Enabling rapid and accurate construction of CCSD(T)-level potential energy surface of large molecules using molecular tailoring approach

The construction of the potential energy surface (PES) of even a medium-sized molecule employing correlated theory, such as CCSD(T), is an arduous task due to the high computational cost. In this Letter, we report the possibility of efficient construction of such a PES employing the molecular tailoring approach (MTA) on off-the-shelf hardware. The full calculation (FC) as well as MTA energies at CCSD(T)/aug-cc-pVTZ level for three test molecules, viz. acetylacetone, N-methyacetamide, and tropolone are reported. All the MTA energies are in excellent agreement with their FC counterparts (typical error being sub-millihartree) with a time advantage factor of 3 to 5. The energy barrier from the ground- to transition-state is accurately captured. Further, the accuracy and efficiency of the MTA method for estimating energy gradients at CCSD(T) level are demonstrated. This work brings out the possibility of the construction of PES for large molecules using MTA with the computational economy at a high level of theory and/or basis set

Primordial black holes from single-field inflation: a fine-tuning audit

All single-field inflationary models invoke varying degrees of tuning in order to account for cosmological observations. Mechanisms that generate primordial black holes (PBHs) from enhancement of primordial power at small scales posit inflationary potentials that transiently break scale invariance and possibly adiabaticity over a range of modes. This requires additional tuning on top of that required to account for observations at scales probed by cosmic microwave background (CMB) anisotropies. In this paper we study the parametric dependence of various single-field models of inflation that enhance power at small scales and quantify the degree to which coefficients in the model construction have to be tuned in order for certain observables to lie within specified ranges. We find significant tuning: changing the parameters of the potentials by between one part in a hundred and one part in $10^8$ (depending on the model) is enough to change the power spectrum peak amplitude by an order one factor. The fine-tuning of the PBH abundance is larger still by 1-2 orders of magnitude. We highlight the challenges imposed by this tuning on any given model construction. Furthermore, polynomial potentials appear to require significant additional fine-tuning to also match the CMB observations.Comment: 16 pages + appendices, 5 figure

Nanotechnological innovation for the production of daughter less Tilapia, Oreochromis niloticus (Linnaeus, 1758)

The aim of present work was to develop a new Fadrozole (FDZ)-loaded Poly (D,L-lactide-co– glycolide) lactide:glycolide (50:50)(PLGA) nanoparticles for effective delivery of the masculinization drug, Fadrozole, as an alternative to commercially available masculinization agents like testosterone (dietary supplementation of 17 ?- methyltestosterone) which are steroids and banned in most EU countries. The FDZ-loaded PLGA NPs were pre-pared by solvent displacement technique. The particle size of FDZ-loaded PLGA NPs was analyzed using LICOMP particle size analyser. It was found to be in the range of 60±66.7 nm to 560±66.7 nm with average size of 201.4±66.7 nm, where the Zeta potential was estimated to be about -20.82 mV, a series of experiments were carried out to induce masculinization using FDZ-loaded PLGA nanoparticles during the sex differentiation period. Tilapia, Oreochromis niloticus fry were treated with FTZ-loaded PLGA nanoparticles at dosages 5, 25, 50 and 100ppm/kg diet for 10, 15 and 30 days. The results indicated an increase in the proportion of males with dosage and duration of treatment. The male percentage was 92.35±0.86 for T7(50 ppm) at 10 days, 97.76±1.12 for T7 (100 ppm) at 15 days and 100 % for both T6 (50ppm) and T7 (100 ppm) at 30 days. This is first time done by using nanotechnology efficiently in Tilapia species which is very important Fresh water aquaculture species in present era. Which showed increase the male population with lesser dose of nano-encapsulated Fadrozole (FDZ) loaded PLGA nanoparticles drug as compared with naked control Fadrozole (FDZ) drug delivery

Diluted Josephson-junction arrays in a magnetic field: phase coherence and vortex glass thresholds

The effects of random dilution of junctions on a two-dimensional Josephson-junction array in a magnetic field are considered. For rational values of the average flux quantum per plaquette $f$, the superconducting transition temperature vanishes, for increasing dilution, at a critical value $x_S(f)$, while the vortex ordering remains stable up to $x_{VL}>x_S$, much below the value $x_p$ corresponding to the geometric percolation threshold. For $x_{VL}<x<x_p$, the array behaves as a zero-temperature vortex-glass. Numerical results for $f=1/2$ from defect energy calculations are presented which are consistent with this scenario.Comment: 4 pages, 4 figures, to appear in Phys. Rev.

Advanced Manifolds for Improved Solid Oxide Electrolyzer Performance

An investigation was conducted to see if additive manufacturing could be used to fabricate more efficient manifold designs for improved flow, reduced stresses, and decreased number of joints to be sealed for a solid oxide electrolyzer used to convert carbon dioxide to oxygen. Computational flow and mechanical modeling were conducted on a NASA Glenn Research Center patented cell and stack design with the potential to achieve a 3-4 times mass reduction. Various manifold designs were modeled, and two were downselected to be fabricated and tested. Some benefit was seen in a baffled manifold design, which directed incoming flow more effectively into the flow channels, compared to the original design, where the flow spent more time within the manifold itself. Flow measurements indicated some non-uniformity of flow across the channels at higher flow rates, which were not predicted by the model. Some possible explanations for the differences are discussed

Ferroelectric and Incipient Ferroelectric Properties of a Novel Sr_(9-x)PbxCe2Ti2O36 (x=0-9) Ceramic System

Sr_(9-x)PbxCe2Ti12O36 system is derived from the perovskite SrTiO3 and its chemical formula can be written as (Sr_(1-y)Pby)0.75Ce0.167TiO3. We investigated dielectric response of Sr_(9-x)PbxCe2Ti12O36 ceramics (x = 0-9) between 100 Hz and 100 THz at temperatures from 10 to 700 K using low- and high-frequency dielectric, microwave (MW), THz and infrared spectroscopy. We revealed that Sr9Ce2Ti12O36 is an incipient ferroelectric with the R-3c trigonal structure whose relative permittivity e' increases from 167 at 300 K and saturates near 240 below 30 K. The subsequent substitution of Sr by Pb enhances e' to several thousands and induces a ferroelectric phase transition to monoclinic Cc phase for x>=3. Its critical temperature Tc linearly depends on the Pb concentration and reaches 550 K for x=9. The phase transition is of displacive type. The soft mode frequency follows the Barrett formula in samples with x=3. The MW dispersion is lacking and quality factor Q is high in samples with low Pb concentration, although the permittivity is very high in some cases. However, due to the lattice softening, the temperature coefficient of the permittivity is rather high. The best MW quality factor was observed for x=1: Q*f=5800 GHz and e'=250. Concluding, the dielectric properties of Sr_(9- x)PbxCe2Ti12O36 are similar to those of Ba_(1-x)SrxTiO3 so that this system can be presumably used as an alternative for MW devices or capacitors.Comment: subm. to Chem. Mate