Lower bound for energies of harmonic tangent unit-vector fields on convex polyhedra

We derive a lower bound for energies of harmonic maps of convex polyhedra in $\R^3$ to the unit sphere $S^2,$ with tangent boundary conditions on the faces. We also establish that $C^\infty$ maps, satisfying tangent boundary conditions, are dense with respect to the Sobolev norm, in the space of continuous tangent maps of finite energy.Comment: Acknowledgment added, typos removed, minor correction

Torsion and bending of nucleic acids studied by subnanosecond time-resolved fluorescence depolarization of intercalated dyes

Subnanosecond time‐resolved fluorescence depolarization has been used to monitor the reorientation of ethidium bromide intercalated in native DNA, synthetic polynucleotide complexes, and in supercoiled plasmid DNA. The fluorescence polarization anisotropy was successfully analyzed with an elastic model of DNA dynamics, including both torsion and bending, which yielded an accurate value for the torsional rigidity of the different DNA samples. The dependence of the torsional rigidity on the base sequence, helical structure, and tertiary structure was experimentally observed. The magnitude of the polyelectrolyte contribution to the torsional rigidity of DNA was measured over a wide range of ionic strength, and compared with polyelectrolyte theories for the persistence length. We also observed a rapid initial reorientation of the intercalated ethidium which had a much smaller amplitude in RNA than in DNA

Time-resolved spectroscopy of macromolecules: Effect of helical structure on the torsional dynamics of DNA and RNA

The torsional rigidity of DNA and RNA is measured via the fluorescence depolarization technique

Variational quantum Monte Carlo simulations with tensor-network states

We show that the formalism of tensor-network states, such as the matrix product states (MPS), can be used as a basis for variational quantum Monte Carlo simulations. Using a stochastic optimization method, we demonstrate the potential of this approach by explicit MPS calculations for the transverse Ising chain with up to N=256 spins at criticality, using periodic boundary conditions and D*D matrices with D up to 48. The computational cost of our scheme formally scales as ND^3, whereas standard MPS approaches and the related density matrix renromalization group method scale as ND^5 and ND^6, respectively, for periodic systems.Comment: 4+ pages, 2 figures. v2: improved data, comparisons with exact results, to appear in Phys Rev Let

Effect of Corn Processing and Reconstitution in High Grain Diets on Feedlot Performance and Carcass Characteristics of Steers and Heifers

A 167-day feedlot trial was conducted to examine the effects of corn processing and reconstitution on growth performance and carcass characteristics of feedlot cattle. Initial weights of the continental cross steers (n = 95) and heifers (n =63) were 690 and 680 Ib, respectively. Diets were 84.5% corn, 7.0% ground grass hay, 4.9% soybean meal, and 3.6% liquid supplement. The grain component of the diet was either dry whole corn (WC), dry rolled corn (RC), corn reconstituted at least 12 h before rolling (RRC), or corn reconstituted with a commercial surfactant3 at least 12 hours before rolling (CRC). Monensin and tylosin were included at 26.9 and 11 .O g/ton, respectively. Dry matter content of the WC, RC, RRC, and CRC diets were 85.62, 85.03, 80.98, and 80.96%, respectively. Dietary treatment had no effect on the feedlot performance of the steers or heifers. Yield grade (YG) was lower (P= .05) for CRC than for RRC cattle (2.96 vs 3.27). Kidney pelvic and heart fat (KPH) was lower (Pc.05) for RC (2.30%) and CRC (2.29%) than for WC (2.48%) and RRC (2.56%) cattle. KPH and YG were the only measured variable affected by dietary treatment indicating little advantage to any of the corn processing methods tested

Grain Sources and Roughage Levels for Limited Feeding Backgrounding Programs

The effects of grain source and roughage level in limited intake feeding programs were evaluated in 622-lb steer calves. Supplemented diets were based on high moisture ear corn (HMEC), whole shelled corn (WSC) + hay to provide similar NDF to the HMEC diet, HMEC diet containing 10% hay and the WSC + hay diet formulated to contain NDF similar to HMEC + hay. Steer calves were blocked by weight and fed to achieve 2.2 Ib ADG for a 52-day period. Steers fed HMEC had higher (P\u3c.01) ADG and lower (P\u3c.01) feed/gain than WSC fed steers. Low crude protein in the hay source caused lower (P\u3c.01) crude protein in WSC diets. Lower crude protein intake could have limited steer growth. NE utilization appeared more efficient (P\u3c.05) for heavy weight block steers, reflecting NRC equation low sensitivity to modest differences in frame size. Roughage level did not affect performance and did not interact with grain source

Substitution of Rolled Barley for Whole Shelled Corn in Finishing Diets for Steers

Rolled barley was substituted for 0, 25, 50, 75 or 100% of the whole shelled corn in finishing diets fed to steers for 84 days. Increasing barley substitution resulted in a linear (P=.12) decrease in ADG and a quadratic (P\u3c.05) decrease in DM1 with no effect on feed conversion. At the termination of the study, barley substitution caused a linear reduction in carcass weight (P\u3c.01) and dressing percent (P\u3c.01). The 100% substitution of barley for corn reduced (Pc.05) the percentage of carcasses grading choice. Dietary net energy values calculated from steer weights, gain and feed intake increased linearly (P\u3c.10) as barley content of the diets increased, possibly reflecting positive associative effects. Published energy values for barley may not be suitable for least cost pricing in all feeding situations

Effect of Corn Processing and Reconstitution on the Digestibility of High Grain Diets

Twelve steers (body weight 955 Ib + 37) were allotted to a 4 x 4 Latin square design digestion trial to examine the effects of corn processing on feed utilization. The grain component of the diet was either dry whole corn (WC), dry rolled corn (RC), corn reconstituted 12 hours before rolling (RRC), or corn reconstituted with a commercial surfactant3 12 hours before rolling (CRC). Dry matter content of the WC, RC, RRC, and CRC diets were 87.91, 87.30, 82.1 9, and 82.14%, respectively. Treatment had no effect on the digestibilities of dry matter (71.00% ± 1.57), organic matter (72.22% ± 1.531, crude protein (57.54% ± 1.66), neutral detergent fiber (52.68% ± 3.071, or starch (85.67% + .98). Neutral detergent fiber digestion was affected by period, but this was not related to bulk density of the corn which ranged from 43 to 56 Ib/bu over periods. Processing did not affect dry matter intake (21.76 Ib/day ± .41), although reconstitution depressed (P \u3c .01) dry matter intake as a percentage of body weight (2.19, 2.24, 2.1 1, and 2.1496, respectively). To quantify differences in particle size, processed grain samples were separated with #5, 7, 10, and 18 mesh sieves. Mean percentages retained on a #5 mesh sieve were 85.26, 58.74, 84.27, and 83.57% for WC, RC, RRC, and CRC, respectively. Subsequent separated fractions of WC and the reconstituted treatments were similar

Superlubricity - a new perspective on an established paradigm

Superlubricity is a frictionless tribological state sometimes occurring in nanoscale material junctions. It is often associated with incommensurate surface lattice structures appearing at the interface. Here, by using the recently introduced registry index concept which quantifies the registry mismatch in layered materials, we prove the existence of a direct relation between interlayer commensurability and wearless friction in layered materials. We show that our simple and intuitive model is able to capture, down to fine details, the experimentally measured frictional behavior of a hexagonal graphene flake sliding on-top of the surface of graphite. We further predict that superlubricity is expected to occur in hexagonal boron nitride as well with tribological characteristics very similar to those observed for the graphitic system. The success of our method in predicting experimental results along with its exceptional computational efficiency opens the way for modeling large-scale material interfaces way beyond the reach of standard simulation techniques.Comment: 18 pages, 7 figure

Dynamical density functional theory for the dewetting of evaporating thin films of nanoparticle suspensions exhibiting pattern formation

Recent experiments have shown that the striking structure formation in dewetting films of evaporating colloidal nanoparticle suspensions occurs in an ultrathin `postcursor' layer that is left behind by a mesoscopic dewetting front. Various phase change and transport processes occur in the postcursor layer, that may lead to nanoparticle deposits in the form of labyrinthine, network or strongly branched `finger' structures. We develop a versatile dynamical density functional theory to model this system which captures all these structures and may be employed to investigate the influence of evaporation/condensation, nanoparticle transport and solute transport in a differentiated way. We highlight, in particular, the influence of the subtle interplay of decomposition in the layer and contact line motion on the observed particle-induced transverse instability of the dewetting front.Comment: 5 pages, 5 figure