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A new cobalt-free perovskite oxide Pr0.5Sr0.5Fe0.8Cu0.2O3−δ (PSFC) has been synthesized and evaluated as cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The chemical compatibility of PSFC with Sm0.2Ce0.8O1.9 (SDC) electrolyte has be proven by XRD, and its electrical conductivity reaches the maximum value of 264.1 S cm−1 at 475 °C. Symmetrical cells with the configuration of PSFC/SDC/PSFC are used for the impedance study and the polarization resistance (Rp) of PSFC cathode is as low as 0.050 Ω cm2 at 700 °C. Single cells, consisting of Ni–YSZ/YSZ/SDC/PSFC structure, are assembled and tested from 550 °C to 800 °C with wet hydrogen (∼3% H2O) as fuel and static air as oxidant. A maximum power density of 1077 mW cm−2 is obtained at 800 °C. All the results suggest that the cobalt-free perovskite oxide PSFC is a very promising cathode material for application in IT-SOFC. [ABSTRACT FROM AUTHOR]

Abstract: Effect of preparation method for Pr0.6Sr0.4Co0.2Fe0.8O3 − δ (PSCF) on its electrochemical performance was investigated. Powder samples were synthesized by hexamethylenetetramine (HMTA) and EDTA–citric acid (EC) techniques, respectively. The particles synthesized by HMTA were smaller than those prepared by EC method as proved by TEM. X-ray photoelectron spectroscopy illuminated that more oxygen sites including oxygen vacancy on the surface of HMTA-derived PSCF exist than that of EC-derived PSCF. The area specific resistance (ASR) value of HMTA-derived PSCF cathode was as low as 0.454Ωcm2 at 600°C, whereas the ASR value of EC-derived PSCF was 0.641Ωcm2. The results in the present study demonstrated the advantages of the HMTA method in the synthesis of highly catalytic active PSCF oxide powder for SOFCs. [Copyright &y& Elsevier]

Abstract: A systematic study and evaluation were performed on the effect of scandium doping at the B site of Pr0.6Sr0.4Co0.2Fe0.8O3−δ (PSCF) on key material properties as cathode for intermediate temperature solid oxide fuel cells (IT-SOFC). The doped products Pr0.6Sr0.4(Co0.2Fe0.8)(1−x)Sc x O3−δ (PSCFS x , x=0.0–0.2) retained perovskite structure confirmed by X-ray diffraction, and their particles were smaller than the non-doped materials as evidenced by TEM. The electrical conductivity (EC) of PSCFS x decreased with increasing Sc3+ content, but EC values were still larger than 100 S cm−1 in temperature range of 300–800 °C as x ≤ 0.1. The thermal expansion coefficients (TEC) of PSCFS x were observed to generally decrease with increasing x especially at lower temperature range of 50–600 °C. In addition, the AC impedance revealed better electrochemical performance of PSCFS x cathode as x ≤ 0.1 than that of the undoped sample PSCF. Therefore, PSCFS x (x ≤ 0.1) shows some potential as cathode electrode for IT-SOFC. The function of Sc3+ dopant was tentatively elucidated and discussed. [Copyright &y& Elsevier]

Abstract: Effects of ethanol supercritical drying treatment on morphology and electrochemical performance of DyBaCo2O5+δ (DBC), as cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs), was comparatively investigated. Powder samples were synthesized by EDTA–citric acid (EC) and ethanol supercritical drying assisted EDTA–citric acid (SCEC) techniques. The scanning electron microscopy (SEM) images show the particles synthesized by SCEC were smaller than those prepared by the EC method. The area specific resistance (ASR) value of SCEC-DBC as cathode was lower than that of DBC-EC cathode. The maximum power density of the single cell with SCEC-DBC cathode was higher than that of the cell with EC-DBC cathode in the investigated temperature range from 550 to 650°C. [Copyright &y& Elsevier]

Acute liver failure (ALF) is an uncommon but dramatic clinical syndrome characterized by hepatic encephalopathy and a bleeding tendency due to abrupt loss of liver function caused by massive or submassive liver necrosis in a patient with a previously healthy liver. The causes of ALF encompass a wide variety of toxic, viral, metabolic, vascular and autoimmune insults to the liver, and identifying the correct cause can be difficult or even impossible. Many patients with ALF develop a cascade of serious complications involving almost every organ system, and death is mostly due to multi-organ failure, hemorrhage, infection, and intracranial hypertension. Fortunately, the outcome of ALF has been improved in the last 3 decades through the specific treatment for the disease of certain etiology, and the advanced intensive care management. For most severely affected patients who fail to recover after treatment, rapid evaluation for transfer to a transplantation center and consideration for liver transplantation is mandatory so that transplantation can be applied before contraindications develop. This review focuses on the recent advances in the understanding of various contributing etiologies, the administration of etiology-specific treatment to alleviate the liver injury, and the management of complications (e.g., encephalopathy, coagulopathy, cardiovascular instability, respiratory failure, renal failure, sepsis and metabolic disturbance) in patients with ALF. Assessment of the need for liver transplantation is also presented.