scholarly journals Pengaruh Perbedaan Kondisi Hidrolisis Terhadap Hasil Isolasi Nanokristalin Selulosa Dari Bonggol Jagung

2017 ◽  
Vol 5 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Endah Purwanti ◽  
Sarah Dampang
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Molecular Hydrogen ◽  
Average Diameter ◽  
Nanocrystalline Cellulose ◽  
Diameter Range ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Cellulose is one of the largest components in corncobs. Cellulose was obtained from corncob in this research that has a yield of 19.6% of 20 grams of corncob powder. The isolated cellulose was characterized by using FTIR and SEM. Cellulose has crystalline chain and insoluble in water or organic solvents. The molecular chain of cellulose is linear and has intra- and inter-molecular hydrogen bonds. One way for cellulose to be easy in the treatment of applications, is to convert microcrystalline cellulose into nanocrystalline cellulose. Nanocrystalline cellulose can be obtained by several methods, one of them by acid hydrolysis. Hydrolysis of cellulose by using sulfuric acid produces nanocrystalline cellulose. Nanocrystalline cellulose can be characterized by using TEM and PSA analysis. CNC 60 has a particle size distribution with a diameter range of 14.3 nm - 45.0 nm and an average diameter of 17.4 nm. Whereas cellulose with CNC 90 has a smaller particle size distribution with a diameter range of 10.0 nm - 17.1 nm and an average diameter of 11.9 nm.

scholarly journals RESEARCH OF THE EJECTING PROPERTIES OF A POLYFRACTION BULK MATERIAL FLOW

2018 ◽  
Vol 3 (3) ◽  
pp. 46-51
Author(s):  
Евгений Попов ◽  
Evgeniy Popov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Material Flow ◽  
Bulk Material ◽  
Aerodynamic Resistance ◽  
Average Diameter ◽  
Resistance Coefficient ◽  
Free Falling ◽  
The Given

This work is aimed at confirming the adequacy of the probabilistic and statistical approach to determining the aerodynamic resistance coefficient of particles in a flow of the free falling polyfractional material, suggested by the author. The aerodynamic resistance coefficient of particles in a flow of falling material is defined by calculating the probability of finding particles out of air shadows of the neighboring particles. The laboratory experiment was performed on the offered experimental samples of bulk materials having different particle size distribution, but the identical average diameter of particles. The design of a laboratory experimental installation which allows determining the consumption of air, ejected by a polyfractional material flow, was described. The amount of the air, ejected with experimental samples, depends on their particle size distribution that confirms the insufficiency of describing the properties of bulk material only with the average diameter value. The given comparison of results of the analytical calculations with experimental data shows the reliability and adequacy of the calculated values.

Particle Size Distribution of SBR and NBR Latexes by UV-VIS Turbidimetry near the Rayleigh Region

1996 ◽  
Vol 69 (4) ◽  
pp. 696-712 ◽  
Author(s):  
Mario A. Llosent ◽  
Luis M. Gugliotta ◽  
Gregorio R. Meira
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Average Diameter ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Data Treatment ◽  
Distribution Shape ◽  
Soft Polymer ◽  
Styrene Butadiene

Abstract This paper deals with data treatment problems that arise when turbidimetry is employed to estimate the particle size distribution (PSD) of soft polymer latexes with low diameter limits around 40 nm. Scanning electron microscopy and dynamic light scattering were used as comparison techniques. Industrial latexes of styrene-butadiene rubber (SBR) and of acrylonitrile-butadiene rubber (NBR) were investigated. The data treatment involved the use of Mie's Model to obtain an average diameter and/or the complete PSD. For estimating the complete PSD, a least squares optimization (with an imposed distribution shape) and a numerical deconvolution procedure (without assumptions on the distribution shape) were attempted. A synthetic example was solved to investigate the limits of the applied numerical methods. For the polymer refractive index functions, Cauchy's Law was used — and its adequate adjustment proved essential for good turbidimetric estimations. A reasonable agreement between the turbidity measurements and the other independent estimations was verified. For the SEM observations, the soft latexes were hardened by irradiation before observation, but negligible diameter variations were detected.

Process Factors Using Centrifugal Spray Drying to Prepare Bauxite Microspheres

2011 ◽  
Vol 399-401 ◽  
pp. 828-833
Author(s):  
Xiao Su Cheng ◽  
Meng Qi Peng ◽  
Yu Fa Zhong
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Spray Drying ◽  
Average Diameter ◽  
Optimal Operation ◽  
Solid Content ◽  
Diameter Distribution ◽  
Drying Process ◽  
Process Factors

The centrifugal spray drying process of bauxite slurry was studied to investigate the influence of slurry solid content on the particle size distribution and the sphericity of the microspheres, and so was operation technology on average diameter and the sphericity of the microspheres. The optimal operation parameters are obtained to prepare high spherical microspheres bauxite with the diameter distribution of 100 μm and whose particle size distribution is narrow: the slurry solid content is 70 wt%, the dry air temperature is 250 °C, the rotation rate of spray head is 6000 rpm and the feed flow rate is 1 L/h in the experiments.

scholarly journals Effect of Pressure on the Particle Size Distribution of Espresso Coffee

KIMIKA ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 30-35
Author(s):  
Erick Christofer I. Gonzales ◽  
Karl Gabriel M. Lloren ◽  
Jihan S. Al-shdifat ◽  
Lica B. Valdez ◽  
Krizzia Rae Gines ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Diffraction Analysis ◽  
Size Distribution ◽  
Fine Particles ◽  
Average Diameter ◽  
Laser Diffraction ◽  
The Other ◽  
Percentage Volume ◽  
Espresso Coffee

Studies regarding particle size distribution, particularly in espressos are surprisingly few. Particle size distribution (PSD) is a plot that displays the average diameter versus percentage volume of the particles present in a sample. With increased awareness amongst coffee drinkers, a study aiming to report the effects of different pressure on particle size distribution of espresso from four different coffee blends was conducted. The method involved pulling of espresso shots at 7, 9, and 11 bar (or atm) from different coffee blends labeled as MA, CO, AL, and MO. Laser diffraction analysis showed different particle size groupings for each set of extraction pressure. Fine particles are within 1.20 to 28.70 µm. The most abundant particle size is centered at 185.4 µm. The particle size distribution of coffee blends composed of 100% Arabica coffee (AL and MO) but sourced from different locations, showed four similar modes or size ranges centered at 3.523, 13.005, 28.70, and 185.4 µm regardless of the extraction pressure or the coffee source. On the other hand, the coffee blends composed of different ratios of Arabica and Robusta (MA and CO) showed different modes depending on the pressure. This indicates the potential of PSD for characterizing the purity of a coffee blend. The particle size distribution can also give insights as to the sensory attributes of the espresso coffee.

The Fundamental Characteristics on Particle Size Distribution of Drilling Rock-Cuttings

2013 ◽  
Vol 275-277 ◽  
pp. 2411-2414 ◽  
Author(s):  
Song Lin Yi ◽  
Zhi Ming Wang ◽  
Xian Zhong Yi ◽  
Wei Chang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Diameter ◽  
Average Diameter ◽  
Rayleigh Distribution ◽  
Drill Cuttings ◽  
Rock Drill ◽  
Distribution Laws ◽  
Shape Characteristics

The properties of particle size distribution of rock cuttings and its shape characteristics are the most important parameters to petroleum drilling engineering. The samples of rock drill-cuttings are collected from 7 wells within the depths of 3500 m in Liaohe Oilfield of China. The particle size distribution laws of these rock samples with the average diameter over 74 μm are analyzed. The result shows that the drill cuttings feature obvious sheet shape and the size distribution curve of the particles is mainly related to the formation rocks and drilling bits. While drilling at the well depths of between 0 and 2000m by the cone bits, particle size distribution of drill cuttings has a form of approximately power function, the probability particle diameter being 8.50～9.27 mm. Drilling at the depths of between 2000 and 2800 m by the cone bits, the size distribution of cuttings has a form of nearly function, the probability particle diameter being 3.04～4.67 mm. Drilling at the depths under 2800m by PDC bits, the size distribution has a form of nearly the Rayleigh distribution, the probability rock diameter being 0.91～0.94 mm.

Effect of Carbon Black Particle Size Distribution on Electrical Conductivity

1978 ◽  
Vol 51 (1) ◽  
pp. 126-132 ◽  
Author(s):  
A. K. Sircar ◽  
T. G. Lamond
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Carbon Black ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Carbon Black Particle ◽  
Average Diameter ◽  
Industrial Practice ◽  
Black Particle ◽  
Gap Width

Abstract Wide particle size distribution (PSD) of carbon black increases electrical conductivity, consistent with the industrial practice of manufacturing conductive grades. An explanation has been offered based on the lower linear average diameter of wider-distribution blacks. Consequently, for the same weight, there is a larger number of particles in the broad-PSD black. The resulting agglomerates are therefore more numerous, although somewhat reduced in dimension because of higher packing density. The larger number of agglomerates results in lower average gap width, which accounts for the increased electrical conductivity.

scholarly journals Features of Hydrodynamics of a Bedisperse Boiling Layer

2021 ◽  
Vol 27 (4) ◽  
pp. 615-624
Author(s):  
O. Yu. Milovanov ◽  
R. L. Isyemin ◽  
D. V. Klimov ◽  
V. S. Kokh-Tatarenko ◽  
O. M. Larina ◽  
...  
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Average Diameter ◽  
Equivalent Diameter ◽  
Boiling Layer

An experimental study of fluidization of two types of bidispersed layer with a pronounced bimodal particle size distribution has been carried out. The possibility of using the equivalent diameter of the mixture particles, calculated from the weight average diameter of the particles constituting the mixture, is shown.

scholarly journals The effects of rheological properties of wall materials on morphology and particle size distribution of microcapsule

2010 ◽  
Vol 28 (No. 5) ◽  
pp. 433-439 ◽  
Author(s):  
Y. Xie ◽  
A. Wang ◽  
Q. Lu ◽  
M. Hui
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Rheological Properties ◽  
Size Distribution ◽  
Spray Drying ◽  
Average Diameter ◽  
Core Material ◽  
Viscous Modulus ◽  
Wall Materials ◽  
Paste Viscosity

The effects of rheological properties of the wall materials on the morphology and particle size distribution of microcapsules prepared by spray-drying were evaluated. Gelatin-sucrose (Gel-Suc), gelatin-peach-gum-sucrose (Gel-PG-Suc), and HI-CAP 100 were used as wall materials with vitamin A as a model core material. Scanning electron microscopy (SEM) showed that microcapsules produced with Gel-Suc exhibited cracks while Gel-PG-Suc produced a smooth surface with few pores, and HI-CAP100 a rounded surface containing characteristic concavities. The volume average diameter (D<sub>4,3</sub>) showed significant variations from 73.9 &plusmn; 1.02 &micro;m and 68.7 &plusmn; 0.85 &micro;m to 29.9 &plusmn; 0.94 &micro;m (P &lt; 0.05). Rheometry indicated that the wall paste viscosity was inversely proportional to the shear rate. Viscosity ranking was Gel-Suc &gt; Gel-PG-Suc &gt; HI-CAP 100. Gel-Suc showed the highest elastic modulus (G') and viscous modulus (G'' values), followed by Gel-PG-Suc and HI-CAP 100. Gel-Suc was associated with moderate quantities of broken microcapsules while HI-CAP 100 generated numerous microcapsules with characteristic dents generated during spray-drying.

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