Journal of Modern Materials
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Comparative Study on the Mechanical Properties of Weft Knitted and Warp Fabric Reinforced Composites
No full textKnitted fabric composites occupy a special interest in the field of engineering and materials science because of their easy to form complex component and high impact energy absorption. Mechanical tests were carried out in the course, wale and slanting directions of the knitted fabric reinforced composites. The stress-strain curves and failure modes of warp and weft knitted fabrics were investigated and compared. The test results revealed from the composite structure fabricated from warp knitted fabric shown better mechanical properties than weft knitted fabric because of the warp knitted fabric distinct by the process of overlap between the stitches that gave better resistance
Structure and New Substructure of α-Ti2O3: X-ray Diffraction and Theoretical Study
No full textThe Crystal structure of both α-Ti2O3 and its new substructure with a halved c-axis has been investigated by single-crystal X-ray diffraction and density functional theory (DFT) calculations. The α-Ti2O3 substructure described in the R-3m space group, reveals an unusual 12-fold high coordination of Ti atoms forming edge and face-sharing distorted hexagonal prisms TiO12 stacking along the c-axis. The Hubbard-corrections predict a close bandgap for both α-Ti2O3 and its substructure; whereas a comparative study of their relative stability indicates that the substructure is thermodynamically less stable
A Comparative Study on Physical and Comfort Properties of Yarns and Hand-woven Fabrics Produced from Virgin and Recycled Fibers
No full textProducts produced from textile industries cannot meet the needs for human kind since the population of the world grows exponentially; due to this the recycling of textile materials has gained massive importance in textile and clothing sector. In this study, it was aimed to analyse recycled fibers effect on the yarn and hand loom fabrics as their proportion increases. For this purpose, OE rotor yarns produced by varying the recycled fibers proportion at 25%, 50, and 75% and compared with 100% virgin cotton yarns. The physical and mechanical properties of the yarns such as unevenness, imperfections, hairiness, breaking force, elongation, were measured by Uster Tester 4 SX, Uster Zweigle Hairiness Tester 5, and Uster Tensorapid 3. Then after hand loom fabrics with plain and twill fabrics are produced from produced yarns of different recycled fiber proportions. The effects of recycled fiber proportion on produced hand-woven fabric properties such as pilling, abrasion resistance and air permeability were also evaluated. Results showed that yarns and fabrics produced from recycled fibers blended with virgin cotton are suitable for applications where the strength of yarns and fabric are less critical, but where unevenness, imperfections and handle properties required thus, hand loom fabrics Produced can suitably used for home furnishing applications like table cover, curtains, wall covers and pillow cases
Study of the Optical, Electrical, Structural and Morphological Properties of Electrodeposited Lead Manganese Sulphide (PbMnS) Thin Film Semiconductors for Possible Device Applications
No full textSemiconductor thin films of lead manganese sulphide (PbMnS) have been successfully deposited on florinated tin oxide (FTO) conductive glass substrate using an electrodeposition method. Lead acetate (Pb(CH3COO)2), manganese sulphate (MnSO4.H2O) and thiourea (CH4N2S) were the precursor used for lead (Pb2+), manganese (Mn2+) and sulphur (S2-) sources respectively. The concentration of manganese (Mn2+) was varied while keeping the concentrations of Pb2+ and S2- constant at 0.2 M and 0.1 M respectively. The deposited films were annealed at temperature of 250 oC and subjected for optical, electrical, structural and morphological characterizations. The results of the characterizations showed that the deposited thin films of PbMnS have high absorbance, high absorption coefficient throughout VIS and NIR regions. The band gap energy of the films is tuned to the order of 1.9 eV to 2.0 eV and tends to constant as concentration of Mn2+ increased. The electrical properties (electrical resistivity and conductivity) of the films are dependent on the concentration of Mn2+ and film thickness. The range of values of the electrical properties is found to be within the range of values for semiconductor materials. The XRD analysis revealed that the deposited thin films of PbMnS is crystalline but the crystallinity declined with increase in concentration of Mn2+. The SEM morphology showed that the surfaces of the films are highly homogeneous in nature and particle sizes are uniform on the substrate with the majority of the particles been spherical in shape. These observed properties exhibited by the deposited thin films of PbMnS make the films good materials for many optoelectronic and electronic applications such as solar cell, light emitting diode (LED), photodetector etc
Mechanical Strengths of Sawdust-Ash-Admixed Gum Arabic Concrete
No full textGum Arabic and sawdust ash were used both as an emulsifier admixture and supplementary cement material to address some of the gaps between pozzolanic and conventional concretes. Four concrete mixtures of 1: 2.24: 2.71, with a water-cement ratio of 0.5, and cement content of 370 kg/m3, was used. The concrete mixtures were designated as M-00, M-00GA, M-10GAS, and M-30GAS, signifying the control, control with gum Arabic (GA), and mix with both gum Arabic and sawdust ash (GAS), respectively. The dosage was 0.5 % of GA and the SDA replacement by wt. % was at 10 % and 30 %, respectively. The concrete samples were cured for 90 days, and tested for mechanical strengths. The results showed that adding GA alone to concrete mixture improved the mechanical strengths of the concrete and the gum Arabic acted like an accelerator. When both GA and SDA were used together in the dosage of 0.5 % with 10 % and 30 % proportions respectively, the mechanical strengths of the concrete decreased. The findings also reported that the two-third strength ratio at 28-days of curing which is used for the conventional concrete in stripping the formwork, may not be appropriate for use on pozzolanic concrete. This is because of the delay in setting times and thus, attaining the required design strength. Therefore, it is proposed to be taken at an age beyond 28 days of curing to carter for the pozzolanic effects which starts well above 28-days
Study on Properties of Concrete with Iron Ore Tailing and Glass Waste
No full textThe aim of this research is to test the characteristics of concrete by substitute fine aggregate with iron ore tailings and partial glass powder as in the place of cement. Concrete with waste products such as glass powder and iron ore tailings offer technical, economic and environmental advantages. In this experimental investigation, glass powder is replaced with cement by 10%, 20% and 30% and iron ore tailings with fine aggregates by 30% which is the optimum percentage. To study the role of glass powder and iron ore tailings combination in concrete. The properties such compressive strength, flexural strength, tensile strength and also durability parameters likely water absorption investigation for M40 concrete is carried out with different percentages of glass powder by keeping the iron ore tailings percentage constant. At 30% glass powder substitution as cement and sand with IOT increases concrete effectiveness. The concrete with 10% glass powder & 30% iron ore tailings showed a higher strength compared to the conventional mix for 28 days. Concrete mix containing 10% GP and 30% IOT showed higher flexural strength of 5.05 MPa for 28 days. Splitting tensile strength value is also increasing i.e., for 10% glass powder and 30% IOT, obtained splitting tensile strength was 4.48 MPa and modulus of elasticity value was has also increased. Water absorption experiment consequences results that water absorption decreases with an increase in GP percentage. The concrete workability tends to decrease when with glass powder content increase. Concrete containing 10% glass powder and 30% IOT showed maximum strength and it is considered as the optimum dosage
Preliminary Evaluation of Composite Panels Produced from Rice Husk and Recycled Polystyrene Material
No full textRice husk particles categorised as fine (size ≤ 0.6 mm), and coarse (0.6 mm ≤ size ≤ 1.8 mm) were mixed with a binder obtained by recycling expanded polystyrene waste, to formulate composites. Formulation was carried out using different particles to binder ratios as follows: 1:1, 1:1.5, 1:2). Fine particle composites were designated F1:1, F1:1.5 and F1:2, while the coarse particle composites were designated C1:1, C1:1.5 and C1:2. The composites were casted, and some physical properties such as: dry/cure time in air (72±4 h - 168±6 h), density (0.48±0.04 g/dm3 – 2.75±0.08 g/dm3), water absorption (2.24±0.46 % - 58.91±1.11 %) and thickness swelling (1.43±0.06 % – 22.65±1.23 %), flammability tests and SEM images of the composite panels obtained were evaluated. Results showed that: dry time and density increased, water absorption and thickness swelling decreased while flammability increased (ignition time decreased and propagation rate increased), as the amount of the recycled polystyrene binder was increased in the composites. Relative to particle size aggregate, coarse particle composites exhibits shorter drying time, lower density, higher water absorption and weaker flame retardation compared to the fine composites with corresponding ratios
Fabrication and Investigation of Mechanical Properties of SiC Particulate Reinforced AA5052 Metal Matrix Composite
No full textIn this present research particulate reinforced aluminium metal matrix composite is developed by using sand mould and liquid stir casting processing route in which AA5052 reinforced with 5 wt. % SiC particulates of 63µm particle size. The density, porosity, micro-hardness, and compressive strength of SiC particulate reinforced AA5052 MMC were investigated and compared these properties with similar properties of unreinforced AA5052. The microstructure of the developed composite was also analysed by using optical microscopy, SEM, and XRD. Developed particulate reinforced Al metal matrix composite gives improved hardness and compressive strength as compared to the unreinforced AA5052. The addition of 5 wt. % SiC particulates increases the density of AA5052
Effect of Concentration Variation on Optical and Structural Properties of TiO2 Thin Films
No full textConcentrations in weight percent (5- 25 wt %) of TiO2 films used to optimize the film formation. The TiO2 films on glass substrates successfully obtained by spin-coating process using TiO2 nanopowder as precursor. Ultraviolet-Visible (UV-Vis), Scanning Electron Microscopy (SEM) equipped with Electron Diffraction X-ray (EDX) and X-ray Diffractometer (XRD) techniques used to characterize the films. The result of electron transport material (TiO2) showed that film prepared from 15 wt % of TiO2 solution and annealed at 450 has highest transmittance at visible light region with indirect optical band gap of 3.24 eV which corresponds to wavelength of 382 nm whereas 20 wt % has indirect band gap of 2.99 nm equivalent to 414.7 nm . The chemical analysis from Electron Diffraction Spectroscopy (EDS) of the material shows titanium and oxygen present at L and K-shells, respectively. The sample crystallized with preferred orientation at (101) from XRD analysis
Compressive and Flexural Strengths of Concrete Containing Ground Palm Kernel Shells as Partial Replacement of Cement
No full textThis study explore the possibility of using waste ground palm kernel (GPK) shells as partial replacement of cement in concrete using mechanical destructive method has been studied. The palm kernel shells were in two forms: the GPK ordinary shells and shells subjected to incomplete combustion (i.e. the GPK “fuel” shells). In the preparation of the concrete specimens the mix ratio was 1: 2: 4 (cement: sand: stone) by weight and the replacement percentage was 0%, 20%, 30%, 40%, 50% and 60% respectively. Concrete specimen were molded in both cubic and cylindrical form and its impact on the mechanical properties such as workability, compressive strength and flexural strength using destructive test method were studied. The cubic specimen were tested at 7, 28 and 60 days whiles the cylindrical specimen were tested at 7 and 28 days. Results of physical and chemical analyses suggest that GPK “fuel” shells have acceptable cementitious properties whiles GPK ordinary shells does not. Generally, the compressive and flexural strengths of concrete containing GPK shells decrease as the replacement percentage increases. However, the values of these properties increase as the period of curing increases. The optimum level of GPK shells replacement is 20% for the ordinary shells and 30% for the “fuel” shells considering compressive strength at 28 days for the cubic samples. For the flexural strength on the cylindrical specimen, up to 60% replacement of cement by GPK shells cured for 28 days has acceptable flexural strength. In spite of the findings that the GPK ordinary shells do not have cementitious properties, the mechanical properties on such concretes can be used in low strength constructions as pavements, walk ways and non structural domestic work at a lower cost than using cement