Effect of nickel oxide - Modified BaCe0.54Zr0.36Y0.1O2.95 as composite anode on the performance of proton-conducting solid oxide fuel cell

The effect of NiO-m-BCZY64 (BCZY64 = BaCe_0.54Zr_0.36Y_0.1O_2.95) as a composite anode with a single anode functional layer (AFL) and gradient AFL on the performance of a button cell was systematically evaluated. The m-BCZY64 is referred to the pristine BCZY64 that was modified by a functionalized activated carbon derived from palm-oil empty fruit bunch (EFB). The electrochemical performance of the cell was investigated by impedance spectroscopy in a controlled atmosphere. The NiO-m-BCZY64 exhibited smaller grain size and homogenous elemental distribution compared to pristine NiO-BCZY64 as observed by SEM/EDX. At T = 800 °C, a button cell consists of NiO:m-BCZY64 with gradient AFL showed the best performance with total resistance (R_T) of 21.12 Ωcm² compared to the cell with single AFL (R_T = 86.04 Ωcm²) and pristine NiO-BCZY64 (R_T = 145.64 Ωcm²). The significant reduction of R_T indicates that the NiO:m-BCZY64 with gradient AFL showed high potential to be used as a composite anode for proton-conducting solid oxide fuel cells.     

A comprehensive study on copper incorporated bio-glass matrix for its potential antimicrobial applications

In this study, sol-gel derived Cu substituted 70S bioglass (70SiO2-(20-x) CaO–10P2O5-xCuO; where x = 0, 0.5, 1, 1.5) were synthesized as a new multifunctional bioactive glasses (BGs). The effect of Cu substitution in the bio-glass matrix was evaluated for its impact on pathogen (Escherichia coli and Staphylococcus aurous). Fourier Transform Infrared spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD), Inductively Coupled Plasma spectroscopy (ICP) and Scanning Electron Microscopy (SEM) revealed that the obtained powders are amorphous silicate glass. The substituted element is present in the desired molar concentration. In vitro bioactivity test was performed in SBF solution by immersion of bioglass pellets. Antibacterial test was carried out against Escherichia coli and Staphylococcus aureus. The results showed that the prepared BGs have a high acellular bioactivity observed by a fast formation of thick and continuous layer of carbonated hydroxyapatite (CHA). The antibacterial properties of the substituted bio-glass matrix was indicated by the growth inhibition of bacterial colonies. The obtained results showed that copper substituted bio-glass is having potential to avoid post-surgical infections and it also represents the capability of hard tissue regeneration.     

Lactobacillus plantarum DR7 improved upper respiratory tract infections via enhancing immune and inflammatory parameters: A randomized,double-blind,placebo-controlled study

The aims of this study were to investigate the effects of Lactobacillus plantarum DR7 isolated from bovine milk against upper respiratory tract infections (URTI) and elucidate the possible mechanisms underlying immunomodulatory properties. The DR7 strain (9 log cfu/d) was administered for 12 wk in a randomized, double-blind, and placebo-controlled human study involving 109 adults (DR7, n = 56; placebo, n = 53). Subjects were assessed for health conditions monthly via questionnaires, and blood samples were evaluated for cytokine concentrations, peroxidation and oxidative stress, and gene expression in T cells and natural killer (NK) cells. The administration of DR7 reduced the duration of nasal symptoms (mean difference 5.09 d; 95% CI: 0.42–9.75) and the frequency of URTI (mean difference 0.32; 95% CI: 0.01–0.63) after 12 and 4 wk, respectively, compared with the placebo. The DR7 treatment suppressed plasma proinflammatory cytokines (IFN-γ, TNF-α) in middle-aged adults (30 to 60 yr old), while enhancing anti-inflammatory cytokines (IL-4, IL-10) in young adults (<30 yr old), accompanied by reduced plasma peroxidation and oxidative stress levels compared with the placebo. Young adults who received DR7 showed higher expression of plasma CD44 and CD117 by 4.50- and 2.22-fold, respectively, compared with the placebo. Meanwhile, middle-aged adults showed lower expression of plasma CD4 and CD8 by 11.26- and 1.80-fold, respectively, compared with the placebo, indicating less T-cell activation. In contrast, both young and middle-aged adults who received DR7 showed enhanced presence of nonresting and mature NK cells compared with those who received the placebo. We postulate that DR7 alleviated the symptoms of URTI by improving inflammatory parameters and enhancing immunomodulatory properties.     

Indigenous marine diatoms as novel sources of bioactive peptides with antihypertensive and antioxidant properties

Several bioactive compounds from microalgae have demonstrated diverse biological activities with positive effects on human health. However, the potential of bioactive peptides as functional foods is still undervalued. Therefore, the exploration of microalgae strains as sources of bioactive peptides could reveal strong and unique bioactivities, especially when these marine sources have never been explored before. For this aim, protein extracts from six indigenous marine diatoms were subjected to enzymatic hydrolysis using four proteases (flavourzyme, pepsin, papain and trypsin). The hydrolysates were then tested for angiotensin converting enzyme (ACE)-inhibitory, antioxidant and antihypertensive properties. Results showed that papain hydrolysates from all microalgae strains exhibited strong ACE-inhibitory activities and antioxidant properties. In particular, protein hydrolysates from Bellerochea malleus were found to reduce blood pressure properties of 17 mmHg after 5 days of oral administration to SHR animals. These results revealed the potential of bioactive peptides from indigenous marine diatoms for use as functional foods or nutraceuticals.     

Towards optimal synchronization in NFV-based environments

Network Function Virtualization (NFV) is known for its ability to reduce deployment costs and improve the flexibility and scalability of network functions. Due to processing capacity limitations, the infrastructure provider may need to instantiate multiple instances of the same network function. However, most of network functions are stateful, meaning that the instances of the same function need to keep a common state and hence the need for synchronization among them. In this paper, we address this problem with the goal of identifying the optimal synchronization pattern between the instances in order to minimize the synchronization costs and delay. We propose a novel network function named Synchronization Function able to carry out data collection and further minimize these costs. We first mathematically model this problem as an integer linear program that finds the optimal synchronization pattern and the optimal placement and number of synchronization functions that minimize synchronization costs and ensure a bounded synchronization delay. We also put forward three greedy algorithms to cope with large-scale scenarios of the problem, and we explore the possibility to migrate network function instances to further reduce costs. Extensive simulations show that the proposed algorithms efficiently find near-optimal solutions with minimal computation time and provide better results compared to existing solutions.     

Influence of graphene oxide surface treatment by diazonium salts on thermoelectrical behavior of polypyrrole-based composites

Journal of Materials Science: Materials in Electronics - In this study, we investigate the influence of crude and surface-treated graphite by diazonium salt on the thermoelectric (TE) properties of...     

A review of solid oxide fuel cell component fabrication methods toward lowering temperature

The solid oxide fuel cells (SOFCs) emerge as an alternative power generation system for high-scale stationary application and power plant station. The SOFC consumption leads to the high-efficiency energy production that forms variety of fuels up to 60% energy conversion; the operation system does not involve the burning process and minimizes the air pollution. Also, the aptitude to provide the cogenerative energy production from the heat waste during the operation process serve SOFC as an attractive green technology and environmentally friendly. However, the SOFC consumption remains limited for transportation and portable applications because the simple design of power source compartment is still the major hurdle in each SOFC component development and commercialization. Therefore, the appropriate fabrication method of each SOFC component is important to achieve the reliability of the SOFC application for the small-scale power generation design. In this paper, an overview of the design types and SOFC components and properties following electrode, electrolyte, interconnect and sealant are discussed and summarized. As the third-generation fuel cells, which entice the commercialization stage, this paper concentrates more on the fabrication method of each SOFC components that were explored including the working principle, advantage, disadvantage and several previous works on each fabrication method, which are described to finding the appropriate fabrication method toward lowering the operating temperature and develop the simple design of SOFC power sources system for the transportation and portable application. The targeted market power production of SOFC system for transportation application is about 5 kW and 250 W for portable application.     

Smoothing of Wind Power Fluctuations for Permanent Magnet Synchronous Generator-Based Wind Energy Conversion System and Fault Ride-through Consideration

Due to the increment of penetration level of wind power generation, output power fluctuation is one of the most important issue's that can destabilize the power system operation. This article mainly deals with the smoothing of the output power fluctuations of a wind energy conversion system based permanent magnet synchronous generator and fault ride-through enhancement during a grid fault. The concerned wind energy conversion system based permanent magnet synchronous generator adopts an AC-DC-AC converter system. The proposed control method limits the wind energy conversion system output power by adjusting the pitch angle of the wind turbine blades when wind speed is above the rated wind speed. In the grid-side converter, a fuzzy logic controller is used to determine the torque reference for which the kinetic energy stored by the inertia of wind turbine can smooth the output power fluctuations of the permanent magnet synchronous generator. Also, the DC-link voltage, controlled by the grid-side inverter, is adjusted in accordance with the output power fluctuations of the permanent magnet synchronous generator using a voltage smoothing index. Moreover, in this aticle, the proposed method ensures that the wind turbine stays operational during grid faults and provides fast restoration once the fault is cleared. To show the effectiveness of the proposed method, simulations under different conditions have been performed by using MATLAB/Simulink® (The Math Works, Natick, MA, USA).     

Thermo‐electric‐visco‐elastic material

In this work, we introduce the Seebeck effect in Ohm's law and Thomson heating effect in generalized Fourier's law, to the equations of the linear theory of electro‐magneto‐thermoviscoelasticity, allowing the second sound effects. A normal mode analysis is used. The resulting formulation is applied to a problem of a rotating thick plate subject to heat on parts of the upper and lower surfaces of the plate that varies exponentially with time. The exact formulas of temperature, displacement, stresses, electric field, magnetic field, and current density are obtained. The considered variables are presented graphically and discussions are made. Seebeck and Peltier effects on thermoelectric viscoelastic material are studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010