Effects of Viscosity and Pressure on Microstructure and Properties of Cf/SiC-ZrB2 Composites by PIP Process

2016 ◽  
Vol 697 ◽  
pp. 506-509 ◽  
Author(s):  
Kai Jiang ◽  
Yan Yan Wang ◽  
Chang Ling Zhou ◽  
Han Li ◽  
Fang Hong Yang
Keyword(s):  
Raw Materials ◽  
Solid Content ◽  
Vacuum Impregnation ◽  
Mixed Solution ◽  
Experimental Conditions ◽  
Rotational Viscometer ◽  
Material Density ◽  
Reasonable Solution ◽  
Preparation Period ◽  
Main Factor

In this paper, using PCS and ZrB2 precursor as raw materials, we prepared Cf/SiC-ZrB2 composites by precursor infiltration and pyrolysis (PIP) process. We studied the solution of different solid content on the influence of porosity and weight gain，and also studied the effect of pressure and other conditions in the process of infiltration. The viscosity of the solution is tested with NDJ-8S digital rotational viscometer. We observed the microstructure of materials through the scanning electron microscope (SEM). The optimum technological parameter was determined by the experiment. The results showed that: a reasonable solution group in relation to the viscosity of the mixed solution，that is the main factor affecting on the performance of the impregnation; The method of vacuum and pressure impregnation can reduce the preparation period and improve material density rapidly. Under the experimental conditions, the best viscosity of the mixed solution is 54.8 mpa•s, the time of vacuum impregnation is 1.5h, and the optimum value of pressure impregnation is 7 MPa.

Minimizing Segregation in Bunkers

1973 ◽  
Vol 95 (1) ◽  
pp. 81-85 ◽  
Author(s):  
K. Clague ◽  
H. Wright
Keyword(s):  
Particle Size ◽  
Flow Regime ◽  
Mass Flow ◽  
Raw Materials ◽  
Model Tests ◽  
Material Density ◽  
Filling Method ◽  
Density Results

Bunkers used in steelworks sinter plants and other applications need to be designed and operated so that the feed emerging is unsegregated. A series of model tests has been carried out to discover which bunker shape, flow regime, and filling method give the least segregation for raw materials of different particle size and density. Results are compared with results from larger bunkers. The main conclusions are that an evenly-filled wedge-shaped mass-flow bunker is best at preventing segregation and that material density has little effect.

Preparation and Characterization of ZrO2 Nanopowders for Solid Oxide Fuel Cells

2010 ◽  
Vol 105-106 ◽  
pp. 660-663 ◽  
Author(s):  
Yun Xia Chen ◽  
Xing Yong Gu ◽  
Chun’e Cao ◽  
Yang Huang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Lattice Distortion ◽  
Raw Materials ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Experimental Conditions ◽  
Hydrothermal Temperature ◽  
Grain Sizes ◽  
Xrd And Tem

ZrOCl2•6H2O and Y(NO3)3 were used as raw materials to fabricated Y2O3 stabilized ZrO2(YSZ) nanopowders by hydrothermal method. The addition of Y2O3, different precipitants, different hydrothermal temperatures and times were studied. XRD and TEM were employed to characterize phase compositions, grain sizes and lattice parameters of the as-prepared YSZ nanopowders. The results show that less than 10nm and well crystallized cubic YSZ were obtained under a certain experimental conditions. Different precipitants affect the formation of precursors and final products. The addition of NaOH is benefit to the growth of YSZ crystals with the max grain size and the minimum lattice distortion among the three kinds of precipitants. Amorphous YSZ powders are obtained at lower hydrothermal temperature of 150°Cfor longer treating time of 6h. However, when the hydrothermal temperature is elevated at 180°C, well crystallized YSZ powders are prepared only treated for 2h.

scholarly journals A Comparative Analytical Study of Some External Finishing (Cladding) Material in Terms of Their Ability to Spread Fire in Multi-story Building Facades in Iraq

2020 ◽  
Vol 10 (5) ◽  
pp. 647-654
Author(s):  
Ahmed A. Alfakhry
Keyword(s):  
Computer Modeling ◽  
Analytical Study ◽  
Raw Materials ◽  
Fire Spread ◽  
Building Facades ◽  
The Difference ◽  
Fire Spreading ◽  
Story Building ◽  
Cladding Material ◽  
Main Factor

The traditional building in Iraq characterised by the using of a certain number of finishing's in external façades like cement plastering, limestone and perforated yellow brick because the raw materials of manufacturing are available locally. Fire spread through the facades is widely recognized as one of the fastest pathways of fire spreading in the buildings, so the appropriate choose of highly performance finishing material against fire will be potentially the main factor in controlling the fire and suppressed it. This study uses computer modeling and fire simulation technology of Pyrosim, FDS and smoke view to compare the difference between the performance of some traditional finishing materials like cement plastering, limestone and perforated yellow brick with the ACPs and their speed to transfer fire from floor to floor if used in multi storey buildings. The study highlighted that traditional finishing materials are more efficient than modern cladding materials and that the performance of ACP-PE is the worst among the materials examined by this study. Moreover, the cement plastering is the worst among the traditional local finishing materials.

scholarly journals KUALITAS PAPAN PARTIKEL BERDASARKAN KOMPOSISI SEKAM PADI DAN KAYU SENGON DENGAN VARIASI KADAR PEREKAT

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Dendi Prayoga ◽  
. Dirhamsyah ◽  
. Nurhaida
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Rice Husk ◽  
Raw Materials ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Solid Content ◽  
Particle Board ◽  
Rice Husks ◽  
Wood Processing

This research aimed to examine the physical and mechanical properties of particle boards based on the composition of raw materials and adhesive content and know the treatment of the composition of raw materials and the best adhesive content and meet the standard JIS A 5908-2003. The research was conducted at Wood Workshop Laboratory, Wood Processing Laboratory Faculty of Forestry,Tanjungpura University and Laboratory of PT. Duta Pertiwi Nusantara Pontianak. The adhesive used is Urea Formaldehyde with 52% Solid Content. Comparison of the composition of rice husks and sengon varies namely rice husk 50%: sengon 50%, rice husk 60%: sengon 40% and rice husk 70%: sengon 30%  and variations in the levels of UF adhesives, namely 14% and 16%, with target density 0,7 gr/cm3. The particleboard was 30 cm x 30 cm x 1 cm Pressing at temperature 140oC for 8 minutes, with  pressure of 25 kg/cm2. The research results of the study of density and moisture content meet the standards JIS A 5908-2003. The best particle values of rice husk and sengon  with composition a ratio of  rice husk 50%: sengon 50% , 16% adhesive content  16%, with density value of  0,7072 gr/cm3, moisture content 9,1949 %, thick development 12,3210 %, water absorption 68,8270 %, MOE 12110,7273 kg/cm2, MOR 161,0025 kg/cm2, firmness sticky 1,9320 kg/cm2, screw holding strength 62,3124 kg.Keywords : adhesive, composition, particle board, rice husk, sengon

scholarly journals Fabrication and Adsorption Optimization of Novel Magnetic Core-shell Chitosan/Graphene Oxide/β-cyclodextrin Composite Materials for Bisphenols in Aqueous Solutions

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5408
Author(s):  
Yichao Gong ◽  
Jianbing Su ◽  
Muyuan Li ◽  
Aixue Zhu ◽  
Guisui Liu ◽  
...  
Keyword(s):  
Composite Material ◽  
Graphene Oxide ◽  
Adsorption Mechanism ◽  
Raw Materials ◽  
Environmentally Friendly ◽  
Magnetic Core ◽  
Magnetic Composite ◽  
Order Kinetic ◽  
Mixed Solution ◽  
Adsorption Parameters

A novel magnetic composite material, Fe3O4@SiO2/chitosan/graphene oxide/β-cyclodextrin (MCGC), was prepared by multi-step methods. Various methods were used to systematically characterize the morphology, composition, structure, and magnetic properties of MCGC. The results obtained show that the composite material has good morphology and crystal structure and can be separated quickly by an external magnetic field. The operation is relatively easy, and the raw materials used to prepare this material are economical, easy to obtain, and environmentally friendly. The performance and adsorption mechanism for using this material as an adsorbent to remove bisphenol A (BPA) and bisphenol F (BPF) from water were studied. The adsorption parameters were optimized. Under optimal conditions, MCGC was found to remove more than 90% of BPA and BPF in a mixed solution (20 mg/L, 50 mL); the adsorption process for BPA and BPF on MCGC was found to follow a Redlich–Peterson isotherm model and Pseudo-second-order kinetic model. The adsorption mechanism for MCGC may involve a combination of various forces. Recycling experiments showed that after five uses, MCGC retained a more than 80% removal effect for BPA and BPF, and through real sample verification, MCGC can be used for wastewater treatment. Therefore, MCGC is economical, environmentally friendly, and easy to separate and collect, and has suitable stability and broad application prospects.

Rheological Characteristics of Juniperus drupacea Fruit Juice (pekmez) Concentrated by Boiling

2008 ◽  
Vol 14 (4) ◽  
pp. 321-328 ◽  
Author(s):  
M. Akbulut ◽  
H. Çoklar ◽  
G. Özen
Keyword(s):  
Flow Characteristics ◽  
Shear Thickening ◽  
Solid Content ◽  
Soluble Solids ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Rheological Parameters ◽  
Soluble Solid Content ◽  
Rotational Viscometer ◽  
Soluble Solid

Rheological parameters of Juniperus drupacea fruit pekmez were evaluated using a rotational viscometer at 10, 20, 30, 40, and 50 °C and at concentrations of 62.8, 68.9, 72.0, and 75.2% total soluble solids. The flow characteristics of Juniperus drupacea fruit pekmez were described by the power law and Herschel—Bulkley models. The Herschel—Bulkley model was found to be the best to describe the rheological property with the coefficient of determination higher than 0.993. Juniperus drupacea pekmez exhibited a time-independent shear thickening behavior. The effect of temperature on viscosity can be described by means of an Arrhenius equation. Depending on the soluble solid contents, the activation energies for flow of diluted samples vary from 78.23 to 60.38 kJ/mol. The effect of soluble solids on viscosity can be described by an exponential equation. Experimental data were fitted to several models in order to describe the effect of temperature and soluble solid content. The combined effect of temperature and soluble solid content on viscosity was also formulated.

Preparation of Zirconium Sol by Precipitation Method

2018 ◽  
Vol 281 ◽  
pp. 52-57
Author(s):  
Lan Li ◽  
Yuan Yuan Song ◽  
Guang Ren Geng ◽  
Fu Tian Liu
Keyword(s):  
Zirconium Dioxide ◽  
Chloride Ion ◽  
Solid Content ◽  
Precipitation Method ◽  
Mixed Solution ◽  
High Solid Content ◽  
Strong Base ◽  
Low Viscosity ◽  
Dioxide Powder ◽  
Very High

Zirconium sol was prepared using precipitation method. In the process, ZrO(OH)2 precipitate was firstly obtained through the addition of strong base into the zirconium ions, and then was washed to remove the chloride ion. Lastly, the obtained ZrO(OH)2 precipitate was dissolved in nitric acid solution to obtain the white mixed solution. The clear and transparent zirconium sol can be obtained after heated the white mixed solution in a water bath. In this study, the effects of three precipitating agents on the properties of zirconium sol were studied. Zirconium sol prepared by using ammonia as precipitating agent is easy to peptize, while its viscosity is very high. On the other hand, zirconium sol prepared by using urea as precipitating agent exhibits low solid content. Notably, the performance of zirconium sol prepared using ammonia and NH4Cl solution as precipitating agent is best due to its low viscosity and high solid content. In addition, zirconium sol, xerogel and zirconium dioxide powder prepared using ammonia and NH4Cl solution as precipitating agent were systematically characterized by SEM, viscometer, XRD, FTIR. The optimal zirconium sol was synthesized using a peptizing time of 8 h under a peptizing temperature was 80 °C, and the dried amorphous xerogel was converted to tetragonal ZrO2 after calcined at 600 °C, while monoclinic at 1000 °C.

scholarly journals Anaerobic Digestion Technology for Methane Production Using Deer Manure Under Different Experimental Conditions

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1819 ◽  
Author(s):  
Hanxi Wang ◽  
Jianling Xu ◽  
Lianxi Sheng ◽  
Xuejun Liu ◽  
Meihan Zong ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Anaerobic Digestion ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Methane Production ◽  
Poultry Manure ◽  
Solid Content ◽  
Production Factor ◽  
Experimental Conditions ◽  
The Magnetic Field

Anaerobic digestion (AD) is an important technology for the treatment of livestock and poultry manure. The optimal experimental conditions were studied, with deer manure as a fermentation material and mushroom residue as an inoculum. At the same time, methane production was increased by adding zeolite and changing the magnetic field conditions. The results showed that a 6% solid content was the best condition for producing methane. The optimal conditions for methane production were obtained by adding 35 g of mushroom residue to 80 g of deer manure at 35 °C. The addition of organic wastewater (OW) improved methane production. The result of improving the methane production factor showed that adding zeolite during the reaction process could increase the methane production rate. When the amount of zeolite was over 8% total solids (TSes), methane production could improve, but the rate decreased. Setting a different magnetic field strength in the AD environment showed that when the distance between the magnetic field and the reactor was 50 mm and the magnetic field strength was 10–50 mT, the methane production increment and the content of methane in the mixed gases increased.

scholarly journals Model analysis of the relationship between intracellular Po2 and energy demand in skeletal muscle

2012 ◽  
Vol 303 (11) ◽  
pp. R1110-R1126 ◽  
Author(s):  
Jessica Spires ◽  
L. Bruce Gladden ◽  
Bruno Grassi ◽  
Gerald M. Saidel ◽  
Nicola Lai
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Contraction ◽  
Energy Demand ◽  
Experimental Studies ◽  
Experimental Conditions ◽  
Permeability Surface ◽  
The Relationship ◽  
And Diffusion ◽  
Main Factor

On the basis of experimental studies, the intracellular O2 (iPo2)-work rate (WR) relationship in skeletal muscle is not unique. One study found that iPo2 reached a plateau at 60% of maximal WR, while another found that iPo2 decreased linearly at higher WR, inferring capillary permeability-surface area ( PS) and blood-tissue O2 gradient, respectively, as alternative dominant factors for determining O2 diffusion changes during exercise. This relationship is affected by several factors, including O2 delivery and oxidative and glycolytic capacities of the muscle. In this study, these factors are examined using a mechanistic, mathematical model to analyze experimental data from contracting skeletal muscle and predict the effects of muscle contraction on O2 transport, glycogenolysis, and iPo2. The model describes convection, O2 diffusion, and cellular metabolism, including anaerobic glycogenolysis. Consequently, the model simulates iPo2 in response to muscle contraction under a variety of experimental conditions. The model was validated by comparison of simulations of O2 uptake with corresponding experimental responses of electrically stimulated canine muscle under different O2 content, blood flow, and contraction intensities. The model allows hypothetical variation of PS, glycogenolytic capacity, and blood flow and predictions of the distinctive effects of these factors on the iPo2-contraction intensity relationship in canine muscle. Although PS is the main factor regulating O2 diffusion rate, model simulations indicate that PS and O2 gradient have essential roles, depending on the specific conditions. Furthermore, the model predicts that different convection and diffusion patterns and metabolic factors may be responsible for different iPo2-WR relationships in humans.

Concrete and Abstract Terms and Relations in Testing a Rule

1974 ◽  
Vol 26 (3) ◽  
pp. 355-359 ◽  
Author(s):  
K. J. Gilhooly ◽  
W. A. Falconer
Keyword(s):  
Abstract Form ◽  
Experimental Conditions ◽  
Improved Performance ◽  
Main Factor

Subjects have more difficulty in correctly testing a conditional rule stated in abstract form than the same rule given in “thematic” form. The “thematic” form of the rule involves both concrete terms and a concrete relation. Four experimental conditions were formed by combining concrete abstract terms and relations. Fifty subjects were tested in each condition. The results indicated that concrete-ness of the terms is the main factor leading to improved performance with “thematic” as against abstract material in the rule testing task.

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