Mechanical behavior of composites reinforced with fibers caroa     

Ana Flavia Camara Bezerra  Laura Hecker de Carvalho  Wilma Sales Cavalcanti  Antonio Gilson Barbosa 《Fibers and Polymers》2016,17(11):1908-1915

Composites were prepared with 13, 23 30 and 40 % fiber and evaluated the mechanical performance in tensile, flexural and impact. The mechanical properties of these composites were also evaluated function of time at 110 °C thermal exposure. Caroa fibers were characterized by techniques such as thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the best mechanical properties were achieved for composites containing 23 to 30 % fiber. The incorporation of 23 % fiber caroa increased both the modulus of elasticity in the tensile test as the flexural strength and impact, the composite with 30 % fiber caroa showed higher tensile strength. The results show that the tensile and flexural strength of the composite decreased with time of thermal exposure. The thermal aging at 110 °C caused a decrease in tensile properties of the composites.  相似文献   

Synthesis and evaluation of hydroxyazolopyrimidines as herbicides; the generation of amitrole in planta          下载免费PDF全文

John M Clough  Richard P Dale  Barry Elsdon  Timothy R Hawkes  Bridget V Hogg  Anushka Howell  Daniel P Kloer  Karine Lecoq  Matthew MW McLachlan  Phillip J Milnes  Timothy JC O'Riordan  Saranga Ranasinghe  Stephen E Shanahan  Karen D Sumner  Shanaaz Tayab 《Pest management science》2016,72(12):2254-2272

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New organic substrates and boron fertilizing for production of yellow passion fruit seedlings     

Raissa Rachel Salustriano da Silva-Matos  Gabriel Barbosa da Silva Jr  Adenaelson de Souza Marques  Maciel Lima Monteiro  Josy Anteveli Osajima 《Archives of Agronomy and Soil Science》2016,62(3):445-455

The identification of alternative substrates suitable for seedling production is very important, while boron nutrition is also relevant due to plant requirement and its difficult management. Thus, four experiments were carried out from October 2012 to April 2013 to evaluate the effect of substrates using decomposed buriti (Mauritia vinifera Mart.) stem (DBS) and boron fertilizing for seedling production of yellow passion fruit (Passiflora edulis Sims). The experimental design was completely randomized in factorial scheme 6 × 2 + 1, referring to the substrates [S1: DBS, S2: soil and sand 1:1 (20%) + DBS (80%), S3: soil and sand 1:1 (40%) + DBS (60%), S4: soil and sand 1:1 (60%) + DBS (40%), S5: soil and sand 1:1 (80%) + DBS (20%), S6: commercial substrate (additional treatment) and S7: soil, sand and manure 1:1:2] with and without boron. The seedling emergence, emergence rate, plant height, stem diameter, root length, root volume and dry mass of roots and shoots were recorded. The substrates S2 (without B fertilizing) and S4 (B fertilized with 0.5 mg dm^?3) produced seedlings with more than 3.0 g of shoot dry mass and at least 30 cm in height, and can be used for production of high-quality yellow passion fruit seedlings.  相似文献   

Tetraoxanes as a new class of efficient herbicides comparable with commercial products          下载免费PDF全文

Raphael C Cusati  Luiz CA Barbosa  Célia RA Maltha  Antônio J Demuner  Alberto Oliveros‐Bastidas  Antônio A Silva 《Pest management science》2015,71(7):1037-1048

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Effect of Progesterone and Ionomycin on Domestic Cat Sperm Motility Patterns and Acrosome Reaction     

AISB Villaverde  EG Fioratti  FC Landim-Alvarenga  JC de Carvalho Balieiro  CM Melo  FO Papa  MD Lopes 《Reproduction in domestic animals》2009,44(S2):309-312

This study was aimed at assessing the changes in sperm motion patterns and the percentage of acrosome reaction (AR) in domestic cat semen after treatment with either ionomycin or progesterone (P₄). Ten ejaculates were collected from five tomcats using an artificial vagina, and were diluted, centrifuged and resuspended in a capacitation medium. Samples were evaluated and divided into seven equal aliquots and, after 2 h at 25°C, were incubated for 30 min at 38°C in 5% CO₂ and then analyzed. Computer-assisted sperm analysis and a combination of three fluorescent probes were used to assess sperm plasma, acrosomal membrane integrity and mitochondrial transmembrane potential. Thirty minutes after the start of incubation, P₄ was added (10 μg/ml) to the P1 group. Groups P2 and P3 were supplemented with P₄ (10 and 20 μg/ml, respectively) only after 2 h of incubation, and groups I1 and I2 were supplemented with ionomycin (4 and 8 μ m , respectively) 2 h after incubation. Group E was supplemented with ethanol (0.6%) at 2 h after incubation and group C received no supplementation. Ionomycin and P₄ treatments led to a hyperactivation-like sperm motion and an increase (p < 0.05) in the percentage of AR. Although a higher (p < 0.05) percentage of AR was obtained in group I2 when compared with all P₄ groups, a decrease (p < 0.05) in total and progressive motility was observed in I2 group. As I1 group was similar to I2 to induce AR without diminishing sperm motility, we can conclude that ionomycin at 4 μ m seems to be more suitable to trigger AR in domestic cat sperm.  相似文献   

Nuclear Configuration, Spindle Morphology and Cytoskeletal Organization of In Vivo Maturing Horse Oocytes     

MAR Siddiqui  EL Gastal  JC Ju  MO Gastal  MA Beg  OJ Ginther 《Reproduction in domestic animals》2009,44(3):435-440

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Characterization of biodiesel and bio-oil from Sterculia striata (chicha) oil     

M.B.P. Mangas  F.N. Rocha  P.A.Z. Suarez  S.M.P. Meneghetti  D.C. Barbosa  R.B. dos SantosS.H.V. Carvalho  J.I. Soletti 《Industrial Crops and Products》2012,36(1):349-354

This work describes the mechanical and solvent extraction of Sterculia striata seed oil. It was determined that the seeds contain up to 41% in oil, which has an unusual composition. Indeed, up to 50% of the fatty acid contain cyclopropenoid ring. The oil was used as raw material to produce bio-oil and biodiesel and their physical-chemical properties were evaluated. Some of the studied physical-chemical properties of the S. striata biodiesel are in acceptable range for use as biodiesel in diesel engines, showing a promising economic exploitation of this raw material in semi-arid regions. It was also observed that the cyclopropenoid ring remains after transesterification and is decomposed during pyrolysis.  相似文献   

Path analysis for selection of drought tolerant sugarcane genotypes through physiological components     

Paulo Pedro da Silva  Lailton SoaresJoão Gomes da Costa  Luciana da Silva VianaJúlio César Farias de Andrade  Eduardo Rebelo GonçalvesJoão Messias dos Santos  Geraldo Veríssimo de Souza BarbosaVelber Xavier Nascimento  Adriana Reis TodaroAlessandro Riffel  Maria Fatima Grossi-de-SaMárcio Henrique Pereira Barbosa  Antônio Euzébio Goulart Sant’AnaCícero Eduardo Ramalho Neto 《Industrial Crops and Products》2012,37(1):11-19

Water deficit is among the main environmental factors limiting agricultural productivity of sugarcane in Northeast Brazil by affecting virtually every aspect of plant growth, with consequent reduction of the agro-industrial productivity of this crop. This study aimed to use path analysis to evaluate the physiological components of sugarcane under two water conditions, with photosynthesis as the basic variable, in order to obtain subsidies that can help the genetic breeding of this crop by selection of superior clones with drought tolerance. The experiment was carried out in a greenhouse with a completely randomized experimental design, 4 × 2 factorial arrangements (four sugarcane genotypes × two soil moisture regimes: control, with 80-100% available water and stressed, with 0-20% water available) and with four replications. Each plot consisted of one pot with 12 kg of substrate containing one plant. Treatments were maintained at a humidity close to field capacity with daily replacement of the evapotranspired water with a water supply for 66 days of cultivation for treatments under stress. Evaluations were conducted on the fourth day after severe water stress at 70 days of cultivation. Data from nine physiological variables were considered, with six of these being used in the model after exclusion of those that were contributing to multicollinearity. Variables used in path analysis were enough to explain the variation found in photosynthesis under both water conditions. Stomatal conductance, transpiration and the SPAD index should be considered as a priority in breeding programs for sugarcane aiming to get more productive and tolerant genotypes to water stress, and selection indexes should be used with due consideration of these variables to promote gains in photosynthesis.  相似文献   

Economic feasibility for producing Imperial Zebra pleco (Hypancistrus zebra) in recirculating aquaculture systems: An alternative for a critically endangered ornamental fish     

Danilo Araujo Soares Pereira  Marcelo Barbosa Henriques 《Aquaculture Economics & Management (Blackwell Science)》2013,17(4):428-448

Abstract

The L46 (Hypancistrus zebra) stands out as one of the most valuable Amazonian species in the international market for ornamental fish and faces a notable problem: the risk of extinction versus the demand for new specimens for aquariums. Considering that breeding in captivity can be a conservational tool for aquatic species and an alternative source for generating income, the objective of the present paper was to verify the economic feasibility of producing H. zebra in recirculation aquaculture systems (RAS), in different scenarios of rearing: residential breeding (S1), mid-size store production (S2) and large-scale production as a supplier (S3). The main profitability indicators used were: net present value (NPV), internal rate of return (IRR) and payback period (PP). The selling price per unit was fixed in US$260.15 (S1/S2) and US$156.09 (S3). The largest investments were made with the acquisition of broodstocks (S1/S2) and property (S3), while the highest costs were with labor (S2/S3) and taxes (S1). Only S1 demonstrated economic profitability (NPV 8.50%?=?US$28,187.85; IRR?=?74.71%; PP?=?1.80?years). Conclusion: the production in this study appeared to be profitable on smaller scales, however the profitability of large-scale production depends upon reducing expenses and increasing the selling price.  相似文献   

Evaluation of Magnetic Coagulant (α-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript>-MO) and its Reuse in Textile Wastewater Treatment     

Tássia Rhuna Tonial dos Santos  Gustavo Affonso Pisano Mateus  Marcela Fernandes Silva  Carolina Sayury Miyashiro  Leticia Nishi  Murilo Barbosa de Andrade  Márcia Regina Fagundes-Klen  Raquel Guttieres Gomes  Rosângela Bergamasco 《Water, air, and soil pollution》2018,229(3):92

The textile industries are characterized as one of the biggest consumers of potable water and chemical products throughout its process, being responsible for the elevated wastewater generation with intense coloration and wide polluting potential. In this context, the present study proposes the development and application of a new coagulant material for textile wastewater treatment. The proposed coagulant (α-Fe₂O₃-MO) was composed by hematite nanoparticles (α-Fe₂O₃) obtained by a simple non-pollutant methodology, associated with Moringa oleifera (MO) seeds saline extract compounds. Coagulation/flocculation (CF) efficiency was evaluated by removal of physicochemical parameters such as apparent color, turbidity, and compounds with absorption at UV_254nm (UV_254nm) through CF tests carried out on Jar test equipment and sedimentation carried out in the presence and absence of external magnetic field (600 k Am^?1). Kinetics sedimentation was from 0 to 90 min. The use of this new coagulant allowed the removal of 92.37% for apparent color, 91.43% for turbidity, and 46.09% for UV_254nm, indicating that the proposed coagulant association was efficient in the treatment of this type of wastewater under external magnetic field with only 10 min of sedimentation. In addition, the resulting sludge from CF process was tested as base material for a new coagulant synthesis, demonstrating great reuse potential. Therefore, the new proposed coagulant, composed of α-Fe₂O₃ and the compounds present in the seed extract of MO, has applicability for textile wastewater treatment demonstrating high removal rate for all evaluated parameters with cost reduction in the proposed treatment for this wastewater.  相似文献