Role of rare earth elements and entropy on the anatase-to-rutile phase transformation of TiO2thin films deposited by ion beam sputtering

The role played by oxygen vacancies and rare earth (RE) elements in the anatase-to-rutile (A−R) phase transformation of titanium dioxide (TiO2) is still a matter of controversy. Here, we report the A−R transformation of TiO2 thin solid films as obtained by ion beam sputtering a RE-decorated titanium target in an oxygen-rich atmosphere. The samples correspond to undoped, single-doped (Sm, Tm, and Tb), and codoped (Sm:Tb, Sm:Tm, and Sm:Tb:Tm) TiO2 films. In the as-prepared form, the films are amorphous and contain ∼0.5 at. % of each RE. The structural modifications of the TiO2 films due to the RE elements and the annealing treatments in an oxygen atmosphere are described according to the experimental results provided by Raman scattering, X-ray photoelectron spectroscopy, and optical measurements. The A−R transformation depends on both the annealing temperature and the characteristics of the undoped, single-doped, and codoped TiO2 films. As reported in the literature, the A−R transformation can be inhibited or enhanced by the presence of impurities and is mostly related to energetic contributions. The experimental results were analyzed, considering the essential and stabilizing role of the entropy of mixing in the A−R transformation due to the introduction of more and multiple quantum states originated in vacancies and impurities in the anatase phase.Fil: Scoca, Diego L.S.. Universidade Estadual de Campinas; BrasilFil: Cemin, Felipe. Universidade Estadual de Campinas; BrasilFil: Aldabe, Sara Alfonsina. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Figueroa, Carlos A.. Universidade de Caxias Do Sul.; BrasilFil: Zanatta, Antonio R.. Universidade de Sao Paulo; BrasilFil: Alvarez, Fernando. Universidade Estadual de Campinas; Brasi

GEOMETRICAL OPTIMIZATION OF MIXED CONVECTIVE FLOWS OVER TRIANGULAR ARRANGEMENT OF CYLINDERS

The present study consists on the numerical evaluation of a triangular arrangement of circular cylinders submitted to transient, two-dimensional, incompressible, laminar and mixed convective flows. The geometrical evaluation is performed by means of Constructal Design. For all simulations it is considered Reynolds and Prandtl numbers of ReD = 100 and Pr = 0.71. Moreover, three different values of Richardson number are investigated: Ri = 0.1 (which represents flows dominated by forced convective), 1.0 (which represents an equilibrium between forced and natural driven forces) and 10.0 (which represents flows with dominance of natural convective). The conservation equations of mass, momentum and energy are solved with the use of Finite Volume Method (FVM). The buoyancy forces are tackled with the Boussinesq approximation. The area occupied by the triangular arrangement of cylinders is a geometric constraint of the problem and the cylinders have the same diameter. The main purpose is to evaluate the effect of Richardson number over the drag coefficient (CD) and Nusselt number (NuD) between the cylinders and the surrounding flow, as well as, over the optimal ratio ST/D (ratio between transversal pitch and the cylinder) for two different values of the ratio SL/D = 1.5 and 2.5 (ratio between longitudinal pitch and the cylinders diameter). Results showed that the effect of ST/D over drag coefficient and Nusselt number is strongly affected by the magnitude of Richardson number. Concerning the Nusselt number, for Ri = 0.1 the optimal geometry which maximizes the NuD is reached for the highest magnitude of ST/D, while for Ri = 10.0 an intermediate optimal ratio of ST/D maximizes the NuD. The Richardson magnitudes also have large influence over the fluid dynamic and thermal behavior of fluid flow for all evaluated geometries. An increase in the ratio SL/D improved the heat exchange of the flow, but decreased the fluid dynamic performance

Effect of Zinc Oxide, Zinc Hydroxychloride, and Tri-basic Copper Chloride on Nursery Pig Performance

A total of 1,215 pigs (PIC 1050 × 280; initially 11.7 lb BW) were used in a 42-d growth trial to determine the effects of ZnO, Zn hydroxychloride (IntelliBond Z; IBZ), and tri-basic copper chloride (IntelliBond C; IBC) on growth performance of nursery pigs. Pigs were allotted by pen weight and assigned to 1 of 5 dietary treatments. Treatments consisted of added Zn as ZnO (3,000 ppm in phase 1 and 2,000 ppm in phase 2); Zn hydroxychloride (IBZ; 1,000 ppm in phase 1 and phase 2); and Cu as tri-basic copper chloride (200 ppm), alone or in combination, as follows: 1) Cu only; 2) ZnO only; 3) ZnO and Cu; 4) IBZ only; and 5) IBZ and Cu. Experimental diets were fed from d 0 to 21. From d 21 to 42, pigs were fed a common diet that contained 200 ppm Cu from tri-basic copper chloride but no additional Zn other than that provided by the trace mineral premix. From d 0 to 21, there was a tendency (P = 0.073) for interaction between Zn source and Cu for ADG, where the addition of Cu to ZnO diets increased ADG; whereas, adding Cu to IBZ diets decreased ADG. Pigs fed added ZnO had greater ADFI (P = 0.018), ADG (P = 0.033), and BW on d 21 (P = 0.042) than those fed added IBZ. From d 21 to 42, pigs previously fed diets with ZnO had greater ADFI (P = 0.040) and a tendency (P = 0.071) for poorer F/G than those previously fed Cu only. Overall, feeding diets with ZnO resulted in greater ADFI (P = 0.026) compared to feeding the diet with Cu only. There was a tendency (P = 0.053) for decreased removal rate when IBZ was added to the diet compared to only adding Cu. Overall, pigs fed diets with ZnO had greater ADFI (P = 0.048) and a tendency (P = 0.074) for increased ADG compared to pigs fed diets with added IBZ. Feed cost marginally increased (P = 0.064) with the addition of ZnO compared to IBZ. Diets with ZnO resulted in greater feed cost (P = 0.018) and a tendency for higher revenue (P = 0.062) compared to the diet with Cu only. Similarly, diets with added IBZ resulted in tendencies for greater feed cost (P = 0.070), revenue (P = 0.052), and income over feed cost (IOFC) (P = 0.071) compared to the diet with Cu only. The results suggest that there are no additive effects of Zn and Cu and no major differences in performance between pigs fed diets with added Zn or Cu. Pigs fed diets with higher levels of ZnO had improved performance compared to those fed added IBZ

Using Caloric Efficiency to Estimate the Energy Value of Soybean Meal Relative to Corn and Its Effects on Growth Performance of Nursery Pigs

An experiment was conducted to estimate the energy value of soybean meal (SBM) relative to corn and determine the effects of increasing amounts of SBM in nursery pig diets. A total of 2,233 pigs (PIC 337 × 1050, Hendersonville, TN), initially 24.2 lb body weight (BW), were placed in 92 pens with 20 to 27 mixed gender pigs per pen. After weaning, pigs were fed common diets for 21 d and then assigned to treatments in a randomized complete block design with BW as the blocking factor. Treatment diets consisted of 21, 27, 33, or 39% SBM, obtained by changing the amount of feed-grade amino acids (AA) and corn, and were fed for 21 d. Soybean meal NE value used in diet formulation was 947 kcal/lb. There were 23 replicates per treatment. Pigs were weighed and feed disappearance measured to calculate average daily gain (ADG), average daily feed intake (ADFI), feed efficiency (F/G), and caloric efficiency (CE). Data were analyzed using the GLIMMIX procedure of SAS with block as a random effect and treatment as a fixed effect. Single degree-of-freedom contrasts were constructed to test the linear and quadratic effects of increasing SBM. There was a tendency (P = 0.090) for a quadratic response for ADG, with an improvement observed up to 33% SBM. There was a tendency (linear, P = 0.092) for a decrease in ADFI as dietary SBM increased. Pigs fed diets with increasing SBM had a tendency (quadratic, P = 0.066) for an improvement in F/G up to 33% SBM then returned to control values when 39% SBM was fed. There was an improvement (linear, P = 0.001; quadratic, P = 0.065) in CE with increasing SBM. Using CE as a means to estimate the energy content of SBM relative to corn, a value of 105.4% of corn energy or 1,277 kcal/lb NE was determined using all 4 data points. When removing the CE value of the 39% SBM treatment due to the quadratic tendency and just using the linear portion of the CE response, SBM was estimated to have 121.1% of corn energy or 1,468 kcal/lb NE. In conclusion, the results of the current study suggest that feeding SBM up to 33% improves ADG, F/G, and CE. The energy value of SBM is estimated between 105 and 121% of corn, much greater than the current suggested value of 78% of corn. This has important ramifications as it increases the value of SBM in diet formulation

Effects of Increasing Zinc, Using Zn Hydroxychloride, on Growth Performance, Carcass Characteristics, and Economic Return of Pigs Housed in a Commercial Environment

A total of 2,430 pigs (PIC 337 × 1050; initially 66.3 lb BW) were used in a 113-d growth trial to determine the effects of increasing Zn on growth performance and carcass characteristics of finishing pigs. Two barns were used for a total of 18 pens per treatment with 27 pigs per pen. Pigs were allotted by average initial BW and assigned to 1 of 5 dietary treatments consisting of 50, 87.5, 125, 162.5, or 200 ppm added Zn from Zn hydroxychloride (Intellibond Z, Micronutrients, Indianapolis, IN). Experimental diets were fed from d 0 to 113 in 5 phases and contained a trace mineral premix that did not contain any added Zn. Overall (d 0 to 113), there were marginally significant quadratic responses in ADFI (P = 0.073) and F/G (P = 0.067), with the lowest ADFI and best F/G observed when 87.5 and 125 ppm of Zn were fed, respectively. There was no evidence for differences in carcass characteristics (P \u3e 0.10). Regarding economic effects, there was a marginally significant (P = 0.075) quadratic response in feed cost per pig and feed cost per pound of gain (P = 0.088). The lowest feed cost per pig and feed cost per pound of gain were observed when 87.5 and 125 ppm of Zn was fed, respectively. In conclusion, there were no improvements in ADG when feeding beyond 50 ppm added Zn; however, feeding 125 ppm Zn resulted in the best F/G

Effects of Soybean Meal Level on Growth Performance of 25- to 50-lb Nursery Pigs

Four experiments were conducted to determine the effects of increasing soybean meal (SBM) level in diets with or without 25% distillers dried grains with solubles (DDGS) on growth performance of nursery pigs raised in university or commercial facilities. Treatments were arranged in a 2 × 3 factorial with main effects of SBM (27.5, 32.5, or 37.5% of the diet) and DDGS (0 or 25% of the diet). A total of 296, 2,502, 4,118, and 711 pigs initially 23.2, 25.7, 27.5, and 27.1 lb body weight (BW) were used in Exp. 1, 2, 3, and 4, respectively. There were 10, 16, 13, and 12 replicates per treatment in Exp. 1, 2, 3, and 4, respectively. After weaning, pigs were fed common diets for approximately 21 d. Then, pens of pigs were assigned to treatments in a randomized complete block design with BW as the blocking factor and experimental diets were fed for 21 d. Pigs were weighed and feed disappearance measured to calculate average daily gain (ADG), average daily feed intake (ADFI), feed-to-gain ratio (F/G), and caloric efficiency (CE). Pigs used in all experiments did not undergo major health challenges during the experimental period and due to the low number of mortality and cull events, statistical analysis was not performed on these variables. The average cull rate was 0.7, 0.5, 0.2, and 0% and the mortality rate was 0.7, 0.3, 0.4, and 0% in Exp. 1 to 4, respectively. There were interactions (P ≤ 0.031) between SBM and DDGS for F/G and CE in Exp. 2 and for ADG and ADFI in Exp. 3. These were mostly driven by increasing SBM negatively affecting performance in a greater magnitude when diets contained DDGS compared to diets without DDGS. The main effects of DDGS and SBM were more consistently observed across experiments. Pigs fed diets with 25% DDGS had decreased (P ≤ 0.001) ADG and ADFI in all experiments as well as poorer (P ≤ 0.025) F/G and CE except for Exp. 3. Feeding increasing amounts of SBM generally did not result in any major impact in ADG, but consistently improved (linear, P ≤ 0.078) F/G and CE across experiments. The mechanism for this response is unclear but could be driven by intrinsic components of SBM, such as isoflavones, or by underestimation of SBM energy value

Effects of Insoluble Fiber Source (Cellulose or Distillers Dried Grains with Solubles) on Growth Performance of Nursery Pigs

A total of 3,171 weanling pigs (PIC 327 × L42) with an initial body weight (BW) of 12.7 lb were used in a 39-d study with 66 or 67 pigs per fence-line feeder (experimental unit) and 12 replicates per treatment. Pens were blocked by BW and allotted to 1 of 4 dietary treatments in a randomized complete block design. The treatment structure was a 2 × 2 factorial with 0 or 1% cellulose (Arbocel, J. Rettenmaier USA, Schoolcraft, MI) and distillers dried grains with solubles (DDGS; 0 or 5% in Phase 1 and 0 or 15% in Phase 2). Dietary phases 1 and 2 were offered from d 0 to 10 and 10 to 25, respectively. From d 25 to 39, pigs received a common diet with 25% DDGS. Growth performance, pig removals, and economic variables were evaluated. From d 0 to 25, there was an interaction between cellulose and DDGS (P = 0.040) for average daily gain (ADG). Pigs fed diets with DDGS and cellulose had lower ADG than those fed diets without DDGS, with pigs fed diets with DDGS without the addition of cellulose having intermediate ADG. From d 25 to 39, there was a marginally significant interaction (P = 0.080) for average daily feed intake (ADFI). Pigs previously fed diets without DDGS and with cellulose had higher ADFI than those fed diets with DDGS and cellulose, and pigs previously fed diets without cellulose had similar ADFI regardless of DDGS inclusion. In the overall period (d 0 to 39), there was an interaction between cellulose and DDGS (P = 0.021) for ADG, similar to d 0 to 25. There was a marginally significant interaction (P = 0.070) for pig removals. Adding cellulose to diets without DDGS resulted in numerical decrease in pig removals, but the inclusion of cellulose to diets with DDGS resulted in increased pig removals. For economics, an interaction was observed between cellulose and DDGS for income over feed cost (IOFC; P = 0.014). Pigs fed diets without DDGS and with the addition of cellulose had higher IOFC compared to pigs fed diets with DDGS and cellulose, with other treatments being intermediate. In summary, the addition of cellulose to diets without DDGS resulted in slight improvements in pig removals and economic variables, with no evidence of impact on growth performance. The reduction in performance observed when cellulose was added to diets that contained DDGS may be due to a negative effect of the high fiber level

Evaluating the Productive Energy Content of High-Protein Distillers Dried Grains in Swine Diets

A total of 300 pigs (DNA 400 × 200), initially 24.5 lb, were used in a study to evaluate the effects of increasing amounts of high-protein distillers dried grains (HP DDG) on growth performance, and to estimate the productive energy of HP DDG. Pens were allocated with 5 pigs each and fed a common diet for 21 d after weaning. Then, pens were assigned to treatments in a randomized complete block design. There were 5 treatments with 12 pen replicates per treatment. Treatments consisted of 0, 10, 20, 30, or 40% HP DDG. Pigs were weighed weekly for 21 d to evaluate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (F/G). Caloric efficiency was obtained by multiplying ADFI by kcal of net energy (NE) per lb of diet and dividing by ADG. Productive energy was estimated based on caloric efficiency relative to the diet without HP DDG. Data were analyzed with the GLIMMIX procedure of SAS with block as a random effect and pen as the experimental unit. From d 0 to 7 and 7 to 14, increasing amounts of HP DDG linearly decreased (P \u3c 0.01) ADG, which was mainly driven by lower (linear, P \u3c 0.01) ADFI. The inclusion of HP DDG negatively impacted (linear; P \u3c 0.01) F/G from d 0 to 7 with no evidence for differences from d 7 to 14 (P ≥ 0.321). From d 14 to 21, there was a decrease (linear, P \u3c 0.01) in ADFI and improvement (linear, P = 0.029) in F/G as HP DDG inclusion increased. Overall (d 0 to 21), pigs fed diets with increasing HP DDG had a linear decrease (P \u3c 0.01) in ADG, ADFI, and final body weight. There was a tendency for a quadratic response (P = 0.051) in F/G, with the best F/G observed for pigs fed diets with 40% HP DDG. There was a linear reduction (P \u3c 0.01) in caloric efficiency with increasing amounts of HP DDG, indicating an underestimation of HP DDG NE. The productive energy of HP DDG was estimated as 1,218 kcal/lb or 97.3% of corn NE

Effects of Standardized Ileal Digestible Histidine:Lysine Ratio on Growth Performance of 15- to 25-lb Pigs

Two experiments were conducted to determine the standardized ileal digestible (SID) His:Lys requirement of 15- to 25-lb nursery pigs. A total of 360 and 350 pigs (DNA 241 × 600), initially 15.6 and 14.5 lb body weight (BW), were used in Exp. 1 and 2, respectively. There were 5 pigs per pen and 12 and 10 replicates per treatment in Exp. 1 and 2, respectively. After weaning, pigs were fed a common pelleted diet for 10 d in Exp. 1 and 7 d in Exp. 2. Then, pens were assigned to treatments in a randomized complete block design with BW as the blocking factor. Dietary treatments consisted of SID His:Lys ratios of 24, 28, 32, 36, 40, and 44% in Exp. 1 and 24, 28, 30, 32, 34, 36, and 42% in Exp. 2. Experimental diets were fed in pellet form for 10 d in Exp. 1 and 14 d in Exp. 2 followed by a common mash diet for 15 d in Exp. 1 and 14 d in Exp. 2. Data were analyzed using the GLIMMIX and NLMIXED procedures of SAS. Competing statistical models were quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). In Exp. 1, increasing SID His:Lys increased (quadratic, P \u3c 0.001) average daily gain (ADG), average daily feed intake (ADFI), and BW and improved (quadratic, P \u3c 0.001) feed-to-gain ratio (F/G). In Exp. 2, ADG increased (quadratic, P = 0.001) and F/G improved (quadratic, P = 0.001) and ADFI linearly increased (P = 0.001) with increasing SID His:Lys. The best-fitting model for all response variables analyzed was the BLL. In Exp. 1, requirement estimates were 29.7%, 29.1%, and 29.8% SID His:Lys for ADG, ADFI, and gain-to-feed ratio (G:F), respectively. In Exp. 2, the SID His:Lys requirements were estimated at 31.0% for ADG and 28.6% for G:F. These results suggest that the NRC may overestimate the SID His:Lys requirement for 15- to 25-lb pigs. Therefore, nursery diets can be formulated with higher inclusion of crystalline amino acids before His becomes limiting

Improving Performance of Finishing Pigs with Added Valine, Isoleucine, and Tryptophan: Validating a Meta-Analysis Model

Based on a recent meta-analysis, we hypothesized that increased dietary Val, Ile, or Trp could correct possible amino acid interactions caused by high dietary Leu in diets containing high levels of corn protein, namely dried distillers grains with solubles (DDGS). A total of 1,200 pigs (PIC TR4 × (Fast LW × PIC L02); initially 74.0 ± 1.38 lb) were used in a 103-d study. The 6 dietary treatments were corn-soybean meal- DDGS-based diets as follows: 1) low level of Lys-HCl (HSBM), 2) high Lys-HCl and moderate Ile, Val, Trp (NC; AA above NRC4 estimates), 3) moderate Lys-HCl and high Ile, Val, Trp (PC), and 4) PC with either increased L-Val (PC+Val), 5) L-Ile (PC+Ile), or 6) L-Trp (PC+Trp). Diets contained 30% DDGS until pigs reached approximately 217 lb, and then pigs were fed diets with 20% DDGS until market. Data were analyzed as a randomized complete block design using the lmer function in the lme4 package in R with pen considered as the experimental unit, body weight, and pen location as a blocking factor, and treatment as a fixed effect with 10 replicates/treatment. In the grower period, ADG was greater (P \u3c 0.05) for the pigs fed HSBM and PC+Val diets than the NC with PC, PC+Ile, and PC+Trp intermediate. Pigs fed HSBM were more (P \u3c 0.05) efficient than the NC and PC with PC+Val, PC+Ile, and PC+Trp being intermediate. In the late finisher period, ADG was greater (P \u3c 0.05) for pigs fed PC+Ile than that of the NC with HSBM, PC, PC+Val, and PC+Trp intermediate. Pigs fed PC+Val had greater (P \u3c 0.05) ADFI than the NC with HSBM, PC, PC+Ile, and PC+Trp being intermediate. However, PC+Ile pigs were more (P \u3c 0.05) efficient than PC+Val pigs with HSBM, NC, PC, and PC+Trp being intermediate. Overall, final body weight (BW), average daily gain (ADG), and hot carcass weight (HCW) were greater (P \u3c 0.05) for pigs fed HSBM, PC+Val, and PC+Ile diets than the NC with PC and PC+Trp intermediate. Pigs fed the PC+Val diet had greater (P \u3c 0.05) average daily feed intake (ADFI) than the NC with pigs fed HSBM, PC, PC+Ile, and PC+Trp intermediate. No differences were detected between treatments for overall F/G or other carcass characteristics. In conclusion, increasing Val or Ile in high Lys- HCl-DDGS-based diets improved growth performance and final BW compared with pigs fed diets containing high levels of Lys-HCl without added Val and Ile. These results demonstrate that the negative effects of high Leu concentrations in corn-DDGS-based diets can be corrected by increasing the ratios of Val and Ile to Lys