scholarly journals Alkalinity–silicon ratio as an assessment factor for the efficiency of silicate slags in wetland rice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thoppil Sreenivasan Sandhya ◽  
Nagabovanalli Basavarajappa Prakash
Keyword(s):  
Silicon Content ◽  
Chemical Properties ◽  
Magnesium Content ◽  
Wetland Rice ◽  
Agronomic Efficiency ◽  
Economic Production ◽  
Incubation Experiments ◽  
Calcium And Magnesium ◽  
Si Content ◽  
Assessment Factor

AbstractSilicate slags are one of the most widely used silicon (Si) source in agriculture. Even though the agronomic significance of slags has been demonstrated in several crops, only a few attempts were made to evaluate these Si sources based on their chemical composition. The main objective of this study was to characterize different silicate slags based on their chemical properties and to explore the effect of these chemical properties on the yield, and Si uptake in wetland rice, and dissolution of Si into the soil. Slags were characterised for pH, calcium and magnesium content (alkalinity, A), silicon content, 5 day Na2CO3 + NH4NO3 extractable Si content, and alkalinity to Si ratio (A/Si). Greenhouse and incubation experiments were also conducted using different silicate slags and wollastonite applied at the rate of 300 kg Si ha−1. Slags with A/Si < 3 were found to be ideal Si sources for the economic production of wetland rice and found consistent in increasing soil Si content and rice Si uptake. We conclude that the A/Si ratio of slags can be used as an important parameter to assess the agronomic efficiency of silicate slags in wetland rice.

scholarly journals THE CALCIUM AND MAGNESIUM CONTENT OF NORMAL URINE

1916 ◽  
Vol 28 (1) ◽  
pp. 237-240
Author(s):  
C.Ferdinand Nelson ◽  
W.E. Burns
Keyword(s):  
Magnesium Content ◽  
Calcium And Magnesium ◽  
Normal Urine

scholarly journals Effect of termite activity on soil under different land management strategies

2017 ◽  
Vol 38 (1) ◽  
pp. 143
Author(s):  
Liane Barreto Alves Pinheiro ◽  
Rodrigo Camara ◽  
Marcos Gervasio Pereira ◽  
Eduardo Lima ◽  
Maria Elizabeth Fernandes Correia ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Management Strategies ◽  
Chemical Properties ◽  
Clay Content ◽  
Exchange Capacity ◽  
Termite Mounds ◽  
Eucalyptus Plantation ◽  
Exchangeable Acidity ◽  
Calcium And Magnesium ◽  
Surrounding Soil

Mound-building termites are important agents of soil bioperturbation, but these species have not been extensively studied thus far. The present study aimed to evaluate the soil particle-size and the chemical attributes of termite mounds and the surrounding soil under different land use strategies. A one-hectare plot was defined for an unmanaged degraded pasture, planted pasture, and for a eucalyptus Corymbia citriodora plantation. In each plot, the top, center, and base sections of five Cornitermes cumulans mounds, and the surrounding soil at the depths of 0-5; 5-10; 10-20 cm, were sampled in the Pinheiral, Rio de Janeiro state. In the three areas, the center of the mounds contained higher clay content, organic carbon, phosphorous, calcium and magnesium, total bases, and cation exchangeable capacity, when compared to the top, base, and the surrounding soils. However, the center had lower values of exchangeable acidity and potassium, of the three areas. In the eucalyptus plantation, the values of pH, total bases, calcium, and magnesium were lower, whereas aluminum, exchangeable acidity, sodium, and cation exchange capacity were higher both in the mounds and in the surrounding soil, in relation to the pastures. There were no differences among the three areas in terms of organic carbon, potassium, phosphorous, and total bases, in the mounds and adjacent soil. Thus, the termite activity altered the clay content and most of the soil chemical properties in all of the studied areas, but only for the center of the mounds. However, the effect of these organisms was different in the eucalyptus plantation in relation to the pasture areas.

The Silicon Content of Body Fluids

1982 ◽  
Vol 27 (1) ◽  
pp. 17-19 ◽  
Author(s):  
J. W. Dobbie ◽  
Mary J. B. Smith
Keyword(s):  
Comparative Study ◽  
Amniotic Fluid ◽  
Atomic Absorption ◽  
Absorption Spectroscopy ◽  
Pancreatic Juice ◽  
Atomic Absorption Spectroscopy ◽  
Silicon Content ◽  
Healthy Subjects ◽  
Clinical Procedures ◽  
Si Content

Samples of bile, pancreatic juice, cerebrospinal, pleural, peritoneal, synovial and amniotic fluid obtained from patients during routine clinical procedures were analysed for their silicon (Si) content by atomic absorption spectroscopy (AAS). Similar Si concentrations were found in each fluid, while these in turn were shown to be similar to the concentration of Si in the serum of 50 healthy subjects (mean serum Si 21.5 μmol/l, SD±4.5). The concentration of Si in 24-hour collections of urine from 50 healthy subjects was also determined (mean urinary Si 194 μmol/l, SD±94). A comparative study was made of serum Si levels in nine different species of domesticated animal.

scholarly journals Variation in Feedstock Wood Chemistry Strongly Influences Biochar Liming Potential

Soil Systems ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 26 ◽  
Author(s):  
Sossina Gezahegn ◽  
Mohini Sain ◽  
Sean Thomas
Keyword(s):  
Functional Group ◽  
Pyrolysis Temperature ◽  
Chemical Properties ◽  
Base Cation ◽  
Surface Functional Group ◽  
Wood Chemistry ◽  
Incubation Experiments ◽  
Phenolic Group ◽  
Capacity Data ◽  
Group Concentration

Chars intended for use as soil amendment (“biochars”) vary greatly in their chemical and physical properties. In the present study, 19 Canadian temperate wood feedstocks were charred across a range of pyrolysis temperatures from 300–700 °C. The resulting 95 biochars were tested for their physio-chemical properties and liming capacity. Data indicated increasing base cation concentrations including Ca, Mg, and K (elements that characteristically form liming compounds, i.e., carbonates) as pyrolysis temperature increased. Acidic surface functional groups were analyzed with modified Boehm titration: Carboxylic and lactonic functional group concentrations decreased and phenolic group concentration increased with pyrolysis temperature. Functional group composition also varied greatly with feedstock: In particular, conifer-derived biochars produced at pyrolysis temperatures <500 °C showed much higher carboxylic and lactonic functional group concentrations than did angiosperm-derived biochars. Liming capacity was assessed using soil incubation experiments and was positively related to biochar pH. Both acidic surface functional group concentration and nutrient element concentration influenced biochar pH: we developed a non-linear functional relationship that predicts biochar pH from the ratio of carboxylic to phenolic moieties, and concentrations of Ca and K. Biochar’s liming components that are inherited from feedstock and predictably modified by pyrolysis temperature provide a basis for optimizing the production of biochar with desired pH and liming characteristics.

Effect of Si, Sr Additions on Microstructure and Mechanical Properties of AZ91 Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 179-182
Author(s):  
S.B. Li ◽  
Zhi Wen Zou ◽  
Shou Mei Xiong
Keyword(s):  
Mechanical Properties ◽  
Silicon Content ◽  
Room Temperature ◽  
Chinese Script ◽  
Az91 Alloy ◽  
Permanent Mold ◽  
Remarkable Effect ◽  
Mg2si Phase ◽  
Β Phase ◽  
Si Content

In present work, Si and Sr elements were added into AZ91 alloy and cast directly into test samples using permanent mold. Mechanical properties of the samples at room temperature were evaluated by tensile test and the microstructure was analyzed. The results show that β-phase (Mg17Al12) of AZ91 alloy decreases with the addition of Si element and Mg2Si phase forms at the same time. Irregular Mg2Si phase precipitates preferentially at the grain boundaries at a low silicon content level. With the increase of the Si content, Mg2Si phase shows a complicated “Chinese- script” shape distributed at the grain boundary which leads to a lower ultimate tensile strength. Subsequently, the addition of Sr element has a remarkable effect on the form and distribution of Mg2Si phase of AZ91-Si alloys.

scholarly journals Silicon content in beers from Korean market and estimation of its alimentary uptake

2013 ◽  
Vol 31 (No. 4) ◽  
pp. 382-389 ◽  
Author(s):  
J.-H Lee ◽  
K.H. Choi ◽  
S.R. Park ◽  
S.A. Shin ◽  
S.A. Kang ◽  
...  
Keyword(s):  
Silicon Content ◽  
Unit Price ◽  
Men And Women ◽  
Si Content ◽  
Korean Market

Silicon content of Korean domestic beer was approximately 13.2 mg/l, which was 142% higher than 9.24 mg/l in imported beer. The contents of Ca and Mg were in the range of 31&ndash;33 mg/l and 39-41 mg/l, respectively, which were similar in Korean domestic and imported beers. Through beer ingestion, the men&rsquo;s average Si intake was approximately 24.3 mg/day, which was 195% higher than the women&rsquo;s average Si intake (12.4 mg/day). In addition, it was found that 20&ndash;29 aged men and women took approximately 33.7 and 25.1 mg/day of Si, respectively, which are higher Si intakes through beer ingestion as compared to other age ranges. As to people in other age-ranges, the women&rsquo;s Si intake through beer ingestion was half that of men&rsquo;s. Domestic beer-1 and beer-2 had 8.50 and 6.45 Si &mu;g/won of Si content per unit price, respectively. Taken together with these results, it was estimated that the more expensive the price of beer, the lower the Si content per unit price. Therefore, it is supposed that the cheap Korean domestic beer is an effective supplier of Si, the beer being considered the major resource for Si intake by humans inKorea. &nbsp;

scholarly journals Distribution of Available Silicon of Volcanic Ash Soils in Jeju Island

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Won-Pyo Park ◽  
Kwan-Cheol Song ◽  
Bon-Jun Koo ◽  
Hae-Nam Hyun
Keyword(s):  
Volcanic Ash ◽  
Chemical Properties ◽  
Jeju Island ◽  
A Value ◽  
Dissolved Silicon ◽  
Highly Correlated ◽  
Si Content ◽  
Pedogenic Processes ◽  
The Relationship ◽  
And Chemical Properties

In soils, dissolved silicon (Si) is adsorbed onto soil particles or is leached into groundwater through the soil profile. Andisols may play an important role in contributing to high dissolved Si concentrations in groundwater on Jeju Island, Korea. In this study, we evaluated the available Si content that potentially affects groundwater composition and investigated the relationship between the available Si content and chemical properties of volcanic ash soil on Jeju Island. We used the 1 M sodium acetate buffer (pH 4.0) to extract the available Si. Selected chemical properties were determined for 290 topsoil samples collected from different land sites throughout Jeju Island, and we analyzed the available Si content in the typifying pedons of Jeju Island and mainland Korea. The available Si content in Jeju Island topsoils ranged from 75 to 150 mg·kg−1, and the available Si content of Andisols in both orchards and grasslands was significantly higher than that of non-Andisols. The available Si content was highly correlated with the amounts of oxalate extractable Si, Al, and Fe in Andisols and was negatively related to the Alp/Alo ratio. With increasing elevation, we detected a decrease in the available Si and allophane content in Andisols, whereas Al-humus complexes increased with increasing elevation. The ratio of available Si in the lowest subsoil/topsoil increased to a value of 6.0, indicating that large amounts of available Si are present in the subsoil. The available Si content in the lowest subsoil of Andisols on Jeju Island was 10 times higher than that in the typifying pedons of the Korean mainland. In contrast, there were no differences in the available Si content between the topsoil and the subsoil of the typifying pedon series of Jeju and mainland non-Andisols because of differences in pedogenic processes. Collectively, our findings indicate that weathering of Andisols on Jeju Island potentially affects the Si concentration in groundwater.

The ameliorative effects of low-grade palygorskite on acidic soil

Soil Research ◽  
2020 ◽  
Vol 58 (4) ◽  
pp. 411
Author(s):  
Jin-Hua Yuan ◽  
Sheng-Zhe E ◽  
Zong-Xian Che
Keyword(s):  
Soil Ph ◽  
Cation Exchange Capacity ◽  
Soil Amendment ◽  
Acid Soil ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Acidic Soil ◽  
Low Grade ◽  
Incubation Experiments ◽  
Acid Neutralisation

Mineral composition and alkaline properties of palygorskite (Pal), and its ameliorative effects on chemical properties of acid soil were investigated. Dolomite was the main form of alkali in Pal and the acid neutralisation capacity of Pal was 215 cmol kg–1. Incubation experiments indicated that Pal incorporation increased soil pH, cation exchange capacity, base saturation and exchangeable K+, Na+, Ca2+ and Mg2+ contents, and decreased the levels of exchangeable H+, Al3+ and acidity, over a 1-year period. The ameliorative mechanisms were the dissolution of major alkaline matter in Pal (i.e. dolomite), and the exchange between released Ca2+ and Mg2+ with H+ in acidic soil. Hence, Pal can be used as a moderate acidic soil amendment.

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