bluuebunny/crossref_metadata_2025 huggingface dataset:
Trypsin inhibitors and phytic acid in oil-extracted meals from seeds of several Brassica species and of Sinapis alba
Authors: Bell J. M. , Rakow G.
Published: March 2010

A total of 124 seed samples representing strains and cultivars of Brassica napus, B. rapa, B. juncea, B. carinata, and Sinapis alba were selected for assays of trypsin inhibitor (TI) and phytic acid (PA). On an oil-extracted basis the TI values ranged from 1.26 to 5.31 units g−1. Values for B. napus ranked highest (3.58, 3.61) and B. juncea lowest (1.26, 1.39, 1.56) (P < 0.05). In a comparison of PA in three cultivars (B. napus, B. rapa, B. juncea), the cultivars differed in PA contents (2.52, 2.94, 2,70, respectively), there were no year-to-year differences over 4 yr (2.56, 2.67 2.68 vs. 2.96) but there were significant location effects (2.12, 2.21 vs. 3.04, 3.42). In a set of 10 cultivars replicated themes, B. juncea PA contents (3.35–3.91) exceeded those of B. napus (2.92, 3.06), and B. carinata (2.72, 3.15) Sinapis alba had the lowest value (2.49). Bronowski (B. napus), the gene source of all low glucosinolate cultivars, contained the most TI (5.31 units g−1) and the least PA (1.93%). Key words: Phytic acid, trypsin inhibitor, Brassica, Brassica napus, Brassica rapa, Brassica juncea, Brassica carinata, Sinapis alba
Dietary folic acid, uterine function and early embryonic development in sows
Authors: Matte J. J. , Farmer C. , Girard C. L. , Laforest J.-P.
Published: March 2010

The present study was designed to determine the role of folic acid on uterine environment and embryonic development during early gestation in the pig. Thirty-two, third parity, crossbred sows received a diet supplemented with 0 or 15 mg kg−1 of folic acid. The treatments started 2 wk before expected estrus and lasted until slaughter on either day 12 or 15 after mating. One uterine horn was used to collect conceptuses and uterine "flushings" for hormonal and metabolite determinations; conceptuses from the other horn were enzymatically dispersed and placed in cell culture with and without dehydroepiandrosterone (DHEA). The decrease in serum folates was attenuated (P ≤ 0.06) and the total and saturated folate binding capacities in early gestation were increased (P < 0.01) in sows receiving additional dietary folic acid. The volume of uterine flushings recovered was greater (P ≤ 0.02) on day 15 than on day 12, as was its content of protein (P ≤ 0.06). In sows receiving the dietary supplement of folic acid, total uterine prostaglandin (PG)E2 was three times higher on day 12 and two times higher on day 15 (P < 0.04) than for sows fed the experimental diet without supplement; although numerically substantial (60% higher), the effect was not significant for PGF2α (P ≥ 0.16). Conceptus homogenates contained more folic acid (P ≤ 0.02) and DNA (P ≤ 0.0001) on day 15 than on day 12. Their total protein content, in sows slaughtered on day 12 of gestation, tended (P ≤ 0.07) to be higher in supplemented than in unsupplemented animals. The synthesis of estradiol-17β by the conceptus cells, used as an index of embryonic maturity, tended (P ≤ 0.07) to be lower for treated than untreated sows, especially in conceptus cell culture without DHEA. Therefore, the improvement in embryonic survival attributed to dietary supplements of folic acid might be linked to changes on the secretion of uterine prostaglandins and possibly on embryonic development. Key words: Folic acid, uterus, embryo, sow
Proline is synthesized from intravenously infused arginine by piglets consuming low proline diets
Authors: Murch S. J. , Wilson R. L. , Murphy J. M. , Ball R. O.
Published: March 2010

Arginine (ARG) may be a significant precursor for proline (PRO) synthesis; therefore in vivo ARG kinetics were studied. Eighteen intact, male, Yorkshire piglets, 2–4 d of age, underwent surgery to install catheters into the jugular vein for blood sampling, the stomach for feeding and the femoral vein for isotope infusion. Piglets were randomly assigned to either a low ARG (–ARG), a low PRO (–PRO) or a control (CON) diet. After 7 d, there was no difference between diets in average daily gain, feed to gain ratio, or in the concentration of protein, fat or ash in the piglet bodies on a dry matter basis. A primed constant infusion of U-14C-ARG (prime = 278 kBq kg−1; constant = 370 kBq kg−1 h−1) was performed for 4 h with blood and breath samples taken at 30-min intervals. There were no significant differences among diets in the amount of 14C-ARG oxidized to 14C-CO2. ARG flux was not significantly different among diets (–ARG = 306.2; –PRO = 584.5; CON = 407.61 μmol kg−1 h−1). Diet affected the fractional rate of conversion of ARG to citrulline (–ARG = 4.7; –PRO = 87.2; CON = 23.1 μmol kg−1 h−1, P = 0.07) and PRO (–ARG = 0.8; –PRO = 56.6; CON = 2.9 μmol kg−1 h−1, P = 0.1). Differences in fractional rate of conversion of labelled ARG to ornithine (–ARG = 14.5; –PRO = 69.3; CON = 19.2 μmol kg−1 h−1) or glutamate (–ARG = 13.3; –PRO = 5.3; CON = 6.5 μmol kg−1 h−1) were not significant. The conversion of ARG to PRO has not previously been reported in vivo in the neonatal piglet. These data indicate that intravenously supplied ARG is a significant precursor for endogenous PRO synthesis in the neonatal piglet. Key words: Arginine, proline, swine, amino acids, urea cycle, requirement
The nutritional value of new high-lysine barley varieties determined with rats and young pigs
Authors: Eggum Bjørn O. , Gabert Vince M. , Jørgensen Henry , Brunsgaard Grete , Jensen Jens
Published: March 2010

Three experiments were conducted to evaluate the nutritive value of four new high-lysine barley mutants, their parent variety Sultan and the high-lysine variety Lysimax. The problem of low yield, frequently encountered in previous studies with high-lysine barley, was overcome for Lysimax in this study; cv. Lysimax yielded 4% more than cv. Sultan. The highest lysine levels: 4.87, 4.75 and 3.96 g 16 g−1 N occurred in cv. Lysimax and Risø mutants (RM) 609 and 1405 compared with 3.48, 3.43 and 3.55 g 16 g−1 N in cv. Sultan and RM 1242 and 1385, respectively. Compared with cv. Sultan, the glutamic acid levels in RM 1405 and 609 and cv. Lysimax were 7.2, 25.8 and 31.3% lower, respectively. Likewise, the proline levels in RM 1405 and 609 and cv. Lysimax were 10.3, 32.2 and 37.9% lower, respectively. In the first experiment, with rats, the barleys were the sole protein sources in the diets. In the second experiment, with young pigs, only cv. Lysimax and RM 1405 were used (700 g kg−1 diet) in two starter diets. In the third experiment, the diets fed to the pigs in the second experiment were diluted with an N-free mixture and fed to rats. In the first experiment, biological values (BV) of cv. Lysimax and RM 609 (89.0% and 91.0%, respectively) were significantly greater than that of cv. Sultan (73.9%). Compared with Sultan true protein digestiblities (TD) and energy digestibility (ED) were slightly lower (P < 0.05), at most 3.6 and 4.2 percentage units, in RM 609, 1385 and 1405 and cv. Lysimax, respectively. In the second experiment with young pigs, the apparent BV of the Lysimax diet (84.1%) was higher (P < 0.05) than that of the RM 1405 diet (77.4%). The ED was 2.1 percentage units lower (P < 0.05) for the Lysimax diet than for the RM 1405 diet. In the third experiment with rats, the BV for the Lysimax diet was higher (P < 0.05) than for the RM 1405 diets, TD and ED were similar (P > 0.05). It is concluded that the development of high-lysine barley varieties is beneficial for meeting the requirements of indispensable amino acids for monogastric animals. Moreover, N excretion into the environment is substantially reduced due to a reduction in the prolamin protein fraction which is rich in glutamic acid and proline. Key words: Rats, pigs, barley, amino acids, digestibility
The effects of ractopamine treatment and gender on chemical components of bacon and ham
Authors: Jeremiah L. E. , Ball R. O. , Uttaro B. , Dick P. , Stobbs L.
Published: March 2010

Cured and smoked ham and bacon 20 pigs equally divided between genders (barrows and gilts) and dietary treatments (0 and 20 ppm ractopamine) were chemically analyzed for specific components (fat, Na, K, Cl and NO2). Cuts from gilts had higher contents of K and NO (P < 0.05) while cute from barrows exhibited higher contents of Na and Cl (P < 0.05). Cuts from ractopamine-treated pigs had higher contents of Na, Cl, K and NO2 (P < 0.05) However, the observed differences in chemical composition between barrows and gilts and between control and ractopamine treatments may be attributable to differences in fat content. Composite results illustrate the chemical composition of ham and bacon from barrows and gilts and confirm the effect of dietary ractopamine in reducing carcass lipids. Key words: Pork, ham, bacon, chemical composition
Lambs produced from cryopreserved sheep embryos derived by in vitro fertilization of aspirated oocytes
Authors: Songsasen N. , Martino A. , Leibo S. P. , Walmsley S. , Pollard J. W. , Buckrell B. C.
Published: March 2010

A total of 104 oocytes were aspirated from 11 mature ewes and 4 prepubertal lambs. After in vitro maturation, fertilization and culture, 11 of the 104 oocytes developed into blastocysts. These were cryopreserved in 1.5 M ethylene glycol. After being thawed, all were transferred into four recipients, two of which became pregnant and delivered a normal lamb. Key words: Oocyte, cryopreservation, in vitro maturation and fertilization, sheep, embryo
Renal functions and urea handling in pregnant and lactating Corriedale ewes
Authors: Rodriguez M. N. , Tebot I. , Bas A. Le , Nievas C. , Cirio A. , Leng L.
Published: March 2010

Renal urea conservation was evaluated in Corriedale ewes during late pregnancy and lactation. Glomerular filtration, renal plasma flow and urea clearance were significantly reduced both states compared with control sheep. Filtered load of urea and urine urea elimination were significantly reduced during lactation (−46% and −45%, respectively, vs. controls). No changes were noted in fractional excretion of urea. Therefore, Corriedale ewes restrict urine urea losses during lactation by reducing glomerular filtration. During late pregnancy, urea sparing is less marked. Key words: Renal functions, urea, pregnancy, lactation, sheep
Effect of high progesterone levels during the growing phase of the dominant follicle of wave 1 in ultrasonically monitored ewes
Authors: Rubianes E. , Castro T. de , Carbajal B.
Published: March 2010

The effect of high progesterone levels in the growth of the largest (dominant) follicle of Wave 1 was monitored by daily ultrasonography in Corriedale ewes. Progesterone treatment decreased the growing rate (P < 0.05), lengthened the static phase (P < 0.05) and tended to decrease the maximum diameter attained by the dominant follicle (P < 0.06). Key words: Ewes, ultrasonography, dominant follicle, progesterone, wave 1
Effect of norgestomet or norgestomet and gonadotropin-releasing hormone on attainment of puberty in beef heifers
Authors: Henderson C. L. , Miller H. L.
Published: March 2010

An experiment was conducted using 133 crossbred beef heifers randomly assigned to three treatments. All heifers were bled weekly to monitor concentration of progesterone. Norgestomet-treated heifers were 26.2 d younger (P < 0.01) and 21.6 kg lighter (P < 0.05) than controls at puberty. Norgestomet plus GnRH-treated heifers were 30.9 d younger (P < 0.01) and 18.8 kg lighter (P < 0.05) than controls at puberty. The effects of hormonal treatment on subsequent pregnancy and calving rates were variable. Key words: Beef heifers, puberty, norgestomet, GnRH, reproductive performance
Estimation of carcass composition by computer image analysis in the cross sections of cross-bred steers
Authors: Karnuah A. B. , Moriya K. , Sasaki Y. , Mitani K. , Yamazaki T.
Published: March 2010

Estimation equations for carcass composition were obtained using the information extracted from the carcass cross section by Computer Image Analysis (CIA). The total kilograms of lean, fat, and bone, and their percentages, were measured on the left side of the carcasses of F1 (cross-bred between Japanese Black and Holstein) steers by physical dissection. Traced data of the cross section between the 5th and 6th ribs (Data set I) and pictures of carcass cross section between the 7th and 8th ribs (Data set II) were subjected to image analysis. Various information on both the individual muscles and the overall outline of the cross section was extracted by the CIA technique. Maximum R2 improvement method of the stepwise procedure was used to choose the best regression equation to estimate carcass composition as total kilograms and percentages of lean, fat, and bone. The data sets were also adjusted for age and the stepwise procedure was also conducted. Coefficients of determination, adjusted for the degrees of freedom (adjusted R2) of the regression equations for estimating carcass composition, were high, i.e., 0.779 to 0.959 for kilograms of lean, fat, and bone, whereas for the percentages of lean, fat, and bone were high, i.e., 0.788 to 0.952, respectively. For the adjusted data, the adjusted R2 for estimating kilograms of lean, fat, and bone with Data sets I and II were 0.729, 0.633, and 0.598, and 0.813, 0.806, and 0.878, respectively, while for the percentages of lean, fat, and bone were 0.793, 0.623, and 0.378, and 0.953, 0.989, and 0.467, respectively. When the estimation equation obtained from the unadjusted Data set I was fitted with the information extracted from Data set II, the correlation coefficients between the values estimated by the equation and the values obtained by physical dissection on carcass composition were high, ranging from 0.70 to 0.92. On the other hand, the correlation coefficients obtained from the adjusted data sets were low. Key words: Estimation equation, computer image analysis, carcass composition, carcass cross section, F1 steers
The effects of catch-up (compensatory) growth on reproductive performance of beef heifers
Authors: Boadi Dinah , Price M. A.
Published: March 2010

Fifty-four heifer calves were allocated to five feeding/weaning treatments at birth in April/May 1990: 1) VEW (n = 11) dams feed-restricted for 3 mo before and 2 mo after calving; calves weaned in June onto gram-supplemented pasture and then into a drylot in October; 2) EW1 (n = 10) dams not restricted; calves weaned in August (unsupplemented pasture) into drylot in October; 3) EW2 (n = 10) dams not feed-restricted; calves weaned directly into drylot in August; 4) LW1 (n = 12) dams feed restricted for 3 mo before, but not after calving; calves weaned directly into drylot in October, 5) LW2 (n = 11): dams not restricted; calves weaned directly into drylot in October. The very early (VEW) and early (EW1, EW2) weaned heifers grew significantly slower than the later-weaned ones (LW1, LW2) from birth to September, and were still significantly lighter at 12–13 mo of age (May 1991). Recovery of liveweight-for-age was achieved by EW2 heifers by 18 mo and VEW and EW1 by about 23 mo of age. Early weaning treatments delayed age but not weight at first estrus (P < 0.05) yet the number of heifers conceiving and calving, and all associated reproductive data, including rebreeding success were unaffected by treatment (P > 0.05). Despite a delay in first estrus, reproductive efficiency and calving performance were not impaired by early feed restriction in heifers conceiving at 15 mo of age. Key words: Beef heifers, feed restriction, fertility, reproduction, catch-up growth
Thin stillage from wheat-based ethanol production as a nutrient supplement for cattle grazing crested wheatgrass pastures
Authors: Ojowi M. O. , Christensen D. A. , McKinnon J. J. , Mustafa A. F.
Published: March 2010

An 84-d trial was conducted to evaluate the use of thin stillage from wheat based ethanol production as a nutrient supplement for cattle grazing crested wheatgrass. Forty medium-frame steers were allotted to eight CWG pastures (5 pasture−1) and supplied with either water or thin stillage as a fluid source. Measurements included daily intake of fluid, biweekly weight gains, start and end of test ultrasonic backfat measurements, and blood plasma samples on days 42, 56, and 70 of the trial. Samples of thin stillage and biweekly clippings of the CWG pastures were collected throughout the trial for analysis. Thin stillage averaged 8.4 ± 0.35, 48.5 ± 1.83, 9.6 ± 1.63, 34.5 ± 4.55, and 3.4 ± 0.44% (DM basis) CP, EE, NDF and ADF, respectively. Cattle with access to thin stillage exhibited superior (P < 0.05) weight gains from day 42 through day 84 of the trial. Cumulative weight gains were 1.39 ± 0.14 and 0.91 ± 0.27 kg d−1, respectively, for the thin stillage and water fed cattle (P < 0.05), an increase of 53%. Fluid intake of the cattle on stillage was 48.2 ± 2.7 L d−1 or 67% greater (P < 0.05) than that for animals on water (28.9 ± 1.53 L d−1). Daily DM intake from thin stillage estimated from fluid intake was 4.1 kg. The superior liveweight gain of cattle fed thin stillage was reflected in higher (P < 0.05) backfat levels at the end of test (2.51 vs. 0.6 mm) and higher (P < 0.05) plasma urea, Mg, and P levels. The results of this study indicate that thin stillage from wheat-based ethanol production is a valuable nutrient source for cattle grazing CWG. Key words: Thin stillage, wheat, crested wheatgrass
Nutritive value of live and dead components of two bunchgrasses
Authors: Houseal G. A. , Olson B. E.
Published: March 2010

On northern latitude winter rangelands, the effects of low forage nutritive value on animal performance are usually mitigated by supplementing livestock, although the amount of supplement is often not adjusted for available forage quantity and nutritive value. The objective of this study was to assess the potential of live (fall, spring) and dead component of two cool-sea-son bunchgrasses to meet nutritional requirements of cattle from fall through spring on a foothills range site in southwestern Montana. Several nutritive characteristics of live and dead components of bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Love) and Idaho fescue (Festuca idahoensis Elmer) were assessed during the winters of 1991–1992 and 1992–1993. In addition, rate and extent of dry matter disappearance, and extent of crude protein disappearance were determined in-situ using ruminally cannulated beef cows. Nutritive value of forage components of bluebunch wheatgrass and Idaho fescue were similar fall through spring. Fall growth was similar in CP and digestibility to April growth, and maintained these levels through winter. With normal forage intake rates on winter range, CP levels of standing dead material would not meet animal protein requirements fall through spring. When fall growth is not abundant, more protein supplement would be needed than when it is abundant. Matching animal requirements to forage availability and nutritive value, supplementing only when necessary and in appropriate amounts, could help reduce costs of winter feeding. Key words: Winter grazing, bluebunch wheatgrass, Idaho fescue, forage quality, cattle
Variability of apparent ileal amino acid digestibility in canola meal for growing-finishing pigs
Authors: Fan M. Z. , Sauer W. C. , Gabert V. M.
Published: March 2010

Studies were conducted with six barrows, average initial body weigh 32.5 kg, fitted with a T-cannula at the distal ileum, to determine some of the factors responsible for the variability in apparent ileal digestibility values of amino acids (AA) in canola meal. The barrows were fed six corn starch-based diets, formulated to contain 18.0% crude protein (CP) on a dry matter (DM) basis from six canola meal samples, according to a 6 × 6 Latin square design. Chromic oxide (0.3%) was used as a digestibility marker. The pigs were fed twice daily, at 08:00 and 20:00 h. The dietary allowance was 1600 g d−1. Each experimental period consisted of 8 d. Ileal digesta were collected at 2-h intervals, for a total of 24 h from 08:00 on day 6 to 08:00 h on day 8. With the exception of proline, there were differences (P < 0.05) in the apparent ileal digestibility values of all AA among the six canola meal samples. Of the indispensable AA in canola meal, the digestibility values of arginine, histidine, and methionine were relatively high, ranging from 79.4 to 84.4, from 76.5 to 81.0%, and from 77.3 to 82.4%, respectively, while the digestibility values of threonine and tryptophan were relatively low, ranging from 59.7 to 66.5 and from 61.7 to 67.5%, respectively. Furthermore, with the exception of arginine, the digestibility values of the indispensable AA were negatively correlated (P < 0.05) with the neutral-detergent fiber (NDF) content in canola meal. In addition with the exception of threonine, tryptophan and valine, the digestibility values of the indispensable AA were positively correlated (P < 0.05) with their respective dietary levels. In conclusion, measured with the ileal analysis method, there were differences (P < 0.05) in the digestibility values of the majority of AA among the canola meal samples. Differences in NDF content were mainly responsible for the variation. In addition, differences in the dietary levels of most AA also contributed, in part, to the variation of AA digestibility values. Key words: Amino acids, ileal digestibility, canola meal, pigs
Effect of inoculation on silage quality and performance of steers fed grass and cereal silages either alone or in combination
Authors: Charmley E. , Winter K. A. , McRae K. B. , Fillmore S. A. E.
Published: March 2010

Two first-cut silages were prepared from orchardgrass/white clover cut at the end of June and ensiled with or without a silage inoculant containing 1 × 10 CFU g−1Lactobacillus casei, L. plantarum, and Streptococcus lactis at an application rate of 1 × 10 CFU g−1 crop. A further two silages were prepared from whole-crop wheat cut in the third week of August and ensiled with or without the same silage inoculant at the same application rate. The objectives of the study were to evaluate the effectiveness of a silage inoculant on silage fermentation, silage quality and animal response. Although inoculation increased lactic acid bacteria numbers in grass at ensiling, there were few observed differences in fermentation characteristics of the silages. Silages were used in a 16-wk feeding trial with 48 steers (initial BW 267 kg). Control and inoculated silages were fed either as 100% grass silage, 50% grass and 50% wheat silage mixture (dry matter basis), or as 100% wheat silage. All steers received a barley/soybean meal supplement at 2 kg d−1 (as-fed basis). Overall, DM intake was similar in control and inoculated silages, but there was an interaction (kg d−1P = 0.051; g kg−1 BW, P = 0.037) between crop and inoculant use indicating that intake was increased by inoculant use in grass silages only. Body weight gain was improved by 10% when inoculant was used (P = 0.006). This resulted in improved feed efficiency in wheat silage treated with inoculant (interaction, P = 0.023). Body weight gain decreased linearly as the proportion of wheat silage in the diet increased (P < 0.001), irrespective of inoculant use. Apparent digestibility of DM and components determined in sheep was higher for grass than wheat silage (P < 0.05), but there was no effect of inoculation on digestibility of either crop type. In this study, the application of inoculant to grass silage improved intake, while its application to wheat silage improved efficiency of feed utilization. Key words: Steer, inoculant, gain, grass silage, wheat silage
The effect of graded levels of melatonin on performance and gastric ulcers in pigs
Authors: Ayles H. L. , Ball R. O. , Friendship R. M. , Bubenik G. A.
Published: March 2010

Graded concentrations of dietary melatonin were fed to examine the effects on performance and gastric ulcers in pigs. Four levels of melatonin, 0, 2.5, 5, and 10 mg kg−1, were fed m a finely ground corn–wheat based diet (578 ± 1.89 μm), designed to induce gastric ulcers, to 64 Yorkshire barrows and gilts between 22.2 ± 2.0 and 102.5 ± 4.3 kg. At postmortem, ulcers were scored from 0 (no ulcer) to 3 (severe ulcer). Volume, percent moisture, pH, and bile acid concentration of the stomach digesta were determined. Melatonin supplementation was associated with a decreasing severity of ulcers (P < 0.05). There were no differences in average daily gain between melatonin treatments, although 10 mg kg−1 diet caused a reduction in feed intake. Bile acid concentration in the stomach digesta was highest in pigs receiving the control diet without melatonin (P < 0.05) and was increased with increasing ulcer severity (P < 0.05). Key words: Swine, ulcer, diet, melatonin, bile, acids
Effect of weaning on epidermal growth factor and its receptor messenger RNA levels in various tissues of piglets
Authors: Peng M. , LeBel D. , Palin M-F. , Pelletier G.
Published: March 2010

Weights of pancreas, liver, and stomach, and total DNA of pancreas and stomach mucosa per body weight were greater (P < 0.05) in weaned piglets than suckling ones at 30 d of age. There was no effect (P > 0.05) of weaning on epidermal growth factor (EGF) and EGF receptor (EGFR) messenger RNA levels in liver, stomach, duodenum, and skeletal muscle. Messenger RNAs of EGF in pancreas increased following weaning in piglets of 27 (P = 0.0001) and 30 (P = 0.004) d of age, indicating a possible involvement of EGF in pancreatic development during this period. Key words: Weaning, EGF, EGFR mRNA, Pig tissues
Ruminal digestion kinetics of temper-rolled hulless barley
Authors: Yang W. Z. , Beauchemin K. A. , Rode L. M.
Published: March 2010

In situ ruminal digestion kinetics of temper-rolled hulless barley were affected by the moisture content of grain prior to processing. A moisture content of 21% resulted in optimum ruminal digestion of temper-rolled hulless barley. Key words: Hulless barley, grain processing, temper-rolling, in situ digestion, ruminal degradability
The role of climate change in the occurrence of algal blooms: Lake Burragorang, Australia
Authors: Vilhena Leticia C. , Hillmer Ingrid , Imberger Jö rg
Published: March 2010

The three‐dimensional hydrodynamic Estuary, Lake and Coastal Ocean Model (ELCOM) was coupled to the ecological Computational Aquatic Ecosystem Dynamics Model (CAEDYM) and to an underflow model to simulate the fate of the constituents from three flood underflow events in Lake Burragorang, Australia, in order to verify the changes in the hydrodynamical behavior that could lead to an algal bloom when the lake water level is low as a consequence of climate change. Simulated patterns of temperature, dissolved oxygen, and turbidity compared well with field data. The ELCOM–CAEDYM simulations demonstrated that the vertical excursion induced by an intrusion depended on the volume of the lake before the arrival of the inflow, on the volume of water inserted by the inflow, and on the proximity between the top insertion of the inflow and the surface layer of the lake. When the water level was low and the inflow volume was high, the underflow constituents mixed into the surface layer and triggered a major algal bloom.
Nitrogen fixation may not balance the nitrogen pool in lakes over timescales relevant to eutrophication management
Authors: Scott J. Thad , McCarthy Mark J.
Published: March 2010

We explored multiyear linear trends in nutrient concentrations, nitrogen (N) : phosphorus (P) ratio, and phytoplankton biomass within the 37‐yr, whole‐ecosystem nutrient enrichment experiment in Lake 227 of the Experimental Lakes Area, Canada. Based on experimental conditions, data were divided into subsets, which included (1) the period from 1969 to 1989 when the lake was fertilized with both N and P; (2) the period from 1990 to 2005 when the lake was fertilized with P alone; and (3) the period from 1997 to 2005 when the lake was fertilized with P alone and which also postdated a food web manipulation experiment, which left the lake without fish. After N fertilization was halted in 1990, total N concentrations decreased, which resulted in a decrease in the ratio of total N to total P and suggested increasing N deficiency. Chlorophyll ά concentration decreased over this same period. Phytoplankton biomass (mg m−3) was highly variable during the food web manipulation experiment but exhibited a clear decrease from 1997 to 2005, which was the longest period of monotonic change in phytoplankton biomass over the entire 37‐yr study. Collectively, these results suggest that Lake 227 has become increasingly N‐limited since N fertilization was halted and indicate that N fixation by cyanobacteria was not sufficient to offset the decrease in external N inputs to Lake 227. Furthermore, phytoplankton biomass decreased in response to decreased N availability, suggesting that the degree of eutrophication can be controlled by managing N inputs concurrently with P.
Derivation of Recovery Kinetics From Stress Relaxation Tests
Authors: Bhaumik Sheila , Mohles Volker , Gottstein Günter , Heering Christoph , Hirt Gerhard
Published: March 2010

The recovery behavior of a commercial aluminum alloy 3103 was investigated by the means of two alternative experimental methods: stress relaxation (SR) and double tension tests (DT). In case of SR, the stress–time evolution after deformation was recorded, and for DT the yield stress after several recovery times were measured. The DT tests were further sub‐divided into tests with and without external load during recovery. The results revealed that the recovery kinetics is clearly accelerated by the external stress during the SR. However, the difference between the DT and SR stresses is much larger. It is caused by continued dislocation glide after the deformation, which causes continued plastic elongation of the specimens. This is demonstrated quantitatively by appropriate evaluation models for both experiments. In contrast to DT, the SR evaluation accounts for the elastic SR due to plastic elongation, but the recovery parameters are the same ones as for DT. This makes it possible to replace DT by SR experiments, which are materially less laborious.
Electrostatic‐induced interfacial assembly of enzymes with nanosheets: Controlled orientation and optimized activity
Authors: An Zhe , He Jing , Lu Shan , Yang Lan
Published: March 2010

In this work, an electrostatic‐induced interfacial assembly of porcine pancreatic lipase (PPL) with the nanosheets of layered double hydroxide (LDHNSs) is designed to rationally control the orientation of bound PPL. The PPL orientation in the bidimensional confinement spacing alters relying on the PPL loading, with the majority of active sites facing the LDH layer at low PPL loading and facing the adjacent protein molecule at high PPL loading. The biocatalytic activity of the bound PPL significantly depends on its orientation. Remarkable enhancement of the bio‐activity has been observed when the PPL/LDHNSs mass ratio is less than 9, and a maximum activity is met with at PPL/LDHNSs = 0.5. In addition, the thermal stability of PPL‐LDHNSs bioactivity has been obviously improved in comparison with soluble PPL. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Comparison of real‐time methods for maximizing power output in microbial fuel cells
Authors: Woodward L. , Perrier M. , Srinivasan B. , Pinto R. P. , Tartakovsky B.
Published: March 2010

Microbial fuel cells (MFCs) constitute a novel power generation technology that converts organic waste to electrical energy using microbially catalyzed electrochemical reactions. Since the power output of MFCs changes considerably with varying operating conditions, the online optimization of electrical load (i.e., external resistance) is extremely important for maintaining a stable MFC performance. The application of several real‐time optimization methods is presented, such as the perturbation and observation method, the gradient method, and the recently proposed multiunit method, for maximizing power output of MFCs by varying the external resistance. Experiments were carried out in two similar MFCs fed with acetate. Variations in substrate concentration and temperature were introduced to study the performance of each optimization method in the face of disturbances unknown to the algorithms. Experimental results were used to discuss advantages and limitations of each optimization method. © 2010 American Institute of Chemical Engineers AIChE J, 2010
High‐throughput microporous tube‐in‐tube microreactor as novel gas–liquid contactor: Mass transfer study
Authors: Chen Jian‐Feng , Chen Gui‐Zi , Wang Jie‐Xin , Shao Lei , Li Peng‐Fei
Published: March 2010

High‐throughput microporous tube‐in‐tube microchannel reactor (MTMCR) was first designed and developed as a novel gas–liquid contactor. Experimentally measured kLα in MTMCR is at least one or two orders of magnitude higher than those in the conventional gas–liquid contactors. A high throughput of 500 L/h for gas and 43.31 L/h for liquid is over 60 times higher than that of T‐type microchannel. An increase of the gas or liquid flow rate, as well as a reduction of the micropore size and annular channel width of MTMCR, could greatly intensify the gas–liquid mass transfer. The interfacial area, α, in MTMCR was measured to be as high as 2.2 × 105 m2/m3, which is much higher than those of microchannels (3400–9000 m2/m3) and traditional contactors (50–2050 m2/m3). The artificial neural network model was proposed for predicting α, revealing only an average absolute relative error of <5%. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Greedy algorithm for scheduling batch plants with sequence‐dependent changeovers
Authors: Castro Pedro M. , Harjunkoski Iiro , Grossmann Ignacio E.
Published: March 2010

This article presents a new algorithm for scheduling multistage batch plants with a large number of orders and sequence‐dependent changeovers. Such problems are either intractable when solved with full‐space approaches or poor solutions result. We use decomposition on the entire set of orders and derive the complete schedule in several iterations, by inserting a couple of orders at a time. The key idea is to allow for partial rescheduling without altering the main decisions in terms of unit assignments and sequencing (linked to the binary variables) so that the combinatorial complexity is kept at a manageable level. The algorithm has been implemented for three alternative continuous‐time mixed integer linear programing models and tested through the solution of 10 example problems for different decomposition settings. The results show that an industrial‐size scheduling problem with 50 orders, 17 units distributed over six stages can effectively be solved in roughly 6 min of computational time. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Formation of SiON networks from silsesquiazanes
Authors: Yokota Hirotaka , Imanari Noriko , Sugahara Yoshiyuki
Published: March 2010

Silsesquiazanes bearing different groups [RSi(NH)1.5]n(R = C12H25, Ph, H) were hydrolyzed and the resulting products were characterized. [C12H25Si(NH)1.5]nwas hydrolyzed by heating in an autoclave with water at 120 °C for 16 h. [PhSi(NH)1.5]nwas hydrolyzed by heating with water at 50 °C for 16 h. [HSi(NH)1.5]nwas dispersed in water at room temperature to induce hydrolysis. In the cases of [C12H25Si(NH)1.5]nand [PhSi(NH)1.5]n, IR analysis showed that SiNHSi bonds remained and that terminal SiNH2bonds in silsesquiazane were preferentially hydrolyzed to form SiOH bonds or SiOSi bonds. Solid‐state29Si CP/MAS NMR analysis revealed the formation of a SiON network containing various Si environments. All the SiH and SiN bonds in [HSi(NH)1.5]n, on the other hand, were converted into SiO bonds. These results reveal that SiON networks can be formed from silsesquiazanes bearing dodecyl and phenyl groups under relatively moderate conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of drying techniques on extraction of Astragalus pieces
Authors: Qianqian Di , Junhong Yang , Jun Zhao
Published: March 2010

To investigate the effect of different drying techniques on the quality of Chinese herb medicine (CHM), drying experiments of Astragalus pieces after rehydration were carried out, and four different kinds of drying techniques viz microwave drying, freeze‐drying, vacuum drying and hot‐air drying, were examined in this paper. The microstructure of dried samples was characterized by means of scanning electron microscope (SEM), and the molecular weight distribution of Astragalus pieces extract was characterized by means of ultrafiltration. Results show that dehydrated rate by microwave drying is five times faster than those by others three drying techniques. The effective component content in the extract of sample dried by microwave drying, with the molecular weight of less than 4000 Da, is higher than those by other three drying techniques. Observations of the SEM images show that the microstructure of sample dried by microwave drying is much similar to that of raw Astragalus pieces, indicating that microwave technique helps keep the penetrability of inner transmission tissues and thin‐wall cell tissues, and benefits to the extraction of effective components of Astragalus pieces. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Hydroentanglement nonwoven filters for air filtration and its performance evaluation
Authors: Patanaik Asis , Anandjiwala Rajesh D.
Published: March 2010

New nonwoven filters are developed for air filtration application with the help of hydroentanglement bonding technique. Different types of nonwoven filters are produced by varying the hydroentanglement processing parameters. The changes in nonwoven filter properties after prolonged exposure to working conditions under cyclic compression play an important role in its long‐term performance characteristics. The performance of the developed filters are evaluated in terms of changes in pore characteristics, filtration parameters, and strength after cyclic compression and compared with the corresponding values before subjecting it to cyclic compression. The developed filter shows good performance characteristics for air filtration with low pressure drop and high efficiency in capturing micron and submicron size particles without any significant changes in its strength. Theoretical understanding of the fluid flow emerging from the nozzles during the hydroentanglement process is simulated by the computational fluid dynamics (CFD). Based on the fluid drag force and impact force of the water jets, a mechanism of fiber bonding is proposed. The impact force of the water jets and fluid drag forces plays an important role in the mechanism of fiber bonding. Nozzle condition also plays an important role in economizing this process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Dynamic mechanical properties of oil palm microfibril‐reinforced natural rubber composites
Authors: Joseph Shaji , Appukuttan Sreekumar P. , Kenny Jose M. , Puglia Debora , Thomas Sabu , Joseph Kuruvilla
Published: March 2010

The dynamic mechanical properties of macro and microfibers of oil palm‐reinforced natural rubber (NR) composites were investigated as a function of fiber content, temperature, treatment, and frequency. By the incorporation of macrofiber to NR, the storage modulus (E') value increases while the damping factor (tan δ) shifts toward higher temperature region. As the fiber content increases the damping nature of the composite decreases because of the increased stiffness imparted by the natural fibers. By using the steam explosion method, the microfibrils were separated from the oil palm fibers. These fibers were subjected to treatments such as mercerization, benzoylation, and silane treatment. Resorcinol‐hexamethylenetetramine‐hydrated silica was also used as bonding agent to increase the fiber/matrix adhesion. The storage modulus value of untreated and treated microfibril‐reinforced composites was higher than that of macrofiber‐reinforced composites. The Tg value obtained for this microfibril‐reinforced composites were slightly higher than that of macrofiber‐reinforced composites. The activation energy for the relaxation processes in different composites was also calculated. The morphological studies using scanning electron microscopy of tensile fracture surfaces of treated and untreated composites indicated better fiber/matrix adhesion in the case of treated microfibril‐reinforced composites. Finally, attempts were made to correlate the experimental dynamic properties with the theoretical predictions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and properties of hydrophilic segmented block copolymers based on poly(ethylene oxide)‐ran‐poly(propylene oxide)
Authors: IJzer A. C. , Arun A. , Reijerkerk S. R. , Nijmeijer K. , Wessling M. , Gaymans R. J.
Published: March 2010

The present article discusses the synthesis and various properties of segmented block copolymers with random copolymer segments of poly(ethylene oxide) and poly(propylene oxide) (PEO‐r‐PPO) together with monodisperse amide segments. The PEO‐r‐PPO contained 25 wt % PPO units and the segment presented a molecular weight of 2500 g/mol. The synthesized copolymers were analyzed by differential scanning calorimetry, Fourier transform infra‐red spectroscopy, atomic force microscopy and dynamic mechanical thermal analysis. In addition, the hydrophilicity and the contact angles (CAs) were studied. The PEO‐r‐PPO segments displayed a single low glass transition temperature, as well as a low PEO crystallinity and melting temperature, which gave enhanced low‐temperature properties of the copolymer. The water absorption values remained high. In comparison to mixtures of PEO/PPO segments, the random dispersion of PPO units in the PEO segments was more effective in reducing the PEO crystallinity and melting temperature, without affecting the hydrophilicity. Increasing the polyether segment length with terephthalic groups from 2500 to 10,000 g/mol increased the hydrophilicity and the room temperature elasticity. Furthermore, the CAs were found to be low 22–39° and changed with the crosslink density. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117:1394–1404, 2010
Synthesis of poly(D,L‐lactic acid) modified by cholic acid via direct melt copolycondensation and its characterization
Authors: Wang Zhao‐Yang , Zhao Hai‐Jun , Wang Qun‐Fang , Ye Rui‐Rong , Finlow David E.
Published: March 2010

From D,L‐lactic acid and the natural functional molecule cholic acid (CA), the biodegradable material poly(D,L‐lactide–cholate) was synthesized via direct copolycondensation. For the CA/lactic acid (LA) molar feed ratio of 1/64, the optimal synthesis conditions were as follows: a prepolymerization time of 8 h, 0.3 wt % SnO catalyst, and melt copolycondensation for 8 h at 160°C, which gave a novel star‐shaped poly(D,L‐lactic acid) (PDLLA) modified by CA with the maximum weight‐average molecular weight of 5600 Da at a yield of 51.9%. The copolymer poly(D,L‐lactide–cholate) at different molar feed ratios was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry, thermogravimetry, and X‐ray diffraction. Decreasing the molar feed ratio of CA/LA from 1/15 to 1/128 reduced the average number of CA units embedded in the copolymer from 4 to 1. With 1/15 CA/LA, the copolymer was not a star‐shaped polymer, and its weight‐average molecular weight was the biggest (weight‐average molecular weight = 12,700 Da, weight‐average molecular weight/number‐average molecular weight = 1.68). With 1/32 CA/LA, the copolymer with two CA units was not a star‐shaped polymer either. With 1/64, 1/100, and 1/128 CA/LA, the copolymer mainly had one CA unit core embedded as a normal star‐shaped PDLLA with four arms, and certain crystallinity could be detected. The novel direct copolycondensation method was simple and practical for the synthesis of the asymmetrical star‐shaped PDLLA material, and it was advantageous for this PDLLA material embedded in the special bioactive molecule CA to be applied in the field of drug delivery and tissue engineering. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Adsorption and recovery of nonionic polymers by neutralization of cellulose fiber surface charge via cationic polyamide‐epichlorohydrin resins
Authors: Hsieh Jeffery S. , Yoo Sukjoon
Published: March 2010

Nonionic copolymers, such as poly(1‐vinylpyrrolidone)‐polystyrene, have been used in the production of filtration membranes, catalysts, and sensors. However, their nonionic character and high solubility in water prevents their efficient recovery from waste streams. Cellulose fibers show potential as recovery agents because they are inexpensive, environmentally friendly, and have a large surface area per unit mass. However, due to the anionic nature of the cellulose fiber surface, their adsorptive behavior is often limited to cationic species. We have shown that low‐dosage application of a cationic polyamide‐epichlorohydrin resin can alter the fiber surface charge so as to provide more neutral surface area for the nonionic polymer to adsorb; furthermore, the adsorbed polyamide‐epichlorohydrin resin does not block the approach of poly(1‐vinylpyrrolidone)‐polystyrene. Single‐component adsorption of poly(1‐vinylpyrrolidone)‐polystyrene was on the order of 10−3 g/g; with polyamide‐epichlorohydrin resin adsorbed on the fiber, the adsorption increased one‐order of magnitude to 10−2 g/g. We believe this significant increase is caused by neutralization of fiber surface charge via polyamide‐epichlorohydrin resin, creating a surface more favorable for adsorption and recovery of nonionic species. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Purification, surface modification of coal ash silica and its potential application in rubber composites
Authors: Mahmood Nasir , Khan Mohammad Sohail , Khan Asad Ullah , Stöckelhuber Klaus Werner , Heinrich Gert
Published: March 2010

This article reports the purification and surface modification of coal ash silica and afterwards its utilization as reinforcing filler in solution‐styrene‐butadiene rubber/butadiene rubber (S‐SBR/BR). The coal ash silica free of unwanted metal ions/mineral oxides was obtained using phosphoric acid. The chemical composition of the purified coal ash silica in comparison to impure coal ash indicates the presence of characteristic hydroxyl functional group at 3440 cm−1 and an increase in the oxygen content as determined with the help of Fourier Transform Infrared and x‐ray photoelectron spectroscopy, respectively. The contact angle analysis shows that after purification the polar part of the surface energy increased to 17.5 from 12 m Jm−2. While the surface area increased to an order of magnitude, i.e., 11.6 to 110.5 m2 g−1. The modification of purified silica particles with bis(3‐triethoxysilylpropyl) tetrasulfane reveal the functionalization of hydroxyl to ‐Si‐O‐R groups as detected at 1560 cm−1. As a consequence, the modified silica based S‐SBR/BR composite resulted in improved mechanical properties due to enhanced silica‐rubber interaction. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010