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A serial of cerium phosphate/reduced graphene oxide (CePO4-rGO) composites were synthesized for the first time by one-pot hydrothermal method. Structural analyses revealed that flaky CePO4 and few-layer rGO were composited homogeneously. It is found that rGO can greatly enhance the conductivity and the adsorption capacity of the composite. With these advantages, the constructed composites were used for electrochemical detection of dopamine (DA) and acetaminophen (APAP). Further studies show that the loading amount of rGO was also very important. When CePO4−0.6rGO was used, wide linear ranges of 1.2−50 μM for DA and 0.5−30 μM for APAP can be obtained, respectively. The detection limits of DA and APAP were 0.013 μM and 0.025 μM with high sensitivities of 25.58 μA μM−1 cm−2 and 13.30 μA μM−1 cm−2 , respectively. Moreover, the modified electrode also has high selectivity, good stability and satisfactory reproducibility. In addition, the modified electrode was also successfully applied to detect DA and APAP in real urine samples. This work provides a simple method for preparing new electrode materials for detecting small biomolecules. [ABSTRACT FROM AUTHOR]

Membrane electrode assembly (MEA) is a core component of fuel cells, and its durability constitutes the bottleneck of fuel cells commercialization. In this paper, the effects of relative humidification (RH) on durability of membrane electrode assembly (MEA) are studied by the limiting current method. In-situ durability tests are carried out for 2040 h under constant current density of 800 mA cm-2 and relative humidification (RH) of 70%. The results are then compared to those of our previously published 1465h-MEA obtained for 1465 h under 100% humidification. The degradation in the voltage during the process is analyzed, and degradation mechanisms are investigated by electrochemical impedance spectroscopy and limiting current methods to analyze the change in oxygen transport resistance of the gas diffusion layer. The data suggest that the decline in the humidification can greatly improve the durability of MEAs, especially from 0 to 1000 h. The voltage decay rate of 2040h-MEA is half that of 1465h-MEA. The main degradation occurs in the substrate layer after durability tests for 2040 h under 70%RH. By comparison, 1465h-MEA operating at 100% RH shows a serious decay not only in the substrate layer but also in the MPL, as confirmed by the changes in contact angles. [ABSTRACT FROM AUTHOR]

In this work, γ-Fe2O3/CNTs composite was facile synthesized by simple hydrothermal method and hydrazine hydrate treatment at low temperature (CNTs = carbon nanotubes). The result of VSM shows that the saturation magnetization of Fe2O3/CNTs composites increase from 0 to 1.29 emu g-1 after hydrazine hydrate treatment, indicating that the Fe2O3 in the composite transforms from a phase to γ phase. Moreover, the electrochemical properties of both a-Fe2O3/CNTs and γ-Fe2O3/CNTs was studied. Compared with a-Fe2O3/CNTs, γ-Fe2O3/CNTs shows enhanced electrochemical performance toward paracetamol determination. Under optimum condition, the γ-Fe2O3/CNTs modified electrode exhibits two linear ranges of 2.5 µM-385 µM and 593 µM-1550 µM and a low detection limit of 0.046 µM. In addition, the constructed sensor can be successfully utilized for detecting paracetamol in different water bodies. This work provides a new clue for the design and construction of excellent electrochemical sensor for paracetamol determination. [ABSTRACT FROM AUTHOR]

The effect of prechlorination on atrazine (ATZ) removal by conventional water treatment process were investigated, and the influence of the key parameters (oxidant concentration, oxidation time, pH, and coagulation conditions) on ATZ removal were evaluated systemically. Results showed that the facilitated effect of prechlorination was limited and the maximum removal efficiency discrepancy is only 15% compared with that by the treatment process without prechlorination. The granular activated carbon (GAC) adsorption filter showed more significant effect than prechlorination. Hence, to ensure the safety of drinking water supply, another oxidant, combined with GAC adsorption and nanofiltration treatment would be an alternative way for ATZ removal in the conventional water treatment process. [ABSTRACT FROM AUTHOR]

In the absence of halogen ion, the convection-dependent competitive adsorption between bis(3-sulfopropy)-disulfide (SPS) and poly(ethylene glycol)-block-poly(propylene glycol) copolymer (EO/PO) on unpowered (in open circuit) copper surface is found in sulfuric acid solution. Galvanostatic measurements and electrochemical impedance spectroscopy were employed to analyze this particular adsorption behavior, revealing that the adsorption of EO/PO is enhanced by increased local convection intensity. The molecular dynamic simulation demonstrates that the increase of EO/PO adsorption decreases the adsorption of coexisting SPS on copper surface, supporting that the enhanced EO/PO adsorption in strong convection condition leads to the decrease of coexisting SPS adsorption on copper surface with the increase of convection intensity. The study of this convection-dependent competitive adsorption behavior enriches the understanding for the convection-dependent adsorption (CDA) behavior on electrolytic copper 'bottom-up' filling. Besides, the competitive adsorption behavior serves as a powerful handle to manipulate the accumulation of SPS at via or trench bottom before electroplating for improving the efficiency of via or trench filling. For example, the silicon wafer trench filling by copper electroplating is significantly accelerated with the introduction of convection-dependent competitive adsorption. Furthermore, a possible mechanism for accelerating trench filling by pre-adsorption process of SPS together with EO/PO is proposed. [ABSTRACT FROM AUTHOR]

To reduce the peak load, dynamic electricity price schemes have been widely used. Refrigerated warehouses consume a large amount of energy, most of which happens during the daytime due to the higher ambient temperature. This work evaluated the potential benefits of integrating energy storage in the refrigerated warehouses. Two types of energy storage systems have been considered, including a cold energy storage system and an electrical energy storage system. A dynamic model has been developed in TRNSYS to study the performance of those two energy storage systems and assess the benefits. Results show that using the cold energy storage to shift power consumption from daytime to nighttime can increase the energy efficiency of the refrigeration system. However, as the electrical energy storage system can shift more power consumption, it can achieve a large cost saving. Compared to the reference system without energy storage, the introductions of a cold energy storage system and an electrical energy storage system can reduce the operational cost by 10 and 53.7% respectively. [ABSTRACT FROM AUTHOR]

A practical fast microvia fillingmethod in copper electroplating is developed with the aid of bottom-localized pre-adsorption of bis(3- sulfopropy)-disulfide (SPS). The pretreatment initiates with accelerator adsorbed at all copper surface. Subsequently, the adsorbed SPS on board surface is broken down by sodium persulfate, but the function of adsorbed SPS at microvia bottom is mostly retained due to the mass transfer limitation. The pre-adsorbed SPS at microvia bottom improves the accumulation of SPS at microvia bottom in electroplating filling, resulting in the speeding up of microvia filling. [ABSTRACT FROM AUTHOR]

Organic Rankine Cycle(ORC) can effectively recover the low grade heat source due to its distinctive thermodynamic performance. Based on Genetic Algorithm, net power output per unit mass of geothermal water is set as the objective function. Evaporation pressure, superheating of the steam, the minimum temperature in the evaporator are analyzed to obtain the optimal performance of the system. The results indicate that under the assumption condition that the optimal level constitution of system parameters is determined as the working fluid of R227ea, the power output of the system of 596kw and the corresponding power output per unit mass of geothermal water of 11.91 kJ/kg. R245ca has the maximal efficiency of 5.75% among the selected 6 working fluids (Butane, R236fa, R227ea, R236ea, R245fa, R245ca). The effect of pinch temperature in evaporator on power output per unit mass is more seriously than that of superheating. It is about 7 times in terms of increasing 1K of R227ea. [ABSTRACT FROM AUTHOR]

Organic Rankine Cycle(ORC) can effectively recover the low grade heat source due to its distinctive thermodynamic performance. Based on Genetic Algorithm, net power output per unit mass of geothermal water is set as the objective function. Evaporation pressure, superheating of the steam, the minimum temperature in the evaporator are analyzed to obtain the optimal performance of the system. The results indicate that under the assumption condition that the optimal level constitution of system parameters is determined as the working fluid of R227ea, the power output of the system of 596kw and the corresponding power output per unit mass of geothermal water of 11.91 kJ/kg. R245ca has the maximal efficiency of 5.75% among the selected 6 working fluids (Butane, R236fa, R227ea, R236ea, R245fa, R245ca). The effect of pinch temperature in evaporator on power output per unit mass is more seriously than that of superheating. It is about 7 times in terms of increasing 1K of R227ea. [ABSTRACT FROM AUTHOR]