Consulta: subjectFacets:"Porosity"
Registros recuperados: 31
Data/hora: 09/06/2024 01:51:57

FORRAGEIRAS TROPICAIS EM CONSÓRCIO COM MILHO E ADUBAÇÃO NITROGENADA SOBRE AS PROPRIEDADES FÍSICAS DO SOLO
Provedor de dados: 196
Autores: Mattei, Eloisa; Rabello de Oliveira, Paulo Sérgio; Costa Crusciol, Carlos Alexandre; Rocha de Moraes Rego, Carlos Augusto; Piano, Jeferson Tiago; da Silveira, Lucas.
Os sistemas integrados de produção lavoura-pecuária (SIPAs) em associação ao sistema de semeadura direta, sofrem ação do pisoteio animal ou do tráfego intenso de máquinas agrícolas, podendo resultar em alterações nas propriedades físicas do solo. O objetivo deste trabalho foi avaliar o efeito da adubação nitrogenada e manejos das forrageiras tropicais nas propriedades físicas do solo. O experimento foi realizado entre outubro de 2017 e janeiro de 2020, em Marechal Cândido Rondon – PR, em blocos ao acaso, com parcelas sub-subdivididas com uma testemunha adicional e quatro repetições. As parcelas foram constituídas por duas espécies forrageiras consorciadas com o milho: Urochloa brizantha e Magathyrsus maximum, mais a testemunha adicional (milho solteiro)....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Porosity; Soil physical quality; Resistance to penetration; Integrated systems; Porosidade; Qualidade física do solo; Resistência à penetração; Sistemas integrados.
Ano: 2021
URL: http://periodicosonline.uems.br/index.php/agrineo/article/view/6318

Caracterización física y micromorfología de materiales orgánicos e inorgánicos para la generación de mezclas de sustratos en la producción de lisiathus (Eustoma grandiflorum)
Provedor de dados: 32
Autores: Anicua Sánchez, Rosa.
La producción de cultivos en maceta está relacionada con la selección de sustratos, que se basa en las propiedades físicas y en particular con el tamaño y la distribución de partículas, que determinan la retención y el movimiento de agua. Por lo que, el objetivo del presente trabajo fue la caracterización de materiales orgánicos e inorgánicos a partir de las propiedades físicas y micromorfológicas para la generación de mezclas en la producción  de Lisianthus. Se realizó la caracterización de sustratos orgánicos (fibra de coco, peat moss, composta y vermicomposta) e inorgánicos (tezontle, piedra pómez, perlita y zeolita); con base en las propiedades físicas como densidad aparente (DA) y densidad real (DR) (Ansorena, 1994); espacio poroso total (EPT),...
Tipo: Tesis
Palavras-chave: Sustratos; Curva de retención de humedad; Porosidad; Lisianthus; Micromorfología; Growing media; Waterrelease curve; Porosity; Lisianthus; Micromorphology.
Ano: 2008
URL: http://hdl.handle.net/10521/1408

STATIC PRESSURE DROP IN LAYERS OF CASTOR BEAN GRAINS
Provedor de dados: 70
Autores: Goneli,André L. D.; Corrêa,Paulo C.; Figueiredo Neto,Acácio; Kirsch,Michele R. H.; Botelho,Fernando M.
ABSTRACT Knowledge regarding the static pressure drop in granular layers is of fundamental importance in the development of efficient drying and aeration projects of agricultural products. Thus, the objective of this study was to evaluate the effects of impurity contents on the static pressure drop in different bed depth of castor bean grains, as well as modify the mathematical models per the obtained experimental data and select the model that best represents this phenomenon. First, impurities in castor bean grains of the Guarani variety were eliminated and 6% of the moisture content (dry basis) was retained. The coarse impurity contents were obtained with 2%, 4%, and 6% of mass addition. The pressure drop in different bed depth of clean and impure castor...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bulk density; Load loss; Porosity; Ricinus communis L.; Moisture content.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200184

INFLUENCE OF SUBSTRATE AND SPECIES ARRANGEMENT OF CULTIVATED GRASSES ON THE EFFICIENCY OF HORIZONTAL SUBSURFACE FLOW CONSTRUCTED WETLANDS
Provedor de dados: 70
Autores: Saraiva,Claudety B.; Matos,Antonio T.; Matos,Mateus P.; Miranda,Suymara T.
ABSTRACT We aimed to evaluate the efficiency of six different horizontal subsurface flow constructed wetlands (HSSF-CWs), with different substrates (gravel and crushed PET bottles), which also varied in relation to the presence and arrangement of plant species (elephant grass and Tifton 85 bermudagrass) in the removal of pollutants from a bulk milk cooling tank (MTWW). Each bed was fed at a flow rate of 0.18 m3 d-1 and average organic load rate (OLR) of 318 kg ha-1 d-1 of BOD5, with hydraulic detention time (HRT) of 1.84 days in the gravel-filled HSSF-CWs (CWS-G) and 2.97 days in the PET-filled HSSF-CWs (CWs-P). The CWs-P were as efficient as the CWs-G in the removal of BOD5, COD, Total-P, and K-Total, being in some cases even more effective (turbidity,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Wastewater; Elephant grass; Tifton 85 bermudagrass; Plants; Porosity.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000300417

Propriedades físicas dos principais solos da Amazônia brasileira em condições naturais.
Provedor de dados: 14
Autores: BAENA, A. R. C.; DUTRA, S.
bitstream/item/31900/1/CPATU-BP33.pdf
Tipo: Séries anteriores (INFOTECA-E)
Palavras-chave: Propriedade física; Densidade; Brasil; Resistance; Physical proprieties; Yield.; Produtividade; Porosidade; Resistência; Solo.; Amazonia; Density; Porosity; Soil.
Ano: 1982
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/381146

Efeitos de diferentes sistemas de cultivo nas propriedades físicas e produtividade do solo.
Provedor de dados: 14
Autores: BAENA, A. R. C.; DUTRA, S.; KITAMURA, P. C.
bitstream/item/40430/1/Boletim-Pesquisa-67-CPATU.pdf
Tipo: Séries anteriores (INFOTECA-E)
Palavras-chave: Propriedade física; Cultivo; Densidade; Capitão Poço; Pará; Brasil; Cultivation; Management; Physical proprierties; Yield.; Manejo; Latossolo Amarelo; Porosidade; Produtividade; Solo.; Amazonia; Density; Porosity; Soil.
Ano: 1985
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/381693

Caracterização físico-hídrica de latossolo amarelo da região de Capitão Poço, Pará.
Provedor de dados: 14
Autores: COSTA, M. P. da; TEIXEIRA, L. B.
bitstream/item/42255/1/Boletim-Pesquisa-133-CPATU.pdf
Tipo: Séries anteriores (INFOTECA-E)
Palavras-chave: Densidade aparente; Capitao Poco; Pará; Brasil; Oxysol; Organic mather; Analysis.; Análise; Água; Argila; Física; Matéria Orgânica; Latossolo Amarelo; Porosidade; Solo.; Amazonia; Bulk density; Clay; Porosity; Soil physics; Water.
Ano: 1992
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/380484

Densidade aparente e porosidade do solo no desenvolvimento do milho.
Provedor de dados: 14
Autores: BAENA, A. R. C.; DUTRA, S.
bitstream/item/59280/1/CPATU-ComTec24.pdf
Tipo: Comunicado Técnico (INFOTECA-E)
Palavras-chave: Desenvolvimento; Densidade; Maize; Development; Growth.; Crescimento; Milho; Porosidade; Solo; Zea Mays.; Density; Porosity; Soil.
Ano: 1979
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/376654

Quantificação do índice de vazios do solo utilizando técnicas de processamento de imagens digitais.
Provedor de dados: 14
Autores: CARVALHO JUNIOR, O. A. de; CARDOSO, F. B. da F.; MARTINS, E. de S.; JUNQUEIRA, F. de F.; CARVALHO, A. P. F. de; REATTO, A.; GUIMARAES, R. F.
RESUMO: Este trabalho apresenta uma abordagem metodológica para obter o índice de vazios de solo (e) utilizando técnicas de processamento de imagens. Como esse método permite uma obtenção automática, o procedimento pode ser considerado mais fácil, mais rápido e mais preciso que técnicas convencionais. A metodologia está baseada na classificação supervisionada de áreas de vazios presentes em seções delgadas de solo. A metodologia pode ser resumida nos passos seguintes: (a) elaboração de seção delgada da amostra de solo (se a porosidade do solo tiver um padrão anisotrópico, várias lâminas devem ser confeccionadas seguindo o eixo de comprimento preferencial; (b) são fotografadas as seções delgadas e gravadas em formato digital em RGB; (c) a imagem colorida é...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Imagem digital; Digital image; Chemicophysical properties.; Cerrado; Propriedade Físico-Química; Porosidade; Sensoriamento Remoto; Solo.; Remote sensing; Porosity; Soil.
Ano: 2002
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567773

Experimental and numerical characterization of an oyster farm impact on the flow
Provedor de dados: 5
Autores: Gaurier, Benoit; Germain, Gregory; Kervella, Youen; Davourie, Julia; Cayocca, Florence; Lesueur, Patrick.
Shellfish farming, particularly oyster farms, suffers from strong siltation phenomena which are harmful to the production of shellfish. The lack of knowledge about the impact of an oyster farm on the wave propagation and on the flow remains a significant difficulty for the comprehension of sediment transport processes in coastal zones. These effects are one of the possible sources of sedimentation. The study presented here focuses on describing finely hydrodynamical phenomena (velocity fields, turbulence parameters) around oyster tables. The analysis is based on experimental trials carried out in a flume tank on reduced models of oyster tables. Experiments highlight the flow perturbations in the near field and constitute a database for validation of...
Tipo: Text
Palavras-chave: Sediment dynamics; Oyster table; LDV measurement; Computational fluid dynamics; Porosity; Boundary layer.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00043/15421/12974.pdf

Phytoplankton morphology controls on marine snow sinking velocity
Provedor de dados: 5
Autores: Laurenceau-cornec, Emmanuel C.; Trull, Thomas W.; Davies, Diana M.; De La Rocha, Christina L.; Blain, Stephane.
During the second KErguelen Ocean and Plateau compared Study (KEOPS2) in October-November 2011, marine snow was formed in roller tanks by physical aggregation of phytoplankton assemblages sampled at 6 stations over and downstream of the Kerguelen Plateau. Sinking velocities, morphology, bulk composition (transparent exopolymer particles, biogenic silica, particulate organic carbon), and phytoplankton contents were measured individually on 66 aggregates to identify controls on sinking velocities. Equivalent spherical diameters (ESD) ranged from 1 to 12 mm, and the particle aspect ratios, Corey shape factors, and fractal dimensions (D-F1 = 1.5, D-F2 = 1.8) were close to those of smaller natural aggregates (0.2 to 1.5 mm) collected in polyacrylamide...
Tipo: Text
Palavras-chave: Sinking velocity Marine snow; Aggregation; Phytoplankton; Porosity.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00352/46275/46044.pdf

Comparison of the physical and geotechnical properties of gas-hydrate-bearing sediments from offshore India and other gas-hydrate-reservoir systems
Provedor de dados: 5
Autores: Winters, W. J.; Wilcox-cline, R. W.; Long, P.; Dewri, S. K.; Kumar, P.; Stern, L.; Kerr, L.
The sediment characteristics of hydrate-bearing reservoirs profoundly affect the formation, distribution, and morphology of gas hydrate. The presence and type of gas, porewater chemistry, fluid migration, and subbottom temperature may govern the hydrate formation process, but it is the host sediment that commonly dictates final hydrate habit, and whether hydrate may be economically developed. In this paper, the physical properties of hydrate-bearing regions offshore eastern India (Krishna-Godavari and Mahanadi Basins) and the Andaman Islands, determined from Expedition NGHP-01 cores, are compared to each other, well logs, and published results of other hydrate reservoirs. Properties from the hydrate-free Kerala-Konkan basin off the west coast of India are...
Tipo: Text
Palavras-chave: Physical properties; Gas hydrate; Porosity; Atterberg limits; Consolidation; Permeability; Shear strength; Scanning electron microscopy.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00289/40036/38799.pdf

CHANGES IN PHYSICAL PROPERTIES OF A TYPIC HAPLOCAMBID BY ANNUAL CROP CULTURE
Provedor de dados: 126
Autores: Seguel,O; Baginsky,C; Contreras,A; Covarrubias,J; Gonzalez,C; Sandoval,M.
As an alternative to organic soil amendments used in the Copiapo Valley (northern Chile), this study analyzed the magnitude of changes in physical soil properties associated with different crop rotations on the rows on a grape orchard. The study was performed in the locality of Los Loros, Atacama Region, during the 2006-2008 seasons. In a Typic Haplocambid soil (2-5% slope, coarse loam) with a 6-year old grape plantation, a control and three crop rotations were established, each with four replicates. Soil samples were taken at three depths (0-10; 10-40; 40-60 cm), evaluating bulk density, penetration resistance, aggregate stability, pore size distribution and air and water flux. Crop rotation did not produce statistical differences in soil density compared...
Tipo: Journal article
Palavras-chave: Porosity; Aggregate stability; Mechanical strength; Productivity.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162011000100001

Correction of seabed layer thickness in processing subbottom profile data.
Provedor de dados: 20
Autores: Wang, Fangqi; Qi, Faqing; Hu, Guanghai; Dong, Lifeng; Tao, Changfei.
The subbottom profiling is an important means of marine engineering survey, hazardous geology study and continental shelf scientific research. The accuracy of subbottom profile data interpretation has a direct impact on the research and investigation results. Because some of profilers’ transducer and hydrophone are separately installed, when the survey area is very shallow, distortion of shallow layers will be caused if it is seen as a self-excited and self-collected single-channel seismic system. According to the principle of subbottom profiler, the distortion correction formula is deduced and analyzed, providing actual value to using C-View software to interpret such subbottom profile data more accurately. In addition, the seabed sediments sound velocity...
Tipo: Journal Contribution
Palavras-chave: Crustal thickness; Sound velocity; Porosity; Forecasting.
Ano: 2012
URL: http://hdl.handle.net/1834/5852

Elastic stresses and plastic deformations in 'Santa Clara' tomato fruits caused by package dependent compression
Provedor de dados: 86
Autores: PEREIRA,ADRIANA VARGAS; CALBO,ADONAI GIMENEZ.
The objective of this work was to study the fruit compression behavior aiming to develop new tomato packages. Deformations caused by compression forces were observed inside packages and in individual 'Santa Clara' tomato fruit. The forces applied by a transparent acrylic lever to the fruit surface caused pericarp deformation and the flattened area was proportional to the force magnitude. The deformation was associated to the reduction in the gas volume (Vg), caused by expulsion of the air from the loculus cavity and reduction in the intercellular air volume of the pericarp. As ripening advanced, smaller fractions of the Vg reduced by the compressive force were restored after the stress was relieved. The lack of complete Vg restoration was an indication of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lycopersicon esculentum; Mechanical damage; Porosity; Storage losses.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2000001200014

Injection of liquid swine slurry and effects on properties of a Nitossolo Vermelho
Provedor de dados: 86
Autores: Rech,Cleber; Albuquerque,Jackson Adriano; Corrêa,Juliano Corulli; Mafra,Alvaro Luiz; Bortolini,Diego.
Abstract: The objective of this work was to evaluate the superficial and injected applications of swine slurry and urea to the soil, regarding their effects on the physical properties of a Nitossolo Vermelho distroférrico under a no-tillage system. The treatments were: injected slurry into the groove with a liquid swine slurry injector (LSSI); slurry on surface, applied on the lines by the LSSI kept raised; urea injected by opening the groove with the LSSI and distributed manually; and corn, under no-tillage, as a control. Sowing and the injection of liquid slurry or urea do not modify the organic carbon content, pH, and aggregation, but alter the soil bulk density and porosity in the mobilized line, and increase the macropores.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Porosity; Soil structure; Urea.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000400518

Physical properties of a rhodic haplustox under two sugarcane harvesting systems
Provedor de dados: 90
Autores: Machado,Walquíria; Telles,Tiago Santos; Tavares Filho,João; Guimarães,Maria de Fátima; Alves,Grace Bungenstab; Borges,José Luiz Bernardo.
This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH) and mechanized harvesting of unburnt green cane (MCH), on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0-0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Saccharum officinarum; Soil bulk density; Porosity; Soil penetration resistance; Soil aggregate stability.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000600004

Soil water dynamics related to the degree of compaction of two brazilian oxisols under no-tillage
Provedor de dados: 90
Autores: Silva,Vanderlei Rodrigues da; Reichert,José Miguel; Reinert,Dalvan José; Bortoluzzi,Edson Campanhola.
Soil water properties are related to crop growth and environmental aspects and are influenced by the degree of soil compaction. The objective of this study was to determine the water infiltration and hydraulic conductivity of saturated soil under field conditions in terms of the compaction degree of two Oxisols under a no-tillage (NT). Two commercial fields were studied in the state of Rio Grande do Sul, Brazil: one a Haplortox after 14 years under NT; the other a Hapludox after seven years under NT. Maps (50 x 30 m) of the levels of mechanical penetration resistance (PR) were drawn based on the kriging method, differentiating three compaction degrees (CD): high, intermediate and low. In each CD area, the infiltration rate (initial and steady-state) and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water infiltration; Mechanical penetration resistance; Kriging; Porosity.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000500003

Soil aggregation and organic carbon of Oxisols under coffee in agroforestry systems
Provedor de dados: 90
Autores: Guimarães,Gabriel Pinto; Mendonça,Eduardo de Sá; Passos,Renato Ribeiro; Andrade,Felipe Vaz.
Intensive land use can lead to a loss of soil physical quality with negative impacts on soil aggregates, resistance to root penetration, porosity, and bulk density. Organic and agroforestry management systems can represent sustainable, well-balanced alternatives in the agroecosystem for promoting a greater input of organic matter than the conventional system. Based on the hypothesis that an increased input of organic matter improves soil physical quality, this study aimed to evaluate the impact of coffee production systems on soil physical properties in two Red-Yellow Oxisols (Latossolos Vermelho-Amarelos) in the region of Caparaó, Espirito Santo, Brazil. On Farm 1, we evaluated the following systems: primary forest (Pf1), organic coffee (Org1) and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Organic matter; Degree of flocculation; Macroaggregates; Porosity.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000100028

Mineralogy of the clay fraction of alfisols in two slope curvatures: IV - spatial correlation with physical properties
Provedor de dados: 90
Autores: Camargo,Livia Arantes; Marques Júnior,José; Pereira,Gener Tadeu.
Although the influence of clay mineralogy on soil physical properties has been widely studied, spatial relationships between these features in Alfisols have rarely been examined. The purpose of this work was to relate the clay minerals and physical properties of an Alfisol of sandstone origin in two slope curvatures. The crystallographic properties such as mean crystallite size (MCS) and width at half height (WHH) of hematite, goethite, kaolinite and gibbsite; contents of hematite and goethite; aluminium substitution (AS) and specific surface area (SSA) of hematite and goethite; the goethite/(goethite+hematite) and kaolinite/(kaolinite+gibbsite) ratios; and the citrate/bicarbonate/dithionite extractable Fe (Fe d) were correlated with the soil physical...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aggregates; Mineral crystallinity; Density; Porosity; Penetration resistance; Cross-semivariogram.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000200002

Soil compaction and eucalyptus growth in response to forwarder traffic intensity and load
Provedor de dados: 90
Autores: Silva,Sérgio Ricardo da; Barros,Nairam Félix de; Costa,Liovando Marciano da; Leite,Fernando Palha.
During timber exploitation in forest stands harvesting machines pass repeatedly along the same track and can cause soil compaction, which leads to soil erosion and restricted tree root growth. The level of soil compaction depends on the number of passes and weight of the wood load. This paper aimed to evaluate soil compaction and eucalyptus growth as affected by the number of passes and wood load of a forwarder. The study was carried out in Santa Maria de Itabira county, Minas Gerais State - Brazil, on a seven-year-old eucalyptus stand planted on an Oxisol. The trees were felled by chainsaw and manually removed. Plots of 144 m² (four rows 12 m long in a 3 x 2 m spacing) were then marked off for the conduction of two trials. The first tested the traffic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Soil bulk density; Water-stable aggregates; Soil penetration resistance; Porosity; Soil organic carbon; Infiltration.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832008000300002

Revisiting the S-index for soil physical quality and its use in Brazil
Provedor de dados: 90
Autores: Jong van Lier,Quirijn de.
The S-index was introduced in 2004 in a publication by A.R. Dexter. S was proposed as an indicator of soil physical quality. A critical value delimiting soils with rich and poor physical quality was proposed. At present, Brazil is world leader in citations of Dexter's publication. In this publication the S-theory is mathematically revisited and extended. It is shown that S is mathematically correlated to bulk density and total porosity. As an absolute indicator, the value of S alone has proven to be incapable of predicting soil physical quality. The critical value does not always hold under boundary conditions described in the literature. This is to be expected because S is a static parameter, therefore implicitly unable to describe dynamic processes. As a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Porosity; Density; Water retention curve; Compaction.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000100001

X-ray computed microtomography in the evaluation of the porous system of soils
Provedor de dados: 91
Autores: Costa,Larissa F.; Balbinot Antonino,Antonio C. D.; Richard J.,Heck; Coutinho,Artur P.; Vasconcelos,Thiago C.; Machado,Cassia B.
ABSTRACT Analysis of shapes, sizes, continuity, orientation and irregularities of pores can help in the study of soil structural modifications induced by soil management. The study of the inter- and intra-aggregate porous space of urban and rural soils by tomographic images is the objective of this work. A morphometric characterization of the pores was carried out with the analysis of distribution of their size, shape and inclination in these two types of soil. The urban soil showed smaller percentage of inter-aggregate voids and more intra-aggregate voids compared with the rural soil. The cumulative distribution of void volumes showed little pore diversity in the urban soil and great presence of large pores (48%), almost twice the voids with same size in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Porosity; Tomographic images; Soil compaction.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000400249

SOIL ATTRIBUTES THREE YEARS AFTER MAKING RIDGES AND OR DRAINS FOR PLANTING GRAPEVINE ROOTSTOCK
Provedor de dados: 94
Autores: VEIGA,MILTON DA; DAMBRÓS,REMI NATALIN; DALBÓ,MARCO ANTÔNIO.
RESUMO Os atributos do solo estão relacionados com o desenvolvimento e a produção das culturas, tanto anuais como perenes. O presente trabalho teve como objetivo determinar os atributos químicos e físicos do solo três anos após a aplicação de sistemas de manejo para implantação de porta-enxertos de videira, em um Nitossolo Vermelho com textura muito argilosa. Os sistemas de manejo consistiram na confecção ou não de camalhões e/ou de drenos antes da implantação das mudas de porta-enxertos Dog Ridge. Os atributos químicos (pH em água e teores de matéria orgânica e de macronutrientes) foram determinados em amostras coletadas na linha da cultura, nas camadas de 0-0,1; 0,1-0,2; 0,2-0,3 e 0,3-0,4 m de profundidade. Os atributos físicos do solo (teor de argila,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: PH; Organic matter; Macronutrients; Bulk density; Porosity; Penetration resistance; Vitis.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452015000300797

Water vapor conductance: a technique using eggshell fragments and relations with other parameters of eggshell
Provedor de dados: 96
Autores: Araújo,Itallo Conrado Sousa de; Leandro,Nadja Susana Mogyca; Mesquita,Mariana Alves; Café,Marcos Barcellos; Mello,Heloisa Helena Carvalho; Gonzales,Elisabeth.
ABSTRACT The objective of this study was to evaluate a technique for quantifying eggshell conductance using shell fragments from hatched eggs. Additional objectives were to calculate the correlation between eggshell conductance, porosity, and thickness and correlate these parameters with incubation data. The study design was fully randomized in a 3 × 3 factorial scheme (three egg regions - large end, equator, and narrow end - and three ages of broiler breeders – 29, 35, and 59 weeks). A total of 216 eggs were used, with 24 repetitions for each treatment. Neither conductance nor shell thickness showed any interaction with egg region. Breeder age influenced eggshell conductance, such that it was greatest in eggshells from 59-week breeders (0.323 mg day−1...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fertile eggs; Porosity; Shell conductance; Shell thickness.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017001200896

Soil physical attributes in forms of sowing the annual winter pasture and intervals between grazing
Provedor de dados: 124
Autores: Veiga,Milton da; Balbinot Junior,Alvadi Antonio; Oliveira,Daniela Aparecida de.
The sowing of winter pastures in areas used for summer grain production and their management under direct cattle grazing can cause changes in soil physical attributes, whose intensity depends on the degree of soil mobilization, grazing interval, stocking rate and weather. To study these aspects it was conducted over four years an experiment in a randomized block with split plots design and four replications. In the main plots were applied two forms of sowing the annual winter pasture (direct seeding and seeding + harrowing) and, in the subplots, four intervals between grazing (7, 14 and 28 days and ungrazed). Undisturbed soil cores were sampled at the end of each grazing cycle, in the 0-0.05 m layer to determine the saturated hydraulic conductivity and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Crop-livestock integration system; Bulk density; Porosity; Saturated hydraulic conductivity; Aggregate stability.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000500005

Soil management of sugarcane fields affecting CO2 fluxes
Provedor de dados: 63
Autores: Tavares,Rose Luiza Moraes; Siqueira,Diego Silva; Panosso,Alan Rodrigo; Castioni,Guilherme Adalberto Ferreira; Souza,Zigomar Menezes de; Scala Jr.,Newton La.
ABSTRACT The harvesting system of green sugarcane, characterized by mechanized harvesting and no crop burning, affects soil quality by increasing the remaining straw left on the soil surface after harvesting, thus, contributing to the improvement of physical, chemical, and microbiological soil attributes, influencing CO2 fluxes. This study aimed to evaluate CO2 fluxes and their relation to soil properties in sugarcane crops under different harvesting managements: burned (B), Green harvesting for 5 years (G-5) and Green harvesting for ten years (G-10). For this, a 1 ha sampling grid with 30 points was installed in each area, all located in the Northeast of São Paulo State, Brazil. In each point, CO2 fluxes were measured and the soil was sampled to analyze...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sacharum officinarum; Principal component analysis; Porosity; Biomass.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000600543

Relationship between thermal properties of canola pods (without seed) with moisture content, porosity and chemical composition of pods
Provedor de dados: 111
Autores: Azadbakht, Mohsen; Ghajarjazi, Ehsan; Ghaderi-Far, Farshid.
Thermal properties of canola pods including coefficients of thermal conductivity, thermal diffusivity and specific heat and chemical composition of rapeseed pods were measured at three levels of conventional canola varieties cultivated in the north of Iran (Hyola 50, Hyola 401 and Hyola 420) and in three times before harvest, while harvest and post-harvest. Then the relationship between the thermal properties of canola pods with chemicals, moisture and porosity were investigated. Conductivity coefficient was resulted from linear thermal method, the specific heat was obtained from mixing method and diffusion coefficients were calculated by the formula. The results showed that changes of variety and time of sampling were significant on thermal conductivity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Thermal conductivity; Specific heat; Thermal diffusivity; Canola pod; Chemical composition; Porosity.
Ano: 2016
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3613

Microporosity of BIF hosted massive hematite ore, Iron Quadrangle, Brazil
Provedor de dados: 42
Autores: VARAJÃO,CÉSAR A.C.; BRUAND,ARY; RAMANAIDOU,ERICK R.; GILKES,ROBERT J.
Massive hematite ore (MHO) is a special high-grade iron ore, used as lump ore in the process of obtaining direct reduction iron (DRI). The influence of porosity on the reducibility of MHO from the Capitão do Mato Mine (Iron Quadrangle, Brazil) was investigated using optical and scanning electron microscopes on drill core and open pit samples. Hematite is the main component of the samples and occurs as granular crystals (10 mum), microplates (1 mum) and euhedral martite (10 to 30 mum). Quartz, maghemite, kenomagnetite and goethite are minor components. Primary micropores (Å to 1 mum) are associated with microplaty crystals that fill cavities between granular hematite. Secondary micropores (Å to 5 mum) related to euhedral martite crystals, are the most...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: BIF; Porosity; Massive hematite ore; Direct reduction iron; Reducibility.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652002000100008

SEM observation of grain boundary structures in quartz-iron oxide rocks deformed at intermediate metamorphic conditions
Provedor de dados: 42
Autores: Lagoeiro,Leonardo; Gonçalves,Cristiane C.
Several studies have demonstrated the effect of a second phase on the distribution of fluid phase and dissolution of quartz grains. However, as most observations came from aggregates deformed under hydrostatic stress conditions and mica-bearing quartz rocks, 3-D distribution of pores on quartz-quartz (QQB) and quartz-hematite boundaries (QHB) has been studied. Several fracture surfaces oriented according to finite strain ellipsoid were analyzed. The pore distribution characterizes the porosity and grain shape as highly anisotropic, which results from the nature and orientation of boundaries. QHB have physical/chemical properties very different from QQB, once the hematite plates have strong effect on wetting behavior of fluid, likewise micas in quartzites....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Deformation mechanisms; Fluid distribution; Grain growth; Porosity; Solution transfer.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300009

Physical attributes of kaolinitic and oxidic oxisols resulting from different usage systems
Provedor de dados: 52
Autores: Centurion,José Frederico; Beutler,Amauri Nelson; Souza,Zigomar Menezes de.
The objective of this study was to assess the physical attributes of a kaolinitic oxisol, medium texture (Haplustox) and an oxidic oxisol, clayey (Eutrustox) under different usage systems, localized in the region of Jaboticabal, SP, Brazil. The usage systems were sugarcane, cotton and forest. Parameters such as soil bulk density, total porosity, macro and microporosity at the depths of 0.0-0.1; 0.1-0.2; 0.2-0.3, and 0.3-0.4 m were evaluated. Haplustox showed greater bulk density and smaller total porosity, macro and microporosity. The usage increased the bulk density in 0.0-0.3 m depth, with greater effects on the kaolinitic oxisol, mainly in 0.1-0.2 m depth in the areas cultivated with sugarcane.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sugarcane; Cotton; Forest; Mineralogy; Porosity; Bulk density.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000500007