On packing, connectivity, and conductivity in mesoscale networks of polydisperse multiwalled carbon nanotubes

The formation of different mesoscale networks in multiwalled carbon nanotube (CNT) systems that are realized by the mixing of CNTs of varying lengths and length dispersities is reported. By this mixing process, we introduce competing length scales; hence, we alter the self-organized packing that contributes to the synergistic effects on the functional properties of the networks. The experimental findings show a gradual change of volume fraction and aspect ratio as well as a 2-fold increase in electrical conductivity for such networks at certain specific compositions, hence an average aspect ratio. Quantitative large-area scanning transmission electron microscopy (STEM) imaging indeed revealed the existence of such mesoscale packing distribution variations. These packing observations suggest that these optimized networks of CNTs fit into an electrical conduction model that attributes its behavior to the formation of conduction knots, i.e., high-volume-fraction regions of relatively short CNTs that are connected by relatively long CNTs. If these conduction knots occupied by many short CNTs are distributed evenly with their nearest-neighbor distance being close to the average length of the CNT population, then the total electrical contact resistance in the conduction path will be effectively minimized. This study shows that optimized macroscale functional material properties can be designed into the initial colloidal dispersions by understanding and thus tuning the self-organization behavior of colloidal matter

First report on the distribution of Aegiceras corniculatum (L.) Blanco (Primulaceae) from the Nicobar archipelago, India

The 2004 Sumatra-Andaman earthquake (9.3 Mw) and subsequent tsunami caused upliftment and subsidencethroughout the Andaman and Nicobar archipelago. This incident has significantly impacted the mangroves (97%vegetation loss) and coastal ecosystems of the Nicobar archipelago. Interestingly, the coastal subsidence hasalso created new intertidal habitats in the erstwhile agricultural lands and terrestrial forests, which provided anopportunity for the colonization of mangrove species. During our long-term monitoring of mangrove colonizationin the Nicobar archipelago, we collected Aegiceras corniculatum  (L.) Blanco (Primulaceae) from Alreak,in Nicobar Islands. The occurrence of this species forms a new distributional record for the Nicobar archipelago.The present article provides detailed information on its taxonomy, ecology, and discusses the potential futurespread of this species in the Nicobar Islands

Epitypification of Andrographis alata (Acanthaceae)

The name Andrographis alata (Vahl) Nees, basionym Justicia alata Vahl, is epitypified here

Removal of hazardous material from wastewater by using metal organic framework (MOF) embedded polymeric membranes

© 2018, © 2018 Taylor & Francis. Heavy metals in wastewater can cause acute and chronic toxicity which leads to learning disabilities, cancer, and even death. In the present work, Zn-based MOF (MOF-5) was prepared, and it is characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscope (SEM) analyses. MOF-5-incorporated polymeric membranes (polyethersulfone [PES], cellulose acetate [CA], and polyvinylidene fluoride [PVDF]) prepared by phase inversion method. The morphology, hydrophilicity, porosity, permeation performance, antifouling properties, and the rejection of Cu (II) and Co (II) metal ions of the membranes were significantly improved with the addition of MOF-5. Higher rejection efficiency for Co (II) in PES/MOF-5 and CA/MOF-5 was found to be 74.40% and 77%, respectively

Angiosperms of Sendirakillai Sacred Grove (SSG), Cuddalore District, Tamil Nadu, India

We provide a checklist of Angiosperm alpha diversity of Sendirakillai Sacred Grove (SSG), a community conserved Tropical Dry Evergreen Forest (TDEF) fragment located on the Coromandel Coast of Cuddalore district (11°44’24” N, 79°47’24” E), Tamil Nadu, South India. Plant specimens were collected either with flowers or fruits and were identified and confirmed with available regional floras, revisions and monographs. In the present study, we have enumerated a total of 180 species and 2 varieties belonging to 151 genera distributed in 66 families from 29 orders according to Angiosperm Phylogeny Group III Classification. More than 30% of the total flora is represented by six families namely Fabaceae (14), Rubiaceae (12), Cyperaceae (10), Apocynaceae (8), Poaceae (8) and Euphorbiaceae (7). Three endemic species to India and three species that are confined to peninsular India and Sri Lanka are recorded from the sacred grove. Threats to the biodiversity of sacred grove are identified and conservation strategies are proposed

Microstructural and High Temperature Wear Characteristics of Plasma Transferred Arc Hardfaced Ni–Cr–Si–B-C Alloy Deposits

Due to the tough working environments, wear damage to nuclear reactor components is frequent. Usually, nuclear elements run at 573 k to 873 k. The feed water controller valves, used for the thundering of coolant flow, wear out faster among the reactor components. Austenitic stainless steels, using different methods for hardfacing, improve wear resistance to the cobalt and nickel alloys. Nickel based hardfacing is more resistant to wear than cobalt based hardfacing at high temperatures thanks to the solid oxide layers. Austenitic stainless-steel substrates generally favor nickel-based hardfaced (Ni–Cr-Si–B-C) over cobalt-driven hardfacing because this reduces radiation-induced nuclear activity. A well-known surface method for depositing nickel hardfacing, minimal dilution, alloys is the Plasma Transfer Arc (PTAs) weld technique. In this study the Ni-based alloy is hardfaced over a 316 L (N) ASS substratum with PTA hardfacing, for a dense of approximately 4–4.5 mm. The substrates and deposits were tested at different temperatures with a pin on disc wear (room temperature, 150 and 250°C).When grinding with 1000 grain SiC abrasive paper, the wear test samples were polished to the roughness value (Ra) of less than 0,25 m.The deposit showed a variety of wear mechanisms regarding the test temperature. Using friction and wear values and wear analysis, the wear mechanisms were determined. There was a considerable wear loss at room temperature (RT).At 423 K operating heat, mild ploughing at short sliding distances and tribo-oxidation were carried out with increasing sliding time.The primary wear mechanism was adherence at the time of operating temperature at 623 K, but as the sliding distance widened, tribo-oxidation improved. In combination with a working hardened substrate, the formation of an oxide layer could significantly reduce the wear loss of nickel-based alloys

Mutated CaV2.1 channels dysregulate CASK/P2X3 signaling in mouse trigeminal sensory neurons of R192Q Cacna1a knock-in mice

Background: ATP-gated P2X3 receptors of sensory ganglion neurons are important transducers of pain as they adapt their expression and function in response to acute and chronic nociceptive signals. The present study investigated the role of calcium/calmodulin-dependent serine protein kinase (CASK) in controlling P2X3 receptor expression and function in trigeminal ganglia from Cacna1a R192Q-mutated knock-in (KI) mice, a genetic model for familial hemiplegic migraine type-1.Results: KI ganglion neurons showed more abundant CASK/P2X3 receptor complex at membrane level, a result that likely originated from gain-of-function effects of R192Q-mutated CaV2.1 channels and downstream enhanced CaMKII activity. The selective CaV2.1 channel blocker \u3c9-Agatoxin IVA and the CaMKII inhibitor KN-93 were sufficient to return CASK/P2X3 co-expression to WT levels. After CASK silencing, P2X3 receptor expression was decreased in both WT and KI ganglia, supporting the role of CASK in P2X3 receptor stabilization. This process was functionally observed as reduced P2X3 receptor currents.Conclusions: We propose that, in trigeminal sensory neurons, the CASK/P2X3 complex has a dynamic nature depending on intracellular calcium and related signaling, that are enhanced in a transgenic mouse model of genetic hemiplegic migraine. \ua9 2013 Gnanasekaran et al.; licensee BioMed Central Ltd

Magazines for youth? : a comparative content analysis of two New Zealand juvenile periodicals

This research project investigated the readership of two New Zealand youth magazines during the period 1945-1947. The magazines, Conquest: the magazine for youth, and Junior Digest: the magazine for girls and boys, were subjected to a content analysis which attempted to capture details of the readers, and describe the types of articles in each magazine in an attempt to discover what kinds of reading tastes young people of the period had. The project produced a description of the kinds of content that were present in the two magazines and in what quantities. By combining this content analysis with demographic data of the readers themselves, who contributed to the magazines by sending letters, jokes, competition entries and jokes, this research was able to show who the specific group of readers were and make conclusions about what they liked. By contrasting the results, it was determined that there were slight differences in the content of the magazines which may have accounted for the failure of Conquest to continue after July 1947, but that the data provided by the content analysis alone was insufficient to allow insight into the broader periodical reading tastes of New Zealand youth in the second half of the 1940s

The first HyDRA challenge for computational vibrational spectroscopy

Vibrational spectroscopy in supersonic jet expansions is a powerful tool to assess molecular aggregates in close to ideal conditions for the benchmarking of quantum chemical approaches. The low temperatures achieved as well as the absence of environment effects allow for a direct comparison between computed and experimental spectra. This provides potential benchmarking data which can be revisited to hone different computational techniques, and it allows for the critical analysis of procedures under the setting of a blind challenge. In the latter case, the final result is unknown to modellers, providing an unbiased testing opportunity for quantum chemical models. In this work, we present the spectroscopic and computational results for the first HyDRA blind challenge. The latter deals with the prediction of water donor stretching vibrations in monohydrates of organic molecules. This edition features a test set of 10 systems. Experimental water donor OH vibrational wavenumbers for the vacuum-isolated monohydrates of formaldehyde, tetrahydrofuran, pyridine, tetrahydrothiophene, trifluoroethanol, methyl lactate, dimethylimidazolidinone, cyclooctanone, trifluoroacetophenone and 1-phenylcyclohexane-cis-1,2-diol are provided. The results of the challenge show promising predictive properties in both purely quantum mechanical approaches as well as regression and other machine learning strategies

Effects of molecular structure on the physical, chemical, and electrical properties of ester‐based transformer insulating liquids

This article presents the experimental studies carried out on the environmental friendly polyol ester insulating liquids to investigate the effect of molecular structure on the physical, chemical, and electrical properties. Six different polyol esters that can be produced from the transesterification of various methyl esters with neopentylglycol/trimethylolpropane alcohols were synthesized and compared with those of refined, bleached, and deodorized palm oil (RBDPO) and mineral transformer oil. The finding suggests that the physical properties like fire point, pour point, and viscosity are very much affected by the molecular weight and molecular composition of the polyol esters. The electrical properties are also highly influenced by the molecular structure‐related characteristics, such as the polarity, dipole polarization, carbon chain length, and degree of branching. The results confirm the findings of previous studies that the polyol esters and RBDPO have more polarity and dipole polarization compared to mineral oil. The experimental evidence showed that the newly synthesized insulating liquids have favorable thermal and electrical properties, thus suggesting that the insulating liquids have the potential to replace conventional insulating liquids to provide a more sustainable power system in the future