920 resultados para growth parameters


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Of late, decrease in mineral oil supplies has stimulated research on use of biomass as an alternative energy source. Climate change has brought problems such as increased drought and erratic rains. This, together with a rise in land degeneration problems with concomitant loss in soil fertility has inspired the scientific world to look for alternative bio-energy species. Euphorbia tirucalli L., a tree with C3/CAM metabolism in leaves/stem, can be cultivated on marginal, arid land and could be a good alternative source of biofuel. We analyzed a broad variety of E. tirucalli plants collected from different countries for their genetic diversity using AFLP. Physiological responses to induced drought stress were determined in a number of genotypes by monitoring growth parameters and influence on photosynthesis. For future breeding of economically interesting genotypes, rubber content and biogas production were quantified. Cluster analysis shows that the studied genotypes are divided into two groups, African and mostly non-African genotypes. Different genotypes respond significantly different to various levels of water. Malate measurement indicates that there is induction of CAM in leaves following drought stress. Rubber content varies strongly between genotypes. An investigation of the biogas production capacities of six E. tirucalli genotypes reveals biogas yields higher than from rapeseed but lower than maize silage.

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The present study with headline investigation on reproduction in two species of Crab Eriphia sebana and Ocypode saratan was carried out in the intertidal zone of Chabahar in thirteen month from December 2004 to December 2005. Checked samplings have been taken, 45 number Crab monthly from any four stations by manual or use trap. During this study the following subjects were measured: Temperature range and salinity, Measurable coast granule, Determination of sex ratio, Relations carapace width with carapace length, Carapace width with total body weight, Gonad weight, gonadosomatic index, condition factor, gastrosomatic index, investigation content in stomach, LM50, Growth parameters, plenty distribution length and width and gonad weight and total body weight. Studied on measurable coast granule were expressed that Ocypode saratan in Desalination station, were nest in soils equable sand and this quantity were confirmed in Pozm station. Sex ratio were assign in desalination area and Pozm M: F 0/44:0/56 and in Tiss and Chabahar M: F 0/45:0/55. Carapace length and carapace width (cm) and body weight (g) Furthest were designated in Ocypode saratan within carapace width sequential: female: 5/42-6/15-105/13 and male: 5/53-6/25-108/91 and in Eriphia sebana within Tiss area sequential: female: 5/12-5/94-110/21 and male 5/14-60/01-114/37. Have been linear relationship between carapace length and carapace width and equaled CW = a CL + b. Weight growth in two species were be modal and equaled BW= aCLb and increased Crab weight by built up carapace width. Maximum gonad weight in Ocypode saratan within desalination area in female have been outcome 3/39 and in male 0/84g and in Eriphia sebana extreme within Tiss during may in female were be 4/18 and in male 1/1g. Stomach content in Eriphia sebana were involved a black until half-purplish liquid and yellowish in Ocypode saratan. Stomach contents identifiable were being in four groups: Molluscoid, Crustacean, Plankton and Fish. Carapace width during the first year of maturation have been LM50:3/77 in Desalination area and LM50:3/92 in Pozm for Ocypode saratan and LM50:4/26 in Tiss and LM50:4/62 in Chabahar. Ability spawning in Eriphia sebana within Tiss has been CW=4/17cm and in Ocypode saratan within Desalination area CW=4/23cm. Maximun value of Loo for Eriphia sebana was equal 59/67 and growth factor K=0/68 within Tiss and Loo =61/64 , K=0/65 for Ocypode saratan within Desalination area. Maximun GSI and GI have been within Desalination area and Tiss and minimum within Pozm and Chabahar. The maturity stages of two species were classifed into six stages. Review on GSI, CF have been showed that relation with temperature and salinity and definer in two species have been spawned in two period that Maximun in spring premier than autumn.

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We introduce an innovative approach to the simultaneous control of growth mode and magnetotransport properties of manganite thin films, based on an easy-to-implement film/substrate interface engineering. The deposition of a manganite seed layer and the optimization of the substrate temperature allows a persistent bi-dimensional epitaxy and robust ferromagnetic properties at the same time. Structural measurements confirm that in such interface-engineered films, the optimal properties are related to improved epitaxy. A new growth scenario is envisaged, compatible with a shift from heteroepitaxy towards pseudo-homoepitaxy. Relevant growth parameters such as formation energy, roughening temperature, strain profile and chemical states are derived.

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O crescimento da população mundial e a tentativa de substituição parcial dos combustíveis fósseis por novas fontes de energia têm levado a uma maior atenção quanto à possível escassez de alimentos e a carência de grandes áreas disponíveis para agricultura. Microalgas, por meio do metabolismo fotossintético, utilizam energia solar e gás carbônico como nutrientes para o crescimento. A microalga Spirulina pode ser utilizada como suplemento alimentar, na biofixação de CO2, como fonte de biocombustíveis e no tratamento de efluentes. A digestão anaeróbia da biomassa microalgal produz biogás e os resíduos deste processo podem ser utilizados como substrato para novos cultivos da microalga. O objetivo deste trabalho foi estudar a conversão de Spirulina sp. LEB-18 em biogás em escala piloto e produzir biomassa microalgal utilizando os efluentes bicarbonato e dióxido de carbono do processo anaeróbio como fonte de nutrientes. Spirulina foi utilizada como substrato na digestão anaeróbia para produção de biogás em escala piloto sob temperaturas variáveis (12- 38 °C). Efluente do processo anaeróbio foi adicionado (20 %, v/v) como fonte de carbono no cultivo da microalga para avaliar o crescimento e a composição da biomassa. A seguir foi avaliada a capacidade da microalga de remover CO2 presente no biogás através de biofixação para obtenção do biocombustível purificado. O biogás produzido sob as diferentes temperaturas apresentou entre 72,2 e 74,4 % de CH4, quando realizado nas temperaturas 12 a 21 °C e 26 a 38 °C, respectivamente. A redução na temperatura do processo anaeróbio provocou um decréscimo na conversão de biomassa em biogás (0,30 para 0,22 g.g-1 ), ocorrendo dentro da faixa adequada e segura para as bactérias metanogênicas (pH 6,9; alcalinidade entre 1706,0 e 2248,0 mg.L-1 CaCO3 e nitrogênio amoniacal 479,3 a 661,7 mg.L-1 ). Os cultivos de Spirulina sp. LEB-18 em efluente anaeróbio contendo 20 % (v/v) e meio Zarrouk modificado (NaHCO3 2,8 e 5,3 g.L-1 ) apresentaram velocidade específica máxima de crescimento entre 0,324 e 0,354 d-1 , produtividade volumétrica entre 0,280 e 0,297 g.L-1 .d-1 e produtividade areal entre 14,00 e 14,85 g.m-2 .d-1 , sem diferenças significativas (p > 0,05) entre as diferentes condições estudadas. Lipídios variaram entre 4,9 e 5,0 % com proporção de ácido linoleico maximizada nos meios com efluente e ácido alfa-linolênico reduzida nesses meios em comparação ao meio Zarrouk completo. Nos ensaios para avaliar a capacidade da microalga Spirulina sp. LEB-18 de remover CO2 contaminante no biogás, as máximas concentrações celulares e produtividades de biomassa variaram, respectivamente, entre 1,12 e 1,24 g.L-1 e 0,11 e 0,14 g.L-1 .d-1 , não apresentando diferenças significativas (p > 0,05) entre os ensaios. A maior fixação diária total (FDT) de dióxido de carbono obtida foi 58,01 % (v/v) em cultivos com adição de biogás contendo 25 % (v/v) CO2. Obteve-se biogás com 89,5 % (v/v) de CH4 após injeção em cultivos de Spirulina, no qual aproximadamente 45 % (v/v) do CO2 injetado foi fixado pela microalga, gerando biomassa para diversas aplicações e biogás purificado.

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Biofilms are the primary cause of clinical bacterial infections and are impervious to typical amounts of antibiotics, necessitating very high doses for treatment. Therefore, it is highly desirable to develop new alternate methods of treatment that can complement or replace existing approaches using significantly lower doses of antibiotics. Current standards for studying biofilms are based on end-point studies that are invasive and destroy the biofilm during characterization. This dissertation presents the development of a novel real-time sensing and treatment technology to aid in the non-invasive characterization, monitoring and treatment of bacterial biofilms. The technology is demonstrated through the use of a high-throughput bifurcation based microfluidic reactor that enables simulation of flow conditions similar to indwelling medical devices. The integrated microsystem developed in this work incorporates the advantages of previous in vitro platforms while attempting to overcome some of their limitations. Biofilm formation is extremely sensitive to various growth parameters that cause large variability in biofilms between repeated experiments. In this work we investigate the use of microfluidic bifurcations for the reduction in biofilm growth variance. The microfluidic flow cell designed here spatially sections a single biofilm into multiple channels using microfluidic flow bifurcation. Biofilms grown in the bifurcated device were evaluated and verified for reduced biofilm growth variance using standard techniques like confocal microscopy. This uniformity in biofilm growth allows for reliable comparison and evaluation of new treatments with integrated controls on a single device. Biofilm partitioning was demonstrated using the bifurcation device by exposing three of the four channels to various treatments. We studied a novel bacterial biofilm treatment independent of traditional antibiotics using only small molecule inhibitors of bacterial quorum sensing (analogs) in combination with low electric fields. Studies using the bifurcation-based microfluidic flow cell integrated with real-time transduction methods and macro-scale end-point testing of the combination treatment showed a significant decrease in biomass compared to the untreated controls and well-known treatments such as antibiotics. To understand the possible mechanism of action of electric field-based treatments, fundamental treatment efficacy studies focusing on the effect of the energy of the applied electrical signal were performed. It was shown that the total energy and not the type of the applied electrical signal affects the effectiveness of the treatment. The linear dependence of the treatment efficacy on the applied electrical energy was also demonstrated. The integrated bifurcation-based microfluidic platform is the first microsystem that enables biofilm growth with reduced variance, as well as continuous real-time threshold-activated feedback monitoring and treatment using low electric fields. The sensors detect biofilm growth by monitoring the change in impedance across the interdigitated electrodes. Using the measured impedance change and user inputs provided through a convenient and simple graphical interface, a custom-built MATLAB control module intelligently switches the system into and out of treatment mode. Using this self-governing microsystem, in situ biofilm treatment based on the principles of the bioelectric effect was demonstrated by exposing two of the channels of the integrated bifurcation device to low doses of antibiotics.

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Avaliaram-se os efeitos da inclusão de farelo de canola em dietas de juvenis de pacu (Piaractus mesopotamicus) sobre parâmetros de crescimento e composição corporal. Um total de 192 alevinos (9 a 15g) foram estocados em 24 tanques de cimento, de 100l de capacidade, durante 103 dias. O farelo de canola foi utilizado em quatro proporções: zero; 9,5%; 19% e 38% da dieta, com ou sem farinha de peixe (12%/dieta), totalizando oito tratamentos. A presença de farinha de peixe não afetou os parâmetros de crescimento avaliados. A inclusão de 38% de farelo de canola na dieta diminuiu o ganho de peso dos peixes, valores médios de 28,74g a 50,70g, e piorou a conversão alimentar aparente, de 1,66 para 2,85. A taxa de eficiência protéica também foi menor nos peixes alimentados com 38% de farelo de canola. As várias proporções de farelo de canola das dietas alteraram os teores de umidade, proteína bruta e lipídios dos peixes. A presença da farinha de peixe, nas dietas, somente influiu no teor de lipídios dos peixes alimentados com dietas contendo 9,5% de farelo de canola. Conclui-se que até 19% de farelo de canola pode ser adicionado às dietas de juvenis de pacu, sem que seu desenvolvimento seja prejudicado.

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In this work, we investigate the influence of some growth parameters such as high microwave power ranging from 3.0 to 4.0 kW and N2 additive on the incorporation of bonded hydrogen defects in nanocrystalline diamond (NCD) films grown through a small amount of pure N2 addition into conventional 4% CH4/H2 plasma using a 5 kW microwave plasma CVD system. Incorporation form and content of hydrogen point defects in the NCD films produced with pure N2 addition was analyzed by employing Fourier-transform infrared (FTIR) spectroscopy for the first time. A large amount of hydrogen related defects was detected in all the produced NCD films with N2 additive ranging from 29 to 87 µm thick with grain size from 47 nm to 31 nm. Furthermore, a specific new H related sharp absorption peak appears in all the NCD films grown with pure N2/CH4/H2 plasma at high powers and becomes stronger at powers higher than 3.0 kW and is even stronger than the 2920 cm−1 peak, which is commonly found in CVD diamond films. Based on these experimental findings, the role of high power and pure nitrogen addition on the growth of NCD films including hydrogen defect formation is analyzed and discussed.

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The aim of the current study was to estimate heritabilities and correlations for body traits at different ages (Weeks 10 and 18 after stocking) in a giant freshwater prawn (Macrobrachium rosenbergii) population selected for fast growth rate in Vietnam. The dataset consisted of 4650 body records (2432 and 2218 records collected at Weeks 10 and 18, respectively) in the full pedigree comprising a total of 18 387 records. Variance and covariance components were estimated using restricted maximum likelihood fitting a multi-trait animal model. Estimates of heritability for body traits (bodyweight, body length, cephalothorax length, abdominal length, cephalothorax width and abdominal width) were moderate and ranged from 0.06 to 0.11 and from 0.11 to 0.22 at Weeks 10 and 18, respectively. Body-trait heritabilities estimated at Week 10 were not significantly lower than at Week 18. Genetic correlations between body traits within age and genetic correlations for body traits between ages were generally high. Our results suggested that selection for high growth rate in GFP can be undertaken successfully before full market size has been reached.

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James (1991, Biometrics 47, 1519-1530) constructed unbiased estimating functions for estimating the two parameters in the von Bertalanffy growth curve from tag-recapture data. This paper provides unbiased estimating functions for a class of growth models that incorporate stochastic components and explanatory variables. a simulation study using seasonal growth models indicates that the proposed method works well while the least-squares methods that are commonly used in the literature may produce substantially biased estimates. The proposed model and method are also applied to real data from tagged rack lobsters to assess the possible seasonal effect on growth.

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Key message Eucalyptus pellita demonstrated good growth and wood quality traits in this study, with young plantation grown timber being suitable for both solid and pulp wood products. All traits examined were under moderate levels of genetic control with little genotype by environment interaction when grown on two contrasting sites in Vietnam. Context Eucalyptus pellita currently has a significant role in reforestation in the tropics. Research to support expanded of use of this species is needed: particularly, research to better understand the genetic control of key traits will facilitate the development of genetically improved planting stock. Aims This study aimed to provide estimates of the heritability of diameter at breast height over bark, wood basic density, Kraft pulp yield, modulus of elasticity and microfibril angle, and the genetic correlations among these traits, and understand the importance of genotype by environment interactions in Vietnam. Methods Data for diameter and wood properties were collected from two 10-year-old, open-pollinated progeny trials of E. pellita in Vietnam that evaluated 104 families from six native range and three orchard sources. Wood properties were estimated from wood samples using near-infrared (NIR) spectroscopy. Data were analysed using mixed linear models to estimate genetic parameters (heritability, proportion of variance between seed sources and genetic correlations). Results Variation among the nine sources was small compared to additive variance. Narrow-sense heritability and genetic correlation estimates indicated that simultaneous improvements in most traits could be achieved from selection among and within families as the genetic correlations among traits were either favourable or close to zero. Type B genetic correlations approached one for all traits suggesting that genotype by environment interactions were of little importance. These results support a breeding strategy utilizing a single breeding population advanced by selecting the best individuals across all seed sources. Conclusion Both growth and wood properties have been evaluated. Multi-trait selection for growth and wood property traits will lead to more productive populations of E. pellita both with improved productivity and improved timber and pulp properties.

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In the present work, solidification of a hyper-eutectic ammonium chloride solution in a bottom-cooled cavity (i.e. with stable thermal gradient) is numerically studied. A Rayleigh number based criterion is developed, which determines the conditions favorable for freckles formation. This criterion, when expressed in terms of physical properties and process parameters, yields the condition for plume formation as a function of concentration, liquid fraction, permeability, growth rate of a mushy layer and thermophysical properties. Subsequently, numerical simulations are performed for cases with initial and boundary conditions favoring freckle formation. The effects of parameters, such as cooling rate and initial concentration, on the formation and growth of freckles are investigated. It was found that a high cooling rate produced larger and more defined channels which are retained for a longer durations. Similarly, a lower initial concentration of solute resulted in fewer but more pronounced channels. The number and size of channels are also found to be related to the mushy zone thickness. The trends predicted with regard to the variation of number of channels with time under different process conditions are in accordance with the experimental observations reported in the literature.

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The tracer diffusion coefficients of the elements as well as the integrated interdiffusion coefficients are determined for the Cu3Sn and Cu6Sn5 intermetallic compounds using incremental diffusion couples and Kirkendall marker shift measurements. The activation energies are determined for the former between 498 K and 623 K (225 A degrees C and 350 A degrees C) and for the latter between 423 K and 473 K (150 A degrees C and 200 A degrees C). Sn is found to be a slightly faster diffuser in Cu6Sn5, and Cu is found to be the faster diffuser in Cu3Sn. The results from the incremental couples are used to predict the behavior of a Cu/Sn couple where simultaneous growth of both intermetallics occurs. The waviness at the Cu3Sn/Cu6Sn5 interface and possible reasons for not finding Kirkendall markers in both intermetallics in the Cu/Sn couple are discussed.

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Diffusion couple experiments are conducted to study phase evolutions in the Co-rich part of the Co-Ni-Ta phase diagram. This helps to examine the available phase diagram and propose a correction on the stability of the Co2Ta phase based on the compositional measurements and X-ray analysis. The growth rate of this phase decreases with an increase in Ni content. The same is reflected on the estimated integrated interdiffusion coefficients of the components in this phase. The possible reasons for this change are discussed based on the discussions of defects, crystal structure and the driving forces for diffusion. Diffusion rate of Co in the Co2Ta phase at the Co-rich composition is higher because of more number of Co-Co bonds present compared to that of Ta-Ta bonds and the presence of Co antisites for the deviation from the stoichiometry. The decrease in the diffusion coefficients because of Ni addition indicates that Ni preferably replaces Co antisites to decrease the diffusion rate. (C) 2014 Elsevier B.V. All rights reserved.