scholarly journals Studying the influence of properties of initial ZrO2-(7 %)Y2O3 powders on properties of ceramic products

2019 ◽  
pp. 44-50
Author(s):  
N. V. Zhirenkina ◽  
M. A. Mashkovtsev ◽  
N. V. Obabkov ◽  
I. F. Zakirov
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Zirconium Oxide ◽  
Ph Value ◽  
Slip Casting ◽  
Mechanical Grinding ◽  
Influence Of Properties ◽  
Influence Of Ph ◽  
Research Show

The paper focuses on the possibility of forming ceramic products by the method of slip casting without the stage of mechanical grinding of powders. We studied the influence of pH value of hydroxides precipitation and hydrothermal treatment on the properties of ZrO2-(7 %)Y2O3 powders, and on the mechanical properties of ceramic products made from synthesized ZrO2-(7 %)Y2O3 powders without a grinding stage. Findings of research show that the quality of ceramic products based on zirconium oxide is more influenced by the specific surface area, rather than the particle size of the initial powders

scholarly journals Influence of pH and ionic strength on the aggregation behaviors of xylan rich hemicelluloses with alkaline lignins

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7608-7622
Author(s):  
Guichun Hu ◽  
Jinguang Hu ◽  
Honglei Chen ◽  
Shunxi Song ◽  
Fuqiang Chu
Keyword(s):  
Particle Size ◽  
Self Assembly ◽  
Main Chain ◽  
Ph Value ◽  
Low Ph ◽  
Ph Values ◽  
Wide Range ◽  
Nacl Concentration ◽  
Aggregation Behaviors ◽  
Influence Of Ph

The evolution of xylan-rich hemicelluloses (XH) aggregation behaviors in the presence of alkaline lignins (AL) under a wide range of pH values and NaCl concentration were investigated via dynamic light scattering and turbidity measurements. XH isolated from wheat straw contain a xylose backbone with arabinose side chains and a small amount of phenol groups. XH tend to aggregate in solution due to their low ratio of arabinose to xylose and hydrophobic phenol groups. AL interact with XH through the phenol groups bonded to the hemicellulose main chain to form an AL-XH complex. As the pH value decreases, the particle size and turbidity of AL, XH and their bonded complex all increase. The size of the AL-XH complex agglomerate is greater than the size of a XH at the same pH value, which indicates that the self-assembly of lignin molecules initiate the aggregation of XH. The particle size and turbidity of XH and AL-XH complexes increase as the XH concentration increase. At low pH values, e.g., 6.0, the particle size of the AL-XH complex more obviously increases compared to the XH particles. The size and turbidity of the AL, XH, and AL-XH complex agglomerates increased as the NaCl concentration increased.

Influence of pH value on the quality of sol–gel derived ZnO films

2007 ◽  
Vol 253 (12) ◽  
pp. 5419-5424 ◽  
Author(s):  
Parmod Sagar ◽  
P.K. Shishodia ◽  
R.M. Mehra
Keyword(s):  
Ph Value ◽  
Sol Gel ◽  
Zno Films ◽  
Influence Of Ph

An Analysis of Limestone Gypsum Desulfurization Systems

2012 ◽  
Vol 550-553 ◽  
pp. 667-670
Author(s):  
Chun Yu Wang ◽  
Jian Qiu Liu ◽  
Peng Guo
Keyword(s):  
Particle Size ◽  
Internal Structure ◽  
Ph Value ◽  
Chloride Ion ◽  
Electric Utility ◽  
High Quality ◽  
Structure Control

Limestone-gypsum desulfurization (LGD) technique is rather popular with the Electric Utility industries in their desulfuration operation. It’s been proved that, Control of PH Value and the concentration of gypsum may prevent scaling. Adoption of rubber or plastic linings based on the medium traits and the types of desulfuration system can prevent corrosion. Simple internal structure, control of pH Value of absorption liquid between 5.6 ~ 5.8, and limestone of the particle size ≤325 meshes particle above 90% may raise the efficiency of absorption tower, and promote its longevity. Control of the concentration of Chloride ion (Cl-) may guarantee a high quality of gypsum products.

scholarly journals Development of Multifunctional Film for Greenhouse Applications in Tropical Regions

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
A. Petchsuk ◽  
D. Srinun ◽  
S. Buchatip ◽  
W. Supmak ◽  
D. Sirikittikul
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Tensile Strength ◽  
Elongation At Break ◽  
Tropical Regions ◽  
Active Radiation ◽  
Uv Absorber ◽  
Light Diffusion ◽  
Roof Design

Single-purpose greenhouse films such as UV-blocking, NIR-blocking, or ultrathermic films are commonly developed in various climate regions. However, multifunctional films of combined functions are rarely explored, especially in the tropical regions. In this research, a multifunctional film having high UV filtration, high NIR reflection, and good light diffusion was developed for a greenhouse cover application in tropical regions. Effects of type, quantity, and particle size of additives on optical properties (280–2500 nm) and mechanical properties of 3-layer laminated films comprising 90% LLDPE/10% EVA polymer matrix and additives were studied. Results show that properties of those films are adjustable by varying types, particle size, and content of additives. The UV transmission of the film was ranged from 13.7 to 32.7 %T, NIR reflection from 12.1 to 19.8 %R, and %haze diffusion from 39.5 to 72.3 where photosynthetically active radiation (PAR) transmission was in the range of 62.6–78.9 %T. Those films exhibit tensile strength of 18–24 MPa, modulus of elasticity of 200–280 MPa, and elongation at break of 610–810%. A field test of the newly developed films as a cover for a greenhouse of 6 m wide ×24 m long ×4.3 m high with double roof design showed a better quality of plant growth in terms of weight, height, and bush width compared to a 7% UV absorber commercial film.

Effect of Al2O3, ZrO2, and TiO2 Addition on the Mechanical Properties and the Microstructure of Natural Hydroxyapatite Obtained from Calf Femoral Bone

2011 ◽  
Vol 493-494 ◽  
pp. 199-204 ◽  
Author(s):  
Ilker Ozden ◽  
M. Ipekoglu ◽  
N. Mahmutyazicioglu ◽  
S. Altıntaş
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Test Specimen ◽  
Sintering Behavior ◽  
Femoral Bone ◽  
Mechanical Grinding ◽  
Mechanical Strengths ◽  
Natural Hydroxyapatite ◽  
Cylindrical Test

Pure hydroxyapatite (HA) was obtained by the calcination of calf femoral bone and was ground manually and by subsequent mechanical grinding to decrease the particle size. Micron-sized Al2O3, ZrO2, and TiO2ceramics were added at different concentrations (5, 10 and 15 wt. %) to the obtained micron-sized HA powder. After adequate mixing cylindrical test specimen were prepared and sintered at 900, 1000 and 1100 °C. The specimen were tested for their compressive strengths and SEM observations and XRD analyses were conducted to determine the effect of different additives and sintering temperatures on the mechanical strengths, morphology and formed phases of the samples. TiO2addition to the HA at 15 wt. % powder resulted in highest compressive strength with good sintering behavior.

Colloidal Processing of Fine Spinel Powders

2012 ◽  
Vol 730-732 ◽  
pp. 82-87 ◽  
Author(s):  
Łukasz Zych ◽  
Anna Wajler ◽  
Radosław Lach
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
High Temperature ◽  
Infrared Detectors ◽  
Slip Casting ◽  
Transparent Ceramics ◽  
Narrow Pore Size Distribution ◽  
High Transparency ◽  
Fine Grained ◽  
Fine Powders

Magnesium-aluminium spinel (MgAl2O4) in the form of transparent ceramics is applied in shields of infrared detectors or emitters, high-temperature widows and elements of military aircrafts and vehicles. Apart from high transparency for specific wave lengths, such materials should have good mechanical properties, especially hardness. It is the reason for production of the fine-grained materials. It seems that they can be produced from submicron powders consolidated by one of colloidal techniques. The work presents preliminary results of investigations on colloidal consolidation of two fine spinel powders with different particle size by pressure filtration and slip casting. The aim of the studies was consolidation of the fine powders leading to green samples with narrow pore size distribution. The samples were then sintered in isothermal conditions. Microstructure, Vickers hardness and transmission in infrared spectrum of the dense materials were examined.

scholarly journals Preparation and Methylene Blue Adsorption Capacity of HDPE/PVA Foaming Composites

2021 ◽  
Author(s):  
Fenghong Li ◽  
Zhe Wang ◽  
Pengzhen Li ◽  
Wei Da ◽  
Weisi Lv ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Methylene Blue ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Raw Material ◽  
Good Effect ◽  
Foaming Agent ◽  
Alpha Olefin ◽  
Negative Effect ◽  
Influence Of Ph

Abstract High density polyethylene (HDPE) and polyvinyl alcohol (PVA) are blended with maleic anhydride grafted amorphous-alpha olefin copolymer as the compatibilizer. The effects of different raw material ratio and the content of compatibilizer and foaming agent on the mechanical properties of the material are studied. It is found that the increasing content of PVA added to HDPE has a negative effect on the properties of the composites. The compatibility and mechanical properties are improved after adding MAH-g-APAO and the most appropriate addition amount is 4%. Foaming agent can make the material lightweight but will decrease the mechanical properties of the material. The composites have a good effect on the removal of methylene blue (MB). Through the experiment, it is found that the initial concentration of MB and adsorption time will also influence the adsorption. The experiment to explore the influence of pH value and temperature of solution on the removal efficiency shows that alkaline environment and high temperature can promote the removal of MB. At 343.15 K, the adsorption capacity (qe) reaches 2.08 mg·g-1. Using the composites to remove dye has the advantages of environmental protection, simple operation and easy recycling. It has broad application prospects in the field of dye wastewater treatment.

Preparation of Ammonium Iron Blue from Copperas and Ammonium Sulfate Wasted Liquid

2014 ◽  
Vol 898 ◽  
pp. 443-446 ◽  
Author(s):  
Feng Chen ◽  
Ming Yu Li
Keyword(s):  
Particle Size ◽  
Ammonium Sulfate ◽  
Ferrous Sulfate ◽  
Ammonia Oxidation ◽  
Ph Value ◽  
Total Iron ◽  
Experimental Result ◽  
Total Iron Content ◽  
Ammonium Iron

Ammonium iron blue was prepared with ferrous sulfate and ammonium sulfate wasted liquid, ferrous sulfate is a byproduct from titanium dioxide production, and ammonium sulfate waste liquid is produced by ammonia oxidation iron oxide red. The influence of some parameters such as n (FeSO4)/n (Na4Fe (CN)6) ratio, PH value , reaction time, reaction temperature were discussed. The total iron content of ammonium iron blue is 35.89% and the quality of ammonium iron blue was accorded with the industrial standard (HG/T 3001-1999). SEM experimental result proved that the particle size of ammonium iron blue was uniform and about 100-200nm, and the structure of ammonium iron blue is Straight edges polyhedron. XRD experimental result showed that the structure of ammonium iron blue was similar to Fe [Fe (CN)]3.

Storage Problems of Poplar Chips from Short Rotation Plantations with Special Emphasis on Fungal Development

2012 ◽  
Vol 8 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Zsuzsanna Horváth ◽  
Béla Marosvölgyi ◽  
Christine Idler ◽  
Ralf Pecenka ◽  
Hannes Lenz
Keyword(s):  
Particle Size ◽  
Health Risk ◽  
Dry Matter ◽  
Ph Value ◽  
Wood Chips ◽  
Raw Material ◽  
Special Focus ◽  
Fungal Development ◽  
Short Rotation ◽  
Fungal Particles

Abstract - There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development.

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