Pineapple leaf fibers (PALF), as the part of a large productive system, based on the availability of fruits for the food industry, offer a large amount of possibilities in term of use of the fibers, which are almost exclusively dedicated to the field of materials, as the reinforcement of polymer matrices, either traditional oil-based ones or biodegradable ones. Pineapple fibers, due to their suitability to textile use, can be introduced into composites not only in the form of short fiber, although the latter remains the most frequent case. As the consequence of this, they are also of interest of the automotive industry, an interest, which is steadily and rapidly growing especially in the last few years. This review tries to elucidate what are the characteristics of pineapple fibers that are particularly important for the automotive industry together with trying to clarify which could be the possibilities in the next future for their wider introduction in this sector.
The knowledge of the mechanical properties of agricultural products plays an essential role during the design, development, programming and utilization of their automated harvesting, handling and processing machines. The aim of this study was to investigate the influence of field practices (pre-harvest treatments) on some mechanical properties of eggplant (Solanum aethiopicum L.) fruits, necessary for the automation of agricultural production. Eggplant (cv. Djamba) was cultivated in the field trial, in four different treatments mediums, which were: Zero amendment (also referred to as the control), organic manure, potassium nitrate (KNO3) and combination of organic manure and KNO3. The eggplant fruits were harvested at peak maturity (35 days after flowering), and their mechanical properties tested, according to standard procedures. Results obtained revealed that field practices had a significant (p ≤0.05) effect on all the mechanical properties investigated. The fruits produced by using the combination of organic manure and KNO3 had superior mass, when compared with other treatments options. The control fruits exhibited the poorest failure force (305.58 N) and failure energy (3.895 Nm); while the fruits cultivated with the combination of organic manure and KNO3 had the highest failure force and failure energy of 636.6 N and 5.312 Nm respectively. The study revealed that the fruits produced with organic manure exhibited superior failure force and failure energy, compared to the fruits produced with KNO3. Additionally, the fruits produced by using organic manure, exhibited the highest deformation (24.01 mm) at failure point; while the control fruits recorded the lowest deformation (18.8 mm). Regarding the puncture properties, the tissues of the fruits produced with organic manure had the least resistivity to puncture force (50.30 N); which was lower than the puncture force of 65.73 N recorded by the control fruits. The highest resistance to puncture force (89.17 N) was observed in the fruits cultivated with KNO3. These results will help to optimize the efficiency of eggplant fruits harvesting and handling machines; thereby reducing the rate of mechanical damage being done to the harvested products.
Usage of alternative fine aggregates in concrete and cement mortar has been gradually increasing by the construction industries around the world due to the escalated shortage in obtaining natural river sand. Manufactured sand and offshore sand can be considered as the principal alternatives which are consumed by most of the contractors for substituting river sand in the construction activities now. However, most of the above sand consumptions are done without deeply analyzing the conformity of the alternatives to concrete and cement mortar. The present study is executed to inspect the fitness of manufactured sand from two different high-grade metamorphic rocks, offshore sand, and blended sands of both manufactured sand types at 25%, 50% and 75% replacement levels with offshore sand to be practiced in concrete and cement mortar by scrutinizing physical properties and quality through series of characterizing experiments. Results reveal that blended sand with all replacement levels can be suitable with respect to particle characteristics such as angularity, surface texture and total specific surface. Regarding resultant particle size distribution, blended sands with 50% replacement level can be the optimum solution in reference to uniform gradation, the density of sand mix, and fineness. 50% and 75% contents of manufactured sand in combined sand types show higher loose and packing densities than river sand. Flowability under the gravity of blended sand types contain 50% to 75% of offshore sand are performed well contemplating different affecting parameters. However, increased manufactured sand content demands more water than river sand and offshore sand. Additionally, hazardous materials such as clay lumps and friable particles, fines and silt are identified within the permissible range based on the requirements by the standard available. Regarding all the above characteristics, blended sands contain two manufactured sand types with 50% replacement level with offshore sand can be suggested as the optimum substitution for river sand in terms of fresh and hardened state properties of concrete and cement mortar.
This study was aimed to evaluate the residual heavy metals concentrations, within the soil of a former petroleum spill site. Soil samples were spatially collected from five locations within a former petroleum spill site, located at Ozoro in Isoko North Local Government Area of Delta State, Nigeria. The concentrations of seven heavy metals (Ni, Cu, Zn, Pb, Cd, Fe and Al) in the soil (0–25 cm) were collected were determined, using the Atomic Absorption Spectrometer. In addition, soil contamination factor and Pollution Load Index were used to assess the heavy metals contamination and distribution within the study area. Results of the soil analysis revealed that the concentrations of the heavy metals were generally higher, when compared with results recorded from the Reference Point. Cadmium (Cd) concentration within the study area exceeded the maximum permissible limit, recommended by World Health Organization (WHO) for soils; while the others heavy metals concentration fall below the maximum permissible limit recommended by WHO for soil. The results revealed that spatial point 3, recorded the highest heavy metals concentrations across the study area. Generally, the contamination factor results showed that there is a considerable degree of residual heavy metals contamination in the cleaned up petroleum spill site. Likewise, the Pollution Load Index results showed that spatial points 2, 3 and 5 zones were highly polluted with heavy metals; while spatial points 1 and 4 zones were moderately polluted with heavy metals. This study exhibited the importance the oil companies to carry out remediation follow-up in petroleum spill area, to avoid accumulation of residual heavy metals in the environment.
This study determined the caloriﬁc value of briquettes made from Pinus caribaea and Eucalyptus citirodora. Sawdust samples were collected from a sawmill in Buruku, Kaduna State. The briquettes were produced in a manually operated hydraulic briquette machine with binder in percentage mixing ratio (starch: binder) 50:50, 60:40 and 70:30. Three (3) replicates of each mixing proportion were produced making a total number of eighteen products. Calorific tests were carried out on the samples using the Gallenkhamp Calorimeter to determine their energy contents. The results indicated that the addition of starch in various proportion increases the average caloriﬁc value when compared to the briquettes produced from 100% pure sawdust material (Control). Also, the result from the Analysis of Variance (ANOVA) showed that the effect of variation of the different proportion of binder on the caloriﬁc value is highly signiﬁcant at P<0.05). In the briquettes, the physical properties of materials used for briquette production, also affects the physical properties of briquettes used in this study e.g moisture contents and density.