Influence of Operating Parameters on Biomass Conversion under Sub‐ and Supercritical Water Conditions

The influence of reaction pressure, reaction time, reaction temperature, and biomass‐to‐water mass ratio R on the conversion of miscanthus biomass to biofuels under sub‐ and supercritical water (SCW) conditions was investigated. The highest total conversion was obtained under SCW conditions and the heating value increased under subcritical and SCW conditions. The findings herein show that near‐supercritical and supercritical water at 400 °C and high pressure can be an effective reaction medium for converting biomass to oils with relatively low oxygen contents in high yields.     

Effect of Avogadro Oil as Corrosion Inhibitor of Thermally Pre-aged Al-Si-Mg Alloy in Sodium Chloride Solution

The corrosion inhibition of thermally pre-aged Aluminium-Silicon-Magnesium (Al-Si-Mg) alloy in 3.5 % NaCl solution with natural Avogadro oil of varying concentrations has been studied using linear polarization techniques. From the results obtained, the corrosion rate decreased with an increase in Avogadro oil concentration. An inhibitor efficiency of 46.7, 58 and 71 % were obtained at 1.5, 3.0, 4.5 g/v Avogadro oil addition in a 3.5 % NaCl solution respectively for the conventional alloy. Results from the linear polarization technique indicate a higher potential value with an increase in the polarization resistance (R _p ) and lower current density in the inhibited samples than the uninhibited Al-Si-Mg alloy as obtained from the Tafel plot extrapolation. There exist some levels of correlation in the inhibitor efficiency between the conventional and the thermally pre-aged Al-Si-Mg alloy/Avogadro oil in 3.5 % NaCl solution.     

Forecasting activity levels in the UK continental shelf: the role of perceptions

The explicit treatment of the role of perceptions in modelling forecasts is uncommon. With respect to future activity levels in the UK Continental Shelf, using the flexibility of add factors in econometric forecasts, this article demonstrates that, in addition to price variations, forecasts are sensitive to perceptions about future resource discovery and recovery rates. A medium-sized multivariate system reflecting the feedback structure of the petroleum supply process was formulated, estimated, and used to forecast activity levels.     

Probabilistic seismic risk assessment of hall buildings in Turkey

Steel space framed hall buildings are dedicated as shelters for people suffering from earthquakes. In general construction, steel space frames are built on reinforced concrete (R/C) frames or wall structures above the bottom side. For this reason, the bottom side has higher rigidity comparing with the upper side. In Turkey, where there is a very high earthquake risk, earthquake‐resistant steel space framed structures is an important issue. In this current research, hall buildings in Turkey, involving two different rigidity parts as R/C and steel, are taken into consideration regarding earthquake effect. In this study, three different hall structures were modeled with different elastic moduli for the analysis part. Nonlinear time history analyses were applied with 25 different earthquake data for performance estimation. After the time history analyses, probabilistic seismic assessment was carried out for the model buildings through fragility analyses. For each model, analysis results were evaluated and compared. As a result, the hall buildings were found to be vulnerable to damage during expected future earthquakes. Moreover, elastic moduli have significant effect on the structural response. Copyright © 2011 John Wiley & Sons, Ltd.     

Variable structure controller with prescribed transient response to control the position of the induction motor drives

This work demonstrates the efficacy of variable structure controllers with prescribed transient response to control the position of the induction motor drives. Based on the function augmented sliding hyper plane, it can be guarantee that the position tracking error converges within a realistic specified time interval. Better-quality performance for variable structure controllers is exhibited over fixed gain PID-controllers. Robustness of variable structure controller against parameter variations and external disturbances is established. Finally, the control algorithm has been validated by both simulation and experimental testing.     

Reliability in dams and the effects of spillway dimensions on risk levels

A general approach is presented for risk engineering and identification of the risk benefits analysis, goals and limits for risk evaluation in certain applications by considering the first-degree secondary moment methods. A computer program is developed in the Java language (DAM_RISK) with the aim to determine the safety levels of spillways in existing dams (or dams in the planning or construction phase). In consideration of a possible risk, observed overflow values are used, with the purpose of the rehabilitation values that need to be known, thus producing data ready for technical and financial analysis. This program is used to perform risk analysis for the Kürtün and Oymapi nar dams in Turkey with the purpose dam rehabilitation at risk. Different spillway dimension and the change in risk for the reservoir damping factors are also presented. The most important conclusion for planners and risk evaluators is the graph that shows the riskless region in spillway dimensions. Various features of the computer program and areas in which it might be further developed are considered in detail. The results of the applications carried out are given in terms of risk evaluations.     

Integrative analysis of cancer pathway progression and coherence

We analyzed the cancer pathways in the KEGG (Kyoto Encyclopedia of Genes and Genomes) database. The database provides a collective of signaling pathway members involved in cancer progression. However, the KEGG cancer pathways, unlike signaling pathways, have not been analyzed extensively with gene expression and mutation data. We transformed the colorectal cancer pathway into discrete X and Y scales and analyzed the relative expression levels of adenoma and carcinoma samples as well as the distribution of mutation targets. The X scale corresponds to the downstream location in a pathway, whereas the Y scale corresponds to the stage of the tumor. The gene expression values of the early stage pathway members are significantly higher than of the rest of the pathway members in colorectal adenoma tissues. The colorectal cancer pathway shows some degree of coherence in the carcinoma samples. The correlated gene pairs responsible for the coherence of the colorectal cancer pathway in the carcinoma samples are supported, in part, by the literature and may suggest novel regulatory associations. Finally, there are more mutation targets in the nucleus as well as the late tumor stages of the KEGG colorectal cancer pathway.     

超临界CO2萃取甜瓜籽油工艺及其脂肪酸组成分析

采用超临界CO2萃取技术提取甜瓜籽油,在单因素实验的基础上,运用正交实验设计优化工艺条件。结果表明超临界CO2萃取甜瓜籽油的最佳工艺条件为:萃取压力30 MPa,萃取温度45℃,萃取时间5 h,CO2流量8 L/min,甜瓜籽粉碎粒度24目。在最佳条件下,甜瓜籽油得率为29.34%。利用GC-MS对甜瓜籽油脂肪酸组成进行分析,结果表明超临界CO2萃取的甜瓜籽油共鉴定出12种脂肪酸,其中饱和脂肪酸以棕榈酸(10.87%)、硬脂酸(5.57%)为主,不饱和脂肪酸以亚油酸(64.29%)、油酸(16.64%)为主。     

Release of phenolic acids from defatted rice bran by subcritical water treatment

BACKGROUND: Oil production from rice bran, an undervalued by‐product of rice milling, produces defatted rice bran (DRB) as a waste material. Although it is considered a less valuable product, DRB still contains useful substances such as phenolic compounds with antioxidant, UV‐B‐protecting and anti‐tumour activities. In this study the phenolic acids in DRB were extracted with subcritical water at temperatures of 125, 150, 175 and 200 °C. RESULTS: Analysis of total phenolics using Folin–Ciocalteu reagent showed about 2–20 g gallic acid equivalent kg^?1 bran in the extracts. High‐performance liquid chromatography analysis showed low contents of phenolic acids (about 0.4–2 g kg^?1 bran). Ferulic, p‐coumaric, gallic and caffeic acids were the major phenolic acids identified in the extracts. Thermal analysis of the phenolic acids was also done. The thermogravimetric curves showed that p‐coumaric, caffeic and ferulic acids started to decompose at about 170 °C, while gallic acid did not start to decompose until about 200 °C. CONCLUSION: Subcritical water can be used to hydrolyse rice bran and release phenolic compounds, but the high temperatures used in the extraction can also cause the decomposition of phenolic acids. Copyright © 2010 Society of Chemical Industry     

Mixed Convection of Non-Newtonian Erying Powell Fluid with TemperatureDependent Viscosity over a Vertically Stretched Surface

The viscosity of a substance or material is intensely influenced by the temperature, especially in the field of lubricant engineering where the changeable temperature is well executed. In this paper, the problem of temperature-dependent viscosity on mixed convection flow of Eyring Powell fluid was studied together with Newtonian heating thermal boundary condition. The flow was assumed to move over a vertical stretching sheet. The model of the problem, which is in partial differential equations, was first transformed to ordinary differential equations using appropriate transformations. This approach was considered to reduce the complexity of the equations. Then, the transformed equations were solved using the Keller box method under the finite difference scheme approach. The validation process of the results was performed, and it was found to be in an excellent agreement. The results on the present computation are shown in tabular form and also graphical illustration. The major finding was observed where the skin friction and Nusselt number were boosted in the strong viscosity.