Oxygen nonstoichiometry and thermodynamic quantities of Perovskite-Type La1- xSrxFeO3-δ(x=0.2, 0.5, 0.8)

In this work, the defect structure analysis of La1-xSrxFeO3-δ (x=0.2, 0.5, 0.8) was presented. Thermogravimetric measurements were performed to determine the change in oxygen nonstoichiometry (Δδ) with oxygen partial pressure (pO2) in 10-19 ≤ (pO2/atm) ≤ 0.21 and temperature in 750 ≤ (T/℃) ≤ 900 range. La1-xSrxFeO3-δ showed a clear electronic stoichiometric point around δ»3-x/2. The relative partial molar enthalpy (ho-hoo) and entropy (so-soo) of oxygen were calculated from δ-pO2-T relation by using Gibbs-Helmholtz equation. The negative sign of ho-hoo and so-soo indicated that the incorporation of oxygen was an exothermic process and showed that the experimentally observed variations in ho-hoo and so-soo with δ matched well with the statistical thermodynamic model proposed by Mizusaki[1]. The defect diagram analysis showed that in n-type regime Fe2+ concentration varied with (pO2)-1/4 whereas in p-type regime Fe4+ concentration varied with (pO2)1/4. Reference [1] J. Mizusaki et al. J. Solid State Chem. 67 (1987) 1-8

Intervention Strategies Based on Information-Motivation-Behavioral Skills Model for Health Behavior Change: A Systematic Review

SummaryPurposeThis study systematically reviewed research on behavioral interventions based on the information-motivation-behavioral skills (IMB) model to investigate specific intervention strategies that focus on information, motivation, and behavioral skills and to evaluate their effectiveness for people with chronic diseases.MethodsA systematic review was conducted in accordance with the guidelines of both the National Evidence-based Healthcare Collaborating Agency and Im and Chang. A literature search was conducted using electronic databases. Randomized controlled trials that tested behavioral interventions based on the IMB model for promoting health behaviors among people with chronic diseases were included. Four investigators independently reviewed the studies and assessed the quality of each study. A narrative synthesis was used.ResultsA total of 12 studies were included in the review. Nine studies investigated patients with HIV/AIDS. The most frequently used intervention strategies were instructional pamphlets for the information construct, motivational interviewing techniques for the motivation construct, and instruction or role playing for the behavioral skills construct. Ten studies reported significant behavior changes at the first post-intervention assessment.ConclusionThis review indicates the potential strength of the IMB model as a theoretical framework to develop behavioral interventions. The specific integration strategies delineated for each construct of the model can be utilized to design model-based interventions

Defect structure of BZCYYb17 and theoretical behavior and performance of SOFC’s with BZCYYb17 electrolyte

In this work, maximum power density of SOFC with BZCYYb17(BaZr0.1Ce0.7Y0.1Yb0.1O3-d) electrolyte as the function of thickness was calculated by integrating partial conductivities of charge carriers under various DC bias conditions at a fixed oxygen chemical potential gradient at both sides of the electrolyte. The partial conductivities were calculated by fitting various total conductivities in diverse thermodynamic conditions (temperature, partial pressure of oxygen and partial pressure of vapor) using equations from defect model. From the fitting, not only we can get the partial conductivities as a function of temperature, oxygen partial pressure and hydrogen partial pressure but also mobility of each carriers and reaction constant of oxidation and hydration. Spatial distribution of oxygen chemical potential and hydrogen chemical potential across the electrolyte were calculated based on Choudhury and Patterson’s model by considering zero electrode polarization. At positive voltage conditions corresponding to SOFC and SOEC, the high conductivity region near n-type to p-type transition was expanded, but ad negative cell voltage conditions, the low conductivity region near n-type to p-type transition was expanded. The current- voltage characteristics in different conditions with temperature and thickness dependence were calculated with vapor partial pressure of each electrode is 0.03, oxygen partial pressure of the cathode 0.21 and hydrogen partial pressure of the anode 0.97

Evaluation of the high temperature solid Oxide cells using La0.1Sr0.9Co0.8Fe0.2O3-δ

The performance of the SOCs using La0.1Sr0.9Co0.8Fe0.2O3-δ (LSCF1982) was characterized by I-V measurement and electrochemical impedance spectroscopy (EIS). The distribution function of relaxation times of EIS was used to analyze the polarization resistance of the cells. The fitting was performed using the appropriate equivalent circuit through DRT analysis. Furthermore, we co-electrolyzed CO2 and H2O to obtain H2 / CO syngas as well as water splitting. The composition of syngas was investigated by gas chromatography and controlled by varying in-let gas composition

Shearing and Mixing Performance of Ultrahigh-Molecular-Weight Hydrolyzed Polyacrylamide (HPAM) Solution in a Helixes Static Mixer

Static mixers have been widely used to dilute high viscosity, high-molecular-weight polymer mother liquor for polymer flooding, in which the mixing performance plays a critical role. In this work, a novel mixing configuration, named as Helixes static mixer, was proposed to reduce high viscosity degradation rate of polyacrylamide solution resulting from mechanical shear during mixing process. Computational fluid dynamics simulations along with experiments were performed to investigate the mixing process. Several criteria such as the intensity of segregation, mixing distance, pressure loss, and shear strain rate were used to evaluate the mixing and shear performance of static mixers. Compared to the SMX and Kenics static mixer, a longer mixing distance is needed for the Helixes static mixer to achieve an ideal mixture. A lower shear strain rate along with less viscosity degradation rate is obtained in flow field of Helixes static mixer. The spiral-lead and helical directions of mixing elements were optimized to improve mixing performance. Experimental results are in good agreement with the numerical simulations on the intensity of segregation. The viscosity degradation rate of HPAM solution which flows through Helixes static mixer is lower than that of SMX and Kenics static mixers

Efficient hybrid organic-inorganic light emitting diodes with self-assembled dipole molecule deposited metal oxides

We investigate the effect of self-assembled dipole molecules (SADMs) on ZnO surface in hybrid organic-inorganic polymeric light-emitting diodes (HyPLEDs). Despite the SADM being extremely thin, the magnitude and orientation of SADM dipole moment effectively influenced the work function of the ZnO. As a consequence, the charge injection barrier between the conduction band of the ZnO and the lowest unoccupied molecular orbital of poly(9,9(')-dioctylfluorene)-co-benzothiadiazole could be efficiently controlled resulting that electron injection efficiency is remarkably enhanced. The HyPLEDs modified with a negative dipolar SADM exhibited enhanced device performances, which correspond to approximately a fourfold compared to those of unmodified HyPLEDs.open442

Enhanced cardiac expression of two isoforms of matrix metalloproteinase-2 in experimental diabetes mellitus.

BackgroundDiabetic cardiomyopathy (DM CMP) is defined as cardiomyocyte damage and ventricular dysfunction directly associated with diabetes independent of concomitant coronary artery disease or hypertension. Matrix metalloproteinases (MMPs), especially MMP-2, have been reported to underlie the pathogenesis of DM CMP by increasing extracellular collagen content.PurposeWe hypothesized that two discrete MMP-2 isoforms (full length MMP-2, FL-MMP-2; N-terminal truncated MMP-2, NTT-MMP-2) are induced by high glucose stimulation in vitro and in an experimental diabetic heart model.MethodsRat cardiomyoblasts (H9C2 cells) were examined to determine whether high glucose can induce the expression of the two isoforms of MMP-2. For the in vivo study, we used the streptozotocin-induced DM mouse heart model and age-matched controls. The changes of each MMP-2 isoform expression in the diabetic mice hearts were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical stains were conducted to identify the location and patterns of MMP-2 isoform expression. Echocardiography was performed to compare and analyze the changes in cardiac function induced by diabetes.ResultsQuantitative RT-PCR and immunofluorescence staining showed that the two MMP-2 isoforms were strongly induced by high glucose stimulation in H9C2 cells. Although no definite histologic features of diabetic cardiomyopathy were observed in diabetic mice hearts, left ventricular systolic dysfunction was determined by echocardiography. Quantitative RT-PCR and IHC staining showed this abnormal cardiac function was accompanied with the increases in the mRNA levels of the two isoforms of MMP-2 and related to intracellular localization.ConclusionTwo isoforms of MMP-2 were induced by high glucose stimulation in vitro and in a Type 1 DM mouse heart model. Further study is required to examine the role of these isoforms in DM CMP