ab initio calculations at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g* for a single point total energy calculation are reported for the importantenergy-minimum conformations and transition-state geometries of 1, 3-diazacyclohepta-1, 2-diene (2) and 1, 3-diazacycloocta-1, 2-diene (3). the c2 symmetric twist-chair (2-tc)conformation of 2 is calculated to be 7.4 kj...

We show that the QCD color transparency of higher-twist contributions to inclusive hadroproduction cross sections, where baryons are produced directly in a shortdistance subprocess, can explain several remarkable features of high-pT baryon production in heavy ion collisions which have recently been observed at RHIC: (a) the anomalous increase of the proton-to-pion ratio with centrality (b): the...

The present work deals with the theoretical study on heat transfer characteristics and the performance of a cylindrical parabolic solar water heater with twisted tape inserted inside the absorber tube. The absorber tube equipped with twisted tape with six different twist ratios 5, 6, 7, 8, 9 and 10. The theoretical work is conducted in a turbulent flow regime and considering water as a working ...

2014 Experimental values are reported for the splay/twist viscoelastic ratios of OHMBBA in the nematic region as a function of temperature. In the experiments the homodyne self-beat technique was used to detect noise intensity spectra of laser light scattered by the nematic liquid crystal. The measured rotational viscosity can be described as a function of the temperature, the order parameter a...

Heat transfer improvement in circular pipe by using nanofluid and twisted tape is presented in this review paper. Experimental and numerical studies are incorporated involving both the range of turbulent and laminar flow. Effect of type and volume fraction of nanofluid on performance of heat transfer was referred along with the length and twist ratio of the tape through the pipe on heat transfe...

Medaka twist, a basic helix-loop-helix (bHLH) transcription factor, is expressed in the sclerotome during embryogenesis. We previously established a line of twist-EGFP transgenic medaka, whose EGFP expression is regulated by the twist promoter; therefore, we could observe the behavior of sclerotomal cells in vivo. In the transgenic medaka embryos, EGFP-positive sclerotomal cells migrated dorsal...

This study aimed to examine HIF-2α, TWIST, and CXCR4 expression in papillary thyroid carcinoma (PTC) and assesses the association of their expression with clinicopathological indicators. HIF-2α, TWIST, and CXCR4 protein expression in 129 PTCs, 61 nodular hyperplasia, and 118 normal thyroid tissue specimens was analyzed using immunohistochemistry. The protein expression levels of these three mol...

We present a higher-twist production mechanism for η c and χ J charmonium at large momentum fraction x F in pion-nucleon collisions. The higher-twist contribution is essentially independent of x F and therefore becomes dominant at large x F , where the leading-twist contribution falls off as (1 − x F) 3. We show that the higher-twist mechanism produces longitudinally polarized χ 1 and χ 2. For ...

In this particular isospin combination of structure functions the contribution of twist-2 operators cancels out exactly and twist-4 contributions are dominant. It is remarkable that in the large Nc limit the twist-4 distribution function of quarks in the pion can be reduced to a convolution of twist-2 pion distribution amplitudes. 2. One can read the contribution of four-quark twist-4 operators...

We show that if a knot admits a prime, twist-reduced diagram with at least 4 twist regions and at least 6 crossings per twist region, then every non-trivial Dehn filling of that knot is hyperbolike. A similar statement holds for links. We prove this using two arguments, one geometric and one combinatorial. The combinatorial argument further implies that every link with at least 2 twist regions ...