13 research outputs found

    Respons Pemberian Kompos Tandan Kosong Kelapa Sawit Dan Zeolit Terhadap Pertumbuhan Bibit Kelapa Sawit Di Pre Nursery

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    This research aims for knowing the response a giving of oil palm seeds in the results of giving empty fruit bunches of oil palm compost and zeolite in pre nursery. The researched was carried outat Faculty of Agricultural screen house, USU (± 25 mdpl) in March – July 2014 using a randomizedblock design with two factors. The first factors was dose empty fruit brunches of oil palm compostwith four levels that were including 0 g/polybag; 15 g/polybag; 30 g/polybag; 45 g/polybag; andthe second factor was dose of zeolite with four levels that were including 0 g/polybag; 5 g/polybag;10 g/polybag; 15 g/polybag. The results of research shows that the application of empty fruitbrunches of oil palm compost had a real impact on the stem diameter and total leaf area. As for thediameter of stem best level was obtained at treatment EFBOP compost 45 g/polybag and total leafbest level was obtained at treatment EFBOP compost 30 g/polybag. Giving the zeolite wasevidently influencial toward the stem diameter, total leaf area, crowns wetness weight, root drynessweight, and crowns dryness weight. Zeolite best level was obtained at treatment zeolite 5g/polybag. The interaction between empty fruit brunches of oil palm compost and zeolite fertilizerwas evidently influencial towards the total leaf area and crowns dryness weight in pre nursery. Besttreatment combination level was found of which was 30 g/polybag of empty fruit brunches of oilpalm compost and5 g/polybag of zeolite

    Modification of Flow Structure Over a Van Model by Suction Flow Control to Reduce Aerodynamics Drag

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    Automobile aerodynamic studies are typically undertaken to improve safety and increase fuel efficiency as well as to  find new innovation in automobile technology to deal with the problem of energy crisis and global warming. Some car companies have the objective to develop control solutions that enable to reduce the aerodynamic drag of vehicle and  significant modification progress is still possible by reducing the mass, rolling friction or aerodynamic drag. Some flow  control method provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled with a modified form of Ahmed\u27s body by changing the orientation of the flow from its original form (modified/reversed Ahmed body). This model is equipped with a suction on the rear side to comprehensively examine the pressure field modifications that occur. The investigation combines computational and experimental work. Computational approach used  a commercial software with standard k-epsilon flow turbulence model, and the objectives was  to determine the characteristics of the flow field and aerodynamic drag reduction that occurred in the test model. Experimental approach used load cell in order to validate the aerodynamic drag reduction obtained by computational approach. The results show that the application of a suction in the rear part of the van model give the effect of reducing the wake and the vortex formation. Futhermore, aerodynamic drag reduction close to 13.86% for the computational approach and 16.32% for the experimental have been obtained

    Bioactive metabolites of Asparagopsis stabilized in canola oil completely suppress methane emissions in beef cattle fed a feedlot diet

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    Asparagopsis taxiformis (Asparagopsis) has been shown to be highly efficacious at inhibiting the production of methane (CH4) in ruminants. To date, Asparagopsis has been primarily produced as a dietary supplement by freeze-drying to retain the volatile bioactive compound bromoform (CHBr3) in the product. Steeping of Asparagopsis bioactive compounds into a vegetable oil carrier (Asp-Oil) is an alternative method of stabilizing Asparagopsis as a ruminant feed additive. A dose-response experimental design used 3 Asp-Oil-canola oil blends, low, medium, and high Asp-Oil which provided 17, 34, and 51 mg Asparagopsis derived CHBr3/kg dry matter intake (DMI), respectively (in addition to a zero CHBr3 canola oil control), in a tempered-barley based feedlot finisher diet, fed for 59 d to 20 Angus heifers (five replicates per treatment). On four occasions, live weight was measured and CH4 emissions were quantified in respiration chambers, and blood, rumen fluid, and fecal samples were collected. At the end of the experiment, all animals were slaughtered, with carcasses graded, and samples of meat and edible offal collected for testing of consumer sensory qualities and residues of CHBr3, bromide, and iodide. All Asp-Oil treatments reduced CH4 yield (g CH4/kg DMI, P = 0.008) from control levels, with the low, medium, and high Asp-Oil achieving 64%, 98%, and 99% reduction, respectively. Dissolved hydrogen increased linearly with increasing Asp-Oil inclusion, by more than 17-fold in the high Asp-Oil group (P = 0.017). There was no effect of Asp-Oil treatment on rumen temperature, pH, reduction potential, volatile fatty acid and ammonia production, rumen pathology, and histopathology (P > 0.10). There were no differences in animal production and carcass parameters (P > 0.10). There was no detectable CHBr3 in feces or any carcass samples (P > 0.10), and iodide and bromide residues in kidneys were at levels unlikely to lead to consumers exceeding recommended maximum intakes. Overall, Asp-Oil was found to be safe for animals and consumers of meat, and effective at reducing CH4 emissions and yield by up to 99% within the range of inclusion levels tested.fals

    Autothermal reforming of palm empty fruit bunch bio-oil: thermodynamic modelling

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    This work focuses on thermodynamic analysis of the autothermal reforming of palm empty fruit bunch (PEFB) bio-oil for the production of hydrogen and syngas. PEFB bio-oil composition was simulated using bio-oil surrogates generated from a mixture of acetic acid, phenol, levoglucosan, palmitic acid and furfural. A sensitivity analysis revealed that the hydrogen and syngas yields were not sensitive to actual bio-oil composition, but were determined by a good match of molar elemental composition between real bio-oil and surrogate mixture. The maximum hydrogen yield obtained under constant reaction enthalpy and pressure was about 12 wt% at S/C = 1 and increased to about 18 wt% at S/C = 4; both yields occurring at equivalence ratio Φ of 0.31. The possibility of generating syngas with varying H2 and CO content using autothermal reforming was analysed and application of this process to fuel cells and Fischer-Tropsch synthesis is discussed. Using a novel simple modelling methodology, reaction mechanisms were proposed which were able to account for equilibrium product distribution. It was evident that different combinations of reactions could be used to obtain the same equilibrium product concentrations. One proposed reaction mechanism, referred to as the ‘partial oxidation based mechanism’ involved the partial oxidation reaction of the bio-oil to produce hydrogen, with the extent of steam reforming and water gas shift reactions varying depending on the amount of oxygen used. Another proposed mechanism, referred to as the ‘complete oxidation based mechanism’ was represented by thermal decomposition of about 30% of bio-oil and hydrogen production obtained by decomposition, steam reforming, water gas shift and carbon gasification reactions. The importance of these mechanisms in assisting in the eventual choice of catalyst to be used in a real ATR of PEFB bio-oil process was discussed

    Timing and variation of supplement intake by breeding cows in the extensive rangelands of northern Australia

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    Supplementation of rangeland cattle with loose-licks or lick-blocks providing urea in the dry season and phosphorus during the rainy season (Louw 1979) has become foundational to successful cattle breeding in northern Australia. Little is known of the between-animal variation in supplement intake in a commercial environment or associated differences in animal performance. As an initial step in study of supplement responses in northern Australia, the between animal variation in supplement intake and the diurnal variation in accessing supplement were evaluated

    Evaluation of remote monitoring units for estimating body weight and supplement intake of grazing cattle

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    Automated weighing systems to monitor BW and supplement intake (SI) of individual grazing cattle are being developed to better understand the seasonal nutrition and performance of grazing livestock. This study established (1) the accuracy and repeatability of a commercial walk-over weighing (WoW) system for estimating BW and (2) the accuracy of an automatic supplement weighing (ASW) unit for estimating SI based on measuring time spent at the unit. The WoW and ASW units monitored BW and SI of 112 cattle consisting of 55 cows and 57 calves grazed on a 32.5 ha paddock for 41 days, with an average of 258 BW records collected per day. Static BWs were recorded at each mustering event (n = 7) and were compared to repeated measurements collected by the WoW on the day of each mustering event. Body weight was overestimated by the WoW, with the predicted BW of calves and cows averaging 10 and 21 kg heavier, respectively, than actual, and root MS prediction errors (RMSPE) of 5.1% and 5.5% of the static BW, respectively. For both calves and cows, 38% of the MS prediction errors (MSPE) was mean bias (MB) error and 9% of MSPE was slope bias error. The concordance correlation coefficient (CCC; 0.90 v. 0.80) and modelling efficiency (MEF; 0.78 v. 0.62) of WoW BW for calves were higher than for cows, indicating that the predicted values were deviating from a 1 : 1 relationship and in particular as weight increases. A rolling average across five or more consecutive BW measures improved the accuracy of the WoW BW estimates. Regarding estimates of SI, the aggregated time the herd spent at the ASW unit was strongly associated with total SI (R2 = 0.92; P P FBZ) used as an intake marker and its derivatives (oxfendazole and oxfendazole sulfone) in the plasma of individual cows, with R2 of 0.54, 0.73 and 0.75, respectively. Although the WoW overestimated static BW, the low bias in the slope indicated that a linear regression model could be developed to adjust the WoW BW to reduce the MB and improve the estimate of WoW BW. The significant positive relationship between time spent at the ASW unit and individual blood FBZ concentration identified the suitability of the ASW unit for estimating SI by grazing cattle

    Prediction of students’ academic performance using ANN with mini-batch gradient descent and Levenberg-Marquardt optimization algorithms

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    Abstract Online learning indirectly increases stress, thereby reducing social interaction among students and leading to physical and mental fatigue, which in turn reduced students’ academic performance. Therefore, the prediction of academic performance is required sooner to identify at-risk students with declining performance. In this paper, we use artificial neural networks (ANN) to predict this performance. ANNs with two optimization algorithms, mini-batch gradient descent and Levenberg-Marquardt, are implemented on students’ learning activity data in course X, which is recorded on LMS UI. Data contains 232 students and consists of two periods: the first month and second month of study. Before ANNs are implemented, both normalization and usage of ADASYN are conducted. The results of ANN implementation using two optimization algorithms within 10 trials each are compared based on the average accuracy, sensitivity, and specificity values. We then determine the best period to predict unsuccessful students correctly. The results show that both algorithms give better predictions over two months instead of one. ANN with mini-batch gradient descent has an average sensitivity of 78%; the corresponding values for ANN with Levenberg-Marquardt are 75%. Therefore, ANN with mini-batch gradient descent as its optimization algorithm is more suitable for predicting students that have potential to fail.</jats:p
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