The Effects of Composition on the Physical Properties of Locally Mined Ceramic Clays in the Atwima Nwabiagya District of Ghana

2011 ◽  
Vol 6 ◽  
pp. 25-35
Author(s):  
S.K. Nimo ◽  
P.S. Kwawukume ◽  
F. Boakye
Keyword(s):  
Weight Loss ◽  
Water Absorption ◽  
Constant Pressure ◽  
Linear Shrinkage ◽  
Shrinkage Porosity ◽  
Thermal Resistivity ◽  
Medium Temperature ◽  
Low Weight ◽  
Work Done ◽  
Insulating Properties

This paper reports work done which seeks to enhance the insulating property of locally mined clays with application to the building and insulation of medium temperature furnaces. Mixtures of locally mined clays with kaolin obtained from Teleku bokasso in the Western Region of Ghana were made. Samples were mixed in different ratios to form composite bodies in the form of bricks of dimensions 7mm×7mm×7mm cast at constant pressure and sintering temperature of 1000 °C. The clays used were characterized in terms of their particle size and chemical composition. The thermal resistivity, water absorption, weight loss, shrinkage, porosity and strength of samples were determined. The results showed that for all samples studied, an increase in Teleku bokasso clay enhanced the insulating properties of the samples from an average of 0.24% for samples containing 20% Teleku bokasso to approximately 2% for samples containing 60% of Teleku bokasso. Mixtures of Teleku bokasso with Afari clay were on the average 1% more thermally resistant than those of Mfensi. Sample A3 (with 40% Teleku bokasso with Afari) is recommended for the building of local furnaces because it had its strength more than doubled (105%) and was by 2% more resistant to heat than M3 (40% Teleku bokasso with Mfensi). All samples showed low weight loss levels, low water absorption, good linear shrinkage and compressive strength.

scholarly journals Performance of Dioscorea rotundata Peel as an Environmental Waste Additive in Enhancing the Insulating Properties of a Local Clay Mineral

2018 ◽  
Vol 15 (1) ◽  
pp. 59-69
Author(s):  
K.G. Akpomie ◽  
C.C. Ezeofor ◽  
O.L. Alum ◽  
U.A. Augustine ◽  
F.N. Ibeanu
Keyword(s):  
Water Absorption ◽  
Clay Mineral ◽  
Low Cost ◽  
Linear Shrinkage ◽  
Sem Analysis ◽  
Apparent Porosity ◽  
Modulus Of Rupture ◽  
Dioscorea Rotundata ◽  
Local Clay ◽  
Insulating Properties

The effect of Dioscorea rotundata peel environmental waste as an insulating additive for local clay was studied. The potential of a low cost indigenous clay mineral obtained from Akpugu-Ezedike in Nigeria for industrial application was also evaluated. The clay was characterized by the Fourier transform infrared spectroscopy, X-ray diffraction and Scanning electron microscopy (SEM). Prepared slurry mixture of the clay and peels were shaped, dried and fired. The chemical composition of the clay was determined by classical methods. Physical properties such as linear shrinkage, total shrinkage, modulus of rupture, apparent density, bulk density, apparent porosity,s welling index and water absorption, modulus of plasticity and refractoriness of the fired samples were determined. The clay was found to have a refractoriness of 12000C. SEM analysis revealed an increase in porosity of the fired clay bodies with increase in dosage of Dioscorea rotundata added. This result was corroborated by the high apparent porosity 49.67 – 60.02% and water absorption recorded 30.92 – 48.44% for the mixed fired samples. The result of this study clearly indicated the potential of Dioscorea rotundata peel as additive in enhancing insulating properties of fired clay as well as the usefulness of the local clay mineral for industrial purposes.

Effects of Molecular Weight of Chitosan on the Biodegradability and Thermal Properties of Polybutylene Succinate/Chitosan Composites

2018 ◽  
Vol 775 ◽  
pp. 26-31
Author(s):  
Sukantika Manatsittipan ◽  
Kamonthip Kuttiyawong ◽  
Kazuo Ito ◽  
Sunan Tiptipakorn
Keyword(s):  
Molecular Weight ◽  
Weight Loss ◽  
Thermal Properties ◽  
Water Absorption ◽  
Melting Temperature ◽  
Microbial Degradation ◽  
Decomposition Temperature ◽  
Molecular Weights ◽  
Significant Difference ◽  
Polybutylene Succinate

In this study, the biodegradability and thermal properties the composites of polybutylene succinate (PBS) and chitosan of different molecular weights (Mn = 104,105, and 106 Da) were prepared at chitosan contents of 0-10 wt%. After 10 days of microbial degradation, the results show that the amount of holes from degradation was increased with either decreasing Mn or increasing chitosan contents. However, the size of holes was increased with increasing Mn and chitosan contents. The results from Differential Scanning Calorimeter (DSC) present that the melting temperature (Tm) of PBS was decreased with increasing chitosan contents. Moreover, there was no significant difference between Tm of the composites with different Mn of chitosan. From the TGA thermograms, the decomposition temperature at 10% weight loss (Td10) was decreased with increasing chitosan contents. Moreover, the water absorption of PBS/chitosan composites was increased with increasing Mn and content of chitosan.

scholarly journals OPTIMUM PERFORMANCE OF STABILIZED EDE LATERITE AS AN ALTERNATIVE CONSTRUCTION MATERIAL

2020 ◽  
Vol 3 (8) ◽  
pp. 1-8
Author(s):  
Adegbenle Bukunmi O
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Construction Material ◽  
High Water ◽  
Good Alternative ◽  
Linear Shrinkage ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Optimum Performance ◽  
High Water Absorption

Laterite samples from Ede area with particle components of 19.7% clay, 32.8% silt and 47.5% sand was stabilized with combined cement, lime and bitumen and test for Compressive strength, Linear Shrinkage, Permeability and Water Absorption. The stabilizers were mixed with laterite soil in different ratios and percentage. The laterite carried 90% which is constant while the three stabilizers shared the remaining 10% in varying form. After 28 days of curing, laterite stabilizer with 90% of laterite, 8% of cement, 1% lime and 1% bitumen (LCLB1) possessed compressive strength of 2.01N/mm2. It Water Absorption Capacity was 3.05%. LCLB4 stabilizer (90% laterite, 6% cement, 2% lime and 2% bitumen) has the same compressive strength with LCLB1 stabilizer but with a high Water Absorption Capacity of 4.2%. The stabilizer of 90% laterite, 3.33% cement, 3.33% lime and 3.33% of bitumen (LCLB8) has the lowest compressive strength of 0.74N/mm2 and the highest Water Absorption Capacity of 5.39%. The results shows that LCLB1 stabilizer is a better stabilizer for strength and blocks made from laterite stabilized with it stand a good alternative to sand Crete blocks in building constructions. The combination of these stabilizers in order to determine a most economical volume combination for optimum performance is highly possible and economical.

Custom Repair of Mandibular Bone Defects with 3D Printed Bioceramic Scaffolds

2017 ◽  
Vol 97 (1) ◽  
pp. 68-76 ◽  
Author(s):  
H. Shao ◽  
M. Sun ◽  
F. Zhang ◽  
A. Liu ◽  
Y. He ◽  
...  
Keyword(s):  
Weight Loss ◽  
Alveolar Bone ◽  
Bone Defects ◽  
Linear Shrinkage ◽  
Tris Buffer ◽  
Bone Tissue Regeneration ◽  
3 Dimensional ◽  
Flexural Resistance

Implanting artificial biomaterial implants into alveolar bone defects with individual shape and appropriate mechanical strength is still a challenge. In this study, bioceramic scaffolds, which can precisely match the mandibular defects in macro and micro, were manufactured by the 3-dimensional (3D) printing technique according to the computed tomography (CT) image. To evaluate the stimulatory effect of the material substrate on bone tissue regeneration in situ in a rabbit mandibular alveolar bone defect model, implants made with the newly developed, mechanically strong ~10% Mg-substituted wollastonite (Ca90%Mg10%SiO3; CSi-Mg10) were fabricated, implanted into the bone defects, and compared with implants made with the typical Ca-phosphate and Ca-silicate porous bioceramics, such as β-tricalcium phosphate (TCP), wollastonite (CaSiO3; CSi), and bredigite (Bred). The initial physicochemical tests indicated that although the CSi-Mg10 scaffolds had the largest pore dimension, they had the lowest porosity mainly due to the significant linear shrinkage of the scaffolds during sintering. Compared with the sparingly dissolvable TCP scaffolds (~2% weight loss) and superfast dissolvable (in Tris buffer within 6 wk) pure CSi and Bred scaffolds (~12% and ~14% weight loss, respectively), the CSi-Mg10 exhibited a mild in vitro biodissolution and moderate weight loss of ~7%. In addition, the CSi-Mg10 scaffolds showed a considerable initial flexural strength (31 MPa) and maintained very high flexural resistance during soaking in Tris buffer. The in vivo results revealed that the CSi-Mg10 scaffolds have markedly higher osteogenic capability than those on the TCP, CSi, and Bred scaffolds after 16 wk. These results suggest a promising potential application of customized CSi-Mg10 3D robocast scaffolds in the clinic, especially for repair of alveolar bone defects.

Closed-Cycle OTEC Systems

1994 ◽  
Author(s):  
William H. Avery ◽  
Chih Wu
Keyword(s):  
Thermal Equilibrium ◽  
Constant Pressure ◽  
Cold Water ◽  
Heat Engine ◽  
Heat Removal ◽  
Working Fluid ◽  
Closed Cycle ◽  
Work Done ◽  
Heat Engine Cycle ◽  
Design Pressure

The Rankine closed cycle is a process in which beat is used to evaporate a fluid at constant pressure in a “boiler” or evaporator, from which the vapor enters a piston engine or turbine and expands doing work. The vapor exhaust then enters a vessel where heat is transferred from the vapor to a cooling fluid, causing the vapor to condense to a liquid, which is pumped back to the evaporator to complete the cycle. A layout of the plantship shown in Fig. 1-2. The basic cycle comprises four steps, as shown in the pressure-volume (p—V) diagram of Fig. 4-1. 1. Starting at point a, heat is added to the working fluid in the boiler until the temperature reaches the boiling point at the design pressure, represented by point b. 2. With further heat addition, the liquid vaporizes at constant temperature and pressure, increasing in volume to point c. 3. The high-pressure vapor enters the piston or turbine and expands adiabatically to point d. 4. The low-pressure vapor enters the condenser and, with heat removal at constant pressure, is cooled and liquefied, returning to its original volume at point a. The work done by the cycle is the area enclosed by the points a,b,c,d,a. This is equal to Hc–Hd, where H is the enthalpy of the fluid at the indicated point. The heat transferred in the process is Hc–Ha Thus the efficiency, defined as the ratio of work to heat used, is: . . . efficiency(η)=Hc–Hd/Hc–Ha (4.1.1) . . . Carnot showed that if the heat-engine cycle was conducted so that equilibrium conditions were maintained in the process, that the efficiency was determined solely by the ratio of the temperatures of the working fluid in the evaporator and the condenser. . . . η=TE–Tc/TE (4.1.2) . . . The maximum Carnot efficiency can be attained only for a cycle in which thermal equilibrium exists in each phase of the process; however, for power to be generated a temperature difference must exist between the working fluid in the evaporator and the warm-water heat source, and between the working fluid in the condenser and the cold-water heat sink.

Quality Technological Properties of Foundry Exhaust Dust as Alternative Ceramic Coating Raw Materials

2015 ◽  
Vol 1088 ◽  
pp. 395-398
Author(s):  
Luiz Oliveira Veriano dalla Valentina ◽  
Marilena Valadares Folgueras ◽  
Wanessa Rejane Knop ◽  
Maria Cristina Pacheco do Nascimento ◽  
Glaucia Aparecida Prates
Keyword(s):  
Water Absorption ◽  
Bulk Density ◽  
Ceramic Coating ◽  
Raw Materials ◽  
Linear Shrinkage ◽  
Inert Atmosphere ◽  
Technological Properties ◽  
Foundry Industry ◽  
Ceramic Manufacturing ◽  
Materials Used

The work evaluates the possibility of the use the exhauster powder generated in the foundry process in ceramic mass atomized semigre type. The raw materials used were semi-stoneware kind atomized powder used on the coating ceramic manufacturing and dust exhaust byproduct supplied by a foundry industry both from brazilian industries . Tests were conducted using a heating rate of 10o.C / min and oxidant and / or inert atmosphere. Specimens contained different amounts of byproduct to the extent of 30% by mass, in order to verify the maximum addition of byproduct and were used in order to analyze the technological properties evaluation (water absorption linear shrinkage, bulk density). at the temperature of 1100 ° C showed higher difference between the results obtained and 1200o C this difference decreased.

Microstructural Analysis of Petroleum Waste Containing Ceramic Tile

2008 ◽  
Vol 591-593 ◽  
pp. 845-848 ◽  
Author(s):  
Bruno C.A. Pinheiro ◽  
J.N.F. Holanda
Keyword(s):  
Water Absorption ◽  
Microstructural Evolution ◽  
Ceramic Tile ◽  
Sintered Density ◽  
Raw Materials ◽  
Microstructural Analysis ◽  
Linear Shrinkage ◽  
Ceramic Tiles ◽  
Petroleum Waste ◽  
Materials Used

In this work is done a study on the sintered microstructure of ceramic tile paste incorporated with petroleum waste. The raw materials used were kaolin, sodic feldspar, quartz and petroleum waste. The ceramic tiles containing up to 5 wt% petroleum waste were prepared by uniaxial pressing and sintered at 1200°C. The microstructural evolution was examined by SEM. In addition, water absorption, linear shrinkage, and sintered density were determined. The results showed that the microstructure of the ceramic tiles is influenced by the added petroleum waste.

Assessment of the Technological Properties of High Temperature Fired Clayey Ceramics Incorporated with Glass Waste

2015 ◽  
Vol 820 ◽  
pp. 449-454
Author(s):  
Alline Sardinha Cordeiro Morais ◽  
Thais Mardegan Louzada ◽  
Veronica Scarpini Candido ◽  
Sergio Neves Monteiro ◽  
Carlos Mauricio Fontes Vieira
Keyword(s):  
High Temperature ◽  
Water Absorption ◽  
Glass Powder ◽  
Linear Shrinkage ◽  
Substantial Improvement ◽  
Industrial Wastes ◽  
Technological Properties ◽  
Glass Waste ◽  
Fluorescent Lamps ◽  
Higher Temperature

The incorporation of industrial wastes into clayey ceramics used in civil construction is becoming a worldwide procedure not only to provide an environmentally correct destination for the waste but, in some cases, to improve the ceramic properties. The objective of the present work was to evaluate the effect of incorporation of a glass powder waste from decontamination process of fluorescent lamps into clayey ceramics. This evaluation was performed based on the technological properties of water absorption, linear shrinkage ad flexural strength. The properties evaluation was complemented by optical microscopy structural observation. The glass waste was incorporated in up to 30 wt% and specimens were uniaxially pressed at 20 MPa and fired at a relatively higher temperature of 1000°C. The results confirmed a substantial improvement of both the water absorption and the strength with glass waste incorporation into clayey ceramics.

Natural durability of organomodified layered silicate filled wood flour reinforced polypropylene nanocomposites

2013 ◽  
Vol 20 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Behzad Kord
Keyword(s):  
Weight Loss ◽  
Flexural Strength ◽  
Water Absorption ◽  
Wood Flour ◽  
Flexural Modulus ◽  
Layered Silicate ◽  
Natural Durability ◽  
Thickness Swelling ◽  
Melt Mixing ◽  
The Impact

AbstractThe effect of organomodified montmorillonite (OMMT) loading on the natural durability properties of polypropylene/wood flour composites exposed to brown-rot fungi (Coniophora puteana) was studied. To meet this objective, the blend composites were prepared through the melt mixing of polypropylene/wood flour at 50% weight ratios, with various amounts of OMMT (0, 3 and 6 per hundred compounds [phc]) in a hake internal mixer. The samples were then made by injection molding. The amount of coupling agent was fixed at 2 phc for all formulations. After specimen and culture medium preparation, the specimens were exposed to the purified fungus at 25°C and 75% relative humidity for 14 weeks. Identical specimens of the same composite, without being exposed to the fungus, were provided as the control specimens. After the discussed periods; weight loss, flexural strength, flexural modulus, hardness, water absorption, and thickness swelling of specimens were measured. Results indicated that OMMT had significant effects on the natural durability of the studied composite formulations. All mechanical properties were affected by the fungus, to a greater extent in the case of specimens without OMMT than the specimens with OMMT. Furthermore, the flexural strength and modulus increased with an increase of OMMT up to 3 phc and then decreased. However, the impact strength, water absorption and thickness swelling was decreased with increase of OMMT loading. Also, the lowest weight loss and the highest hardness were observed in the composite containing 6 phc organoclay. The morphology of the nanocomposites was examined by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Morphological findings revealed that intercalation came from the sample with 3 phc concentration of OMMT, which implies the formation of intercalation morphology and better dispersion than 6 phc.

Property Changes of SiO2 Aerogel on Insulation Performance under Different Time and High Temperature Condition

2014 ◽  
Vol 602-603 ◽  
pp. 349-352 ◽  
Author(s):  
Jie Yang ◽  
Jing Liu ◽  
Xue Ye Sui ◽  
Rui Xiang Liu ◽  
Chang Ling Zhou ◽  
...  
Keyword(s):  
Weight Loss ◽  
Secondary Particle ◽  
Treatment Temperature ◽  
Heat Temperature ◽  
Secondary Particles ◽  
Long Time ◽  
High Temperature Condition ◽  
Property Changes ◽  
Insulation Performance ◽  
Insulating Properties

To study the impacts of structural change of SiO2 aerogel on its insulating properties, the samples were treated in long time (0-12h) at 500°C, 600°C, 700°C and 800°C. The results show that with the time increased, the shrink extends in thickness, the weight loss and the density is basically unchanged under the 500°Cand 600°C. As for 700°C and 800°C, the results were treated with 0-12h, the shrink extends in thickness, the weight loss and density increases considerably. Besides, the structure and composition of SiO2 aerogel after the different temperature treaded with 0.5h were tested. The results show that when the heat treatment temperature is between 200-800°C, the small pores in SiO2 aerogel collapses and large pores increase, and the density is stil1 able to maintain the 1ow value due to the unbroken skeleton. When the heat temperature is between 800-1000°C, the secondary particle size increases and the rnutual integration of the secondary particles occurs, the density will be significantly increased.

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