1,149 research outputs found

    Dry matter and area partitioning, radiation interception and radiation-use efficiency in open-field bell pepper

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    The objective of this study was to determine some key components of a model for bell pepper growth and yield under non-limiting water and nutrient conditions using data from field trials conducted in Southern Portugal. DM partitioning, at least before fruiting, and specific area indices for leaves, stems and fruits were conservative in relation to normalized thermal time. The interception model had a good performance. It was based on the exponential extinction of radiation on the area covered by the plants, the ellipsoidal leaf-angle distributionmodel (X-parameter 2.48 and 2.89), and absorptivities of the leaves for PAR and NIR, 0.8 and 0.2, respectively. Radiation-use efficiency (RUE) was determined and presented in four different forms. RUE did not change substantially throughout the growing season. RUE of irrigated pepper crops grown in our experiments was around 1.6 g MJ 1 of intercepted PAR. The models and parameter values presented in this study may be useful to simulate the development and growth of fieldgrown pepper cro

    Influence of cultivation conditions on the bioenergy potential and bio-compounds of Chlorella vulgaris

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    This study aims to evaluate the influence of cultivation conditions on the bioenergy and high value biocompounds contents of Chlorella vulgaris. Results show that the use of nitrate rich media, from 170.7 mg/L, favors a faster biomass growth, reaching values above 800 mg/L biomass. In addition, it favors higher pigments concentrations with more emphasis for the cultures with a nitrate concentration of 569 mg/L, where chlorophyll-a and carotenoids reached maximum concentrations of 6 and 2 mg/L, respectively. As regards the lipid content, nitrate deprivation (<28.4 mg/L) favors the accumulation of lipid content by microalgae (around 42%). The use of media with lower iron concentrations (0.5 mg/L) was favorable for obtaining biomass with higher concentrations of chlorophyll-a, at an initial stage, with values varying from 0.2 to 0.6 mg/L. In the tests carried out under mixotrophic conditions (addition of glucose), it was observed that contamination occurred in all the cultures, possibly due to the high concentration of carbon source that had values between 0.5 and 1.5 g/L of glucose, and consequently, growth decreased.Authors thank the financial support of the project IF/01093/2014/CP1249/CT0003 and research grants IF/01093/2014 and SFRH/BPD/112003/2015 funded by national funds through FCT/MCTES, and project UID/EQU/00305/2013 – Center for Innovation in Engineering and Industrial Technology – CIETI. This work was financially supported by: project UID/EQU/00511/2019 – Laboratory for Process Engineering, Environment, Biotechnology and Energy – LEPABE funded by national funds through FCT/MCTES (PIDDAC); Project POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy — LEPABE, UID/EQU/00511/2013) funded by FEDER through COMPETE2020-POCI and by national funds through FCT; Project “LEPABE-2-ECO-INNOVATION” — NORTE-01-0145-FEDER-000005, funded by Norte Portugal Regional Operational Programme (NORTE 2020), under PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

    Dynamics of a faceted nematic-smectic B front in thin-sample directional solidification

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    We present an experimental study of the directional-solidification patterns of a nematic - smectic B front. The chosen system is C_4H_9-(C_6H_{10})_2CN (in short, CCH4) in 12 \mu m-thick samples, and in the planar configuration (director parallel to the plane of the sample). The nematic - smectic B interface presents a facet in one direction -- the direction parallel to the smectic layers -- and is otherwise rough, and devoid of forbidden directions. We measure the Mullins-Sekerka instability threshold and establish the morphology diagram of the system as a function of the solidification rate V and the angle theta_{0} between the facet and the isotherms. We focus on the phenomena occurring immediately above the instability threshold when theta_{0} is neither very small nor close to 90^{o}. Under these conditions we observe drifting shallow cells and a new type of solitary wave, called "faceton", which consists essentially of an isolated macroscopic facet traveling laterally at such a velocity that its growth rate with respect to the liquid is small. Facetons may propagate either in a stationary, or an oscillatory way. The detailed study of their dynamics casts light on the microscopic growth mechanisms of the facets in this system.Comment: 12 pages, 19 figures, submitted to Phys. Rev.

    Use Of Organic Compost Containing Waste From Small Ruminants In Corn Production

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    Composting is a useful way of transforming livestock waste into organic fertilizer, which is proven to increase soil nutrient levels, and thus crop yield. Remains from production and slaughter of small ruminants can become a source of important elements for plant growth, such as N, after microorganism-driven decomposition.The aim of this investigation was to evaluate the effects of this compost on soil fertility and on the nutritional status and yield of the corn crop. The experiment was conducted in a Haplic Luvisol in a randomized block design with six treatments and five application rates of the organic compound in Mg ha-1: 3 (half the standard rate), 6 (standard rate), 9 (one and a half times the standard rate), 12 (twice the standard rate), and 24 (four times the standard rate) and an additional treatment with mineral fertilizers (110, 50 e 30 kg ha-1 of N, P2O5 and K2O, respectively), with four blocks. Evaluations were performed for two harvests of rainfed crops, measuring soil fertility, nutritional status, and grain yield. The compost increased P, K, Na and Zn values in the 0.00-0.20 m layer in relation of mineral fertilization in 616, 21, 114 and 90% with rate 24 Mg ha-1 in second crop. Leaf N, Mg, and S contents, relative chlorophyll content, and the productivity of corn kernels increased in 27, 32, 36, 20 e 85%, respectively, of low rate (3 Mg ha-1) to high rate (24 Mg ha-1) with of application of the compost. Corn yield was higher with application of organic compost in rate of 24 Mg ha-1 than mineral fertilizer combination in second crop. © 2016, Revista Brasileira de Ciencia do Solo. All rights reserved.4

    Classical Solutions in a Lorentz-violating Maxwell-Chern-Simons Electrodynamics

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    We take as starting point the planar model arising from the dimensional reduction of the Maxwell Electrodynamics with the (Lorentz-violating) Carroll-Field-Jackiw term. We then write and study the extended Maxwell equations and the corresponding wave equations for the potentials. The solution to these equations show some interesting deviations from the usual MCS Electrodynamics, with background-dependent correction terms. In the case of a time-like background, the correction terms dominate over the MCS sector in the region far from the origin, and establish the behaviour of a massless Electrodynamics (in the electric sector). In the space-like case, the solutions indicate the clear manifestation of spatial anisotropy, which is consistent with the existence of a privileged direction is space.Comment: latex, 8 page

    Sistema tradicional de manejo de caprinos: I. Desempenho de crescimento de caprinos SRD na fase de aleitamento

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    The effects of season, sex and type of birth as well as all possible interactions were studied for birth weight (BW), weights at 41 (W1), 69 (W2), 97 (W3), and 125 (W4) days after birth and weight gains at intervals between the time of birth and 41 days of age (G1), 41 and 69 days (G2), 69 and 97 days (G3), 97 and 125 days (G4) of age after birth. Data were initialy recorded on 120 kids born in the years 1979 and 1980 and raised at the Centro Nacional de Pesquisa de Caprinos research farm, Sobral, State of Ceará, Brazil. The analysis of variance showed that season of birth had a highly significant (P<0.005) effect on alt weights analysed and on G1 and G4. The significant level was smaller (P<0.025) for G2 and G3 . Kids born in the rainy season were heavier and had higher weight gains than kids born in the dry season. Sex had a significant influence on BW, W2, W4 (P<0.05), W3 (P<0.025), W1 and G1 (P<0.005). Males were superior to females, except in G4 where an inverse trend was observed. Type of birth was significant (P<0.005) for all the weight variables studied, including G1. Single born kids showed higher weight gains than did multiple born kids. With the exception of the season X type of birth interaction which was significant (P <0.025) for BW, all other interactions analized were none significant for the variables studied.Foram estudados os efeitos da estação, sexo e tipo de nascimento, bem como os das interações possíveis, sobre os pesos ao nascimento (PN); aos 41 (P1); aos 69 (P2); aos 97 (P3) e aos 125 (P4) dias de idade e sobre os ganhos de peso do nascimento aos 41 (G1); dos 41 aos 69 (G2); dos 69 aos 97 (G3) e dos 97 aos 125 (G4) dias de idade. Foram utilizados 120 cabritos, criados na área experimental do Centro Nacional de Pesquisa de Caprinos, em Sobral, CE, nascidos entre os anos de 1979 e 1980. As análises de variância indicaram que a estação de nascimento influenciou de maneira significativa (P<0,005) todos os pesos estudados, além das variáveis G1 e G4, e ao nível de P<0,025, as variáveis G2 e G3. Os animais nascidos na estação chuvosa foram mais pesados e apresentaram maior ganho de peso, em relação aos nascidos na estação seca. O sexo influenciou o P1 e G1 (P<0,005) e o PN, P2 e P4 (P<0,05) e P3 (P<0,025), sendo que, nessas variáveis, os machos foram superiores às fêmeas, exceto em G4, nas quais se observou tendência inversa. Houve influência do tipo de nascimento sobre todos os pesos estudados, inclusive sobre o G1, (P<0,005); os animais nascidos de partos simples mostraram maior ganho de peso que os nascidos de partos múltiplos. Com exceção da interação estação X tipo de nascimento, que influenciou de maneira significativa (P<0,025) o PN, as demais interações não apresentaram efeito significativo sobre as variáveis estudadas

    Cryptoferromagnetic state in superconductor-ferromagnet multilayers

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    We study a possibility of a non-homogeneous magnetic order (cryptoferromagnetic state) in heterostructures consisting of a bulk superconductor and a ferromagnetic thin layer that can be due to the influence of the superconductor. The exchange field in the ferromagnet may be strong and exceed the inverse mean free time. A new approach based on solving the Eilenberger equations in the ferromagnet and the Usadel equations in the superconductor is developed. We derive a phase diagram between the cryptoferromagnetic and ferromagnetic states and discuss the possibility of an experimental observation of the CF state in different materials.Comment: 4 pages, 1 figur

    Dietary xylanase and live yeast supplementation influence intestinal bacterial populations and growth performance of piglets fed a sorghum-based diet

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    This study was to evaluate the effect of xylanase supplementation and the addition of live yeast, Saccharomyces cerevisiae, on growth performance and intestinal microbiota in piglets. One hundred and eighty commercial crossbred 23-d-old piglets (PIC 417) were sorted by initial BW and allocated to 3 treatments: control (CTR) diet, CTR diet supplemented with xylanase at 16,000 birch xylan units/kg (XYL) and XYL diet supplemented with live yeast (2 × 10 10 CFU/g) at 1 kg/t (XYL + LY). Each treatment had 10 replicates, with 6 animals each. A sorghum-based diet and water were available ad libitum for 42 d of the study. Average daily gain (ADG) and average daily feed intake (ADFI) were measured from 0 to 42 d (23- to 65-d-old) and feed conversion ratio (FCR) calculated. At the end of the study, bacterial identification through 16S rRNA (V3 to V4) sequencing of the ileal and caecal digesta from one piglet per replicate was performed. No treatment effects were observed on ADFI. Pigs offered the live yeast in addition to the xylanase had increased ADG compared with those supplemented with xylanase alone (XYL + LY vs. XYL; P = 0.655). FCR was improved with XYL and XYL + LY compared with CTR (P = 0.018). Clostridiaceae counts in the ileum tended to reduce by 10% with XYL and 14% with XYL + LY compared to CTR (P = 0.07). XYL and XYL + LY increased the counts of Lactobacillaceae in the caecum compared with CTR (P < 0.0001). Dietary supplementation of live yeast combined with xylanase improved growth performance and microbial balance of piglets during the nursery phase

    Superconducting fluctuations and the Nernst effect: A diagrammatic approach

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    We calculate the contribution of superconducting fluctuations above the critical temperature TcT_c to the transverse thermoelectric response αxy\alpha_{xy}, the quantity central to the analysis of the Nernst effect. The calculation is carried out within the microscopic picture of BCS, and to linear order in magnetic field. We find that as TTcT \to T_c, the dominant contribution to αxy\alpha_{xy} arises from the Aslamazov-Larkin diagrams, and is equal to the result previously obtained from a stochastic time-dependent Ginzburg-Landau equation [Ussishkin, Sondhi, and Huse, arXiv:cond-mat/0204484]. We present an argument which establishes this correspondence for the heat current. Other microscopic contributions, which generalize the Maki-Thompson and density of states terms for the conductivity, are less divergent as TTcT \to T_c.Comment: 11 pages, 5 figure

    The receptor AT1 appears to be important for the maintenance of bone mass and AT2 receptor function in periodontal bone loss appears to be regulated by AT1 receptor

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    A large number of experimental studies has demonstrated that angiotensin II (Ang II) is involved in key events of the inflammatory process. This study aimed to evaluate the role of Ang II type 1 (AT1) and Ang II type 2 (AT2) receptors on periodontitis. Methods: Experimental periodontitis was induced by placing a 5.0 nylon thread ligature around the second upper left molar of AT1 mice, no-ligature or ligature (AT1-NL and AT1-L), AT2 (AT2-NL or AT2-L) and wild type (WT-NL or L). Alveolar bone loss was scanned using Micro-CT. Cytokines, peptides and enzymes were analyzed from gingival tissues by Elisa and RT-PCR. Results: The blockade of AT1 receptor resulted in bone loss, even in healthy animals. Ang II receptor blockades did not prevent linear bone loss. Ang II and Ang 1-7 levels were significantly increased in the AT2-L (p < 0.01) group compared to AT2-NL and AT1-L. The genic expression of the Mas receptor was significantly increased in WT-L and AT2-L compared to (WT-NL and AT2-NL, respectively) and in AT1-L. Conclusions: Our data suggest that the receptor AT1 appears to be important for the maintenance of bone mass. AT2 receptor molecular function in periodontitis appears to be regulated by AT1
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