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Study of the Effect of Various Fillers on the Properties of Epoxy Oligomers
Issue:
Volume 9, Issue 4, December 2021
Pages:
73-76
Received:
9 September 2021
Accepted:
26 September 2021
Published:
23 November 2021
Abstract: The shell of eggs, kaolin and fiberglass epoxy oligomers and fillers were taken as the object of research and compositions based on them were prepared, the physical and mechanical properties of the composition were studied using the most modern research methods. properties were determined by conducting several tests (tensile, bending, composite density, water absorption, hardness). Epoxy-based compositions were prepared and their properties were studied using various fillers. For this purpose, polyethylene polyamine ED-20 brand epoxy oligomer and its hardener were used. In scientific research, the effect of various fillers on the properties of epoxy resin has been studied experimentally. The dependence of the composition of the insoluble part of ENO on the drying time at a temperature of 110°C - 150°C was determined. It was found that the inclusion of fillers in the composite material greatly affects the mechanical properties. Thus, in a certain mass fraction of kaolin and eggshell powder, the adhesion strength increased, but the subsequent increase in the amount of fillers decreased. In general, it can be noted that the tensile strength of unmodified epoxy resin is higher than the strength of epoxy compositions, and the modulus of elasticity is lower. This indicates that the addition of filler to the epoxy resin and glass / epoxy resin reduced the tensile strength and increased the modulus of elasticity. The result allows the buoy to be used in industry.
Abstract: The shell of eggs, kaolin and fiberglass epoxy oligomers and fillers were taken as the object of research and compositions based on them were prepared, the physical and mechanical properties of the composition were studied using the most modern research methods. properties were determined by conducting several tests (tensile, bending, composite den...
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Effect of Different Source and Rates of Biochar Application on Selected Physic-Chemical Properties of Acidic Soil in Western Ethiopia
Issue:
Volume 9, Issue 4, December 2021
Pages:
77-82
Received:
29 October 2021
Accepted:
17 November 2021
Published:
24 November 2021
Abstract: Soil acidity is the serious problem in the western Ethiopia. Therefore the aim of this experiment was to study the effect of different source and rates of biochar application on the selected physic chemical properties of acidic soil. The experiment involved factorial combinations of three sources biochar (maize, sesame and soybean) and five rates of biochar (0, 2, 4, 6, 8 and 10 t ha−1) laid out in randomized complete block design with three replications. Soil samples were collected at a depth of 0–15 cm and the selected physic chemical properties of acidic soil were analyzed by standard laboratory procedure. The result indicated that the maximum mean of soil moisture (4.3) was recorded at 8 t ha−1 of soybean biochar and all soil treated biochar were sandy clay textural class except at sesame source at 10 t ha-1 results sandy loam. They also maximum Electrical conductivity (0.087), soil pH (H2O) (6.81), organic carbon (2.96%), organic matter (5.10), total nitrogen (0.25%), Available K+ (23.17) Available P (13.96), calcium (8.19) and base saturation percentage (79.53) were recorded from sesame source with 10 tha-1 rates but the maximum cation exchange capacity (27.18) and potassium (2.38) where recorded at from maize source at 6 t ha-1rates of biochar while the maximum magnesium and sodium where recorded from the sesame source at 8t ha-1 rates. The result indicates that the sesame source of biochar application with the rates of 10 t ha-1 were significantly improved the physical and chemical properties of acidic soil but additional research work were needed regarding to integrated management of soil acidity is different location and different Agro-ecology.
Abstract: Soil acidity is the serious problem in the western Ethiopia. Therefore the aim of this experiment was to study the effect of different source and rates of biochar application on the selected physic chemical properties of acidic soil. The experiment involved factorial combinations of three sources biochar (maize, sesame and soybean) and five rates o...
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The Effect of N, P, K, and Si Fertilizers on pH, P-available, P-uptake and Black Rice Yield (Oryza sativa L. indica) on Dryland Inceptisols
Anni Yuniarti,
Marenda Ishak Sonjaya Sule,
Dirga Sapta Sara,
Hafizh Naufal Suryandani
Issue:
Volume 9, Issue 4, December 2021
Pages:
83-87
Received:
2 July 2021
Accepted:
27 July 2021
Published:
27 November 2021
Abstract: Black rice is a type of rice variety found in Indonesia and is well-known as a functional food with a high anthocyanin content which beneficial for those who consume it. Dryland has the potential to support growth of black rice plants, because it has a wide distribution in Indonesia, but has problems with soil fertility such as soil pH and low availability of P nutrients. The problem in dryland requires proper handling, one of which is by using N, P, K, and Si fertilizers. This study aims to determine the effect of N, P, K, and Si fertilizers on pH, P-available, P uptake, and yield of black rice (Oryza sativa L. indica) on dryland Inceptisols. This research was conducted from November 2020 to March 2021 at Soil Fertility and Plant Nutrition Research Area, Faculty of Agriculture, Padjadjaran University, Sumedang district, West Java and the analysis process at the Laboratory of Soil Chemistry and Plant Nutrition, Department of Soil and Land Resources Sciences, Faculty of Agriculture, Padjadjaran University. The experimental design was carried out using a randomized block design consisting of eight treatments with four replications. The doses of N, P, K fertilizers used were ¾ and 1 (Urea 300 kg ha-1, SP-36 50 kg ha-1, and KCl 50 kg ha-1) and the doses of silica fertilizer used were 2, 1½, and 1 (2 mL L-1). The results showed that the combination of fertilizer with a dose of 1 N, P, K followed by 1 silica gave the highest yield of black rice on dryland as much as 77.78 g plant-1 or equivalent to 10.58 t ha-1.
Abstract: Black rice is a type of rice variety found in Indonesia and is well-known as a functional food with a high anthocyanin content which beneficial for those who consume it. Dryland has the potential to support growth of black rice plants, because it has a wide distribution in Indonesia, but has problems with soil fertility such as soil pH and low avai...
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On the Formation Mechanism of Indigo Blue and Indigo Red from Vegetable Source
Francisco Sánchez-Viesca,
Reina Gómez
Issue:
Volume 9, Issue 4, December 2021
Pages:
88-91
Received:
10 November 2021
Accepted:
27 November 2021
Published:
7 December 2021
Abstract: In this communication a series of ionic reactions is advanced in order to explain not only indigo blue formation but also the continuous presence of indigo red as companion, and why this compound is always found in minority. Indican is the glycoside found in Indigofera tinctoria from which the mixture of indigo blue and indigo red is obtained by means of air oxidation in alkaline medium. A reaction mechanism for the hydrolysis of indican, which was advanced decades ago, is criticized in this paper. Fifty years ago a radical mechanism was suggested for indigo formation. However, the supposed reactive species, indoxyl radical, was not detected by electron spin resonance. Besides, there is no free radical promoter, and indirubin (indigo red) was not considered. A series of ionic reactions explain the formation of both indigoids, and why indigo red occurs in minor proportion. Indoxyl, 3-hydroxyindole, is the aglycone from indican. Reaction of indoxyl with oxygen is catalyzed by calcium hydroxide, indoxyl hydroperoxide being formed. Internal reaction in this intermediate produces 3-oxo-indolenine, which reacts with indoxyl carbanion to give leucoindigo. Further steps lead to indigo blue. Indirubin is formed from indoxyl hydroperoxide by dehydration to isatin, a keto lactam. Condensation of isatin salt with 3-indolinone affords indigo red. This step is retarded due to electric hindrance.
Abstract: In this communication a series of ionic reactions is advanced in order to explain not only indigo blue formation but also the continuous presence of indigo red as companion, and why this compound is always found in minority. Indican is the glycoside found in Indigofera tinctoria from which the mixture of indigo blue and indigo red is obtained by me...
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