scholarly journals Interaction of plasma with beryllium

2021 ◽  
Vol 2064 (1) ◽  
pp. 012070
Author(s):  
I A Sokolov’ ◽  
M K Skakov ◽  
A Z Miniyazov ◽  
T R Tulenbergenov ◽  
G K Zhanbolatova
Keyword(s):  
Bulk Density ◽  
Pore Diameter ◽  
Density Increase ◽  
Plasma Parameters ◽  
Helium Atoms ◽  
Plasma Irradiation ◽  
Hydrogen Deuterium

Abstract In this work shows some results of studying the microstructure of HP-56 beryllium after plasma irradiation. The experiments revealed a change in the microstructure of beryllium after irradiation with hydrogen, deuterium and helium atoms. The pore diameter and their bulk density increase depending on the plasma parameters.

Formation of dense silicon carbide by liquid silicon infiltration of carbon with engineered structure

2008 ◽  
Vol 23 (5) ◽  
pp. 1237-1248 ◽  
Author(s):  
Jesse C. Margiotta ◽  
Dajie Zhang ◽  
Dennis C. Nagle ◽  
Caitlin E. Feeser
Keyword(s):  
Silicon Carbide ◽  
Bulk Density ◽  
Phenolic Resin ◽  
Pore Diameter ◽  
Chemical Reactivity ◽  
Liquid Silicon ◽  
Crystalline Cellulose ◽  
Carbon Preform ◽  
Median Pore ◽  
The Ideal

Fully dense and net-shaped silicon carbide monoliths were produced by liquid silicon infiltration of carbon preforms with engineered bulk density, median pore diameter, and chemical reactivity derived from carbonization of crystalline cellulose and phenolic resin blends. The ideal carbon bulk density and minimum median pore diameter for successful formation of fully dense silicon carbide by liquid silicon infiltration are 0.964 g cm−3 and approximately 1 μm. By blending crystalline cellulose and phenolic resin in various mass ratios as carbon precursors, we were able to adjust the bulk density, median pore diameter, and overall chemical reactivity of the carbon preforms produced. The liquid silicon infiltration reactions were performed in a graphite element furnace at temperatures between 1414 and 1900 °C and under argon pressures of 1550, 760, and 0.5 Torr for periods of 10, 15, 30, 60, 120, and 300 min. Examination of the results indicated that the ideal carbon preform was produced from the crystalline cellulose and phenolic resin blend of 6:4 mass ratio. This carbon preform has a bulk density of 0.7910 g cm−3, an actual density of 2.1911 g cm−3, median pore diameter of 1.45 μm, and specific surface area of 644.75 m2 g−1. The ideal liquid silicon infiltration reaction conditions were identified as 1800 °C, 0.5 Torr, and 120 min. The optimum reaction product has a bulk density of 2.9566 g cm−3, greater than 91% of that of pure β–SiC, with a β–SiC volume fraction of approximately 82.5%.

scholarly journals Changes in Soil Bulk Density Resulting from Construction and Conventional Cable Skidding Using Preplanned Skid Trails

2007 ◽  
Vol 24 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Jingxin Wang ◽  
Chris B. LeDoux ◽  
Pam Edwards
Keyword(s):  
Bulk Density ◽  
Soil Bulk Density ◽  
Density Increase ◽  
Hardwood Forest ◽  
Forest Site ◽  
Extraction Equipment ◽  
Harvest Site

Abstract A harvesting system consisting of chainsaw felling and cable skidder extraction was studied to determine soil bulk density changes in a central Appalachian hardwood forest site. Soil bulk density was measured using a nuclear gauge preharvest and postharvest systematically across the harvest site, on transects across skid trails, and for a subset of skid trail transects closest to log landing after each of the first ten loaded machine passes. Bulk density was also measured in skid trails after their construction but prior to skidding. Bulk density did not change significantly across the harvest site, because the extraction equipment stayed on the preplanned skid trails. Bulk density increased on the skid trails as a result of construction by crawler bulldozer and during skidding. Bulk density in the skid trail increased by 30% because of construction by a crawler bulldozer. Fifty-five percent of the increase in bulk density attributable to skidding occurred after one loaded pass, and 80% of the bulk density increase was experienced after two loaded passes. Bulk density increased by only 5% between passes five and ten.

scholarly journals Characteristics of plasma parameters and turbulence in the isotope-mixing and the non-mixing states in hydrogen–deuterium mixture plasmas in the large helical device

2020 ◽  
Vol 61 (1) ◽  
pp. 016012
Author(s):  
K. Ida ◽  
M. Yoshinuma ◽  
K. Tanaka ◽  
M. Nakata ◽  
T. Kobayashi ◽  
...  
Keyword(s):  
Plasma Parameters ◽  
Hydrogen Deuterium ◽  
Mixing States

Ranges of Hydrogen, Deuterium, and Helium Atoms in Amorphous Silicon and Tungsten

2020 ◽  
Vol 65 (1) ◽  
pp. 145-150
Author(s):  
D. S. Meluzova ◽  
P. Yu. Babenko ◽  
A. P. Shergin ◽  
A. N. Zinoviev
Keyword(s):  
Amorphous Silicon ◽  
Helium Atoms ◽  
Hydrogen Deuterium ◽  
And Tungsten

scholarly journals Characterization of soil structure and porosity under long-term conventional tillage and no-tillage systems

2009 ◽  
Vol 33 (6) ◽  
pp. 1837-1844 ◽  
Author(s):  
João Tavares Filho ◽  
Daniel Tessier
Keyword(s):  
Bulk Density ◽  
Management System ◽  
Soil Structure ◽  
Pore Diameter ◽  
Conventional Tillage ◽  
Water Retention Curve ◽  
No Tillage ◽  
Sample Collection ◽  
Red Latosol ◽  
Physical And Chemical

Different management systems tend to modify soil structure and porosity over the years. The aim of this study was to study modifications in the morphostructure and porosity of dystroferric Red Latosol (Oxisol) under conventional tillage and no-tillage over a 31- year period. The study began with the description of soil profiles based on the cropping profile method, to identify the most compact structures, define sample collection points for physical and chemical analysis, and determine the water retention curve. A forest soil profile was described and used as reference. The results showed that, under conventional tillage, the microaggregate structure of the Oxisol was fragmented between 0 and 0.20 m, and compact (bulk density = 1.52 Mg m-3) in the sub-surface layer between 0.20 and 0.50 m. Under no-tillage, the structure became compacted (bulk density = 1.40 Mg m-3) between 0 and 0.60 m, but contained fissures and biopores. The volume of the class with a pore diameter of > 100 µm under no-tillage was limited, but practically non-existent in the conventional management system. On the other hand, the classes with a pore diameter of < 100 µm were not affected by the type of soil management system.

scholarly journals Effect of Carbonation on Long-Term Measurements of Sorption Isotherms of Autoclaved Aerated Concrete

2015 ◽  
Vol 1126 ◽  
pp. 81-86
Author(s):  
Olga Koronthalyova ◽  
Ľubomír Bagel
Keyword(s):  
Bulk Density ◽  
Water Vapour ◽  
Cementitious Materials ◽  
Density Increase ◽  
Water Vapour Sorption ◽  
Moisture Contents ◽  
Autoclaved Aerated Concrete ◽  
Vapour Sorption ◽  
Aerated Concrete

The laboratory measurement of water vapour adsorption/desorption curves is a standard tool for determination of the moisture capacity of porous building materials in hygroscopic region. However, in case of cementitious materials, additional processes like carbonation can occur during the measurement. Generally, process of carbonation affects the pore structure of the material and results in an increase of its bulk density. Therefore, for determination of correct sorption curves the carbonation caused bulk density increase has to be eliminated. In this work the both mentioned effects of carbonation on the measured water vapour sorption isotherm were quantified for autoclaved aerated concrete (AAC). Within the monitored 9-year period, the carbonation caused noticeable changes in microstructure of the tested AAC samples, namely a decrease of the specific surface area of pores and the portion of very small pores. These microstructure changes affected the moisture storage capacity too – the obtained equilibrium moisture contents of the partly carbonated AAC were lower than the ones of the AAC close to the original state. It was also confirmed that in case of continuous measurement of the water vapour sorption curve the carbonation induced bulk density increase could result in an overestimation of the equilibrium moisture contents.

Influence of density on selected properties of furniture particleboards made of raspberry Rubus idaeus L. lignocellulosic particles

2019 ◽  
Vol 105 ◽  
pp. 62-70
Author(s):  
GRZEGORZ KOWALUK ◽  
ANITA WRONKA
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Density Profile ◽  
Rubus Idaeus ◽  
Density Increase ◽  
Mechanical Parameters ◽  
Thickness Swelling ◽  
Laboratory Conditions ◽  
Mechanical And Physical Properties

Influence of density on selected properties of furniture particleboards made of raspberry Rubus idaeus L. lignocellulosic particles. The aim of the research was to determine the effect of density of three layer furniture particleboard, produced in laboratory conditions, in the three different densities: 500, 650 and 800 kg/m3, on their selected mechanical and physical properties. The fraction share of the particles used, as well as bulk density of the produced particles have been also measured. The tests have shown that with increasing density of the tested panels in the mentioned range, there is a significant improvement of mechanical parameters, but the thickness swelling of the panels unfavorably raises. The density increase causes also changes in density profile.

A novel approach to white liquor control in a continuous digester using the Box-Jenkins methodology to predict chip bulk density

TAPPI Journal ◽  
2015 ◽  
Vol 14 (6) ◽  
pp. 395-402
Author(s):  
FLÁVIO MARCELO CORREIA ◽  
JOSÉ VICENTE HALLAK D’ANGELO ◽  
SUELI APARECIDA MINGOTI
Keyword(s):  
Bulk Density ◽  
Moving Average ◽  
Pulp Mill ◽  
Statistical Decision ◽  
White Liquor ◽  
Novel Approach ◽  
Cooking Process ◽  
Eucalyptus Kraft Pulp ◽  
Relevant Variables ◽  
Kraft Cooking

Alkali charge is one of the most relevant variables in the continuous kraft cooking process. The white liquor mass flow rate can be determined by analyzing the chip bulk density fed to the process. At the mills, the total time for this analysis usually is greater than the residence time in the digester. This can lead to an increasing error in the mass of white liquor added relative to the specified alkali charge. This paper proposes a new approach using the Box-Jenkins methodology to develop a dynamic model for predicting chip bulk density. Industrial data were gathered on 1948 observations over a period of 12 months from a Kamyr continuous digester at a bleached eucalyptus kraft pulp mill in Brazil. Autoregressive integrated moving average (ARIMA) models were evaluated according to different statistical decision criteria, leading to the choice of ARIMA (2,0,2) as the best forecasting model, which was validated against a new dataset gathered during 2 months of operations. A combination of predictors has shown more accurate results compared to those obtained by laboratory analysis, allowing a reduction of around 25% of the chip bulk density error to the alkali addition amount.

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