-of-the-art niching EAs tested on an extensive collection of benchmarks, we observe a consistent statistical superiority enjoyed by our proposed niching algorithm
TL;DR: A multipopulation-based adaptive differential evolution (DE) algorithm to solve dynamic optimization problems (DOPs) in an efficient way that uses Brownian and adaptive quantum individuals in conjunction with the DE individuals to maintain the diversity and exploration ability of the population.
Abstract: This article proposes a multipopulation-based adaptive differential evolution (DE) algorithm to solve dynamic optimization problems (DOPs) in an efficient way The algorithm uses Brownian and adaptive quantum individuals in conjunction with the DE individuals to maintain the diversity and exploration ability of the population This algorithm, denoted as dynamic DE with Brownian and quantum individuals (DDEBQ), uses a neighborhood-driven double mutation strategy to control the perturbation and thereby prevents the algorithm from converging too quickly In addition, an exclusion rule is used to spread the subpopulations over a larger portion of the search space as this enhances the optima tracking ability of the algorithm Furthermore, an aging mechanism is incorporated to prevent the algorithm from stagnating at any local optimum The performance of DDEBQ is compared with several state-of-the-art evolutionary algorithms using a suite of benchmarks from the generalized dynamic benchmark generator (GDBG) system used in the competition on evolutionary computation in dynamic and uncertain environments, held under the 2009 IEEE Congress on Evolutionary Computation (CEC) The simulation results indicate that DDEBQ outperforms other algorithms for most of the tested DOP instances in a statistically meaningful way
TL;DR: In this paper, a co-precipitation method was used to synthesize 6-13 nm sized 0D superparamagnetic Fe3O4 nanocrystals under a N2 atmosphere as a function of temperature.
Abstract: Uniform 6–13 nm sized 0D superparamagnetic Fe3O4 nanocrystals were synthesized by an aqueous ‘co-precipitation method’ under a N2 atmosphere as a function of temperature to understand the growth kinetics. The crystal phases, surface charge, size, morphology and magnetic characteristics of as-synthesized nanocrystals were characterized by XRD, Raman spectroscopy, FTIR, TG-DTA, BET surface area, dynamic light scattering along with zeta potential, HR-TEM, EDAX, vibrating sample magnetometry and Mossbauer spectroscopy. TEM investigation revealed highly crystalline spherical magnetite particles in the 8.2–12.5 nm size range. The kinetically controlled as-grown nanoparticles were found to possess a preferential (311) orientation of the cubic phase, with a highest magnetic susceptibility of ∼57 emu g−1. The Williamson–Hall technique was employed to evaluate the mean crystallite size and microstrain involved in the as-synthesized nanocrystals from the X-ray peak broadening. In addition to FTIR and Raman spectra, Rietveld structural refinement of XRD confirms the magnetite phase with 5–20% maghemite in the sample. VSM and Mossbauer spectral data allowed us to fit the magnetite/maghemite content to a core–shell model where the shell is 0.2–0.3 nm thick maghemite over a magnetite core. The activation energy of <10 kJ mol−1 calculated from an Arrhenius plot for the complex process of nucleation and growth by diffusion during synthesis shows the significance of the precipitation temperature in the size controlled fabrication processes of nanocrystals. Brunauer–Emmett–Teller (BET) results reveal a mesoporous structure and a large surface area of 124 m2 g−1. Magnetic measurement shows that the particles are ferromagnetic at room temperature with zero remanence and zero coercivity. This method produced highly crystalline and dispersed 0D magnetite nanocrystals suitable for biological applications in imaging and drug delivery.