Treatment of singularities in 2-D domains using BIEM

The singularities which arise when there is a sudden change of boundary conditions are modelled using spectral shape interpolation functions. The procedure can be used for elasticity as well as potential theory and to any degree of accuracy with respect to the smooth part of the curve

Effects of Managing Heifers to Calve First at Two \u3ci\u3evs\u3c/i\u3e Three Years of Age on Longevity and Lifetime Production of Beef Cows

Resources used by cow herds for beef production vary greatly. To optimize reproduction and other production characteristics in the cow herd, breeding and management should be matched with the feed resources available for production. One management decision is whether to develop replacement females to calve first as 2-year-olds or as 3-year-olds. When feed resources are limited or expensive relative to other costs and value of output, it may be economical to delay the first calving until 3 years of age. When feed resources are adequate to support rapid growth and development of heifers and thus to reduce age at puberty to 14 months of age or less, then calving at 2 years of age may be optimum. another management decision is whether or not cows should be culled the first time they are open, or held over for another opportunity to breed (in lieu of keeping an additional replacement heifer). This study was conducted to evaluate effects of 2-year-old vs 3-year-old first calf management on longevity and lifetime production of cows and on current economics of beef production

Effects of Heterosis on Longevity in Beef Cattle

Longevity can be important to the economic efficiency of beef production. The longer cows remain productive in a herd, the fewer the number of replacement heifers needed and the greater the calf output per cow maintained. In this way, more heifers can be sold for feeding and slaughter, and the cost of growing out replacement females to a productive age is reduced. Less culling of infertile cows also increases output per cow exposed. This study was conducted to determine effects of heterosis on longevity and associated factors in crosses of the Hereford, Angus, and Shorthorn breeds

An Unified Approach To Pseudo Scalar Meson Photoproductions Off Nucleons In The Quark Model

An unified approach to the pseudo scalar meson ($\pi, \eta$, and $K$) photoproduction off nucleons are presented. It begins with the low energy QCD Lagrangian, and the resonances in the s- and u- channels are treated in the framework of the quark model The duality hypothesis is imposed to limit the number of the t-channel exchanges. The CGLN amplitudes for each reaction are evaluated, which include both proton and neutron targets. The important role by the S-wave resonances in the second resonance region is discussed, it is particularly important for the $K, \eta$ and $\eta^\prime$ photoproductions.Comment: 31 pages in Latex fil

Pulse Frequency Effect on Neutron Damage in -Iron: A KMC Analysis

The pulsed nature of the irradiation and the high neutron dose are the critical factors in an Inertial Fusion Energy reactor (IFE). The damage that structural materials suffer under these extremes conditions require a careful study and assessment. The goal of our work is to simulate, trough the multiscale modeling approach, the damage accumulation in {alpha}-Fe under conditions relevant to a IFE Reactor. We discuss how the pulse frequency, 1 Hz, 10 Hz, and the dose rate of 10{_} and 10{_}dpa/s affect the damage production and accumulation. Results of the damage that this demanding environment can produce on a protected first structural exposed to 150 keV average recoil ion will be presented. A further comparison it has been made with the damage produced by a continuous irradiation at similar average dose

The Kaon-Photoproduction Of Nucleons In The Quark Model

In this paper, we develop a general framework to study the meson-photoproductions of nucleons in the chiral quark model. The S and U channel resonance contributions are expressed in terms of the Chew-Goldberger-Low-Nambu (CGLN) amplitudes. The kaon-photoproduction processes, $\gamma p\to K^+ \Lambda$, $\gamma p\to K^+ \Sigma^0$, and $\gamma p\to K^0\Sigma^+$, are calculated. The initial results show that the quark model provides a much improved description of the reaction mechanism for the kaon-photoproductions of the nucleon with less parameters than the traditional phenomenological approaches.Comment: 25 pages, 9 postscript figures can be obtained from the author

Pseudoscalar Glueball Mass: QCD vs. Lattice Gauge Theory Prediction

We study whether the pseudoscalar glueball mass in full QCD can differ from the prediction of quenched lattice calculations. Using properties of the correlator of the vacuum topological susceptibility we derive an expression for the upper bound on the QCD glueball mass. We show that the QCD pseudoscalar glueball is lighter than the pure Yang-Mills theory glueball studied in quenched lattice calculations. The mass difference between those two states is of order of $1/N_c$. The value calculated for the $0^{-+}$ QCD glueball mass can not be reconciled with any physical state observed so far in the corresponding channel. The glueball decay constant and its production rate in $J/\psi$ radiative decays are calculated. The production rate is large enough to be studied experimentally.Comment: 18 pages, LaTex fil

BcB_c spectroscopy

In the framework of potential models for heavy quarkonium the mass spectrum for the system ($\bar b c$) is considered. Spin-dependent splittings, taking into account a change of a constant for effective Coulomb interaction between the quarks, and widths of radiative transitions between the ($\bar b c$) levels are calculated. In the framework of QCD sum rules, masses of the lightest vector $B_c^*$ and pseudoscalar $B_c$ states are estimated, scaling relation for leptonic constants of heavy quarkonia is derived, and the leptonic constant $f_{B_C}$ is evaluated.Comment: IHEP 94-51, LATEX, 39 page

Assessment of the roughness factor effect and the intrinsic catalytic activity for hydrogen evolution reaction on Ni-based electrodeposits

The hydrogen evolution reaction (HER) was studied in 30 wt.% KOH solution at temperatures ranging between 30 and 80 °C on three type of electrodes: (i) rough pure Ni electrodeposits, obtained by applying a large current density; (ii) smooth NiCo electrodeposits; (iii) smooth commercial Ni electrodes. By using steady-state polarization curves and electrochemical impedance spectroscopy (EIS) the surface roughness factor and the intrinsic activities of the catalytic layers were determined. These techniques also permitted us to determine the mechanism and kinetics of the HER on the investigated catalysts. Different AC models were tested and the appropriate one was selected. The overall experimental data indicated that the rough/porous Ni electrode yields the highest electrocatalytic activity in the HER. Nevertheless, when the effect of the surface roughness was taken into consideration, it was demonstrated that alloying Ni with Co results in an increased electrocatalytic activity in the HER when comparing to pure Ni. This is due to an improved intrinsic activity of the material, which was explained on the basis of the synergism among the catalytic properties of Ni (low hydrogen overpotential) and of Co (high hydrogen adsorption).Isaac Herraiz-Cardona is grateful to the Ministerio de Ciencia e Innovacion (Spain) for a postgraduate grant (Ref. AP2007-03737). This work was supported by Generalitat Valenciana (Project PROMETEO/2010/023)Herraiz Cardona, I.; Ortega Navarro, EM.; Garcia-Anton, J.; Pérez-Herranz, V. (2011). Assessment of the roughness factor effect and the intrinsic catalytic activity for hydrogen evolution reaction on Ni-based electrodeposits. International Journal of Hydrogen Energy. 36(16):9428-9438. https://doi.org/10.1016/j.ijhydene.2011.05.047S94289438361

Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to 300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m 2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years