Abstract
The analysis of the time profile of electrical signals produced by energy depositions in germanium detectors allows discrimination of events with different topologies. This is especially ...relevant for experiments searching for the neutrinoless double beta decay of
$$^{76}$$
76
Ge to distinguish the sought-after signal from other background sources. The standard calibration procedures used to tune the selection criteria for double-beta decay events use a
$$^{228}$$
228
Th source, because it provides samples of signal-like events. These samples exhibit energy spatial distributions with subtle different topologies compared to neutrinoless double-beta decay events. In this work, we will characterize these topological differences and, with the support of a
$$^{56}$$
56
Co source, evaluate biases and precision of calibration techniques which use such event samples. Our results will be particularly relevant for future experiments in which a solid estimation of the efficiency is required.
The mygalomorph spiders of the family Atypidae are among the most archaic spiders. The genus Atypus Latreille, 1804 occurs in Eurasia and northern Africa, with a single enigmatic species, Atypus ...snetsingeri Sarno, 1973, known only from a small area in southeastern Pennsylvania in eastern USA. A close relationship to European species could be assumed based on geographic proximity, but A. snetsingeri more closely resembled Asian species. This study was undertaken to learn more about the genetics of A. snetsingeri, its habitat requirements and natural history. Molecular markers (CO1 sequences) were compared to available data for other atypids and showed that A. snetsingeri is identical with A. karschi Dönitz, 1887 native to East Asia. Natural history parameters in Pennsylvania were also similar in every respect to A. karschi in Japan, therefore, we propose that the spider is an introduced species and the specific epithet snetsingeri is relegated to a junior synonym of A. karschi. Cytogenetic analysis showed an X0 sex chromosome system (42 chromosomes in females, 41 in males) and we also detected nucleolus organizing regions and heterochromatin, the latter for the first time in the Atypoidea. In Pennsylvania the spider is found in a variety of habitats, from forests to suburban shrubbery, where the above-ground webs are usually attached vertically to trees, shrubs, or walls, although other webs are oriented horizontally near the ground. Prey include millipedes, snails, woodlice, carabid beetles and earthworms. Atypus karschi is the first known case of an introduced purse-web spider. It is rarely noticed but well-established within its range in southeastern Pennsylvania.
Enhanced Catalytic Activity of a Cd Arora, Zinnia; Markad, Datta; Khullar, Sadhika ...
Catalysis letters,
07/2023, Volume:
153, Issue:
7
Journal Article
Peer reviewed
Using a new unsymmetrical and flexible primary amide-functionalized ligand, a novel crystalline complex, Cd((S)-2-BPMEG)(H.sub.2O)(ClO.sub.4).sub.2.sup..2H.sub.2O (1), has been synthesized under ...ambient conditions and characterized by various analytical techniques. Its activated form (1a), obtained upon heating under vacuum at 80 °C for 8 h, acts as an excellent heterogeneous catalyst (2 mol% and 30 min at 25-27 °C) for the solvent-free cyanosilylation reaction of various derivatives of benzaldehyde, aliphatic, cycloaliphatic and heterocyclic aldehydes with trimethylsilyl cyanide (TMSCN) in 97-100% conversion. Compared to the symmetrical analogue, its catalytic activity enhanced by an order of magnitude is remarkable. The catalyst is recyclable up to five consecutive cycles without significant loss of activity and structural integrity.
Constructing core/shell nanoarrays with optimal structure and composition can maximize solar light utilization. In the present work, a distinct regular array of SiC/TiO.sub.2 core/shell nanoarray ...photoanodes with improved charge separation is successfully achieved through two sequential steps of electrochemical etching and atomic layer deposition. The suitable band offset between SiC and TiO.sub.2 results in forming a type-II heterojunction at the SiC/TiO.sub.2 interface, which efficiently promotes electron-hole separation. Under simulated sunlight illumination (100 mW/cm.sup.2), the SiC/TiO.sub.2 nanoarray composite photoanode exhibits a significantly improved photocurrent of 3.62 mA/cm.sup.2 at 1.4 V versus Ag/AgCl, which demonstrates significantly increased photoelectrochemical (PEC) activity compared to the intrinsic SiC photoanode. The significant enhancement of PEC behaviors is mainly assigned to the improved electron-hole separation at the surface of the junction, combined with the synergistic effect of the highly oriented nanochannel array configuration, single-crystal character of the etched entire SiC nanoarray film, as well as the incorporation of N dopants.
The separators with excellent thermal stability and electrolyte wettability are pivotal for ensuring the safety and performance of lithium-ion batteries (LIBs). Poly (ether ether ketone) (PEEK) is a ...potential separator material that meets these criteria. However, the poor solubility and high melting temperature of PEEK limit its practical production and application. Herein, we report a safe and convenient strategy to fabricate lithiated poly (ether ether ketone) (LPEEK) separators via lithiation of PEEK and thermally induced phase separation below the melting point. And the pore structure of LPEEK separators can be regulated by the amount of polyvinylpyrrolidone. Compared with commercial polypropylene (PP) separators and other PEEK separators, our LPEEK separators exhibit excellent thermal stability (LPEEK, almost no change at 200 °C; PP, shrink 4.4% at 100 °C) and electrolyte wettability (electrolyte contact angle: LPEEK, 0°; PP, 37.9°). Meanwhile, the LPEEK separators can still be used normally after 200 °C high-temperature treatment and are promising candidates for the LIB separators used at high temperatures. The proposed method holds promise for the industrial production of PEEK separators.
Parameters controlling the reduction of nickel hydrotalcite-based catalysts have been investigated in order to optimize the activity of the catalyst for CO.sub.2 methanation. Beside the variation of ...temperature and duration in the reduction process of the catalysts with hydrogen, two different reduction modes have been explored. The first one is the direct reduction of the dried uncalcined hydrotalcite-based precursor material whereas the second one is given by the reduction of the same type of precursor material but having been subjected to a calcination step prior to reduction. The corresponding kinetic measurements for the two principally different catalyst preparation schemes reveal that omitting the calcination step can largely be beneficial. Standard characterization data (XRD, BET, TG-FTIR, XPS) for the different catalytic materials will be presented.
