PubAg

Main content area

You searched for: Subject "sand fraction" Remove constraint Subject: "sand fraction"
Start Over

Search

708  Search Results

« Previous | 1 - 20 of 708 |
Number of results to display per page

Search Results

1. Transitional behavior in well-graded soils: An example of completely decomposed granite

Author:
Elkamhawy, Elsayed; Zhou, Bo; Wang, Huabin
Source:
Engineering geology 2019 v.253 pp. 240-250
ISSN:
0013-7952
Subject:
sand fraction,   etc   ; fabrics; granite; granite soils; isotropy; microstructure; soil mineralogy;     Show all 7 Subjects
Abstract:
... This study presents the results of a series of isotropic compression tests and drained and undrained triaxial shearing tests on naturally graded and reconstituted completely decomposed granite soils to investigate their compressive response and transitional behavior. Naturally graded soils exhibited unique isotropic compression and critical state lines within the stress levels studied. Soils recon ...
DOI:
10.1016/j.enggeo.2019.02.027

2. The mass ratio of splashed particles during raindrop splash phenomenon on soil surface

Author:
Beczek, Michał; Ryżak, Magdalena; Sochan, Agata; Mazur, Rafał; Bieganowski, Andrzej
Source:
Geoderma 2019 v.347 pp. 40-48
ISSN:
0016-7061
Subject:
sand fraction,   etc   ; kinetic energy; liquids; microorganisms; particle size distribution; pollutants; splash erosion; water content;     Show all 8 Subjects
Abstract:
... Soil splash is the first step of water erosion, therefore a good understanding of it is important in order to describe this multifaceted phenomenon. One of the methods describing this process is the use of splash cups, which allow us to determine the mass of soil material ejected by the impact of water drops. The aim of this study was to determine the mass ratio of splashed particles during raindr ...
DOI:
10.1016/j.geoderma.2019.03.028

3. An Appraisal on the Interpolation Methods Used for Predicting Spatial Variability of Field Hydraulic Conductivity

Author:
Ghosh, Biplab; Pekkat, Sreeja
Source:
Water resources management 2019 v.33 no.6 pp. 2175-2190
ISSN:
0920-4741
Subject:
sand fraction,   etc   ; hydraulic conductivity; hydrologic models; kriging; prediction; sand; silt; soil types; texture;     Show all 9 Subjects
Abstract:
... Knowledge of spatial variability of soil hydraulic conductivity is a key parameter for hydrological modeling. Spatial variability of soil hydraulic conductivity, Kₛ is attributed to soil heterogeneities associated with texture/structure, different initial conditions, meteorological changes, and clogging. The spatial variability is quantified by employing interpolation methods to point measurements ...
DOI:
10.1007/s11269-019-02248-1

4. Vibration and acoustic signal characteristics of solid particles carried in sand-water two-phase flows

Author:
Wang, Kai; Liu, Gang; Li, Yichen; Qin, Min; Wang, Jinbang; Wang, Gang; Mei, Dou
Source:
Powder technology 2019 v.345 pp. 159-168
ISSN:
0032-5910
Subject:
sand fraction,   etc   ; acoustics; powders; sand; signal-to-noise ratio; turbulent flow; vibration; water flow;     Show all 8 Subjects
Abstract:
... Sand particle detection in pipe flow is industrially important. Here, we developed and evaluated two non-invasive methods (vibration and acoustic) with two homotypic mutual assist sensors to measure sand and to investigate the relationship between sand particles and the vibro-acoustic signal characteristics generated by sand-wall impingement in water flow. The time-behavior statistical characteris ...
DOI:
10.1016/j.powtec.2018.12.092

5. Can magic sand cause massive degradation of a gravel-bed river at the decadal scale? Shi‑ting River, China

Author:
An, Chenge; Parker, Gary; Hassan, Marwan A.; Fu, Xudong
Source:
Geomorphology 2019 v.327 pp. 147-158
ISSN:
0169-555X
Subject:
sand fraction,   etc   ; earthquakes; gravel; laboratory experimentation; models; rivers; sand; sediment transport; China;     Show all 9 Subjects
Abstract:
... Massive bed degradation (20 m in 7 years) has been observed in the Shi‑ting River, Sichuan Province, China, since the 2008 Wenchuan Ms. 8.0 earthquake. The reason for the massive bed degradation has not been well understood. A hypothesis has been proposed that relates bed degradation to the augmentation of sand supply after the earthquake. The effect of sand on gravel mobility (magic sand effect) ...
DOI:
10.1016/j.geomorph.2018.10.026

6. Does sand content in spawning substrate result in early larval emergence? Evidence from a lithophilic cyprinid fish

Author:
Bašić, Tea; Britton, J. Robert; Rice, Stephen P.; Pledger, Andrew G.
Source:
Ecology of freshwater fish 2019 v.28 no.1 pp. 110-122
ISSN:
0906-6691
Subject:
sand fraction,   etc   ; Barbus barbus; Salmonidae; eggs; fish; larvae; rivers; sand; socioeconomics; spawning;     Show all 10 Subjects
Abstract:
... The spawning success of lithophilic salmonids is strongly influenced by the fine sediment content (“fines”) of spawning substrates, yet knowledge on the impacts of fines on the spawning of non‐salmonid lithophiles remains limited, despite their ecological and socio‐economic importance in European rivers. Consequently, the aim here was to use an ex‐situ experiment to investigate the impact of sand ...
DOI:
10.1111/eff.12435

7. Occurrence, sources and ecotoxicological risks of polychlorinated biphenyls (PCBs) in sediment cores from urban, rural and reclamation-affected rivers of the Pearl River Delta, China

Author:
Wang, Wei; Bai, Junhong; Zhang, Guangliang; Jia, Jia; Wang, Xin; Liu, Xinhui; Cui, Baoshan
Source:
Chemosphere 2019 v.218 pp. 359-367
ISSN:
0045-6535
Subject:
sand fraction,   etc   ; aroclors; benthic organisms; bioactive properties; ecotoxicology; guidelines; local government; microbial carbon; risk; river deltas; rivers; sediments; urbanization; China;     Show all 14 Subjects
Abstract:
... Sediment cores were collected to a depth of 40 cm (50 cm for urban river sediments) in the Pearl River Delta of China from rural river sediments and river sediments undergoing the process of urbanization and reclamation. Polychlorinated biphenyls (PCBs) in sediment cores were determined to evaluate their levels, distribution, possible sources and potential risks aimed at providing effective inform ...
DOI:
10.1016/j.chemosphere.2018.11.046

8. Optimizing wavelength selection by using informative vectors for parsimonious infrared spectra modelling

Author:
Ng, Wartini; Minasny, Budiman; Malone, Brendan P.; Sarathjith, M.C.; Das, Bhabani S.
Source:
Computers and electronics in agriculture 2019 v.158 pp. 201-210
ISSN:
0168-1699
Subject:
sand fraction,   etc   ; algorithms; carbon; cation exchange capacity; clay; covariance; data collection; infrared spectroscopy; least squares; models; pH; prediction; wavelengths;     Show all 13 Subjects
Abstract:
... Infrared spectroscopy has been widely adopted by various agricultural research. The typical spectra variables contain thousands of wavelengths. These large number of spectra variables often contribute to collinearity, and redundancies rather than relevant information. Variable selection of the predictors is an important step to create a robust calibration model from these spectra data. This paper ...
DOI:
10.1016/j.compag.2019.02.003

9. Effects of Cultivating Years on Survival of Culturable Escherichia coli O157:H7 in Greenhouse Soils

Author:
Yao, Zhiyuan; Zhang, Hao; Liang, Chunling; Wang, Yingzhe; Wu, Yuping
Source:
Journal of food protection 2019 v.82 no.2 pp. 226-232
ISSN:
0362-028X
Subject:
sand fraction,   etc   ; Escherichia coli O157; Weibull statistics; electrical conductivity; greenhouse soils; plastic greenhouses; public health; total nitrogen; vegetables; China;     Show all 10 Subjects
Abstract:
... The extent to how Escherichia coli O157:H7 can survive in soil and the predominant factors that determine its survival are crucial issues from a public health point of view. This study investigated the survival of E. coli O157:H7 in vegetable soils in plastic-greenhouse cultivation over 0, 1, 4, 8, and 12 years in southern China. Results showed that the survival times (td) calculated from the Weib ...
DOI:
10.4315/0362-028X.JFP-18-287

10. Evaluation of a machine to determine maximum bulk density of soils using the vibratory method

Author:
Leonard, Lynessa; Ekwue, Edwin I.; Taylor, Anika; Birch, Robert
Source:
Biosystems engineering 2019 v.178 pp. 109-117
ISSN:
1537-5110
Subject:
sand fraction,   etc   ; buildings; bulk density; clay loam soils; clay soils; equipment; roads; sandy soils; soil compaction; soil density; water content;     Show all 11 Subjects
Abstract:
... Engineering buildings and other structures such as dams and roadways require soil compaction during construction, so as to limit settling of structures after construction. Optimum water content that results in the maximum soil density is normally desired, so that compaction could be done at this water content. This has to be determined by prior laboratory soil tests usually carried out using the s ...
DOI:
10.1016/j.biosystemseng.2018.11.006

11. Joint multifractal analysis for three variables: Characterizing the effect of topography and soil texture on soil water storage

Author:
Biswas, Asim
Source:
Geoderma 2019 v.334 pp. 15-23
ISSN:
0016-7061
Subject:
sand fraction,   etc   ; geometry; landscapes; soil profiles; soil texture; soil water; soil water storage; texture; topography; water storage; Saskatchewan;     Show all 11 Subjects
Abstract:
... Multifractal analysis describes heterogeneity in the distribution of a variable by characterizing and summarizing the variability across scales. Joint multifractal analysis has been widely employed to characterize scale relationships between two variables co-existing along a single geometric support. In this study, joint multifractal analysis was used for three variables coexisting in the same geo ...
DOI:
10.1016/j.geoderma.2018.07.035

12. Prediction and mapping of soil clay and sand contents using visible and near-infrared spectroscopy

Author:
Tümsavaş, Zeynal; Tekin, Yücel; Ulusoy, Yahya; Mouazen, Abdul M.
Source:
Biosystems engineering 2019 v.177 pp. 90-100
ISSN:
1537-5110
Subject:
sand fraction,   etc   ; clay; clay fraction; irrigated farming; least squares; models; near-infrared spectroscopy; prediction; sand; soil sampling; texture; Turkey (country);     Show all 12 Subjects
Abstract:
... The aim of this research was to examine the potential of visible and near infrared (Vis–NIR) spectroscopy for the prediction and mapping of sand and clay fractions of soils in one irrigated field having clay texture in Karacabey district of Bursa Province, Turkey. Eighty six soil samples, collected from the study area, were divided into calibration (80%) and validation (20%) sets. A partial least ...
DOI:
10.1016/j.biosystemseng.2018.06.008

13. Biodiversity in tropical plantations is influenced by surrounding native vegetation but not yield: A case study with dung beetles in Amazonia

Author:
Beiroz, Wallace; Barlow, Jos; Slade, Eleanor M.; Borges, Cézar; Louzada, Julio; Sayer, Emma J.
Source:
Forest ecology and management 2019 v.444 pp. 107-114
ISSN:
0378-1127
Subject:
sand fraction,   etc   ; Eucalyptus; biodiversity; canopy; case studies; community structure; conservation buffers; dung beetles; entropy; forests; functional diversity; indigenous species; insect communities; landscapes; plantations; soil texture; timber production; Amazonia;     Show all 18 Subjects
Abstract:
... Human-modified forests, including plantations and managed forest, will be a major component of tropical landscapes in the near future. To conserve biodiversity across modified tropical landscapes we must first understand what influences diversity in planted areas. We studied dung beetle communities in Eucalyptus plantations to assess the influence of local (canopy openness and soil texture) and la ...
DOI:
10.1016/j.foreco.2019.04.036

14. A multi-proxy quantitative record of Holocene hydrological regime on the Heixiazi Island (NE China): indications for the evolution of East Asian summer monsoon

Author:
Zhang, Zhenqing; Yao, Qiang; Bianchette, Thomas A.; Liu, Kam-biu; Wang, Guoping
Source:
Climate dynamics 2019 v.52 no.11 pp. 6773-6786
ISSN:
0930-7575
Subject:
sand fraction,   etc   ; Holocene epoch; carbonates; climate; equations; hydrology; ice; magnetism; marshes; monsoon season; regression analysis; summer; China; Eurasia; Pacific Ocean; Siberia;     Show all 16 Subjects
Abstract:
... The Holocene hydrological regime on the Heixiazi Island is critical for understanding the evolution of the East Asian summer monsoon (EASM) for the island’s climate-sensitive location on the northern fringe of the EASM domain. In this paper, a marsh depression on the central island was selected to reconstruct the locally hydrological variation and to discuss its indications for the Holocene EASM e ...
DOI:
10.1007/s00382-018-4544-1

15. Multifunctionality debt in global drylands linked to past biome and climate

Author:
Ye, Jian‐Sheng; Delgado‐Baquerizo, Manuel; Soliveres, Santiago; Maestre, Fernando T.
Source:
Global change biology 2019 v.25 no.6 pp. 2152-2161
ISSN:
1354-1013
Subject:
sand fraction,   etc   ; arid lands; climatic factors; debt; desertification; deserts; ecological function; ecosystems; land degradation; soil nutrients; soil texture; species richness; temperature; topography; vegetation;     Show all 15 Subjects
Abstract:
... Past vegetation and climatic conditions are known to influence current biodiversity patterns. However, whether their legacy effects affect the provision of multiple ecosystem functions, that is, multifunctionality, remains largely unknown. Here we analyzed soil nutrient stocks and their transformation rates in 236 drylands from six continents to evaluate the associations between current levels of ...
DOI:
10.1111/gcb.14631

16. Variability and correlation of physical attributes of soils cultivated with cacao trees in two climate zones in Southern Bahia, Brazil

Author:
Arévalo-Hernández, César Oswaldo; da Conceição Pinto, Flavia; de Souza Júnior, José Olimpio; de Queiroz Paiva, Arlicelio; Baligar, Virupax C.
Source:
Agroforestry systems 2019 v.93 no.3 pp. 793-802
ISSN:
0167-4366
Subject:
sand fraction,   etc   ; Theobroma cacao; agroforestry; climatic zones; farms; normal distribution; porosity; resistance to penetration; soil density; soil quality; soil sampling; soil types; Brazil;     Show all 13 Subjects
Abstract:
... Cacao (Theobroma cacao) is a very important crop in Southern Bahia, Brazil, which needs good climate and soil conditions and management for great productivity. In this region, cacao is grown on a large number of soil types, and soil properties have great effects on its sustainability and production potentials. The aim of this study was to evaluate the variability of physical attributes of soils cu ...
DOI:
10.1007/s10457-017-0176-4

17. The feasibility of predicting the spatial pattern of soil particle-size distribution using a pedogenesis model

Author:
Ma, Yuxin; Minasny, Budiman; Welivitiya, W.D. Dimuth P.; Malone, Brendan P.; Willgoose, Garry R.; McBratney, Alex B.
Source:
Geoderma 2019 v.341 pp. 195-205
ISSN:
0016-7061
Subject:
sand fraction,   etc   ; digital elevation models; landscapes; overland flow; particle size; particle size distribution; prediction; risk; runoff; soil formation; soil profiles; soil surveys; temporal variation; weathering; New South Wales;     Show all 15 Subjects
Abstract:
... Particle-size distribution (PSD) plays an important role in influencing a number of soil physical, chemical, and biological properties. Currently, digital soil mapping (DSM) methods based on empirical observations have been widely used in mapping PSD. However, DSM methods rarely consider soil genetic processes. This paper investigated the use of a mechanistic soil evolution model, State Space Soil ...
DOI:
10.1016/j.geoderma.2019.01.049

18. Quartz grain surfaces – A potential microarchive for sedimentation processes and parent material identification in soils of Jordan

Author:
Kemnitz, Helga; Lucke, Bernhard
Source:
Catena 2019 v.176 pp. 209-226
ISSN:
0341-8162
Subject:
sand fraction,   etc   ; Eocene epoch; Regosols; analytical methods; basalt; bedrock; landscapes; limestone; material identification; plagioclase; quartz; sandstone; soil profiles; storms; weathering; Jordan;     Show all 16 Subjects
Abstract:
... Using SEM-supported microsurface and analytical methods we studied quartz and rare feldspar grains of the sand fraction >250 μm from three soil profiles in Jordan. The soils including a Lithosol are of different maturity and diagenetic alteration of their bed rocks, which are sandstone, limestone, and basalt. The profiles had been investigated during projects on the environmental history of the re ...
DOI:
10.1016/j.catena.2018.12.038

19. Characterizing Spatial Variability of Soil Textural Fractions and Fractal Parameters Derived from Particle Size Distributions

Author:
MOHAMMADI, Meysam; SHABANPOUR, Mahmoud; MOHAMMADI, Mohammad Hossein; DAVATGAR, Nasser
Source:
Pedosphere 2019 v.29 no.2 pp. 224-234
ISSN:
1002-0160
Subject:
sand fraction,   etc   ; clay fraction; fractal dimensions; geometry; geostatistics; kriging; models; particle size; particle size distribution; silt; silt fraction; soil sampling; Iran;     Show all 13 Subjects
Abstract:
... Soil particle size distribution (PSD) is a fundamental physical property affecting other soil properties. Characterizing spatial variability of soil texture is very important in environmental research. The objectives of this work were: 1) to partition PSD of 75 soil samples, collected from a flat field in the University of Guilan, Iran, into two scaling domains using a piecewise fractal model to e ...
DOI:
10.1016/S1002-0160(17)60425-9

20. Does Particulate Organic Matter Fraction Meet the Criteria for a Model Soil Organic Matter Pool?

Author:
CURTIN, Denis; BEARE, Michael H.; QIU, Weiwen; SHARP, Joanna
Source:
Pedosphere 2019 v.29 no.2 pp. 195-203
ISSN:
1002-0160
Subject:
sand fraction,   etc   ; biodegradability; fractionation; land use; models; organomineral complexes; particle size; particulate organic matter; pastures; sand; silt loam soils; soil carbon; soil organic matter; ultrasonics; New Zealand;     Show all 15 Subjects
Abstract:
... There is a well-recognized need for improved fractionation methods to partition soil organic matter into functional pools. Physical separation based on particle size is widely used, yielding particulate organic matter (POM, i.e., free or “uncomplexed” organic matter > 50 μm) as the most labile fraction. To evaluate whether POM meets criteria for an ideal model pool, we examined whether it is: 1) u ...
DOI:
10.1016/S1002-0160(18)60049-9