scholarly journals Characteristic of Silica Level (SiO3) Resulted from the Extraction of Rice Husk Ash with KOH Solvent towards the Amount of Heating Time

2018 ◽  
Vol 7 (3.36) ◽  
pp. 143
Author(s):  
Riza Wirawan ◽  
Himawan Hadi Sutrisno ◽  
Desi Ambarwati ◽  
Andralisa Febriani

Silica is widely available in nature including the ones in the form of crystal granule, gel and colloid. Silica is known to have a higher boiling point than other materials. The production of silica gel from rice husk ash has a characteristic in the amount of silicone level which depends on its heating time during extraction. This research aims at increasing production of silicone element in rice husk ash extraction method using kalium hydroxide (KOH), with heating time variation during its solution, namely between 15, 30, 45 and 60 minutes. With an observation using EDS, the relationship of heating time toward the silicone level on the resulted material can be discovered. The 15-minute heating time contains the highest silicone level compared to the 30, 45 or even 60-minute heating time. 

1971 ◽  
Vol 54 (4) ◽  
pp. 870-873
Author(s):  
Walter A Pons

Abstract A reflectance fluorodensitometer employing illumination of chromatograms with longwave UV light at 45° angles to the plate surface and measurement of reflected fluorescence at 90° was found to be suitable for measuring aflatoxins on silica gel-coated thin layer plates. The relationship of peak area vs. concentration was linear for 1–20 ng aflatoxins B1 and G1/ spot. Degradation of aflatoxins was slight. Five repetitive scans of the same chromatogram containing 5 ng each of B1 and G1 reduced the recorded areas an average of 1% per scan. Consecutive scans of 8 identical standard chromatograms containing 5 ng each of B1 and G1 and 1.5 ng each of B2 and G2 showed a reproducibility, as measured by coefficients of variation, of ±4–5% (B1 and G1) and ±5–9% (B2 and G2), representing the combined errors of standard application, TLC development, and scanning. Analysis of aflatoxins in purified sample extracts from 6 contaminated oilseed meals, 3–500 μg afla toxins/kg, in which the same TLC plates were scanned by a transmission densitometer and the reflectance densitometer yielded essentially equivalent values.


2013 ◽  
Vol 712-715 ◽  
pp. 858-864
Author(s):  
Yong Hong Wang ◽  
Xi Ming Tan ◽  
Xiong Jun He ◽  
Li Wu ◽  
Bo Dong ◽  
...  

The temperature has been reduced in the aggregate heating, mixing, transportation and paving for Warm mix asphalt mixture (WMA),but the temperature of hot mix mixes has no diversification. So the mixing ratio of warm mix asphalt mixed material cannot be completely designed to the HMA and it should be designed by the mixing ratio of WMA. Through analyzing the relationship of aggregate moisture content and getting the performance of the allowed moisture . Combining with the principle of conservation of energy and laboratory to get the conclusion of the aggregate heating time and heating temperature, in order to calculate the construction control parameters, and it will promote the application of asphalt pavement in the construction.


Author(s):  
Mohamed Nabil ◽  
Ashraf Essa ◽  
Magdy Mahmoud ◽  
Mohamed Rabah

The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA), and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a replacement of the cement with rice husk ash and slag combined with chemical activator. NaOH, Ca(OH)2, and KOH were used in varying weights and molar concentrations. Partial replacement of cement was tested for its consistency, setting time, flow, compressive strength, and fire. The consistency and setting time of the Partial Z-Cement (Zero cement) paste increase with increasing RHA content. The replacement of cement mortar achieves a compressive strength of 22–25MPa at  28 days with 5% NaOH or at 2.5or non used activator molar concentrations. The tested slabs were made of concrete and reinforced with bars with 10 mm diameter having and compressive strength evaluated from the compressive tests. The analysis of the slab deflection behavior has been presented after fire of samples. The results show the different character of the load-deflection relationship of a replacement of the cement with rice husk ash and slag reinforced slabs compared to traditionally reinforced slabs.  


2019 ◽  
Vol 1402 ◽  
pp. 044052
Author(s):  
H H Sutrisno ◽  
R Wirawan ◽  
A Febriani ◽  
D Ambarwati
Keyword(s):  

2014 ◽  
Vol 1025-1026 ◽  
pp. 574-579 ◽  
Author(s):  
Nuchanaporn Pijarn ◽  
Pichit Galajak

Silica gel is the chemical substance that has many good advantages such as absorbed moisture, porosity, small diameter, high surface area, and lightweight. It was synthesized by using rice husk ash via sol – gel heating in the microwave technique. The objectives in this work compose of synthesis silica gel by using the microwave technique before characterizatization. This raw material was archived from rice husk ash, obtained from agricultural waste. The silica gel, synthesized by conventional method (CVM) and commercial silica gel (COM), was also studied for comparison purposes. The results showed that successfully synthesized the silica gel by sol - gel technique using microwave. The XRD pattern of silica gel enhanced from this method was not sinificantly different as compared with CVM and COM methods. And the physical properties of this technique could be debated. The particle size of silca gel was determined by zetasizer and it was approxmately 50-70 nm. The pore size diameter, pore volume, and specific surface area of silica gel were calculated by Flowsorb II and a Quantachrome Autosorp-1. The pore size diameter, pore volume, and specific surface area of silica gel are 10-30 nm, 0.7-1.0 cm3/g, and 400-700 m2/g, respectively. Consequently, this work is considered to be the waste to make useful, and a great way to save energy and time in the silica gel synthesis.


2016 ◽  
Vol 16 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Nawarat Piladaeng ◽  
Niwat Angkawisittpan ◽  
Sahalaph Homwuttiwong

Abstract This paper deals with an investigation of the dielectric properties of concretes that includes rice husk ash using a planar coaxial probe. The planar coaxial probe has a planar structure with a microstrip and coaxial features. The measurement was performed over the frequency range of 0.5-3.5 GHz, and concrete specimens with different percentages of rice husk ash were tested. The results indicated that the dielectric constant of the concretes was inversely proportional to the frequency, while the conductivity was proportional to the frequency. The dielectric constant decreased with the increasing age of the concrete at the frequency of 1 GHz. The conductivity of the concrete decreased with the increasing age of the concrete at the frequency of 3.2 GHz. In addition, the dielectric constant and the conductivity decreased when the compressive strength increased. It was also shown that the obtained dielectric properties of the concrete could be used to investigate the relationship between the compressive strength and age of the concrete. Moreover, there is an opportunity to apply the proposed probe to determine the dielectric properties of other materials.


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