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Nanoparticles (NPs) are released directly or indirectly into nature with increased production and consumption, and their effects on insects, which occupy a large place in the ecosystem, are of interest. There is also interest in the potentially toxic effects of NPs applied to hive pests on parasitoids, honey bees, and host-parasitoid relationships. The influence of aluminum oxide (Al2O3) NPs on the biological features of the hive pest Galleria mellonella, total counts of hemocyte, and hemocyte types; as well as on the biological features of the endoparasitoid Pimpla turionellae were investigated. The data obtained revealed that Al2O3 NPs caused a decrease in the larval, pupal, and adult development time of G. mellonella. The immature developmental time of P. turionellae was reduced. It was also demonstrated that Al2O3 NPs decreased the total counts of hemocytes in G. mellonella larvae; granulocyte, spherulocyte, oenocytoid, and prohemocyte counts decreased at all NP concentrations, while plasmatocyte counts increased. The data showed that Al2O3 NPs affected the biological properties of the hive pest model organism G. mellonella and indirectly affected its endoparasitoid P. turionellae. In addition, Al2O3 NPs showed a suppressive effect on cellular immune system responses, decreasing hemocyte counts. Our study results suggest that honey bees, honeycomb pests, and parasitoids may be negatively affected by NPs, which have increased in recent years as environmental pollutants, and that NPs may have insecticidal effects. [ABSTRACT FROM AUTHOR]

Abstract Wax deposition in production tubing and pipelines is very critical in Nigeria petroleum industry. It can lead to a reduction in production, shut-in of wells, choking of flow lines, failure of downhole equipment, increased power requirement and loss in revenue. In the bid to address this issue, a Niger Delta crude oil sample was characterized in this study to know its wax deposition tendency and other chemical properties. The effect of temperature on the viscosity of the crude oil sample was studied, and the degree of viscosity reduction (DVR) of the crude oil sample in the presence of poly (ethylene-butene) (PEB) and nano-aluminium oxide (Al2O3) blend at different temperatures was evaluated. 100 ppm of nano-Al2O3 blend with 1000 ppm, 2000 ppm and 5000 ppm of PEB, respectively, was added to the crude oil sample at different temperatures, and the degree of viscosity reduction (DVR) in each blend at 10 °C, 15 °C, 20 °C, 30 °C and 35 °C was evaluated. The blend with 2000 ppm of PEB with 100 ppm nano-Al2O3 is the best for offshore application as it gave the highest DVR of 77.9% and 73.7% at 10 °C and 15 °C, respectively, while the other blends gave a DVR of about 70% at 10 °C and 15 °C. As the crude sample temperature approached the wax appearance temperature of 29 °C, the DVR of PEB/Al2O3 blend drastically reduced. PEB/Al2O3 blend inhibited wax precipitation, and at low temperatures, a significant reduction in the viscosity of the crude oil sample was observed, which makes it a good recommendation for offshore application.

Wax deposition in production tubing and pipelines is very critical in Nigeria petroleum industry. It can lead to a reduction in production, shut-in of wells, choking of flow lines, failure of downhole equipment, increased power requirement and loss in revenue. In the bid to address this issue, a Niger Delta crude oil sample was characterized in this study to know its wax deposition tendency and other chemical properties. The effect of temperature on the viscosity of the crude oil sample was studied, and the degree of viscosity reduction (DVR) of the crude oil sample in the presence of poly (ethylene-butene) (PEB) and nano-aluminium oxide (Al2O3) blend at different temperatures was evaluated. 100 ppm of nano-Al2O3 blend with 1000 ppm, 2000 ppm and 5000 ppm of PEB, respectively, was added to the crude oil sample at different temperatures, and the degree of viscosity reduction (DVR) in each blend at 10 °C, 15 °C, 20 °C, 30 °C and 35 °C was evaluated. The blend with 2000 ppm of PEB with 100 ppm nano-Al2O3 is the best for offshore application as it gave the highest DVR of 77.9% and 73.7% at 10 °C and 15 °C, respectively, while the other blends gave a DVR of about 70% at 10 °C and 15 °C. As the crude sample temperature approached the wax appearance temperature of 29 °C, the DVR of PEB/Al2O3 blend drastically reduced. PEB/Al2O3 blend inhibited wax precipitation, and at low temperatures, a significant reduction in the viscosity of the crude oil sample was observed, which makes it a good recommendation for offshore application. [ABSTRACT FROM AUTHOR]

The study investigates the effect of aluminium oxide nanoparticles as additive to pongamia methyl ester (PME) blends on performance, combustion and emission characteristics of a single cylinder direct injection diesel engine operated at constant speed at different operating conditions. The test fuels are indicated as B25 (75% diesel and 25% PME) and B25A50 (75% diesel and 25% PME and 50 ppm Aluminium oxide nanoparticles) and B25A100 (75% diesel and 25% PME and 100 ppm Aluminium oxide nanoparticles) respectively. The results indicate that the brake thermal efficiency for aluminium oxide nanoparticles blended pongamia methyl ester increases slightly while brake specific fuel consumption (BSFC) decreases when compared to other blends. The carbon monoxide (CO), unburnt hydrocarbon (HC) and smoke emission marginally decreases as compared to mineral diesel. Oxides of nitrogen (NO x ) emissions are higher for aluminium oxide nanoparticles blended pongamia methyl ester. Higher cylinder gas pressure and higher heat release rate were observed for aluminium oxide nanoparticles blended pongamia methyl ester. From the study, the blending of aluminium oxide nanoparticles in biodiesel blends produces most promising results in engine performance and also reduces the harmful emission from engines. [ABSTRACT FROM AUTHOR]

Recently, the biosafety and potential influences of nanoparticles on central nervous system have received more attention. In the present study, we assessed the effect of aluminium oxide nanoparticles (Al2O3-NPs) on spatial cognition. Male Wistar rats were intravenously administered Al2O3-NP suspension (20 mg/kg body weight/day) for four consecutive days, after which they were assessed. The results indicated that Al2O3-NPs impaired spatial learning and memory ability. An increment in malondialdehyde levels with a concomitant decrease in superoxide dismutase activity confirmed the induction of oxidative stress in the hippocampus. Additionally, our findings showed that exposure to Al2O3-NPs resulted in decreased acetylcholinesterase activity in the hippocampus. Furthermore, Al2O3-NPs enhanced aluminium (Al) accumulation and disrupted mineral element homoeostasis in the hippocampus. However, they did not change the morphology of the hippocampus. Our results show a connection among oxidative stress, disruption of mineral element homoeostasis, and Al accumulation in the hippocampus, which leads to spatial memory deficit in rats treated with Al2O3-NPs. [ABSTRACT FROM AUTHOR]

Highlights: [•] Trophic transfer of alumina nanoparticles using Chlorella ellipsoides and Ceriodaphnia dubia. [•] Subtle alterations in the feeding behaviour of the daphnids. [•] Disruption the energy flow through the food chain. [•] Transmission electron microscopy validated the disrupted feeding behaviour. [Copyright &y& Elsevier]

Abstract: The growing commercial applications had brought aluminium oxide nanoparticles under toxicologists’ purview. In the present study, the cytotoxicity of two different sized aluminium oxide nanoparticles (ANP1, mean hydrodynamic diameter 82.6±22nm and ANP2, mean hydrodynamic diameter 246.9±39nm) towards freshwater algal isolate Chlorella ellipsoids at low exposure levels (≤1μg/mL) using sterile lake water as the test medium was assessed. The dissolution of alumina nanoparticles and consequent contribution towards toxicity remained largely unexplored owing to its presumed insoluble nature. Herein, the leached Al3+ ion mediated toxicity has been studied along with direct particulate toxicity to bring out the dynamics of toxicity through colloidal stability, biochemical, spectroscopic and microscopic analyses. The mean hydrodynamic diameter increased with time both for ANP1 [82.6±22nm (0h) to 246.3±59nm (24h), to 1204±140nm (72h)] and ANP2 [246.9±39nm (0h) to 368.28±48nm (24h), to 1225.96±186nm (72h)] signifying decreased relative abundance of submicron sized particles (<1000nm). The detailed cytotoxicity assays showed a significant reduction in the viability dependent on dose and exposure. A significant increase in ROS and LDH levels were noted for both ANPs at 1μg/mL concentration. The zeta potential and FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (SEM, TEM, and CLSM). At 72h, significant Al3+ ion release in the test medium [0.092μg/mL for ANP1, and 0.19μg/mL for ANP2] was noted, and the resulting suspension containing leached ions caused significant cytotoxicity, revealing a substantial ionic contribution. This study indicates that both the nano-size and ionic dissolution play a significant role in the cytotoxicity of ANPs towards freshwater algae, and the exposure period largely determines the prevalent mode of nano-toxicity. [Copyright &y& Elsevier]