6,722 research outputs found
Synthesis, characterization, TDDFT calculation and biological activity of tetradentate ligand based square pyramidal Cu(ii) complexes
No full textDistorted square pyramidal complexes [Cu(L1)(H2O)]·ClO4 (1), [Cu(L2)(H2O)]·ClO4 (2) and [Cu(L3)(H2O)]·ClO4 (3) (HL1 = o-{[2-(2-aminoethylamino)ethylimino]methyl}phenol; HL2 = 2-{[2-(2-aminoethylamino)ethylimino]methyl}-6-methoxyphenol; HL3 = o-{1-[2-(2-aminoethylamino)ethylimino]ethyl}phenol) have been synthesized, and characterized by X-ray crystallography and spectroscopic analysis. All the complexes exhibit fluorescence at room temperature [λex = 267 nm, λem = 312, 329 and 357 nm, φ = 0.52 for 1; λex = 272 nm, λem = 312, 329 and 355 nm, φ = 0.46 for 2; λex = 265 nm, λem = 312, 356 and 377 nm, φ = 0.33 for 3]. The electronic structure and photophysical properties of the ligands and complexes were calculated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods using the B3LYP, B3PW91 and MPW1PW91 functionals, with 6-31G (d-p) and LanL2DZ basis sets. The results of TD-DFT calculations are functional-dependent and among the functionals, B3LYP was able to best reproduce the experimental results. Catecholase activity of 1-3 has been investigated using 3,5-di-tert butyl catechol (3,5-DTBC) as the model substrate and found that complexes are active for catalyzing the aerobic oxidation of 3,5-DTBC to 3,5-di-tert butyl benzoquinone (3,5-DTBQ). The compound with more distorted square pyramidal geometry shows a higher rate of catalytic activity. All the complexes have been tested for their anticancer activities in human breast (MCF7) cancer cell lines. Complexes show dose dependent suppression of cell viability with IC50 values 30, 68 and >100 μM for 1, 2 and 3, respectively. Anticancer activities of 1-3 and cisplatin were compared, and found that 1-3 were relatively less active than cisplatin
Edible Packaging: Mechanical Properties and Testing Methods
No full textTraditionally people use food packaging materials from nonrenewable sources such as plastics obtained from petroleum. The traditional food packaging materials play a significant role in the total plastics consumption of the world. They are nonbiodegradable, cause environmental pollution, and large carbon adds to water footprint in their manufacturing process. Subsequently, this leads to a heavy dependence on nonrenewable resources. Reducing the amount of nonrenewable material by biodegradable and renewable sources of packaging holds the potential to improve waste disposal and decrease the cost of packaging and overall product. The need for alternatives to petrochemical-based plastics is more than ever. The current trend in food packaging calls for the utilization of natural, “environment-friendly” materials, which also have some additional functional properties wherever possible and with some cost benefit. Biodegradable packaging is a very good alternative packaging and a specialized type of biodegradable packaging, that is, the “edible packaging,” is a very good alternative as they also have some other benefits like enhancing shelf life, maintaining the freshness of foods, and can be eaten along with the food without altering the original organoleptic characteristics of the food. The two main considerations with the use of edible packaging can be understood from its name itself, which are firstly “edible,” it means the package is an integral part of the food and may or may not be consumed together with the product and hence should have all the necessary properties. At present, 12 types of edible films are approved by FDA and commercially used, which are made up of materials like polysaccharides, lipids, cellulose, chitosan, starch (potato, corn, wheat, rice), hemicellulose, hydrocolloids like gums (guar, pectin) and alginates, and plant and animal proteins. Secondly, the material chosen should have all the properties to protect the food from the outer environment, provide a good barrier against light, water vapor, other gases, and also have the required mechanical strength to protect the food against damages incurred during storage, transportation, and handling
Leptogenesis with Majoron dark matter
No full textWe discuss a model of neutrino mass based on the type I seesaw mechanism embedded in a spontaneously broken global lepton number framework with a Z2 symmetry. We show that the resulting Majoron is a viable freeze-in dark matter candidate. Two right-handed neutrinos are assumed to have dominant off-diagonal masses suggesting resonant leptogenesis as the origin of baryon asymmetry of the Universe. Explicit higher dimensional lepton number violating operators, are shown to play a crucial role in simultaneously controlling both the Majoron production in the early Universe and the right handed neutrino mass splitting relevant for resonant leptogenesis. We perform a combined analysis of Majoron dark matter and leptogenesis, discussing the relative importance of self energy and vertex contributions to CP asymmetry, and explore the parameter space, leading to an intricate relation between neutrino mass, dark matter and baryon asymmetry
Bibliographics for the 983 eprints in the live archives of E-LIS : trends and status report up to 7th July 2004, based on author-self-archiving metadata
No full textThe priority for ideas and philosophy related to "Network Theory" have been traced back and documented by Braun(2004),and credit goes to Karinthy(1929).The IT has empowered to realise it, as the most practical phenomena and it is no more a humour. The OAI (Open Archives Initiatives)and ACIS (Academic Contributor Information System)are progressive in the direction ,which may lead to realise the "Collective Genius" at global level. Focus of present study is on Author-Self-Archiving (A-S-A)Metadata of the 983 Eprints in the Live Archives of the E-LIS (EPrints of Library and Information Science),which were approved till 7th July 2004.The A-S-A Metadata was used for librametric analysis. Self-explanatory bibliographics are illustrated.The highlights include: Conference papers (34%); highest approval, June 2004 (28%); published archives (76%);not refereed (52%); not in public domain (60%); highest self-archiving-author (De Robbio, Antonella).The Nos. of EPrints having single JITA domain specifications were: Theoretical and general aspects of libraries and information(27); Information use and sociology of information(80);Users,literacy and reading(13);Libraries as physical collections(30);Publishing and legal issues(57);Management(13);Industry, profession and education(36);Information sources, supports, channels(113) ; Information treatment for information services, Information functions and techniques (101); Technical services libraries, archives and museums(25); Housing technologies(1); Information technology and library technology(92); and Inter-domainery (395) i.e. having specifications of two or more than two JITA classes
A Unified Shell model for Buoyancy-Driven Turbulence
No full textWe construct a unified shell model for stably stratified and convective turbulence. Shell model simulation of stably stratified flow in turbulent regime exhibit Bolgiano-Obukhbov (BO) scaling in which the kinetic energy spectrum varies as . However, simulation of convective turbulence shows Kolmogorov's spectrum. These results are consistent with the direct numerical simulations of Kumar {\em et al.} [Phys. Rev. E {\bf 90}, 023016 (2014)]. We also observe a dual scaling ( and ) for a limited range of parameters in stably stratified flow
MaxMin Separation Problems: FPT Algorithms for st-Separator and Odd Cycle Transversal
No full textIn this paper, we study the parameterized complexity of the MaxMin versions of two fundamental separation problems: Maximum Minimal st-Separator and Maximum Minimal Odd Cycle Transversal (OCT), both parameterized by the solution size. In the Maximum Minimal st-Separator problem, given a graph G, two distinct vertices s and t and a positive integer k, the goal is to determine whether there exists a minimal st-separator in G of size at least k. Similarly, the Maximum Minimal OCT problem seeks to determine if there exists a minimal set of vertices whose deletion results in a bipartite graph, and whose size is at least k. We demonstrate that both problems are fixed-parameter tractable parameterized by k. Our FPT algorithm for Maximum Minimal st-Separator answers the open question by Hanaka, Bodlaender, van der Zanden & Ono [TCS 2019].
One unique insight from this work is the following. We use the meta-result of Lokshtanov, Ramanujan, Saurabh & Zehavi [ICALP 2018] that enables us to reduce our problems to highly unbreakable graphs. This is interesting, as an explicit use of the recursive understanding and randomized contractions framework of Chitnis, Cygan, Hajiaghayi, Pilipczuk & Pilipczuk [SICOMP 2016] to reduce to the highly unbreakable graphs setting (which is the result that Lokshtanov et al. tries to abstract out in their meta-theorem) does not seem obvious because certain "extension" variants of our problems are W[1]-hard
Story of the Story-Teller: A Conversation with Ramendra Kumar
No full textRamendra Kumar (Ramen) is an award-winning writer, storyteller and inspirational speaker with 42 books to his name. Ramen’s writings have been published by many of the leading publishers in the county and translated into 30 languages. They have found a place in several textbooks and anthologies. He has written across all genres ranging from picture books to adult fiction, satire, poetry, travelogues, biographies and on issues related to parenting and relationships. He has been invited to literary festivals held in Denmark, Greece, Sharjah, Sri Lanka as well Indian events including the prestigious Jaipur Litfest to conduct storytelling sessions and creative writing workshops. He has also been empanelled by Pearson India Education Services as well as several schools to conduct workshops. He was nominated as a Jury Member for the Best Children’s Author Category of The Times of India’s ‘Women AutHer’ Awards 2020. Many of his stories have been showcased by popular audio streaming, apps both within and outside the country, such as Spotify, Gaatha, Talking Stories Radio – London et al.
An Engineer & an MBA, Ramen was serving as the General Manager (Corporate Communications), SAIL, Rourkela Steel Plant, when he took Voluntary Retirement to pursue his passion, in August 2020. To know more about the writer, you can visit his website www.ramendra.in & his page on Wikipedia. Dr. Sagar Kumar Sharma interviews the author and unfolds the pages of his life.
 
Controlling the sharpness of ZnO tetrapods by restricted zinc oxidation in the open air: a low turn-on field emitter stabilized by graphene
No full textA simple, novel and economical approach was developed for the synthesis of ZnO tetrapods through the controlled open air oxidation of a commercial zinc foil. Unrestricted by stringent criteria such as the maintenance of a high vacuum level or the usage of catalysts, this protocol yields scalable amounts of high quality tetrapods, thus highlighting its convenience over other reported methods. A thin coating of gold on top of the zinc foil is found to restrict the free open air oxidation and thus plays a pivotal role in this alternative kind of tetrapod formation. Investigations using cathodoluminescence spectroscopy confirmed the high optical quality of the tetrapods. Additionally, these tetrapods are found to exhibit an excellent electron emission performance. Finally, with the expectation of gaining better field enhancement, thermally reduced graphene oxide is attached to the tetrapods. This hybrid system is observed to possess outstanding electron emission activity with very low turn-on and threshold field values, as well as much improved stability, which were not achieved for the separate components. This indicates the potential usability of these materials in field emission nanodevices
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