Color centers in hexagonal boron nitride monolayers: A group theory and ab-initio analysis

We theoretically study physical properties of the most promising color center candidates for the recently observed single-photon emissions in hexagonal boron nitride (h-BN) monolayers. Through our group theory analysis combined with density functional theory (DFT) calculations we provide several pieces of evidence that the electronic properties of the color centers match the characters of the experimentally observed emitters. We calculate the symmetry-adapted multi-electron wavefunctions of the defects using group theory methods and analyze the spin-orbit and spin-spin interactions in detail. We also identify the radiative and non-radiative transition channels for each color center. An advanced ab-initio DFT method is then used to compute energy levels of the color centers and their zero-phonon-line (ZPL) emissions. The computed ZPLs, the profile of excitation and emission dipole polarizations, and the competing relaxation processes are discussed and matched with the observed emission lines. By providing evidence for the relation between single-photon emitters and local defects in h-BN, this work provides the first steps towards harnessing quantum dynamics of these color centers.Comment: 11 pages, 5 figure

Analisis Laju Aliran Panas Pada Reaktor Tanki Alir Berpengaduk Dengan Half - Coil Pipe

Untuk menghasilkan produk berkualitas tinggi dalam jumlah besar dan continue (mass production), Perusahaan melakukan pengendalian kualitas dengan langkah awal berupa pengidentifikasian kecacatan produk dan lamanya waktu proses agar dapat mengurangi siklus waktu proses produksi seminimal mungkin. Oleh karena itu, penulis melakukan analisis laju aliran panas, jenis aliran fluida, pipa perambatan panas, daya pengaduk untuk mengetahui seberapa besar pengaruh faktor tersebut dalam proses pencairan material lateks. Metode dari pengujian ini meliputi : pengumpulan data di lapangan, melakukan perhitungan dari data yang terkumpul, dan menarik kesimpulan. Dari hasil pengujian ini diketahui bahwa waktu proses dan pencampuran bahan lateks di dalam tanki dipengaruhi oleh viskositas dinamik lateks, laju perpindahan panas steam pada half-pipe coil dan daya agitator atau pengaduk

The role of dietary nucleotide on energy sources and growth function of common carp, Cyprinus carpio

Considering the effects of dietary nucleotides on growth and metabolism, this study was conducted to determine the effect of different levels of this nutrient on the sources of the body needed energy, and growth performance of common carp. Fish with average (±SD) weight of 7.5±0.2g were fed to five levels of dietary nucleotides containing 0, 0.1, 0.2, 0.3 and 0.4 percent for 8 weeks. Fish were fed 5 times daily according the satiation. After 56 days, the results showed that the level 0.2% nucleotide had the highest growth rate in terms of weight and length, but other parameters such as body weight, specific growth rate and feed conversion ratio, differences were not significantly changed. Biochemical analysis of serum parameters and proximate analysis showed that the physiological function of fish affected by different levels of nucleotides whereas in the energy supply sources, including glucose, triacyleglycerol, total protein and albumin there were no significant difference in cholesterol and lipid content of carcass. This study conveys a positive effect on the biosynthesis of dietary nucleotides on energy sources and growth functions, while the common carp has ability to synthesize this substance into the body, the level of 0.2% in the diet can affection *Corresponding author sufficient effect on growth and some biochemical indices

A New Calcareous Nannofossil Record from the Lower Jurassic of Kermanshah, Western Iran: Implications for Biostratigraphy and Evolutionary Reconstructions

Calcareous nannofossils are used here for the first time in order to establish a precise biostratigraphic framework for the Kermanshah Radiolarite Formation, an outcropping in Western Iran. The new data presented here challenge the previous tentative age interpretations (Pliensbachian to early Toarcian) based upon radiolarians. Calcareous nannofossil assemblages and events unequivocally indicated that the pelagic limestones and marls are late Sinemurian in age (NJT 3b nannofossil subzone), and that these are thrusted over shales and cherts dated as uppermost Sinemurian (NJT 3b-c nannofossil subzone) and lowermost Pliensbachian (NJT 4 nannofossil zone). This result leads not only to reconsideration of the age of the radiolarite formations, which are widespread in the Zagros orogenic system, but also a better understanding of the stratigraphic relationships between the various lithological units known in the area. Besides these new stratigraphic inferences, the calcareous nannofossil assemblages of the uppermost Sinemurian– lowermost Pliensbachian successions revealed the common presence of new morphologies of the Mitrolithus genus, never described before. These findings allow for the description of three new species, M. montgolfieri, M. pseudonannoconus, and M. tethysiensis, and reveal the existence of homeomorphy between the spine structure of conical Lower Jurassic coccoliths and the widespread Cretaceous nannoconids. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Nonlinear corrections for the nuclear gluon distribution in eAeA processes

An analytical study with respect to the nonlinear corrections for the nuclear gluon distribution function in the next-to-leading order approximation at small $x$ is presented. We consider the nonlinear corrections to the nuclear gluon distribution functions at low values of $x$ and $Q^{2}$ using the parametrization $F_{2}(x,Q^{2})$ and using the nuclear modification factors where they have been obtained with the Khanpour-Soleymaninia-Atashbar-Spiesberger-Guzey model. The CT18 gluon distribution is used as baseline proton gluon density at $Q_{0}^{2}=1.69~\mathrm{GeV}^2$. We discuss the behavior of the gluon densities in the next-to-leading order and the next-to-next-to-leading order approximations at the initial scale $Q_{0}^{2}$, as well as the modifications due to the nonlinear corrections. We find the QCD nonlinear corrections are significant for the next-to-leading order accuracy than the next-to-next-to-leading order for light and heavy nuclei. The results of the nonlinear GLR-MQ evolution equation are similar to those obtained with the Rausch-Guzey-Klasen gluon upward and downward evolutions within the uncertainties. The magnitude of the gluon distribution with the nonlinear corrections increases with a decrease of $x$ and an increase of the atomic number A

A Role of Myocardin Related Transcription Factor-A (MRTF-A) in Scleroderma Related Fibrosis.

In scleroderma (systemic sclerosis, SSc), persistent activation of myofibroblast leads to severe skin and organ fibrosis resistant to therapy. Increased mechanical stiffness in the involved fibrotic tissues is a hallmark clinical feature and a cause of disabling symptoms. Myocardin Related Transcription Factor-A (MRTF-A) is a transcriptional co-activator that is sequestered in the cytoplasm and translocates to the nucleus under mechanical stress or growth factor stimulation. Our objective was to determine if MRTF-A is activated in the disease microenvironment to produce more extracellular matrix in progressive SSc. Immunohistochemistry studies demonstrate that nuclear translocation of MRTF-A in scleroderma tissues occurs in keratinocytes, endothelial cells, infiltrating inflammatory cells, and dermal fibroblasts, consistent with enhanced signaling in multiple cell lineages exposed to the stiff extracellular matrix. Inhibition of MRTF-A nuclear translocation or knockdown of MRTF-A synthesis abolishes the SSc myofibroblast enhanced basal contractility and synthesis of type I collagen and inhibits the matricellular profibrotic protein, connective tissue growth factor (CCN2/CTGF). In MRTF-A null mice, basal skin and lung stiffness was abnormally reduced and associated with altered fibrillar collagen. MRTF-A has a role in SSc fibrosis acting as a central regulator linking mechanical cues to adverse remodeling of the extracellular matrix