Development of a Four-Phase Remedial Scheme to Clean Up Petroleum-Hydrocarbon Contaminated Soils

In this study, a four-phase remedial scheme was developed for in situ cleanup of petroleum-hydrocarbon contaminated soils. The developed remedial scheme contained the following four phases: surfactant flushing, groundwater flushing, chemical oxidation using KMnO4 as the oxidant, and enhanced bioremediation. Laboratory bench-scale experiments were performed to evaluate the effectiveness of this developed remedial scheme on the treatment of diesel oil contaminated soils. In the surfactant and groundwater flushing batch experiment (the first and second phases), biodegradable surfactant, Simple Green (SG) (5% by weight) was applied to flush diesel oil contaminated soils with initial total petroleum-hydrocarbon (TPH) concentration of approximately 31,500??mg?kg-1. Results show that more than 90% of TPH could be removed after flushing with 40 pore volumes (PVs) of SG, followed by 25?PVs of groundwater. In the KMnO4 oxidation experiment (third phase) with initial soil TPH concentration at approximately 4,900??mg?kg-1, up to 65% of TPH removal efficiency can be obtained when 1% by weight of KMnO4 was applied for oxidation. Results also reveal that the slight increase in TPH removal was observed in experiments with SG addition (0.1% by volume) owing to increased dissolution and desorption of TPH from soils. In the enhanced bioremediation (fourth phase) batch experiments, a petroleum-hydrocarbon degrading bacterium was isolated from the soil materials after the KMnO4 oxidation experiments and identified as Pseudomonas sp. via biochemical tests and further confirmation of DNA sequencing. Results from biodegradation experiments indicate that the isolated bacterium, which survived after KMnO4 oxidation process, was capable of degrading TPH caused by diesel oils, and caused the TPH to drop from 2,105 to 487??mg?kg-1 within 15?days of incubation. The effectiveness of the four-phase remedial scheme was further confirmed by a semicontinuous batch experiment. Results from this study indicate that the four-phase scheme is a promising technology for the treatment of petroleum-hydrocarbon contaminated soils.     

多孔CaO颗粒碳酸化反应特性的实验研究

为研究CaO颗粒形貌、颗粒分散性、颗粒孔隙特性及反应温度对CaO碳酸化反应的影响,通过水合作用和乙醇溶液调质制备多孔CaO颗粒,采用扫描电镜、比表面积分析、孔隙结构等方法对多孔CaO颗粒进行表征,利用热分析天平对多孔CaO颗粒的碳酸化反应特性进行研究。结果表明:水合作用与乙醇溶液调质能改变颗粒分散性及颗粒孔隙特性,有利于提高CaO钙转化率;CaO碳酸化反应在700℃左右时钙利用率达到最大。     

Isothermal treatment influence on nanometer-size carbide precipitation of titanium-bearing low carbon steel

The precipitation kinetics of nano-size TiC particles in ferrites depends on the annealing temperature. At 700 °C, 725 °C, and 750 °C, the majority of nano TiC particles are found to distribute along the austenite/ferrite interfaces. These nano-size carbides strengthen the ferrite matrix. At the lower annealing temperatures of 650 °C and 675 °C, a few randomly distributed nano TiC precipitates develop in the ferrite matrix from the supersaturated ferrite solid solution. In this case, the strength of the ferrite is attributed to the nanoparticle strengthening and solid-solution strengthening.     

Crystallization kinetics of amorphous Ga-Sb films extended for phase-change memory

Performance of phase-change materials based on Ga-Te-Sb was found getting better with decreasing Te content in our earlier studies. We concerned much properties of Te-free, Sb-rich binary Ga-Sb, which has been known to possess extremely fast crystallization behavior. Non-isothermal and isothermal crystallization kinetics of amorphous Sb-rich Ga-Sb films were explored by temperature dependent electrical resistance measurements. The crystallization temperature (183 to 261 degrees C) increases with decreasing Sb content (91 to 77 at%). The activation energy and rate-factor vary with Sb contents and reach the maximum at Ga19Sb81. The kinetic exponent is smaller than 1.5 at Sb < 85 at% denoting that the mechanism is one-dimensional crystal-growth from nuclei. The temperature corresponding to 10-year data-retention, evaluated from films, is 180 degrees C (Ga19Sb81) and 137 degrees C (Ga13Sb87), respectively. We verified memory performance using test-devices made of Ga16Sb84 working at voltages with 100 ns pulse-width.     

GaSe Formation at the Cu(In,Ga)Se2/Mo Interface–A Novel Approach for Flexible Solar Cells by Easy Mechanical Lift‐Off

Implementing photovoltaic devices based on high efficiency thin‐film technologies on cheap, light‐weight and flexible polymeric substrates is highly appealing to cut down costs in industrial production and to accelerate very large scale deployment of photovoltaics in the upcoming years. Lift‐off processes, which allow separating active layers from primary substrates and subsequent transfer onto an alternative substrate without modifying the upstream production process and without performance losses, are an emerging alternative to direct growth on polymeric substrates. This study concerns the feasibily of direct mechanical lift‐off process for high efficiency Cu(In,Ga)Se₂ (CIGS) thin film solar cells grown by coevaporation on glass/molybdenum substrates without performance losses. The study presents an in depth characterization (SEM,AFM,GIXRD,XPS) of samples leading to excellent lift‐off properties. They are explained by a specific gallium rich CIGS graded interface structure according to the interfacial sequence glass/Mo/MoSe₂/Ga_xSe_y/Ga‐rich‐CIGS. The interfacial layer, attributed to GaSe, has a layered structure and out performs the molybdenum diselenide layered layer which forms spontaneously at the interface Mo/CIGS. It allows a very easy lift‐off process at the interface GaSe/CIGS thanks to Van‐der‐Waals adhesion mechanism in GaSe. Key physical‐chemical parameters are identified and analyzed. After lift‐off, an efficiency of 14.3%, higher than the initial reference CIGS solar cell efficiency (13.8%) is measured.     

In vitro transformation by hepatitis B virus DNA

There is strong epidemiological evidence that the hepatitis B virus (HBV) contributes to the development of hepatocellular carcinoma (HCC). In several immortalized cell lines, an in vitro transforming activity of HBV DNA and expression vectors for the viral protein X (HBx) has now been demonstrated. Furthermore, it appears as if still unknown parts of the HBV genome other than HBx contribute to the transforming activity of HBV DNA in vitro. Only one of several studies found that HBx-transgenic mouse lines develop HCC. A mouse line transgenic for the large surface protein of HBV develops HCC due to concomitant necroinflammatory infection. Growing evidence shows the importance of recombination of integrated viral DNA and cellular DNA for HCC development. A direct transforming potential of one of these viral integrates has been demonstrated. Chemical carcinogens are more effective in HBV-containing cell lines or transgenic mice.     

Design, synthesis and some uses of receptor-specific agonists and antagonists of vasopressin and oxytocin

Selective agonists and antagonists are powerful tools for studies on AVP and OT receptors and on the physiological and pathophysiological roles of AVP and OT. Here we show how some of these peptides and their radiolabelled derivatives were designed. We also present examples of the currently available cyclic and linear OT and AVP agonists and antagonists from our laboratories.     

Changes in the countercurrent system in the renal papilla: diuresis increases pH and HCO3- gradients between collecting duct and vasa recta

This study was designed to elucidate the acid-base balance local to the collecting duct urine (CD) and vasa recta blood (VR) in the rat renal papilla in diuresis. The pH changes were measured in both a furosemide-induced and a volume-load-induced diuresis, whereas the PCO2 (i.e., CO2 tension) and HCO3- concentration were measured only in a furosemide-induced diuresis. In an antidiuresis, the pH of the VR was more acidic than that of the systemic arterial blood (DeltapH = 0.44-0.73). Additionally, the pH of the ascending VR was significantly lower than that of the descending VR (DeltapH = 0.14-0. 16). In diuresis, the pH of the CD decreased (DeltapH = 0.81-0.97), while the pH of the descending and the ascending VR increased; however, the increase was only significant in the ascending VR (DeltapH = 0.23-0.30). Consequently, the significant difference in the pH gradient between the descending and the ascending VR was eliminated. The PCO2 values in the CD and the ascending VR were not different from those in antidiuresis, while the HCO3- concentration in the CD and the ascending VR, respectively, decreased and increased significantly. Thus, in diuresis, the decrease in the pH of the CD and the increase in the pH of the ascending VR result, respectively, from the decrease and the increase in the HCO3- concentration, with no changes in the PCO2 values.