In situ chemical oxidative polymerisation for ordered conducting polythiophene nanostructures in presence of dioctyl sodium sulfosuccinate

Polythiophenes (PTs) have been synthesized by chemical oxidative polymerization of thiophene in the presence of an anionic surfactant dioctyl sodium sulfosuccinate (AOT) using ferric chloride as an oxidant in chloroform solvent. Different monomer/surfactant ratios have been employed to study the effect of surfactant on synthesis and properties of polythiophenes. The PTs have been characterized by FT-IR spectroscopy, wide-angle powder X-ray diffraction and elemental analysis. The properties of PTs prepared using AOT surfactant have been compared with those of PT synthesized without surfactant. Four probe electrical conductivity measurements of the samples reveal that the conductivity is in the range of (7.4–1.0)×10-3 S cm-1 for AOT doped polythiophene samples. The band gap of the polymers determined from diffuse reflectance spectroscopy is in the range of 2.25–2.50 eV. Scanning electron microscopic images of the samples exhibited spherical nanoparticle morphology with size in the range of 800 ± 50 nm

Radiofrequency spectroscopy of a linear array of Bose-Einstein condensates in a magnetic lattice

We report site-resolved radiofrequency spectroscopy measurements of Bose-Einstein condensates of 87Rb atoms in about 100 sites of a one-dimensional 10 micron-period magnetic lattice produced by a grooved magnetic film plus bias fields. Site-to-site variations of the trap bottom, atom temperature, condensate fraction and chemical potential indicate that the magnetic lattice is remarkably uniform, with variations in trap bottoms of only +/- 0.4 mG. At the lowest trap frequencies (radial and axial frequencies 1.5 kHz and 260 Hz, respectively), temperatures down to 0.16 microkelvin are achieved in the magnetic lattice and at the smallest trap depths (50 kHz) condensate fractions up to 80% are observed. With increasing radial trap frequency (up to 20 kHz, or aspect ratio up to about 80) large condensate fractions persist and the highly elongated clouds approach the quasi-1D Bose gas regime. The temperature estimated from analysis of the spectra is found to increase by a factor of about five which may be due to suppression of rethermalising collisions in the quasi-1D Bose gas. Measurements for different holding times in the lattice indicate a decay of the atom number with a half-life of about 0.9 s due to three-body losses and the appearance of a high temperature (about 1.5 microkelvin) component which is attributed to atoms that have acquired energy through collisions with energetic three-body decay products

Biogeochemical and ecological impacts of boundary currents in the Indian Ocean

Monsoon forcing and the unique geomorphology of the Indian Ocean basin result in complex boundary currents, which are unique in many respects. In the northern Indian Ocean, several boundary current systems reverse seasonally. For example, upwelling coincident with northward-flowing currents along the coast of Oman during the Southwest Monsoon gives rise to high productivity which also alters nutrient stoichiometry and therefore, the species composition of the resulting phytoplankton blooms. During the Northeast Monsoon most of the northern Indian Ocean boundary currents reverse and favor downwelling. Higher trophic level species have evolved behavioral responses to these seasonally changing conditions. Examples from the western Arabian Sea include vertical feeding migrations of a copepod (Calanoides carinatus) and the reproductive cycle of a large pelagic fish (Scomberomorus commerson). The impacts of these seasonal current reversals and changes in upwelling and downwelling circulations are also manifested in West Indian coastal waters, where they influence dissolved oxygen concentrations and have been implicated in massive fish kills. The winds and boundary currents reverse seasonally in the Bay of Bengal, though the associated changes in upwelling and productivity are less pronounced. Nonetheless, their effects are observed on the East Indian shelf as, for example, seasonal changes in copepod abundance and zooplankton community structure. In contrast, south of Sri Lanka seasonal reversals in the boundary currents are associated with dramatic changes in the intensity of coastal upwelling, chlorophyll concentration, and catch per unit effort of fishes. Off the coast of Java, monsoon-driven changes in the currents and upwelling strongly impact chlorophyll concentrations, seasonal vertical migrations of zooplankton, and sardine catch in Bali Strait. In the southern hemisphere the Leeuwin is a downwelling-favorable current that flows southward along western Australia, though local wind forcing can lead to transient near shore current reversals and localized coastal upwelling. The poleward direction of this eastern boundary current is unique. Due to its high kinetic energy the Leeuwin Current sheds anomalous, relatively high chlorophyll, warm-core, downwelling eddies that transport coastal diatom communities westward into open ocean waters. Variations in the Leeuwin transport and eddy generation impact many higher trophic level species including the recruitment and fate of rock lobster (Panulirus cygnus) larvae. In contrast, the transport of the Agulhas Current is very large, with sources derived from the Mozambique Channel, the East Madagascar Current and the southwest Indian Ocean sub-gyre. Dynamically, the Agulhas Current is upwelling favorable; however, the spatial distribution of prominent surface manifestations of upwelling is controlled by local wind and topographic forcing. Meanders and eddies in the Agulhas Current propagate alongshore and interact with seasonal changes in the winds and topographic features. These give rise to seasonally variable localized upwelling and downwelling circulations with commensurate changes in primary production and higher trophic level responses. Due to the strong influence of the Agulhas Current, many neritic fish species in southeast Africa coastal waters have evolved highly selective behaviors and reproductive patterns for successful retention of planktonic eggs and larvae. For example, part of the Southern African sardine (Sardinops sagax) stock undergoes a remarkable northward migration enhanced by transient cyclonic eddies in the shoreward boundary of the Agulhas Current. There is evidence from the paleoceanographic record that these currents and their biogeochemical and ecological impacts have changed significantly over glacial to interglacial timescales. These changes are explored as a means of providing insight into the potential impacts of climate change in the Indian Ocean

Spatial, temporal, and demographic patterns in prevalence of smoking tobacco use and attributable disease burden in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019

Background Ending the global tobacco epidemic is a defining challenge in global health. Timely and comprehensive estimates of the prevalence of smoking tobacco use and attributable disease burden are needed to guide tobacco control efforts nationally and globally. Methods We estimated the prevalence of smoking tobacco use and attributable disease burden for 204 countries and territories, by age and sex, from 1990 to 2019 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. We modelled multiple smoking-related indicators from 3625 nationally representative surveys. We completed systematic reviews and did Bayesian meta-regressions for 36 causally linked health outcomes to estimate non-linear dose-response risk curves for current and former smokers. We used a direct estimation approach to estimate attributable burden, providing more comprehensive estimates of the health effects of smoking than previously available. Findings Globally in 2019, 1.14 billion (95% uncertainty interval 1.13-1.16) individuals were current smokers, who consumed 7.41 trillion (7.11-7.74) cigarette-equivalents of tobacco in 2019. Although prevalence of smoking had decreased significantly since 1990 among both males (27.5% [26. 5-28.5] reduction) and females (37.7% [35.4-39.9] reduction) aged 15 years and older, population growth has led to a significant increase in the total number of smokers from 0.99 billion (0.98-1.00) in 1990. Globally in 2019, smoking tobacco use accounted for 7.69 million (7.16-8.20) deaths and 200 million (185-214) disability-adjusted life-years, and was the leading risk factor for death among males (20.2% [19.3-21.1] of male deaths). 6.68 million [86.9%] of 7.69 million deaths attributable to smoking tobacco use were among current smokers. Interpretation In the absence of intervention, the annual toll of 7.69 million deaths and 200 million disability-adjusted life-years attributable to smoking will increase over the coming decades. Substantial progress in reducing the prevalence of smoking tobacco use has been observed in countries from all regions and at all stages of development, but a large implementation gap remains for tobacco control. Countries have a dear and urgent opportunity to pass strong, evidence-based policies to accelerate reductions in the prevalence of smoking and reap massive health benefits for their citizens. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

Ohm's law (PhysCasts)

How do the currents flowing through copper and iron wires, of same length and diameter, compare if the same voltage is applied across them

Capacitor charging (PhysCasts)

A capacitor with C=3.1 μF is fully charged using a 6 V battery. The battery is then removed and the capacitor is connected to an uncharged capacitor with C=9.3 μF through a switch. Find the charge on each capacitor once the equilibrium is reached after closing the switch

Multiple lens system - a combination of converging and diverging lenses (PhysCasts)

An object is placed 15 cm before a convex lens with focal length 5 cm. A concave lens of focal length 10 cm is placed after the first lens with 20 cm separation between them. Make a ray diagram and confirm your answers by numberical calculations

Gauss's law - a solid sphere in a shell (PhysCasts)

A uniformly charged insulating sphere of radius a and net charge -2Q is placed inside the cavity of a conducting shell of an inner radius b and other radius c. If the shell has a net charge of 3Q and is concentric to the sphere, find the electric field in different regions (a) Rb (d)bc

Trapping of ultracold atoms in a magnetic lattice

This dissertation presents the realization of a periodic array of Bose-Einstein condensates in a magnetic lattice consisting of an array of magnetic microtraps. Bose-Einstein condensation occurs when atoms confined in the magnetic microtraps are cooled to sufficiently low temperature that they all occupy the lowest quantum state of the traps. Evidence for the onset of Bose-Einstein condensation in multiple sites of the magnetic lattice is provided by radiofrequency spectroscopy. The realization of a periodic array of Bose-Einstein condensates in a magnetic lattice represents a major step towards the implementation of magnetic lattices to simulate exotic phenomena in lattices of complex geometry in materials science

Cloning and characterization of the gene encoding HMG CoA reductase from black night shade (<i>Solanum nigrum </i>L.)<b style=""></b>

66-72The first committed step in the pathway for biosynthesis of isoprenoids in plants is catalyzed by 3-hydroxy 3- methylglutaryl CoA reductase (HMGR; EC:1.1.1.34). Here we report for the first time, the cloning of a partial genomic DNA sequence encoding HMGR from a medicinal herb, Solanum nigrum L. This plant is associated with resistance against potato cyst nematode and the late blight pathogen, Phytophthora infestans. The clone Snhmgr (GenBank Acc.No. DQ 229901) had 582 base pairs (bp) with a 462 bp open reading frame (ORF), encoding 142 amino acid polypeptide. The in-silico analysis of Snhmgr sequence revealed about 85% identity with hmgr genes in other solanaceous plants. Phylogenetic analysis indicated that Snhmgr was more identical with tomato hmgr on evolutionary basis and belonged to the solanaceous cluster, including hmgr genes from tomato, potato, tobacco and capsicum. Functional analysis of conserved domains of Snhmgr showed CoA reductase, NAD binding and substrate binding activities