Browse

1 - 10 of 2,312 items :

Clear All

Abstract

Studies on the adsorption of Pb(II) on plantain peels biochar (PPB) was conducted. The carbonized and activated, biochar was characterized using Braunauer-Emmett-Teller (BET) surface area and x-ray diffraction crystallography (XRD). BET analysis of the PPB indicated that the pore size (cc/g) and pore surface area (m2/g) was 8.79 and 16.69 respectively. Result of the XRD evaluated through Debye-Scherrer equation, showed a nanostructure with crystallite size of 14.56 nm. Effects of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Results showed that the adsorption of lead from aqueous solution increased with an increase in pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Weber and Morris intraparticle diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies indicated the potential of plantain peel biochar as an effective, efficient and low cost adsorbent for remediating lead (II) ions contaminated environment.

Abstract

Hormonal changes in humans and animals can be attributed to endocrine disrupting chemicals (EDCs). Studies have found that excessive exposure to natural and artificial environmental chemicals and toxins can have adverse effects on the endocrine system and reproductive health. The endocrine system creates and releases hormones that regulate the development of organs and how they function. Any disruption to hormones affects the development and functioning of the reproductive system, the brain and the neurological system. Research and reports on the subject have been published by international experts and organizations including the World Health Organization (WHO), United Nations Environment Programme (UNEP), International Labour Organization (ILO) and Endocrine Society. To fully comprehend the effect of EDCs on humans and wildlife, it is essential to understand epigenetics and its transgenerational effects on hormone development. Here, we extensively explore and review the research on the sources of EDCs, their effects and why exposure to EDCs is of concern, and treatments for EDC exposure.

Abstract

The ingestion of aluminum from food containers such as cookware, cans, utensils and wrappings and its subsequent release into the environment is a growing public health concern. Aluminum is widely used in manufacturing cookware due to its malleability, high heat conductivity, light weight, durability, availability and affordability. This paper therefore gives a review of most relevant literatures on the benefits and risks of the various types of aluminum cookware in use, the composition and the public health effects of aluminum ingestion. Studies that reported the leaching of aluminum from cookware into food and environmental effects of aluminum leaching were also reviewed. In the developing countries, aluminum cookwares are produced from scrap metals and has been reported to leach harmful substances including heavy metals such as: nickel, arsenic, copper, cadmium, lead, and aluminum into cooked food. Several factors have been reported to increase the rate of leaching of metals from aluminum cookwares. Exposure to metals from aluminum cookware and the public health effects have not been well studied, hence, our recommendation for more studies to elucidate the health effect of this practice. This review also presents measures that can limit exposure to the risks that may arise from the use of aluminum cookware.

Abstract

Single cell supercapacitors with electrodes of varying amounts of graphene and carbon black, formed via the electrospinning process with a carbon-based Polyacrylonitrile (PAN), were tested in 1M H2SO4. From the tested samples, the overall data indicates no correlation between impedance and capacitance energy values. However, the breakdown of the various samples showed mixed results of; good correlations between lower impedance resulting in higher and lower capacitance; while other samples showed higher impedance correlating to both higher and lower capacitance. No correlation was observed between the Impedance value and the thickness of the samples. Furthermore, carbon mole content was not a major factor in determining impedance; therefore, structure is not a major contributor to impedance. Whereas, carbon mole content is a major contributor to capacitance energy; Hence, impedance provides an alternative control point to increasing energy ( 2-10X times ), that can be retrofitted to existing systems, or to increase the energy storage beyond current levels by adjusting/controlling impedance in new designs. The data is indicating impedance is not constant and is varying. The mechanism of varying impedance is unclear and requires further research. However, it is thought to mimic the energy level and stability of matter (atoms). Therefore, impedance varies or oscillates accordingly to achieve an impedance level stability, and hence the term “Orbital Impedance Stability”. Thoughts into Impedance being an Energy Field, to be provided in next publication (In-sha’-ALLAH). This research is concluding that our conventional understanding of impedance is limited in scope. New approaches and further research is needed to better understand impedance behavior. A better understanding of impedance is essential to a breakthrough in energy storage devices from capacitors and batteries, to electric generation and distribution of energy, to magnetic levitation, medical drugs and other energy improvements.

Abstract

An experiment was carried out to study the effect of post-harvest dipping and various packaging materials on quality traits of mandarin at the laboratory of Project Implementation Unit (Citrus zone) Udayapur, Katari from January to February 2019. The parameters observed were physiological loss in weight, juice content, titrable acidity, total soluble solids, TSS/TA ratio and shelf life. The packaging materials include individual newspaper wrapping, perforated polyethene and corrugated box. Gibberellic acid with a concentration of 100 ppm was used as a dipping material. The experiment was laid out in Completely Randomized Design (CRD) with 8 treatment replicated 3 times. The result showed that among eight treatments combination, fruits treated with GA3 in combination with perforated polyethene recorded minimum physiological loss in weight (1.99%) and control (19.08%). High retention of juice content (40.30%), total soluble solids(12.83 brix) and titrable acidity (0.60%) was recorded in fruits treated with GA3 in combination with perforated polyethene in 24 days of storage. Fruits treated with GA3 in combination with perforated polyethene attained shelf life of 48 days followed by perforated polyethene with a shelf life of 44 days. Finding of the experiment may prove to be helpful in rural area to store mandarin with minimum loss as markets are far from the village.

Abstract

The volume of pharmaceuticals discharged into the environment increases daily as a consequence of human life. In the present study, the seasonal variation of ibuprofen in sediment, biota, water, and their exposure risk were investigated in River Owena and Ogbese, Nigeria. The high-performance liquid chromatography coupled to a mass spectrometer (HPLC-MS/MS) was used to analyze the samples after clean up and pre-concentration by solid-phase extraction. The mean concentration of IBU in the samples spanned a range of 1.75 - 2.75 μg/g in sediment, 0.01 – 15.00 μg/g in fish, and 0.00002 – 0.005 μg/ml in water. The measurement of IBU in the sediment and water was significantly elevated in the dry season than the wet season, whereas the opposite was the case in biota. There was a significant interaction between season, media, and rivers with respect to IBU occurrence in the sampled rivers. The calculated bio-water accumulation factor (BWAF) was as high as 750,000 μg/g in fish, proving IBU is extremely bio-accumulative. The ecotoxicological risk assessment for average and worst possible outcome showed that the risk quotient (RQ) for IBU present in the water was sufficient to cause toxicity to fish in both freshwater bodies. The potential bioavailability of IBU to aquatic fauna for prolonged periods spanning several months can result in its circling back into the food web afterward. The baseline info provided by this study in these freshwaters may provide valuable information for the implementation of safety limits for the management of IBU influx into the environment.

Abstract

The allelopathic potential of essential oil extracts from Artemisia herba-alba Asso. was assessed on seed germination of nine weeds and two wheat varieties. The samples were collected from El-Rasfa région (Sétif, Algeria). The essential oil was extracted using hydrodistillation of aerial part and characterized using gaz chromatography coupled with mass spectroscopy. The bioassays with organic solvent (ethanol) were tested using four different concentrations (0.2, 0.4, 0.6 and 0.8 µl/ml of oil/ethanol) on seed and seedling growth of the nine weeds and two wheat varieties. The yield obtained is 1.19%, and 36 compound had been identified. The main components are: camphor (28.58%), cis-thujone (22.03%), eucalyptol (11.65%) and trans-thujone (7.03%). The results of bioassays show that essential oil extracts has a significant effect on seed germination and seedling growth of the major weed tested and two wheat varieties. In conclusion, this study shows that the essential oil tested has an interesting allelopathic potential.

Abstract

The experiment was conducted at the level of a pilot farm located in eastern Algeria under a humid bioclimatic stage, during two successive crop years. The study focused on a F1 generation of barley (Hordeum vulgare L.) consisting of twelve hybrids from a complete diallel cross between the two locals varieties (Saida and Tichedrett) and two other introduced varieties (Nadawa and Fouara). The aim was to determine the value of parental genotypes as genitors and to analyze their descendants, while evaluating the phenotypic variability of ten quantitative variables. Analysis of the variance revealed a significant difference for the whole of parameters studied in the parents as in their descendants. Additive and non-additive effects are involved in the genetic control of the analyzed variables. The Hayman model (1954) seems acceptable for five variables on ten variables studied for which additive effects are more important than dominance effects. The analysis of the heterosis effect was significant for the characters tested. For the productivity of the plant, eight hybrids on twelve have expressed a positive heterosis compared to the mid- parent, six combinations on twelve have registered a positive heterosis compared to the over-batter parent and compared to the best variety with an overall heterosis of 17.53%.

Abstract

This study was conducted to evaluate anti-acetylcholinesterase and insecticidal and antifungal activities of the endophytic fungus Trichoderma sp, isolated from Ricinus communis L. leaves, against Locusta migratoria L. and Botrytis cinerea Pers.: Fr.. To evaluate the insecticidal and antifungal activities, different concentrations of the fungal extract were applied against L. migratoria (0.2, 0.3, 0.4 g/l) and against B. cinerea (1, 2, 3 g/l). It was found that the mortality of the targeted insects was positively proportional to fungal extract concentration and time after exposure (24, 48, 72 hours). The concentration 0.4 g/l appeared to be the most effective after 72 hours with mortality rate of 56.52%. Regarding antifungal activity, the concentration 3 g/l was the most effective against B. cinerea after 7 days, with an inhibition rate of 92.06% (excellent antifungal activity). Moreover, it was found that at 4 ug/ml the fungal extract had a maximum inhibitory capacity of Ache of 80% for acetylcholenesterase. Preliminary phytochemical analyses revealed the presence of alkaloids, flavonoids, phenols and saponins. In addition the colony of this endophytic fungus produced chitinases and proteases, which explained its important antifungal and insecticidal activities.