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Search Results: 1 - 10 of 22176 matches for " plant performance. "
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Foundation and perspectives of the use of plant extracts as performance enhancers in broilers
Rizzo, PV;Menten, JFM;Racanicci, AMC;Santarosa, J;
Revista Brasileira de Ciência Avícola , 2008, DOI: 10.1590/S1516-635X2008000400001
Abstract: feed is responsible for about 70% of broilers production costs, leading to an increasing number of studies on alternative dietary products that benefit bird performance and lower production costs. since the 1950s, antimicrobial additives are the most frequently used performance enhancers in animal production and their positive results are observed even in high-challenge conditions. since the 1990s, due to the ban of the use of some antibiotics as growth promoters and the growing trend of the public to consume natural products, plant extracts have been researched as alternatives to antibiotic growth promoters. the first study that evaluated the antibacterial activities of plant extracts was carried out in 1881; however, they started to be used as flavor enhancers only during the next decades. with the emergence of antibiotics in the 1950s, the use of plant extracts as antimicrobial agents almost disappeared. there are several studies in literature assessing the use of plant extracts, individually or in combination, as antimicrobials, antioxidants, or digestibility enhancers in animal feeds. research results on the factors affecting their action, such as plant variety, harvest time, processing, extraction, as well as the technology employed to manufacture the commercial product and dietary inclusion levels show controversial results, warranting the need of further research and standardization for the effective use of plant extracts as performance enhancers, when added to animal feeds. this article aims at presenting plant extracts as alternatives to antibiotics, explaining their main modes of action as performance enhancers in broiler production.
Application of Fuzzy Comprehensive Evaluation on COGAG Power Plant of Performance  [PDF]
Menglin Shao, Qianchao Liang, Dong Yan, Heng Qin, Jun Xiang
Journal of Power and Energy Engineering (JPEE) , 2014, DOI: 10.4236/jpee.2014.29005

A fuzzy comprehensive evaluation of COGAG power plant performance is given by using a method of fuzzy mathematics, and multilevel fuzzy evaluation model is set up. Taking a naval ship as an example, the major parameters related to COGAG power plant performance are obtained by computer simulation, and a set of synthetic performance evaluation index system is established. The result shows that the strong fuzzy propulsion system performance indexes can be quantified by this fuzzy evaluation model in order to provide the reference for choosing the optimal design of ship propulsion system.

Performance of a 270 MW Gas Power Plant Using Exergy and Heat Rate  [PDF]
D. A. Aderibigbe, G. Osunbor
Energy and Power Engineering (EPE) , 2019, DOI: 10.4236/epe.2019.112002
Abstract: The performance of a 270 MW (9 × 30 MW) AES Corporation barge mounted gas turbine power plant in Nigeria is evaluated using the heat rate and entropy generation by the components of the plant to characterize the irreversibility in each component when operating at different loads between 90% and 25%. The power plants have the peculiarity that three of the plants were supplied by three (3) different Original Equipment Manufacturers (OEM); A, B and C. This study is sequel to the fact that the gas turbines were the first independent power plants in the country and after more than fifteen years of operation, it is reasonable to evaluate the performance of the major components. By analyzing the thermodynamic performance of these components, the study demonstrates the utility value of exergy efficiency as an important parameter in the evaluation of major components in a gas power plant. Exergy efficiency is shown to be an important parameter in ranking the power plant components, identifying and quantifying the possible areas of reduction in thermodynamic losses and improvement in efficiencies. A new relationship is derived to demonstrate the correlation between the exergy efficiency and the heat rate of a 30 MW gas power plant. The prediction of the derived relationship correlates well with the observed operational performance of the 30 MW power plants. The combustion chamber in each of the plants provides the maximum exergy destruction during operation. Its exergy efficiency is shown to exhibit good correlation with its energy efficiency and the plant rational exergy. The implication is that from an operational and component selection viewpoint in the specifications of a gas power plant, knowledge of the Heat Rate which is usually provided by the OEM is adequate to make a reasonable inference on the performance of some critical components of the plant.
Produtividade e estabilidade fenotípica de cultivares de milho em três municípios do Estado do Pará
Souza, Francisco Ronaldo Sarmanho de;Ribeiro, Pedro Hélio Estevam;Veloso, Carlos Alberto Costa;Corrêa, Luiz André;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002000900010
Abstract: the area cultivated with grains in the state of pará, brazil, is around 553 thousand hectares and 57% of this area is cultivated with corn. corn average yield is very low due to the production systems adopted which do not include the use of fertilizers, liming and adapted cultivars. the objective of this work was to evaluate the yielding performance and the phenotypic stability of corn cultivars under four environments. thirty-seven commercial and pre-commercial corn cultivars were used in a simple 6x6 lattice. the plots consisted of two rows of 5 m, spaced 0.90 m apart with 5 plants/m after thinning. there were significant differences by the f test for most sources of variation taken into account. within the group of highest yielding cultivars, yield varied from 5.64 to 6.58 ton/ha and within the second group, between 4.03 and 5.52 ton/ha of grains. the variety br-5102 used as control was classified in the highest-yielding cultivars group, outyielding more than 66% of the cultivars tested. the cultivars which presented the lowest risk of adoption for recommendation were ag 4051, c 333b and 984-n. the results showed that it is possible to identify cultivars bearing good yielding performance and good stability.
Antibiosis and antixenosis of six commonly produced potato cultivars to the green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae)
Mottaghinia, L;Razmjou, J;Nouri-Ganbalani, G;Rafiee-Dastjerdi, H;
Neotropical Entomology , 2011, DOI: 10.1590/S1519-566X2011000300012
Abstract: the antibiotic and antixenotic resistance of six commonly produced potato cultivars in iran including aozonia, agria, cosima, cosmos, kondor and savalan to the green peach aphid, myzus persicae sulzer, were investigated under laboratory conditions at 20 ± 2oc, 65 ± 5% rh and 16:8h (l:d) in 2009. antibiosis experiments showed significant differences in the developmental time, nymphal survivorship, fecundity, adult longevity of the green peach aphid among the potato cultivars. intrinsic rate of natural increase (rm) for apterous aphids varied significantly with the potato cultivars on which the aphids were reared. this value ranged from 0.225 to 0.293 females/female/day, which was lowest on cosmos and highest on aozonia. additionally, the estimated net reproductive rate (r0) and finite rate of increase (λ) for apterous aphids were the lowest on cosmos. for the antixenosis experiment, no significant difference was found in aphid's preference to the potato cultivars. however, aozonia was preferred more than the other five cultivars by the apterous aphids. therefore, our results demonstrated that among the investigated cultivars the cosmos cultivar is moderately resistant to the green peach aphid.
Adición de aceites vegetales a la dieta de cabras lecheras: efecto sobre la digestibilidad y los resultados productivos
Martínez-Marín,AL; Pérez-Hernández,M; Pérez-Alba,LM; Carrión-Pardo,D; Gómez-Castro,AG;
Archivos de medicina veterinaria , 2012, DOI: 10.4067/S0301-732X2012000100004
Abstract: the aim of this study was to investigate the effects of differently unsaturated vegetable oils added to dairy goat diets on apparent digestibility and performance traits. twelve malague?a goats were randomly assigned to one of four treatments: no oil (control), 48 g/d of high oleic sunflower oil (gao), regular sunflower oil (rsfo) or linseed oil (lin). the basal diet was made of alfalfa hay and a pelleted concentrate, which included the respective oil and chromium as indicator. the experimental period lasted 21 days. the digestibility of dietary components, except for fat, did not differ between treatments (p > 0.05). oil inclusion in the diet significantly (p < 0.05) increased fat digestibility. there were no significant differences (p > 0.05) in dry matter intake, milk yield and milk composition between treatments. it was concluded that moderate amounts of unsaturated plant oils can be added to dairy goat diets without negative effects on diet digestibility or performance traits.
Performance evaluation of integrated treatment plant of trickling filter and constructed wetland
P.M Maheesan,,G Srinikethan,,Harikumar P.S
International Journal of Engineering Science and Technology , 2011,
Abstract: A system consisting of trickling filter followed by a vertical intermittent flow constructed wetland system under laboratory condition was evaluated for the treatment of domestic wastewater. The system was able to produce final effluents with low concentrations of both organic and nutrients. Mean effluent concentrations were,respectively: BOD: 22.22mg/L;COD:64.58mg/L;SS:27.63mg/L;NH4-N:0.62mg/L;P:1.72mg/L. The study shows that the integrated treatment system of trickling filter and vertical intermittent flow constructed wetlands can be effectively used a treatment option for a treatment with positive attributes of conceptual simplicity and lesser energy consumption.
Biomass Production, Productivity and Physiological Changes in Moth Bean Genotypes at Different Salinity Levels
Nishi Mathur,Joginder Singh,Sachendra Bohra,Avinash Bohra
American Journal of Plant Physiology , 2006,
Abstract: Responses of three genotypes (CZM-105, HM-61 and RMB-108) of moth bean (Vigna aconitifolia) grown under four levels of NaCl salinity (0, 5, 10 and 15 dS m-1) were studied on plant growth, seed yield and nitrogen metabolism at the maturity stage. Increasing salinity levels progressively decreased plant height, leaf area, shoot dry matter and seed yield in all the genotypes. However, CZM 105, displayed higher salt tolerance whereas RMB-108 was most sensitive with 48.5% reduction in seed yield at 15 dS m-1 of NaCl. Genotype HM-61 displayed an intermediate tolerance to salinity. Salt-induced changes in the levels of total chlorophyll, soluble protein, free amino acids and activities of nitrate reductase, glutamine synthetase, glutamate synthase and glutamate dehydrogenase were consistently less in tolerant genotype CZM 105 as compared to moderately tolerant HM-61 and salt sensitive genotype RMB-108 at all levels of salinity.
Growth response and carcass characteristics of Japanese quail to Mentha piperita plant supplementation
Babak Aminzade,Behzad Karami,Elias Lotfi
Animal Biology & Animal Husbandry , 2012,
Abstract: In current study, the effect of Mentha piperita plant (MPP) supplementation on performance and carcass characteristics in Japanesequail was investigated. A total of 180 quails (male and female) were carried out in completely randomized design with diet consisted of thebasal diet as the control (0MPP), diets with MPP at 1.5% (15 g/kg MPP) and 3% (30 g/kg MPP). Four replicates with 15 quails were allocatedto each experimental treatment and the birds were reared for 42 days. The diets were formulated according to NRC (1994) guidelines and contained24% protein and 2900 kcal/kg ME. The results showed that weight gain, feed intake and feed conversation was significantly affected bylevels of MPP (p<0.05). Quails fed with 1.5% MPP had more percentage of breast muscle compared to quails fed 0 and 3% MPP. Feed conversionratio was significantly improved in quails received 1.5% compared to 3% (p<0.05). There was no significant difference for percentage ofcarcass and thigh muscle among experimental treatments. The result showed adding various levels of MPP was improved feed conversion ratioand increase body weight in Japanese quail.
Thermo-Dynamical Analysis on Electricity-Generation Subsystem of CAES Power Plant  [PDF]
Wenyi Liu, Gang Xu, Yongping Yang
Journal of Power and Energy Engineering (JPEE) , 2014, DOI: 10.4236/jpee.2014.24097

Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart power grids. Linked with the flow structure and dynamic characteristic of electricity generation subsystem and its components, a simulation model is proposed. Thermo-dynamical performance on off-design conditions have been analyzed with constant air mass flux and constant gas combustion temperature. Some simulation diagrams of curve are plotted too. The contrast of varied operation mode thermal performance is made between CAES power plant and simple gas turbine power plant.

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