scholarly journals Effect of Alkali Pollutant in Influencing Crack Propagation in Soils

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Junhong Yuan ◽  
Jingbo Cui ◽  
Jianmei Chang ◽  
Guanhong Zhang ◽  
Mingxi Liu
Keyword(s):  
Sodium Carbonate ◽  
Water Loss ◽  
Clayey Soil ◽  
Loss Ratio ◽  
Climate Conditions ◽  
Surface Cracking ◽  
The Third ◽  
Carbonate Concentration ◽  
Shrinkage Cracks ◽  
Cracking Process

Shrinkage, deformation, and cracking will occur under extreme climate conditions such as drought, due to the accumulation of salt inside the soil during the evaporation of water on the surface of the soil. In this study, the image processing method was used to quantitatively analyze the dehydration cracking process of clay polluted by alkaline pollutant sodium carbonate on the basis of experiments. The mechanism of the effect of sodium carbonate concentration on the shrinkage cracks of clay was discussed through the analysis and comparison of different concentrations of sodium carbonate samples. The results showed that the water loss and shrinkage cracks of alkaline contaminant clay were developed in different stages. Firstly, first-level cracks developed diagonally or parallel to the edge of the container, and then second-level cracks developed along the main cracks with an angle of close to 90°. Most of the third-level or higher-level cracks were approximately perpendicular to the second-level cracks or the edge of the container and developed in parallel. In the cracking stage, the water loss ratio of the sample had a good positive correlation with the surface crack ratio. The slope of the fitted curve increased with the increase of the sodium carbonate concentration. With the increase of sodium carbonate concentration, the water loss ratio and the width of first-level cracks of clayey soil decreased, and the total length and the number of cracks increased, while the surface cracking ratio increased first and then decreased.

scholarly journals Effect of Na2CO3 degumming concentration on LiBr-formic acid-silk fibroin solution properties

2016 ◽  
Vol 20 (3) ◽  
pp. 985-991
Author(s):  
Zhi Liu ◽  
Yuqin Wan ◽  
Hao Dou ◽  
Ji-Huan He
Keyword(s):  
Formic Acid ◽  
Silk Fibroin ◽  
Sodium Carbonate ◽  
High Efficiency ◽  
Lithium Bromide ◽  
Solution Properties ◽  
Acid System ◽  
Acid Dissolution ◽  
Carbonate Concentration ◽  
Degumming Process

Salt-acid system has been proved to be of high efficiency for silk fibroin dissolution. Using salt-acid system to dissolve silk, native silk fibrils can be preserved in the regenerated solution. Increasing experiments indicate that acquirement of silk fibrils in solution is strongly associated with the degumming process. In this study, the effect of sodium carbonate degumming concentration on solution properties based on lithium bromide-formic acid dissolution system was systematically investigated. Results showed that the morphology transformation of silk fibroin in solution from nanospheres to nanofibrils is determined by sodium carbonate concentration during the degumming process. Solutions containing different silk fibroin structure exhibited different rheological behaviors and different electrospinnability, leading to different electrospun nanofibre properties. The results have guiding significance for preparation and application of silk fibroin solutions.

scholarly journals Influence of sodium carbonate addition on weight loss of bagasse alkaline black liquor during pyrolysis

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2428-2441
Author(s):  
Xusheng Li ◽  
Jinlong Wang ◽  
Derong Yan ◽  
Yongjun Yin ◽  
Shuangfei Wang
Keyword(s):  
Activation Energy ◽  
Weight Loss ◽  
Sodium Carbonate ◽  
Black Liquor ◽  
Reduction Reaction ◽  
Loss Ratio ◽  
N2 Atmosphere ◽  
Microscopic Morphology ◽  
Weight Loss Ratio

To understand the effects and the mechanism of sodium carbonate (Na2CO3) addition on the bagasse alkaline black liquor (BABL) pyrolysis, the reaction variables such as temperature, heating rate, and amount of Na2CO3 addition into BABL-solids were investigated under N2 atmosphere from 50 °C to 1000 °C by thermogravimetic analysis (TGA). Scanning electron microscopy (SEM) and the Coats–Redfern method (CRM) were employed for surface microscopic morphology observations and kinetic analysis, respectively. The results showed that Na2CO3 plays an inhibiting and promoting role during devolatilization (200 °C to 650 °C) and the reduction stages (650 °C to 1000 °C), respectively. Adding Na2CO3 into BABL-solids tends to increase the thickness of the salt layer covering the BABL-solids surface, which increases the activation energy and reduces the weight loss ratio of BABL-solids pyrolysis within 200 °C to 650 °C. Adding Na2CO3 into the BABL-solids tends to increase the number of alkaline compounds or the active site of the reduction reaction, which reduces the activation energy and increases the weight loss ratio of BABL-solids pyrolysis within 650 °C to 1000 °C. The role of Na2CO3 as an additive could be well understood by studying the influence mechanism of Na2CO3 on BABL-solids pyrolysis.

Application of electrical resistivity method in the characterization of 2D desiccation cracking process of clayey soil

2020 ◽  
Vol 265 ◽  
pp. 105416 ◽  
Author(s):  
Ni An ◽  
Chao-Sheng Tang ◽  
Qing Cheng ◽  
De-Yin Wang ◽  
Bin Shi
Keyword(s):  
Electrical Resistivity ◽  
Clayey Soil ◽  
Resistivity Method ◽  
Desiccation Cracking ◽  
Electrical Resistivity Method ◽  
Cracking Process

A study on the influence of sodium carbonate concentration on the synthesis of high Mg calcites

CrystEngComm ◽  
2016 ◽  
Vol 18 (1) ◽  
pp. 157-163 ◽  
Author(s):  
Heng Yang ◽  
Shiqiang Chai ◽  
Yuzhe Zhang ◽  
Yurong Ma
Keyword(s):  
Sodium Carbonate ◽  
Calcium Ions ◽  
Hydrothermal Process ◽  
Organic Additives ◽  
Amorphous Precursor ◽  
Molar Ratios ◽  
Carbonate Concentration ◽  
Pure Phase

High Mg calcites in pure phase with controlled magnesium contents were synthesized by using amorphous precursor through a hydrothermal process in the absence of organic additives. It is found that the Mg contents in the high Mg calcites increase with the increase of the molar ratios of carbonate and calcium ions in the mother solutions.

scholarly journals Effect of Sodium Carbonate Concentration in Calgon on Hydrometer Analysis Results

2018 ◽  
Author(s):  
Arshdeep Kaur ◽  
George C. Fanourakis
Keyword(s):  
Sodium Carbonate ◽  
Clay Content ◽  
The Other ◽  
Sodium Hexametaphosphate ◽  
Carbonate Content ◽  
Fine Grained ◽  
Carbonate Concentration ◽  
Dispersing Agent ◽  
Effective Combination ◽  
Dispersing Agents

Calgon (a combination of sodium hexametaphosphate and sodium carbonate) has proved to be the most effective dispersing agent in determining the grain size distribution of fine-grained soils by means of the hydrometer analysis. Previous research on the effect of the sodium hexametaphosphate content of dispersing agents on the clay contents showed that the addition of sodium carbonate to sodium hexametaphosphate increases its dispersing effectiveness. Hence, Calgon 35:7 was used /recommended by many researchers/methods and proved to be the most effective dispersing agent. Although previous work focusing on the effect of varying the concentration of sodium hexametaphosphate in Calgon has been reported, the effect of the concentration of sodium carbonate in Calgon has not been assessed and reported. For this reason, in this investigation a series of hydrometer test analyses were conducted using the 152H and ASTM 152H: E100 hydrometers with Calgon in ratios of 35:0, 35:20 and 35:30.  It was observed that with any increase in sodium carbonate content beyond 7 grams, the percentage clay content actually decreased tremendously in the case of hydrometer 152H. However, for the other hydrometer, Calgon (35:0) proved to be most effective combination. Thus, the increase in the sodium carbonate content in Calgon, beyond 7 g/ litre, is not recommended.

Simple Models for Surface Cracking

1988 ◽  
Vol 130 ◽  
Author(s):  
Paul Meakin
Keyword(s):  
Thin Films ◽  
Surface Layer ◽  
Simple Model ◽  
Crack Initiation ◽  
Crack Growth ◽  
Growth Kinetics ◽  
Growth Process ◽  
Surface Cracking ◽  
Cracking Process ◽  
Initiation Period

AbstractA simple model for crack growth in thin films deposited onto a substrate has been developed. This model results in the generation of cracking patterns which have a remarkably realistic appearance. In the simulations a slow crack initiation period is followed by a period of rapid crack growth in which quite linear cracks are formed. Later on the crack growth process becomes slower and less regular as the cracking process relieves much of the stress in the surface layer. In this model pre-existing defects have a large effect on the crack growth kinetics and morphology.

Impact of biochars on swell-shrinkage behavior, mechanical strength, and surface cracking of clayey soil

2014 ◽  
Vol 177 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Yutong Zong ◽  
Danping Chen ◽  
Shenggao Lu
Keyword(s):  
Mechanical Strength ◽  
Clayey Soil ◽  
Surface Cracking ◽  
Shrinkage Behavior

scholarly journals SIMULATING OF FUTURE CLIMATE CONDITIONS ON THE EFFECT OF IRRIGATION ON SUGARCANE YIELD IN SOUTHERN BRAZIL

2021 ◽  
Vol 96 (2) ◽  
pp. 446-470
Author(s):  
Eduardo De Castro Mattos ◽  
Thaís Cattarine Henriques Tomé ◽  
Rafael Braghieri Menillo ◽  
Fábio Ricardo Marin
Keyword(s):  
Atmospheric Carbon Dioxide ◽  
Clayey Soil ◽  
Climatic Conditions ◽  
Economic Feasibility ◽  
Future Scenarios ◽  
Production Environment ◽  
Irrigation Systems ◽  
Planting Dates ◽  
Climate Conditions ◽  
Carbon Dioxide Co2

The objective of this study was to evaluate the technical and economic feasibility of installing central pivot irrigation systems in current days (Scenario A) and in two future scenarios, one with a 10% increase in rainfall (Scenario B1) and the other with 10% reduction in rainfall (Scenario B2). For both future scenarios, an increase of 2ºC in the global temperature and the concentration of atmospheric carbon dioxide (CO2) increasing to 528 ppm (parts per million) were considered. For the study, the recommendation for an area of clayey soil and with the sugarcane cycle was evaluated on three different planting dates: May 15, August 15 and November 15. The DSSAT/CANEGRO model was used, and under the current conditions, the simulations indicated greater yield for planting in May, both for rainfed and irrigated. For scenario B1, there was an increase in yield of 22% for rainfed and 33% for irrigated. In addition, irrigation provided yield gains in the two future scenarios of 13% and 14% for B1 and B2, respectively. Based on the results obtained, central pivot irrigation proved economically viable in the simulated climatic conditions. Therefore, the increase in sugarcane production provided by irrigation in agronomic management was sufficient to make investment in the region in question feasible. It is suggested to repeat the study in other regions, since the existing synergy between the factors that define agricultural yield can change the decision making about the implantation of irrigation systems in the production environment.

scholarly journals SELECTION OF EUCALYPTUS CLONES AND ADJUSTMENT OF POTASSIUM DOSES FOR EXTENDED DROUGHT IN BAHIA SAVANNA

2016 ◽  
Vol 40 (6) ◽  
pp. 1031-1039 ◽  
Author(s):  
Thalita Fernanda Sampaio ◽  
Tiago Elias Dalcin ◽  
Julio Cesar Bogiani ◽  
Edson Seizo Mori ◽  
Iraê Amaral Guerrini
Keyword(s):  
Water Stress ◽  
Experimental Design ◽  
Water Deficit ◽  
Water Use ◽  
Water Loss ◽  
Energy Production ◽  
Climate Conditions ◽  
Trunk Diameter ◽  
Opening And Closing ◽  
Selection Of

ABSTRACT The use of clones adapted to regions with water deficit caused by well-defined and prolonged dry periods, as happens in the western part Bahia, is a way to overcome water stress. The adjustment of potassium (K) also influences this aspect, because it regulates the opening and closing of stomata, impeding water loss by plants and making them more efficient in water use. Therefore, the aim of this study was to evaluate the performance of eucalyptus clones grown for energy production in response to potassium levels in soil and climate conditions, in the municipality of Luis Eduardo Magalhães, located in western Bahia state. A randomized block with four replications in a split plot was used as experimental design. Six eucalyptus clones (AEC-056, CEA-144, CEA-220, CEA-224, CEA-103 and CEA-1528) and four doses of K2O (0, 30, 60 and 120 kg ha-1) were tested. At two years old, clone 1528 showed greatest productivity, with the tallest height and trunk diameter, while 056 showed the lowest performance. Different K requirements were observed among eucalyptus clones for both growth and productivity.

scholarly journals Application of Sulfentrazone in Stages of Germination of IAC 90 Cassava Cuttings in Clay Soils and Sandy

2015 ◽  
Vol 33 (2) ◽  
pp. 305-314
Author(s):  
J.S. Zimmer ◽  
S.D. Ferreira ◽  
J.R. Ramella ◽  
A.C.P. Rodrigues-Costa ◽  
N.V. Costa
Keyword(s):  
Experimental Design ◽  
Clayey Soil ◽  
Sandy Soils ◽  
Development Stage ◽  
Clay Soils ◽  
Initial Growth ◽  
Initial Development ◽  
The Third ◽  
Productive Potential

Weeds interfere dramatically in the productive potential of cassava; however, information regarding herbicides that are selective to crops is still scarce. Thus, the aim in this study was to assess the initial growth of IAC 90 cassava plants after the application of sulfentrazone at different stages of germination of cassava in clayey and sandy soils. Three experiments were simultaneously deployed: the first experiment consisted in the application of sulfentrazone in the non-germinated stage of cassava cuttings; the second one in the stage of germinated cassavas cuttings (0.9 cm shoots); and the third one in applications in the stage of cassava cuttings with buds emerging (6.5 cm shoots and emerging from the soil). For each experiment the experimental design in randomized blocks was used in the 2 x 5 factorial arrangement with four replications. The factors were composed of two soils (sandy and clayey) and five doses of sulfentrazone (0, 250, 500, 750 and 1,000 g ha-1). It was found that depending on the herbicide dose, development stage of the buds of cassava cuttings and the type of soil, damage can occur in the initial development of the IAC 90 cassava plants. The greatest potential of sulfentrazone selectivity has occurred in applications in the non-germinated cassava cuttings stage and in doses lower than 500 g ha-1 in the clayey soil.

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