scholarly journals Rice Husk Ash Pozzolan as Valuable Supplement in Concrete for Industrial and Domestic Applications

2019 ◽  
pp. 1-7
Author(s):  
A. E. Duke ◽  
E. E. Eno
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Coarse Grain ◽  
Test Machine ◽  
Particle Sizes ◽  
Rice Husks ◽  
Average Strength ◽  
Controlled Burning

Controlled burning of rice husks at<700°C produced rice husk ash (RHA) which is predominantly amorphous silica (SiO2). RHA was used as a substitute for laterite and cement in proportions of 5%, 10%, 15%, 20%, 25% and 30% of concrete. The concrete was cured for 7 days, 14 days, 21 days, and 28 days respectively. It was observed that 20% of RHA provides the optimum strength. The effects of different particle sizes of 75, 150, 212, 300, 425 and 600 microns (µm) were tested using a compression test machine. A graph of average strength against particle size indicates 2.9 Nm-2 as the optimum strength at 75 µm and 1.2 Nm-2 as the minimum at 150 µm. From the ash size distribution, the presence of grains of several different sizes was observed. The grains were weighed using a weighing machine and a graph of particle size against percentage plotted to determine the particle size distribution. This showed that rice husk ash (RHA) is coarse grain material.

scholarly journals PENGARUH pH LARUTAN DAN UKURAN PARTIKEL ABU SEKAM PADI TERHADAP PENURUNAN KADAR CONGO RED

Molekul ◽  
2007 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
Tien Setyaningtyas ◽  
Uyi Sulaeman
Keyword(s):  
Particle Size ◽  
Rice Husk ◽  
Congo Red ◽  
Contact Time ◽  
Adsorption Process ◽  
Rice Husk Ash ◽  
Raw Material ◽  
Particle Sizes

Rice husk used as a raw material to produce the rice husk ash. The purpose of this research were to determine the optimum contact time and maximum pH of congo red adsorption by rice husk ash, to find out the influence of particle size to adsorption The rice husk was washed, then soaked in HCl 3.84 M to remove mineral impurities, and it was dried and heated for four hours at the temperature 6000 C. The yield gained from this research is 23.44%. Optimum contact time started at after five minutes and maximum pH is six for the tree mention particle sizes 50, 100 and 140 mesh. Particle size didn’t give any significant effect to adsorption process with percent decreasing of congo red is 84.97 %, 90.39 %, 89.32 % respectively.

Effect of Rice Husk Particle Size on Tensile and Density of Recycled PPVC Composite

2013 ◽  
Vol 812 ◽  
pp. 145-150 ◽  
Author(s):  
Azizul Rahman Farah Nordyana ◽  
Ahmad Zafir Romli ◽  
Mohd Hanafiah Abidin
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Rice Husk ◽  
Filler Loading ◽  
Particle Sizes ◽  
Hot Press ◽  
Rice Husks ◽  
Elongation At Break ◽  
Density Result

This study is to measure the effect of various rice husks particle size on density, tensile strength, Youngs modulus and elongation at break of PPVC composite. Rice husk was grind before being sieved to particle sizes of 60 μm, 60 μm < particle size 80 μm, and 80 μm < particle size 100μm. Each size was compounded with PPVC at same filler loading which is 20 % rice husk and being pressed using hot press machine. Tensile strength, Youngs modulus and elongation at break increased as particle size increases. The highest value for tensile strength, Youngs modulus and elongation at break are 21.48 MPa, 1344.88 MPa and 2.29 % respectively. However, it is different for density result which decreased as particle size increases. The results obtained from the study shows that the bigger the size of the rice husks, the better the composite tensile properties.

scholarly journals On microphysical processes of noctilucent clouds (NLC): observations and modeling of mean and width of the particle size-distribution

2010 ◽  
Vol 10 (2) ◽  
pp. 3605-3625
Author(s):  
G. Baumgarten ◽  
J. Fiedler ◽  
M. Rapp
Keyword(s):  
Particle Size ◽  
Linear Relationship ◽  
Size Distribution ◽  
Eddy Diffusion ◽  
Particle Sizes ◽  
Noctilucent Clouds ◽  
Atmospheric Variability ◽  
Distribution Width ◽  
Particle Properties ◽  
Microphysical Processes

Abstract. Noctilucent clouds (NLC) in the polar summer mesopause region have been observed in Norway (69° N, 16° E) between 1998 and 2009 by 3-color lidar technique. Assuming a mono-modal Gaussian size distribution we deduce mean and width of the particle sizes throughout the clouds. We observe a quasi linear relationship between distribution width and mean of the particle size at the top of the clouds and a deviation from this behavior for particle sizes larger than 40 nm, most often in the lower part of the layer. The vertically integrated particle properties show that 65% of the data follows the linear relationship with a slope of 0.42±0.02. For the vertically resolved particle properties (Δz=0.15 km) the slope is smaller and only 0.39±0.03. We compare our observations to microphysical modeling of noctilucent clouds and find that the distribution width depends on turbulence, the time that turbulence can act (cloud age), and the sampling volume/time (atmospheric variability). The model results nicely reproduce the measurements and show that the observed slope can be explained by eddy diffusion profiles as observed from rocket measurements.

scholarly journals PRODUCTION OF SODIUM SILICATE FROM RICE HUSK ASH WITH REGULATORY SETS MAGNESIUM

Tibuana ◽  
2020 ◽  
Vol 3 (01) ◽  
pp. 47-52
Author(s):  
Yanatra budi Pramana ◽  
M. Amin Pahlevi ◽  
Zhulianto Ashari ◽  
M. Fariz Effendi ◽  
Fibra Gilang Ramadhan
Keyword(s):  
Sodium Silicate ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Silica Content ◽  
Cosmetic Products ◽  
Rice Husks ◽  
Mg Addition ◽  
Increase Silica Content

Utilization of rice husks in Indonesia in general is still very limited. Utilization of silica contained in rice husk ash, which has been used, among others, in the manufacture of sodium silicate. Silica compounds themselves can be used in and manufacturing basic materials for electronic and ceramic equipment, glass, rubber, cosmetic products, and pharmaceuticals. The addition of Mg can increase the silica content (SiO2) in rice husk ash. The best results show an effective Mg ratio of Mg addition to increase silica content is 1: 1. produces the highest amount of silica which is 58.12% of the rice husk ash with a size of 140 mesh

scholarly journals MINERAL ABUNDANCE AND PARTICLE SIZE DISTRIBUTION DERIVED FROM IN-SITU SPECTRA MEASUREMENTS OF YUTU ROVER OF CHANG’E-3

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 85-89
Author(s):  
H. Lin ◽  
X. Zhang ◽  
Y. Yang ◽  
X. Wu ◽  
D. Guo
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Landing Site ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Particle Sizes ◽  
The Mean ◽  
The Difference ◽  
Yutu Rover

From geologic perspective, understanding the types, abundance, and size distributions of minerals allows us to address what geologic processes have been active on the lunar and planetary surface. The imaging spectrometer which was carried by the Yutu Rover of Chinese Chang’E-3 mission collected the reflectance at four different sites at the height of ~&amp;thinsp;1&amp;thinsp;m, providing a new insight to understand the lunar surface. The mineral composition and Particle Size Distribution (PSD) of these four sites were derived in this study using a Radiative Transfer Model (RTM) and Sparse Unmixing (SU) algorithm. The endmembers used were clinopyroxene, orthopyroxene, olivine, plagioclase and agglutinate collected from the lunar sample spectral dataset in RELAB. The results show that the agglutinate, clinopyroxene and olivine are the dominant minerals around the landing site. In location Node E, the abundance of agglutinate can reach up to 70&amp;thinsp;%, and the abundances of clinopyroxene and olivine are around 10&amp;thinsp;%. The mean particle sizes and the deviations of these endmembers were retrieved. PSDs of all these endmembers are close to normal distribution, and differences exist in the mean particle sizes, indicating the difference of space weathering rate of these endmembers.

scholarly journals Optimization of nanostructured/nano sized rice husk ash preparation

2020 ◽  
Vol 17 (3(Suppl.)) ◽  
pp. 0953
Author(s):  
Medhat Mostafa ◽  
Hamdy Salah ◽  
Amro B. Saddek ◽  
Nabila Shehata
Keyword(s):  
Particle Size ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Particle Shape ◽  
Rice Husk Ash ◽  
Loss On Ignition ◽  
Shape Distribution ◽  
Disk Mill ◽  
Grinding Time

The objective of the study is developing a procedure for production and characterization of rice husk ash (RHA). The effects of rice husk (RH) amount, burning/cooling conditions combined with stirring on producing of RHA with amorphous silica, highest SiO2, lowest loss on ignition (LOI), uniform particle shape distribution and nano structured size have been studied. It is concluded that the best amount is 20 g RH in 125 ml evaporating dish Porcelain with burning for 2 h at temperature 700 °C combined with cooling three times during burning to produce RHA with amorphous silica, SiO2 90.78% and LOI 1.73%. On the other hand, cooling and stirring times affect the variation of nano structured size and particle shape distribution. However, no crystalline phases were found in RHA in all cases. Results proved that the Attritor ball mill was more suitable than vibration disk mill for pulverizing nano structured RHA with 50% of particle size (D50) lower than 45 mm and 99 % of particle size (D99) lower than 144 mm to nanosized RHA with D50 lower than 36 nm and D99 lower than 57 nm by grinding time 8.16 min to every 1 g RHA without changes in morphousity of silica.

Effects of vegetation cover on sediment particle size distribution and transport processes in natural rainfall conditions on post-fire hillslope plots in South Korea

Soil Research ◽  
2016 ◽  
Vol 54 (8) ◽  
pp. 937 ◽  
Author(s):  
Ewane Basil Ewane ◽  
Heon-Ho Lee
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Vegetation Cover ◽  
Rainfall Intensity ◽  
Transport Processes ◽  
Vegetation Recovery ◽  
Particle Sizes ◽  
Sediment Size ◽  
Aggregate Breakdown ◽  
Soil Burn Severity

Sediments were collected from four slow vegetation recovery plots, six fast vegetation recovery plots and five unburned plots at a post-fire site on a rainfall event basis and sorted for size distribution. The aim was to evaluate the effects of vegetation cover, soil aggregate stability, slope and rainfall intensity on sediment size distribution, transport selectivity and erosion processes between the burned and unburned treatment plots. Sediment detachment and transport mechanisms and the particle size transport selectivity of the eroded sediment were assessed based on enrichment ratios (ER) and mean weighted diameter (MWD) methods. The most eroded particle size class in all treatment plots was the 125–250μm class and, generally, the percentage of eroded particle sizes did not increase with slope and rainfall intensity. Higher MWD of the eroded sediment was related to a higher percentage of bare soil exposed and gravel content associated with high soil burn severity and soil disaggregation in the slow vegetation recovery plots. The enrichment of finer clay silt particle sizes increased with varying maximum 30-min rainfall intensity (I30) in the slow vegetation recovery plots, and reflected increased aggregate breakdown and transport selectivity, whereas no good relationship was found in the fast vegetation recovery and unburned plots with varying I30. A minimum I30 of <3.56mmh–1 and a maximum of 10.9mmh–1 were found to be the threshold rainfall intensity values necessary for aggregate breakdown and transport of finer particles by both rainsplash and rainflow in the slow vegetation recovery plots, whereas the response was weak in the fast vegetation recovery and unburned plots following varying I30 dominated only by rainsplash transport closer to the plot sediment collector. The results show that higher vegetation cover in the fast vegetation recovery and unburned plots reduces erosive rainfall energy by 5.6- and 17.7-fold respectively, and runoff energy by 6.3- and 21.3-fold respectively, limiting aggregate breakdown and transport selectivity of finer particles compared with the slow vegetation recovery plots.

scholarly journals Streaming instability of multiple particle species in protoplanetary disks

2018 ◽  
Vol 618 ◽  
pp. A75 ◽  
Author(s):  
Noemi Schaffer ◽  
Chao-Chin Yang ◽  
Anders Johansen
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Protoplanetary Disks ◽  
Single Species ◽  
Stokes Number ◽  
Dust Particles ◽  
Particle Sizes ◽  
Particle Species ◽  
Streaming Instability ◽  
Large Particles

The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10−1−100, one where τs = 10−4−10−1, and finally one where τs = 10−3−100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we find in our multispecies simulations that different particle sizes interact via the gas and as a result their dynamics changes compared to the single-species case. The larger species trigger the streaming instability and create turbulence that drives the diffusion of the solid materials. We measured the radial equilibrium velocity of the system and find that the radial drift velocity of the large particles is reduced in the multispecies simulations and that the small particle species move on average outwards. We also varied the steepness of the size distribution, such that the exponent of the solid number density distribution, dN∕da ∝ a−q, is either q = 3 or q = 4. Overall, we find that the steepness of the size distribution and the discrete versus continuous approach have little impact on the results. The level of diffusion and drift rates are mainly dictated by the range of particle sizes. We measured the scale height of the particles and observe that small grains are stirred up well above the sedimented midplane layer where the large particles reside. Our measured diffusion and drift parameters can be used in coagulation models for planet formation as well as to understand relative mixing of the components of primitive meteorites (matrix, chondrules and CAIs) prior to inclusion in their parent bodies.

scholarly journals Particle size distribution of sawdust and wood shavings mixtures

2010 ◽  
Vol 56 (No. 4) ◽  
pp. 154-158 ◽  
Author(s):  
T. Vítěz ◽  
P. Trávníček
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Distribution Function ◽  
Network Analysis ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Mass Fraction ◽  
Particle Sizes ◽  
Wood Shavings ◽  
Number Of Particles

Particle size distribution of the sample of waste sawdust and wood shavings mixtures were made with two commonly used methods of mathematical models by Rosin-Rammler (RR model) and by Gates-Gaudin-Schuhmann (GGS model).On the basis of network analysis distribution function F (d) (mass fraction) and density function f (d) (number of particles captured between two screens) were obtained. Experimental data were evaluated using the RR model and GGS model, both models were compared. Better results were achieved with GGS model, which leads to a more accurate separation of the different particle sizes in order to obtain a better industrial profit of the material.

scholarly journals Hydrochloric Acid Pretreatment of Different Types of Rice Husk Ash Influence on the Properties of Cement Paste

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1524 ◽  
Author(s):  
Jing Liu ◽  
Chunyan Xie ◽  
Chao Fu ◽  
Xiuli Wei ◽  
Dake Wu
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Cement Paste ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Control Sample ◽  
Control Group ◽  
Rice Husks ◽  
Acid Pretreatment ◽  
Blank Control Group

When properly processed, rice husk ash (RHA) comprises a large amount of SiO2, which exhibits a high pozzolanic activity and acts as a good building filler. In this paper, the effects of rice husk ash content, acid pretreatment, and production regions on the compressive and flexural properties and water absorption of a cement paste were studied. The experimental results showed that the compressive strength of the rice husk ash was the highest with a 10% content level, which was about 16.22% higher than that of the control sample. The rice husk after acid pretreatment displayed a higher strength than that of the sample without the acid treatment, and the rice husk from the Inner Mongolia region indicated a higher strength than that from the Guangdong province. However, the flexural strength of each group was not significantly different from that of the blank control group. The trend observed for the water absorption was similar to that of the compressive strength. The variation in the RHA proportions had the greatest influence on the properties of the paste specimens, followed by the acid pretreatments of the rice husks. The production regions of the rice husks indicated the least influence.

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