Synthesis and Characterization of Zinc (II) Phthalocyanine for Screening Potential Solar Cell Dye Application

Phthalocyanine molecules have the potential to be used in select Dye Sensitized Solar Cells (DSSCs) and Luminescent Solar Concentrators (LSCs), due to UV-Vis absorbance in the 300-450 (nm) Soret Band, corresponding to π HOMO-1 to π* LUMO transition and 550-690 (nm) Q-band, corresponding to π HOMO to π* LUMO transitions. In this study Tetranitro Zinc (II) Phthalocyanine is synthesized via base catalysis before the product is characterized via IR, 1H NMR & UV-Vis analysis. Assessing the desirability of the Tetranitro Zinc (II) Phthalocyanine as a solar organic semiconducting dye in DSSCs and LSCs. The desirability is assessed by novel computational DFT calculations, of the aggregation binding mode to deduce if Aggregation-Caused Quenching (ACQ) is occurring in the aggregated sample. ACQ is known to reduce DSSCs and LSCs generation of useful photo-active current. Aggregation-Caused Quenching (ACQ) is mathematically indicated in Phthalocyanine aggregation and Tetranitro Zinc (II) Phthalocyanine’s desirability is assessed for further use in DSSCs and LSCs.

Comparative Study on Physical and Comfort Properties of Yarns and Hand-woven Fabrics Produced from Virgin and Recycled Fibers

Products 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

Semiconductor 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 cadmium (Cd2+), 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.

Study on Properties of Concrete with Iron Ore Tailing and Glass Waste

The 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.

Mechanical Strengths of Sawdust-Ash-Admixed Gum Arabic Concrete

Gum 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.

Structure and New Substructure of α-Ti2O3: X-ray Diffraction and Theoretical Study

The 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 Review of Alternative Building Materials for Sustainable Construction Towards Sustainable Development

The study reviewed Alternative Building Materials for sustainable construction towards sustainable development. The study was able to identify some Alternative Building Materials, their features, classes (types), and importance for sustainable construction toward sustainable development. The study uses a systematic literature review and content analysis. Some of the Alternative Building Materials include laterite soil, brick wastes, rice husk ash burnt refuse ash, fly ash, periwinkle shell powder, earthworm cast, pulverized burned clay, periwinkle shell aggregate, tubali, earth/mud blocks or bricks, laterite blocks, bamboo for roofing & ceiling, palm front roofing, clay/mud plaster. The classes of the Alternative Building Materials include: modified conventional industrial materials, unconventional/ indigenous/ traditional materials, and modified unconventional/traditional indigenous materials. The features of sustainable construction materials include recyclability, insulation and thermal conductivity and deconstruct ability, availability, manufacturing and price, flexibility and high life time expectancy. The importance of Alternative Building Materials includes: the protection of the environment through reduce energy use and also cutting down CO2 emission, provision of affordable housing, energy conservation, meeting increasing demands for housing stock, provision of employment opportunities, the development and propagation of indigenous technological ingenuity and skills of our local people. The study advocates for the integration of the entire stakeholders in the construction industry towards utilisation of Alternative Building Materials for sustainable construction towards sustainable development. The study also advocates for the cataloguing of all Alternative Building Materials so as to create awareness to all the potential clients and stakeholders of the industry regarding their availability and importance.

Investigation of Failure Criteria and Experimental Process of the Composite Specimen with Mechanical Joints under Tensile Loading

Generally, composite materials are used to obtain better engineering properties, including higher hardness, greater strength, lower weight, heat resistance, moisture and corrosion, which are not present in homogeneous materials such as metals, which are more commonly used in composite design. In this article, experimental study of the composite specimen with mechanical joints under tensile loading, joints of composite material structures, failure criteria in composite materials, tensile impact test is investigated. The results of research work it shows that maximum strength, the hand lay-up can be designed with [0º, 45º, 90º, -45º] s and layers with 45º fibers is very important, because these fibers in these layers have a significant role in increasing the resistance of the piecework under shear stresses due to the passage of stress lines along the hole; In other words, the maximum cut occurs at a 45º angle, and these layers resist this shear stress.

Preliminary Evaluation of Composite Panels Produced from Rice Husk and Recycled Polystyrene Material

Rice 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.

Removal of Heavy Metals from Stormwater Using Porous Concrete Pavement

This study aimed to investigate the heavy metals, i.e. Cu, Pb, Ni, and Zn removal efficiency from stormwater runoff of a porous concrete pavement (PCP). A model of PCP was designed with the porosity and co-efficient of permeability of the pavement were 27.2% and 1.83 cm/sec, respectively. Artificial stormwater containing heavy metals are passed through the pavement at a constant rainfall rate to mimic the stormwater rainfall-runoff condition. The artificial stormwater infiltrated through the pavement were then collected at two different pavement layers at different time instances. From the experimental investigations, it is observed that Cu, Pb, Ni and Zn concentrations are significantly reduced in the treated stormwater. At the first collection point which is located below the sub-base layer and coarse sand layer of the pavement, the concentrations of Cu, Pb and Zn reduced 56%, 67% and 93% respectively compared to their initial concentration, Ni concentration reduced only 20%. At the second collection point which is located below the coarse and fine sand layers beneath the pavement, the concentrations of Cu, Pb, Zn, and Ni are reduced 92%, 89%, 100%, 100%, respectively.