Mean first passage time for fission potentials having structure

A schematic model of over-damped motion is presented which permits one to calculate the mean first passage time for nuclear fission. Its asymptotic value may exceed considerably the lifetime suggested by Kramers rate formula, which applies only to very special, favorable potentials and temperatures. The additional time obtained in the more general case is seen to allow for a considerable increment in the emission of light particles.Comment: 7 pages, LaTex, 7 postscript figures; Keywords: Decay rate, mean first passage tim

Comment on ``Superconducting PrBa_2Cu_3O_x''

Recently, Zou et al. (Phys. Rev. Lett. 80, 1074, 1998) reported the observation of bulk superconductivity (SC) for a PrBa_2Cu_3O_x (Pr123) single crystal grown by the traveling-solvent floating zone (TSFZ) method. The aim of this Comment is to show the inconsistency of the value of effective magnetic moment \mu_{eff} reported by Zou et al. (2.92\mu_B) with their magnetic susceptibility data. The estimation made directly from their data points gives a considerably smaller value of \mu_{eff}=2.09\mu_B. At the same time the values of mu_{eff}=2.9\mu_B and 3.1\mu_B were obtained for our Pr123 single crystals grown by flux method for H||ab-plane and H||c-axis, respectively. This suggests that Pr occupies only about a half of the RE sites in TSFZ crystal. The other half of the RE sites is occupied most probably by the nonmagnetic Ba. Noteworthy, SC with T_c=43 K was observed earlier for Pr_{0.5}Ca_{0.5}Ba_2Cu_3O_{7-y} thin films. Ba^{2+} has a larger ionic radius than Pr^{3+} and so the substitution of Ba for Pr could give a natural explanation not only for the SC in TSFZ Pr123 but also for the elongation of the distance between the CuO_2 planes observed by Zou et al.Comment: Slightly extended version of Comment accepted to Phys. Rev. Lett. (v.81, N24, 1998), tentatevely to be publ. 14Dec98. 1 page, REVTex; 1 EPS fi

Rumen Undegradable Protein and Bambermycins Supplementation of Calves Grazing Corn Residue

Steer calves grazing non- irrigated corn residue were supplemented with a corn residue and by- product pellet that contained either Soypass, soybean meal, or processed soybean meal at a rate of 4 lb / d. Additionally, a supplement was fed at 1 lb / d that provided 0 or 20 mg / steer daily of bambermycins (Gainpro®). There was no interaction between bambermycins inclusion and pellet type. Likewise, there was no effect of pellet type or bambermycins on ending BW or ADG. In order to maximize gain of calves grazing corn residue it is important to provide a supplement that ensures adequate levels of both energy and rumen undegradeable protein

Evaluation of Fractionated Distillers Grains (High Protein and Bran Plus Solubles) on Performance and Carcass Characteristics in Finishing Diets

A finishing study evaluated the effect of feeding a new, high protein distillers grains along with corn bran plus condensed distillers solubles compared to traditional wet distillers grains, traditional dry distillers grains and a corn-based control. Each byproduct replaced corn at 40% of the diet dry-matter. Intake was not affected by treatment; however gain and carcass weight were greater and feed conversion improved for high protein distillers and corn bran plus solubles than either type of traditional distillers grains or corn. Based on feed efficiency, the feeding values of high protein distillers grains and corn bran plus solubles are 121% and 125% that of corn, respectively. These new byproducts appear to be viable options for producers to utilize in finishing diets

Evaluation of Corn Bran Plus Solubles on Performance and Carcass Characteristics in Finishing Diets

A finishing study was conducted to determine the effect of feeding corn bran plus solubles, a new feed resulting from a pre-fermentation fiber removal process, compared to wet distillers grains plus solubles at two levels of inclusion (20% and 40% of diet DM). Intake increased with inclusion of byproduct, and steers fed 20% wet distillers had the greatest intakes numerically. Byproduct inclusion, regardless of type, increased daily gain over the corn-based control. Feed conversions were improved with increased inclusion of both Bran + Solubles and wet distillers, and both were superior to the control. Increased inclusion of both byproducts resulted in a linear increase in carcass weight. Feeding Bran+Solubles resulted in performance and carcass characteristics similar to wet distillers at both 20% and 40% inclusion

Effect of Backgrounding System on Performance and Profitability of Yearling Beef Steers

Five summer management strategies were compared following grazing corn residue through winter. Cattle were assigned to be 1) summer finished, 2) graze bromegrass, 3) graze bromegrass and fed distillers grains at 0.6% of BW, 4) backgrounded in a drylot pen to gain 1.70 lb/d, or 5) backgrounded in a drylot pen to gain 2.35 lb/d. Results differed by year, however, in general as backgrounding ADG increased, days required on feed to reach an equal fat endpoint decreased. In year 1, ADG of cattle grazing bromegrass was less than cattle backgrounded in pens. There was no difference in finishing ADG for summer backgrounded steers. In year 2, steers grazing bromegrass with no supplement had the lowest summer ADG but exhibited compensatory growth in the feedlot. Overall, backgrounding systems increase carcass weights when cattle are finished to an equal fat thickness

Evaluation of Distillers Grains Components Singly or in Combination in a Calf Fed Feedlot Study

A finishing study was conducted to determine the value of the fiber, protein, fat, and solubles components from wet distillers grains plus solubles (WDGS) alone or in combination for feedlot cattle in comparison to WDGS diets. The fiber portion alone did not improve F:G. When protein was included in the composite with fiber, F:G improved. With fat and solubles both added separately, F:G continued to improve. None of the components alone could make up the feeding value of WDGS, however the composite diet of fiber, protein, fat, and solubles combined matched the performance observed when WDGS is fed

Effect of Continuous or Rotational Grazing on Growing Steer Performance and Land Production

Individual animal performance and animal production per acre were evaluated for steers grazing smooth bromegrass over 2 consecutive years. Treatments consisted of steers continuously grazing smooth bromegrass and initially stocked at either 4.0 animal unit months (AUM)/ac (HI) or 2.8 AUM/ac (LO) or steers rotationally grazing smooth bromegrass and initially stocked at 4.0 AUM/ac (ROT). Average calculated stocking rate for the LO, HI, and ROT treatments was greater than initial stocking rates due to the use of put and take animals. In vitro organic matter digestibility and crude protein of rotationally grazed pastures was relatively constant as the grazing season progressed, whereas continuous grazing showed a decrease in digestibility. However, there were no differences in gain between treatments. Treatment pastures grazed at a higher intensity, regardless of grazing method, had greater calculated stocking rate than pastures grazed at a lower intensity. Gain per acre, however, did not differ among treatments. Overall, although there was an increase in diet sample quality associated with rotational grazing compared to continuously grazed pastures, greater emphasis should likely be placed on managing an appropriate grazing intensity, rather than grazing method

Effect of Revalor-XR and Revalor-XH on Heifer Performance and Carcass Characteristics

A feedlot study evaluated the effects of 4 implant strategies (Revalor-XR on day 1, Revalor-XH on day 1, Revalor-200 on day 1, and Revalor-200 on day 70) on growth performance and carcass characteristics of feedlot heifers compared to non-implanted heifers fed 198 days. Intake was not impacted by treatments. Implanted cattle had greater carcass-adjusted ADG and lower F:G compared to cattle that received no implant. Implanted treatments had significantly greater HCW, dressing percentages, and lower marbling scores compared to non-implanted cattle. Heifers implanted with Revalor-XR, Revalor-XH, and Revalor-200 on day 70 had larger LM area resulting in lower calculated yield grades compared to Revalor-200 administered on day 1 and control cattle. The response in gain, feed efficiency, and yield grade suggest that Revalor-XR, Revalor-XH, and Revalor-200 implanted on day 70 respond similarly when heifers are fed to similar days

Evaluation of Reimplant Window with Revalor-200 ® on Steer Performance and Carcass Characteristics

A feedlot study utilizing 800 crossbred steers (initial BW = 727 ± 55 lb) compared 5 different terminal implant (Revalor-200) times (160, 120, 100, 80, or 40 d prior to harvest) for steers fed 180 days on performance and carcass characteristics. All steers were implanted with Revalor-IS as an initial implant at trial initiation. Carcass-adjusted final BW, ADG, and F:G responded quadratically, with cattle implanted 80 to 120 d prior to harvest being the greatest. However, there was less than a 2% difference in performance between 120 and 80 days on terminal implant. Hot carcass weight responded quadratically, with no difference in fat thickness, rib eye area, marbling score, or calculated yield grade. When solved for the first derivative, all variables were maximized at 87 to 104 days on terminal implant when steers are fed for 180-d