Supercritical carbon dioxide extraction of bioactive flavonoid from Strobilanthes crispus (Pecah Kaca)

The bioactive flavonoid compounds of Strobilanthes crispus (Pecah Kaca) leaves obtained by using supercritical carbon dioxide (SC-CO₂) extraction were investigated and the obtained crude extract yields were compared in order to select the best operation parameters. Since carbon dioxide is a non-polar solvent, ethanol was used as co-solvent to increase the polarity of the fluid. The studied parameters were pressure (100, 150 and 200 bar), temperature (40, 50 and 60 °C) and dynamic extraction time (40, 60 and 80 min). The optimum extraction condition occurred at 200 bar, 50 °C and 60 min. Based on the mean value, pressure had dominant effect on the extraction yield. Apart from the optimum SFE conditions two other conditions namely at minimum (100 bar, 40 °C, 40 min) and maximum (200 bar, 60 °C, 80 min) levels of each studied parameters as control runs were analyzed by HPLC to determine the major bioactive flavonoid compounds from S. crispus. Under the optimum conditions eight flavonoid compounds were identified; they were (+)-catechin, (?)-epicatechin, rutin, myricetin, luteolin, apigenin, naringenin and kaempferol.     

The sintering temperature of ash, agglomeration, and defluidisation in a bench scale PFBC

Five Australian black coals were studied in a bench scale pressurised fluidised bed combustor (PFBC) to investigate the agglomeration propensity. It was found that coals with higher proportions of calcium aluminosilicate showed higher propensity for agglomeration and defluidisation. The pressure-drop sintering technique can predict the agglomeration propensity for coals. Samples with a sintering temperature lower than the operating temperature of the PFBC showed agglomeration. The laboratory ash can be a good representative of the PFBC ash when studying agglomeration and defluidisation.     

Effects of cereal breakfasts on postprandial glucose,appetite regulation and voluntary energy intake at a subsequent standardized lunch; focusing on rye products

Background  

Rye products have been demonstrated to lower the acute insulin demand, induce a low and prolonged blood glucose response (high Glycemic Profile, GP) and reduce subclinical inflammation. These products may therefore contribute to a lowered risk of obesity, type 2 diabetes and cardio vascular disease. The objective of the present paper was to evaluate the mechanism for a reduced postprandial insulin demand with rye products, and to explore possible appetite regulating properties.     

A Quantitative Measure to Evaluate Competing Designs for Non‐linear Dynamic Process Identification

The strategy for the collection of information (i.e., data) for model development is called experimental design. Optimal design seeks to maximize the information content under constraints of time and sampling. In the system identification literature the dominant strategy has been the method of pseudo random sequences (PRS). However, this work demonstrates that statistical design of experiments (SDOE) can provide greater information content as quantitatively measured by the D‐optimal criterion.     

An overview on oxyfuel coal combustion—State of the art research and technology development

Oxyfuel combustion is seen as one of the major options for CO₂ capture for future clean coal technologies. The paper provides an overview on research activities and technology development through a fundamental research underpinning the Australia/Japan Oxyfuel Feasibility Project. Studies on oxyfuel combustion on a pilot-scale furnace and a laboratory scale drop tube furnace are presented and compared with computational fluid dynamics (CFD) predictions. The research has made several contributions to current knowledge, including; comprehensive assessment on oxyfuel combustion in a pilot-scale oxyfuel furnace, modifying the design criterion for an oxy retrofit by matching heat transfer, a new 4-grey gas model which accurately predicts emissivity of the gases in oxy-fired furnaces has been developed for furnace modelling, the first measurements of coal reactivity comparisons in air and oxyfuel at laboratory and pilot-scale; and predictions of observed delays in flame ignition in oxy-firing.     

Effects of microwave radiation on electrodeposition processes at tin-doped indium oxide (ITO) electrodes

In situ microwave activation is investigated for the electrodeposition of a metal (gold) and for a metal oxide (hydrous Ti(IV) oxide) onto tin-doped indium oxide (ITO) film electrodes. It is demonstrated that localized microwave heating of the ITO film can be exploited to affect electrodeposition processes.The electrochemically reversible and temperature sensitive one-electron redox system Fe(CN)₆^3−/4− was employed in aqueous solution in order to calibrate the average surface temperature at the ITO film electrode. In the presence of microwave radiation the average electrode surface temperature reached ca. 363 K whereas under the same conditions the bulk solution temperature reached ca. 313 K. Therefore localized heating of the ITO film appears to be important.The rate of electrodeposition of gold from an aqueous 1 mM tetrachloroaurate(III) solution in 0.1 M KCl (adjusted to pH 2) is enhanced by microwave activation. However, the morphology of deposits remains un-effected. Hydrous titanium (IV) oxide films were electrodeposited from an aqueous solution of 1 mM TiCl₃ in 0.1 M acetate buffer pH 4.7. Dense films with blocking character were obtained with conventional heating but a fibrous more open deposit forms in the presence of microwaves.     

Tuning the optical properties of poly(o-phenylenediamine-co-pyrrole) via template mediated copolymerization

Tailoring of conjugated monomers via copolymerization is a facile method to obtain tunable spectral, morphological and optical properties. To investigate the effect of copolymerization of pyrrole with o-phenylenediamine on the optoelectronic properties of the synthesized copolymers, the present work reports the synthesis of copolymers of o-phenylenediamine with pyrrole with varying mol ratios via chemical polymerization in methylene blue (MB) medium. Copolymerization was confirmed by Fourier transform infrared spectroscopy and ultraviolet-visible studies. Ultraviolet-visible spectroscopy revealed variation in the optical properties with the change in the monomer ratio. Fluorescence studies showed that the copolymer containing 80% poly(o-phenylenediamine) revealed highest quantum yield among all the copolymers. The emission color could therefore be tuned by careful selection of narrow band co-monomers, which could help in designing tunable fluorescence emitting materials for potential application in OLED devices.     

Adults' physical activity patterns across life domains: Cluster analysis with replication.

Objective: Identifying adults' physical activity patterns across multiple life domains could inform the design of interventions and policies. Design: Cluster analysis was conducted with adults in two U.S. regions (Baltimore/Washington, DC, n = 702; Seattle, WA [King County], n = 987) to identify different physical activity patterns based on adults' reported physical activity across four life domains: leisure, occupation, transport, and home. Objectively measured physical activity, and psychosocial and built (physical) environment characteristics of activity patterns were examined. Main Outcome Measures: Accelerometer-measured activity, reported domain-specific activity, psychosocial characteristics, built environment, body mass index. Results: Three clusters replicated (κ = .90–.93) across both regions: Low Activity, Active Leisure, and Active Job. The Low Activity and Active Leisure adults were demographically similar, but Active Leisure adults had the highest psychosocial and built environment support for activity, highest accelerometer-measured activity, and lowest body mass index. Compared to the other clusters, the Active Job cluster had lower socioeconomic status and intermediate accelerometer-measured activity. Conclusion: Adults can be clustered into groups based on their patterns of accumulating physical activity across life domains. Differences in psychosocial and built environment support between the identified clusters suggest that tailored interventions for different subgroups may be beneficial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deposition of boron doped DLC films on TiNb and characterization of their mechanical properties and blood compatibility

Abstract

Diamond-like carbon (DLC) material is used in blood contacting devices as the surface coating material because of the antithrombogenicity behavior which helps to inhibit platelet adhesion and activation. In this study, DLC films were doped with boron during pulsed plasma chemical vapor deposition (CVD) to improve the blood compatibility. The ratio of boron to carbon (B/C) was varied from 0 to 0.4 in the film by adjusting the flow rate of trimethylboron and acetylene. Tribological tests indicated that boron doping with a low B/C ratio of 0.03 is beneficial for reducing friction (μ = 0.1), lowering hardness and slightly increasing wear rate compared to undoped DLC films. The B/C ratio in the film of 0.03 and 0.4 exhibited highly hydrophilic surface owing to their high wettability and high surface energy. An in vitro platelet adhesion experiment was conducted to compare the blood compatibility of TiNb substrates before and after coating with undoped and boron doped DLC. Films with highly hydrophilic surface enhanced the blood compatibility of TiNb, and the best results were obtained for DLC with the B/C ratio of 0.03. Boron doped DLC films are promising surface coatings for blood contacting devices.     

Color and thiobarbituric acid values of cooked top sirloin steaks packaged in modified atmospheres of 80% oxygen, or 0.4% carbon monoxide, or vacuum

Case-ready fresh beef is typically packaged in a modified-atmosphere with approximately 80% oxygen and 20% carbon dioxide. Recently, USDA approved distribution of fresh meats in a master bag system using 0.4% carbon monoxide (CO). This study compared effects of packaging system (vacuum, 80% oxygen, 0.4% carbon monoxide), fresh meat storage time (7-21 days) and cooking temperature (49-79 °C) on extent of myoglobin denaturation, color and rancidity in cooked top sirloin steaks. Steaks packaged in 80% oxygen or CO retained desirable red color for 14 and 21 days storage, respectively. Steaks stored in 80% oxygen exhibited the greatest TBA values and myoglobin denaturation at all storage times and cooking temperatures. Steaks stored in high oxygen developed brown interior color at internal temperatures as low as 57 °C, the premature browning effect. Premature browning and rancidity associated with steaks packaged in 80% oxygen was prevented by packaging in 0.4% CO or vacuum.