scholarly journals Edaphic attributes in pedoforms of gullies, in the Southeast region of Brazil

2021 ◽  
Vol 14 (4) ◽  
pp. 1-13
Author(s):  
João Henrique Gaia Gomes ◽  
Marcos Gervasio Pereira ◽  
Fabiana da Costa Barros ◽  
Cristiane Figueira da Silva ◽  
Vanessa Aparecida Freó ◽  
...  
Keyword(s):  
Convex Surface ◽  
External Surface ◽  
Particle Density ◽  
Internal Surface ◽  
Clay Content ◽  
Fine Sand ◽  
Soil Characteristics ◽  
Physical Characteristics ◽  
Aluminum Saturation ◽  
Physical And Chemical

Water erosion acts as the main form of soil degradation, promoting the release of particles that associated with factors such as climate, relief, soil vegetation and use and occupation favor this process. This study aimed to evaluate whether gullies are more likely to be present in a specific type of landform and how physical and chemical soil characteristics vary between the internal and external environments of concave and convex gullies. The study was performed in the Cachimbal River sub-basin, Pinheiral (RJ). Gullies were mapped and the quantitative and qualitative evaluations (occurrence in concave or convex surface). For each type of landform, one gully was selected. Soil samples (disturbed and undisturbed) were collected from the internal and external surfaces of each gully at a depth of 0-10 cm and soil chemical and physical characteristics were determined. More gullies were present in convex landforms and differences in soil characteristics were observed between the internal and external gully surfaces, but not between different landforms. Ca+2, S value, H+Al, T value, Mg+2, TOC and K+ were associated with the external surface, and P, Al+3, aluminum saturation, V%, and pH with the internal surface. Natural and total clay content, and soil and particle density were the physical characteristics associated with the external surface, and total and fine sand content, porosity, degree of flocculation, and silt content with the internal surface.

scholarly journals Water and physical characteristics of irrigated soils in the Massif of Mugan-Salyan / Woda i charakterystyki fizyczne nawadnianych gleb w Masywie Mugaw-Salyan

2012 ◽  
Vol 17 (1) ◽  
pp. 61-67
Author(s):  
Mustafa Gilman Mustafayev
Keyword(s):  
Physical Properties ◽  
Soil Properties ◽  
Particle Density ◽  
Clay Content ◽  
Physical Characteristics ◽  
Water Capacity ◽  
Irrigated Soils

Abstract Detailed information about the water and physical properties of irrigated soils in the Massif of Mugan- -Salyan is given in the paper. Results of the study showed differences in the soil properties. The field water capacity of soil in the zone was 25.32-30.30% or 1.26-1.56 g·cm-3, particle density was 2.53-2.88 g·cm-3, porosity - 44.16-54.20%; clay content - 22.54-70.10% and the velocity of soaking the soil with water ranged between 9.24 and 55.84 cm·h-1. Such variability of the indices points to a need for reclamation measures in the soils.

scholarly journals Taxonomical Classification of Arable Lands in the District Pulwama of Kashmir, India

2017 ◽  
Vol 5 (1) ◽  
pp. 33-44
Author(s):  
N. Z Rehman ◽  
Masrat Maqbool ◽  
D Ram ◽  
J. A Wani
Keyword(s):  
Particle Density ◽  
Clay Content ◽  
Particle Size Analysis ◽  
Mean Value ◽  
Size Analysis ◽  
Essential Requirement ◽  
Crop Establishment ◽  
Taxonomical Classification ◽  
Physical And Chemical

Knowledge about morphological, physical and chemical characteristics of soil is an essential requirement for successful crop establishment and output in an area. Taking this concept into cognizance, nine representative soil profiles exposed in the study area were assessed for various properties. Results revealed that the topographical as well as soil morphological features were diverse thereby leading to development of different soil assets. The soils showed varying degree of profile development on foothills (A-C), low hill plateaus (A-Bw-C) and inland valleys (A-Bt-C) horizons, respectively. Particle size analysis revealed that the variation of sand, silt and clay content ranged from 11.7 to 60.6, 22.3 to 60.5 and 17.1 to 35.3 percent, respectively. Organic carbon ranged from 0.02 to 1.72 percent with a mean value of 0.42 percent. Bulk density and particle density ranged from 1.21 to 1.58 Mg m-3 and 2.3 to 2.8 Mgm-3, respectively. The soils were finally recognized to fall under the Entisol, Mollisol and Alfisol orders under taxonomical classification and II, III and IV classes under capability classification with limitations of slope, erosion and wetness. Proper soil managements and diversification of crops can decrease the risk of crop failures caused by such soil limitations.

Kerusakan Pada Material Pipa Air Bersih Akibat General Corrosion

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
M. N. Setia Nusa
Keyword(s):  
Chemical Composition ◽  
Failure Analysis ◽  
External Surface ◽  
Internal Surface ◽  
General Corrosion ◽  
Water Pipe ◽  
Corrosion Attack ◽  
Corrosion Failure ◽  
Environment Factor

Water pipe of 4.5” diameter and has been operated for 8 year having failure due to corrosion attack on its external and internal surface. It is conducted failure analysis to find out the cause of corrosion by having testing examination of visual fractography, metalography,, SEM EDAX, hardness and chemical composition. Testing and examination results show that the failure / corroded pipe has a for in of general corrosion on the external surface due to environment factor or ground factor arround the pipe and on the internal surface was influenced by excessive root weld creating protrude which then causing turbolens and deposite to accelerate corrosion attack.Pipa berdiameter 4.5” yang berfungsi mengalirkan air bersih dan telah beroperasi selama 8 tahun, terjadi kerusakan berbentuk korosi pada permukaan luar pipa dan permukaan dalam. Untuk itu dilakukan analisa kerusakan untuk mengetahui penyebab terjadinya korosi dengan pengujian dan pemeriksaan secara visual,Fractography, Metallography, SEM, EDAX, Uji Kekerasan dan Uji Komposisi Kimia. Hasil pemeriksaan dan pengujian pada pipa yang rusak / korosi berbentuk jenis general korosi pada permukaan luar pipa yang diakibatkan faktor lingkungan atau tanah disekitar pipa, sedangkan pada bagian dalam pipa dipengaruhi oleh adanya lelehan pengelasan yang kurang sempurna sehingga menimbulkan benjolan yang mengakibatkan aliran air didalam pipa tidak lancar sehingga terjadi turbolensi yang menimbulkan endapan dan mengakibatkan percepatan terjadinya korosi.Keywords: Pipe, environtment, turbolens, corrosion, failure

scholarly journals Experimental Determination of the Heat Transfer Coefficient of Real Cooled Geometry Using Linear Regression Method

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 180
Author(s):  
Asif Ali ◽  
Lorenzo Cocchi ◽  
Alessio Picchi ◽  
Bruno Facchini
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Linear Regression ◽  
Surface Temperature ◽  
Transfer Coefficient ◽  
External Surface ◽  
Internal Surface ◽  
Regression Method ◽  
Thermal Transient

The scope of this work was to develop a technique based on the regression method and apply it on a real cooled geometry for measuring its internal heat transfer distribution. The proposed methodology is based upon an already available literature approach. For implementation of the methodology, the geometry is initially heated to a known steady temperature, followed by thermal transient, induced by injection of ambient air to its internal cooling system. During the thermal transient, external surface temperature of the geometry is recorded with the help of infrared camera. Then, a numerical procedure based upon a series of transient finite element analyses of the geometry is applied by using the obtained experimental data. The total test duration is divided into time steps, during which the heat flux on the internal surface is iteratively updated to target the measured external surface temperature. The final procured heat flux and internal surface temperature data of each time step is used to find the convective heat transfer coefficient via linear regression. This methodology is successfully implemented on three geometries: a circular duct, a blade with U-bend internal channel, and a cooled high pressure vane of real engine, with the help of a test rig developed at the University of Florence, Italy. The results are compared with the ones retrieved with similar approach available in the open literature, and the pros and cons of both methodologies are discussed in detail for each geometry.

A Study of the Chemical and Physical Characteristics of the Soils from the South of Piauí for Soil-Cement Brick Production

2016 ◽  
Vol 869 ◽  
pp. 112-115 ◽  
Author(s):  
Francisca Pereira de Araújo ◽  
Edson Cavalcanti Silva Filho ◽  
João Sammy Nery de Souza ◽  
Josy Anteveli Osajima ◽  
Marcelo Barbosa Furtini
Keyword(s):  
Organic Matter ◽  
Particle Density ◽  
Environmentally Friendly ◽  
Physical Characteristics ◽  
Chemical Characteristics ◽  
The South ◽  
Physical Chemical ◽  
Soil Cement ◽  
Made In

Soil-cement bricks are good examples of environmentally friendly products. This brick is the combination of soil with compacted cement with no combustion in its production. In this work the physical chemical characteristics of the soil from Piaui for producing this material were investigated. Samples of the soil were collected in three potteries from the county of Bom Jesus and pH analysis were carried out, as well as the rate of organic matter, texture, particle density, limits of liquidity and plasticity rates. The results have shown that the soils have acid tones (pH 5,49 a 6,11), which can be neutralized by adding cement, and organic matter percentages up to 1%. The samples have shown predominantly clay-rich textures with adequate plasticity limits, however, values of liquidity limits and particle density above recommended. Altogether, these soils tend to present viability concerning soil-cement brick production, provided that corrections with additives are made in order to minimize this effect.

Influence of Compaction Energy and Bentonite Clay Content in the Soil Hydraulic Conductivity

2016 ◽  
Vol 851 ◽  
pp. 858-863
Author(s):  
Osvaldo de Freitas Neto ◽  
Olavo Francisco dos Santos Jr. ◽  
Fagner Alexandre Nunes de França ◽  
Ricardo Nascimento Flores Severo
Keyword(s):  
Soil Sample ◽  
Laboratory Tests ◽  
Particle Density ◽  
Bentonite Clay ◽  
Clay Content ◽  
Capital City ◽  
Silty Sand ◽  
Laboratory Test Results ◽  
Compaction Energy ◽  
Field Works

This paper intends to evaluate changes in permeability of a soil sample from Formação Barreiras, in Natal, the capital city of Rio Grande do Norte State, related to the degree of compaction and the adding of clay to the soil sample. In field works, samples were collected and permeability and density tests were performed. In laboratory, grain size distribution, Attemberg limits and particle density tests were conducted. Afterwards, compaction and permeability tests fulfilled the set of laboratory tests, with changes in compactive energy and sample clay content. The results from field and laboratory tests were compared and the relationship between compaction energy and sample clay content were portrayed. The soil was classified as silty sand. Field and laboratory test results were quite similar. As expected, the tests indicated that permeability is inversely proportional to both compaction energy and sample clay content in the soil tested.

scholarly journals CONTROL OF GRAPEVINE DECLINE WITH THE USE OF DRAINS AND RIDGES

2016 ◽  
Vol 38 (2) ◽  
Author(s):  
REMI NATALIN DAMBROS ◽  
MARCO ANTONIO DALBÓ ◽  
CRISTIANO JOÃO ARIOLI ◽  
MILTON DA VEIGA
Keyword(s):  
Soil Fungi ◽  
Clay Content ◽  
Field Studies ◽  
Soil Characteristics ◽  
Southern Brazil ◽  
Plant Mortality ◽  
Drastic Reduction ◽  
Santa Catarina ◽  
Grapevine Decline ◽  
Santa Catarina State

ABSTRACT The incidence of grapevine decline and dye back is quite severe in grapevine-growing regions of southern Brazil, especially in the Midwest of Santa Catarina State. Field studies on problematic areas identified the presence of the Brazilian ground pearl or margarodes (Eurhizococcus brasiliensis Hempel) and soil fungi (Cylindrocarpon, Fusarium and others) associated with the disease. Soil characteristics such as high clay content and poor aeration were associated with the problem. To evaluate the effect of pre-planting tillage in reducing the incidence of grapevine decline, an experiment was carried out with two rootstocks and three pre-planting tillage (regular plowing, drains, and ridges) in an area where high plant mortality had been previously observed. Pre-planting tillage with the use of ridges along the rows gave the best results with a drastic reduction in the decline incidence. The number of ground pearl cysts was unaffected by pre-planting tillage and did not relate with the incidence of decline and death of plants.

scholarly journals P-sorption and desorption in Savanna Brazilian soils as a support for phosphorus fertilizer management

2013 ◽  
Vol 37 (6) ◽  
pp. 521-530 ◽  
Author(s):  
Flávio Araújo Pinto ◽  
Edicarlos Damacena de Souza ◽  
Helder Barbosa Paulino ◽  
Nilton Curi ◽  
Marco Aurélio Carbone Carneiro
Keyword(s):  
Clay Content ◽  
Soil Characteristics ◽  
Fertilizer Management ◽  
Phosphorus Fertilizer ◽  
Phosphorus Adsorption ◽  
P Sorption ◽  
Brazilian Soils ◽  
Soil Clay ◽  
Sand Base ◽  
Soil Clay Content

Phosphorus (P) sorption by soils is a phenomenon that varies depending on soil characteristics, influencing its intensity and magnitude, which makes it a source or drain of P. The objective of this study was to determine the Maximum Phosphorus Adsorption Capacity (MPAC) and desorption of P from soils under native Savanna Brazilian and verify the correlation between MPAC and P Capacity Factor (PCF) with the chemical and physical properties of these soils. The study was conducted in seven soils under native Savannas. The Langmuir isotherms were adjusted from the values obtained in sorption assays, being evaluated the MPAC, the energy adsorption (EA) and PCF, which was calculated according to the levels of P-adsorbed and P-sorbed. Values of MPAC were classified as high in most soils, ranging from 283 up to 2635 mg kg-1 of P in the soil and were correlated with soil organic matter, clay, silt, sand, base saturation and pH. The PCF was higher in soils where the MPAC was also higher. The use of only one attribute of soil (clay content) as a criterion for the recommendation of phosphated fertilization, as routinely done, is susceptible to errors, needing the use of more attributes for a more accurate recommendation, as a function of the complexity of the interactions involved in the process.

scholarly journals Calcium, magnesium and potassium in mineral soils from the southern half of Finland

1973 ◽  
Vol 45 (3) ◽  
pp. 254-261
Author(s):  
Armi Kaila
Keyword(s):  
Clay Content ◽  
Total Content ◽  
Fine Sand ◽  
Clay Soils ◽  
Surface Layers ◽  
Surface Soils ◽  
Exchangeable Ca ◽  
Heavy Clay ◽  
Southern Half ◽  
Mineral Soils

210 samples of mineral soils from the southern half of Finland with mainly an acid precambrian bedrock, were analysed for the total contents of Ca, Mg and K, and for the portion of these nutrients which could be exchanged by N NH4OAc (pH 7), dissolved by 0.1 N HCI at room temperature, or released by N HCI at 50° C. The total content of Ca was lowest in samples of heavy clay, 0.78±0.14 % in the surface soils and 0.92±0.10 % in the deeper layers. The mean content in the groups of other soils was at least about 1.1 %. The total content of Mg increased with an increase in the clay content (r = 0.81***). It ranged from 0.6±0.1 % in the sand and fine sand samples to 1.53±0.19 % in the heavy clay soils of the surface layers and to 1.89±0.12 % in those of the deeper layers. Also in the groups of loam and silt soils and of the coarser clay soils, respectively, the Mg content was in the deeper layers higher than in the surface soils. The total content of K also increased with the clay content (r=0.73***) from 1.7±0.1 % in the sand and fine sand soils to 2.74±0.21 % in the heavy clay soils of the surface layers and to 3.10±0.07 % in those of the deeper layers. The portion of exchangeable Ca was relatively high: in the groups of surface soils from more than one tenth to one third of the total amount. The corresponding average amounts released by even the more drastic treatment with acid were not markedly higher. Only a few per cents of total Mg were exchangeable and slightly higher amounts were dissolved by 0.1 N HCI, whereas the treatment with N HCI at 50° C released about half of the total Mg. Exchangeable K and K dissolved by 0,1 N HCI did not exceed 1 % of the total K, except slightly in the heavy clay soils; the average amounts released by N HCI ranged from 5 to 18 % of the total K. The plant availability of these nutrients was discussed.

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