Exploring interfacial interactions,dielectric, ferroelectric and piezoelectric properties of ultrahigh molecular weight polyethylene/graphene oxide nanocomposites

Graphene oxide (GO) incorporated ultra-high molecular weight polyethylene (UHMWPE) nanocomposites were prepared by encapsulating GO by UHMWPE in an aqueous media via high-shear mixing, which were subsequently dried and compression molded. Morphological characterizations via scanning electron microscopy revealed the intercalation of UHMWPE chains in the graphitic stacks corresponding to GO. Further, dielectric permittivity of UHMWPE/GO nanocomposite of 1 wt% GO showed a drastic increase (~61) as compared to pure UHMWPE (~2) due to an enhanced interfacial polarization. A significantly higher value of remnant polarization (~10 nC/cm²) and coercive field (~3 kV/cm) was observed in UHMWPE/GO nanocomposite of 1 wt% GO, which showed a strong hysteresis loop of polarization versus electric field plot as compared to pure UHMWPE, which displayed a very weak hysteresis loop. The piezoelectric coefficient (d₃₃) of ~9.5 pm/V was estimated in UHMWPE/GO nanocomposite of 1 wt% GO via piezoresponse force microscopy. Nanocomposite sensor devices were also fabricated and piezoelectric output voltage of ~6 V was recorded in UHMWPE/GO nanocomposite of 1 wt% of GO. We report here for the first time the unique ferroelectric and piezoelectric properties displayed by UHMWPE/GO nanocomposites.     

Syngas Production via Bi-Reforming of Methane Over Fibrous KCC-1 Stabilized Ni Catalyst

Topics in Catalysis - Bi-reforming of methane (BRM) technology has the potential to serve as an alternative energy source while also mitigating greenhouse gas emissions. However, the main hurdle in...     

Do Energy Resources matter for Growth Level? The dynamic effects of different strategies of renewable energy,carbon emissions on sustainable economic growth

Clean Technologies and Environmental Policy - This study examines the association between renewable energy strategies and carbon emissions on sustainable economic growth under affordable and clean...     

A Facile Microwave Assisted Synthesis of La@PbS Nanoparticles and Their Characterizations for Optoelectronics

Journal of Inorganic and Organometallic Polymers and Materials - In this report, we studied the optical and dielectric properties of lanthanum doped lead sulphide (La@PbS) nanoparticles prepared by...     

Adaptive event-triggered robust H∞ control for Takagi–Sugeno fuzzy networked Markov jump systems with time-varying delay

This paper considers an adaptive event-triggered robust H_∞ control for the Takagi–Sugeno (T-S) fuzzy under the networked Markov jump systems (NMJSs) with time-varying delay. First, a new adaptive event-triggered scheme is developed to guarantee the T-S fuzzy NMJSs, and as a result, communication energy consumption reduced while device efficiency is maintained. Besides, an asynchronous operation method is adopted to deal with the mismatched premise variables between the fuzzy system and the fuzzy controller. One of the main objectives of this article is to construct the fuzzy state-feedback controller (mode-dependent) in a closed-loop form for stochastic stability for all admissible parameter uncertainties with an H_∞ performance index. Different from the conventional triggering mechanism, in this paper, the parameters of the triggering function are based on a new adaptive law that is obtained online rather than a predefined constant. To achieve the less conservative control design, a new type of stochastic Lyapunov–Krasovskii functional is designed by decomposing method, in which the delay interval transforms into various equidistant subintervals in terms of linear matrix inequalities. An example of a truck-trailer application is used to demonstrate the effectively of the proposed algorithms.     

Estimation of Aluminium in HTPB Based Composite Solid Propellants by hydrogen evolution method

Hydrogen gas evolution method has been applied to determine the percentage of aluminium (Al) in hydroxy-terminated polybutadiene (HTPB) based composite solid propellants premix/pastes. The determination is not effected by the presence of Zn, Fe, Cu or small amounts of silicon but magnesium has been found to interfere in the analysis. The results are obtained with remarkable accuracy and reproducibility.     

Effect of temperature on fatty acid composition in the Nile tilapia (Oreochromis niloticus): A temperature dependent nutritive lipid profile

In this study, the effects of temperature on the fatty acids profile and the effects of temperature on the degree of unsaturation of fatty acids of Oreochromis niloticus were investigated. The analysis was performed by gas chromatography. The study showed that there were large temperature variations (10.0–32.0°C) during the study period (January–December). The highest crude fat content was found in January (3380 mg/100 g) and the lowest in June (2050 mg/100 g). The fatty acids profile showed significantly different diversity (p < 0.05). Total saturated fatty acid (∑SFA) content ranged from 409.54 to 1297.61 mg/100 g, monounsaturated fatty acid (∑MUFA) from 207.68 to 665.81 mg/100 g, and polyunsaturated fatty acid (∑PUFA) from 175.12 to 972.23 mg/100 g. The ∑MUFA and ∑PUFA concentrations were highest in January and lowest in June, and the ∑SFA concentration was lowest in January and highest in June. EPA and DHA contents were highest in January (198.96 mg/100 g) and lowest in June (48.76 mg/100 g). The contents of omega-3 (653.17 mg/100 g) and omega-6 fatty acids (252.54 mg/100 g) were highest in January and lowest in June (ω-3; 106.43 and ω-6; 60.91 mg/100 g). It concluded that the degree of unsaturation of fatty acids increases with decreasing temperature. In this study, the nutritional quality of the FAs profile was assessed using lipid quality indices. The indices indicating dietary quality of lipids by their values: Atherogenic index (0.47), thrombogenic index (0.38), hypocholesterolemic to hypercholesterolemic (3.00), meat fat quality (6.78), ω6/ω3 ratio (0.39), PUFA/SFA (2.37), MUFA/SFA (1.62), PUFA/MUFA (1.46), and PUFA + MUFA/SFA (3.99). These values are within the recommended range, indicating that the lipid profile of O. niloticus has high nutritional quality, which can be further improved by harvesting the fish during the winter season. Due to the nutritional importance of O. niloticus, the culture of this species could have significant interest to the people of Karachi, especially the coastal communities. To promote the nutritional diet in local population, the government should support the aquaculture of Nile tilapia.