Application of fuzzy c-means algorithm as a novel method to predict density of mixtures of Athabasca bitumen and heavy n-alkane

The significant number of oil reservoir are bitumen and heavy oil. One of the approaches to enhance oil recovery of these types of reservoir is dilution of reservoir oil by injection of a solvent such as tetradecane into the reservoirs to modify viscosity and density of reservoir fluids. In this investigation, an effective and robust estimating algorithm based on fuzzy c-means (FCM) algorithm was developed to predict density of mixtures of Athabasca bitumen and heavy n-alkane as function of temperature, pressure and weight percent of the solvent. The model outputs were compared to experimental data from literature in different conditions. The coefficients of determination for training and testing datasets are 0.9989 and 0.9988. The comparisons showed that the proposed model can be an applicable tool for predicting density of mixtures of bitumen and heavy n-alkane.     

Applying FCM-ANFIS algorithm as a novel computational method for prediction of viscosity of bitumen and heavy alkane mixture

Recently the studies expressed that the noticeable number of oil reservoirs in all over the world are heavy oil and bitumen reservoirs. So the importance of enhancement of oil recovery (EOR) processes for heavy oil and bitumen reservoirs is highlighted. The Dilution of the reservoir fluid by solvents such as tetradecane is one of well-known methods for these types of reservoirs which effects oil recovery by decreasing viscosity. In the present study, Fuzzy c-means (FCM) algorithm was coupled with Adaptive neuro-fuzzy inference system (ANFIS) to predict viscosity of bitumen and tetradecane in terms of temperature, pressure and weight percent of tetradecane. The coefficients of determination for training and testing steps were calculated such as 0.9914 and 0.9613. The comparison of results and experimental data expressed that FCM-ANFIS algorithm has great potential for estimation of viscosity of bitumen and tetradecane.     

N.m.r. line shape-relaxation correlation analysis of bitumen and oil sands

The first results of the analysis of bitumen and oil sands using the recently developed n.m.r. spingrouping technique are presented. The n.m.r. relaxation experiments were carried out on bitumen, and on natural and dried oil sands samples. The results indicate that the spin-grouping can resolve and quantify several components of the samples studied. The bitumen and bitumen fraction of the oil sands are resolved according to their spin-spin relaxation times into three major groups: solid-like (rigid), solid-like (mobile) and semi-liquid. The water in the oil sands exists in two different environments. Tentatively one environment is assigned to be the bridges between the sand grains, while the other is assigned to be the clay surface. One can conclude that with spin grouping of complex mixtures the decomposition (in which components are resolved according to their dynamic state) is possible. The accuracy of such resolution is of the order of a few per cent.     

Effects of passive and active modified atmosphere packaging conditions on ready-to-eat table grape

The effects of passive and active modified atmosphere packaging conditions (MAP) on quality of packaged table grape were investigated. To this aim, three films made up of oriented polypropylene and characterized by a different thickness (20, 40 and 80 μm, respectively) were used to package the grape in air (passive MAP) and under three different initial headspace gas compositions (active MAP). As controls, grape samples were also stored without packaging. During a prolonged storage period at refrigerated temperature (5 °C) the headspace gas concentrations, the mass loss, the microbiological stability and the sensory acceptability were monitored. Results obtained highlight that all selected packaging films significantly prevent product decay, thus promoting a substantial shelf life prolongation, if compared to the unpackaged product. In particular, the best results were recorded with the thickest polymeric matrix sealed in air, that assured a shelf life more than 70 days. The active MAPs were not found significant for a shelf life prolongation, due to the fast equilibrium of gas reached in the bags and due to a more pronounced product dehydration.     

Thermal properties of new varieties of yam starches

Starches isolated from yam varieties of Dioscorea alata and Dioscorea cayenensis‐rotundata species were prepared at different time–temperature conditions and characterised by DSC, amperometric iodine titration, light microscopy and rheology and compared to native and chemical modified tapioca starches. The observation by light microscopy showed different morphologies of the granules when heated above 100°C and the tendency for disintegration decreased in the order native tapioca starch > yam starch > modified tapioca starch. Differences between yam and tapioca starches were also revealed by DSC. Yam starch enthalpy is higher than tapioca starch, but the peak temperature is low. However, the significant differences between yam and the other tested starches were found in terms of their rheological behaviour. The viscosity of yam starch was very stable at high temperatures on the viscograph. With this property, yam starch can be used as thickening and gelling agent in food.     

Effects of calf diet, antioxidants, packaging type and storage time on beef steak storage

The effect of basal dietary supplemented with vegetable oils plus vitamin E (sunflower, soybean, linseed and a basal diet control), type of packaging (MAP or vacuum), addition of natural antioxidant (grape seed, rosemary) and storage time (0, 7, 14 and 21 days) on lipid oxidation, color stability, vitamin E content, and total aerobic bacterial counts in steaks of Longissimus thoracis was studied. The triple interaction diet × time × packaging affected oxidative stability, redness and yellowness of the meat. TBARS values did not increase with time in vacuum-packaged samples for all dietary treatments. However, samples from MAP and control showed the highest TBARS values after 21 days of storage (0.72 mg MDA/kg of meat, P < 0.05). Both exogenous antioxidant extracts and MAP maintained low total aerobic counts in steaks until the 21st day. Calves should be fed a diet supplemented with L-VE, stored in MAP and treated with grape seed extract to extend the shelf life of their meat.     

Simultaneous determination of Sunset yellow and Tartrazine in soft drinks using gold nanoparticles carbon paste electrode

The monitoring of synthetic dyes in foods is very important due to their potential harmfulness to human beings. Herein, a carbon-paste electrode (CPE) that is chemically modified with gold nanoparticles (nAu) was fabricated and used for the determination of Sunset yellow (SY) and Tartrazine (Tz). Cyclic and differential pulse voltammetry (CV and DPV) results revealed two well-resolved anodic peaks for SY and Tz with remarkably increase in oxidation signals of these colourants. Based on this, a novel electrochemical method was developed for the simultaneous determination of SY and Tz. High sensitivity and selectivity, sub-micromolar detection limit, high reproducibility and regeneration of the electrode surface by simple polishing make the nAu-CPE electrode very suitable for the determination of SY and Tz in commercially available soft drinks. The detection limits was 3.0 × 10⁻⁸ and 2.0 × 10⁻⁹ mol l⁻¹ for SY and Tz, respectively, which are remarkably lower than those reported previously for SY and Tz using other modified electrodes.     

Effect of processing temperature on the bitumen/MDI-PEG reactivity

Reactive polymers are lately gaining acceptance to give added value to a residue of the crude oil refining process such as bitumen. The resulting material should display enhanced mechanical properties to be considered for advanced applications in construction. In the present paper, we report the effect of processing temperature on the reaction between bitumen compounds and an isocyanate-based reactive polymer, synthesized by reaction of polymeric MDI (4,4′-diphenylmethane diisocyanate) with a low molecular weight polyethylene-glycol (PEG). Rheokinetics experiments, viscosity measurements at 60 °C, atomic force microscopy (AFM) characterization, thin layer chromatography (TLC-FID) analysis and thermogravimetric studies (TGA) were performed on the reactive polymer and on samples of MDI-PEG modified bitumen containing 2 wt.% of the polymer. Results showed the existence of an optimum processing temperature arisen as a consequence of opposite effects: microstructural availability for the formation of a polymer–bitumen network, reaction ability and polymer thermal degradation. Consequently, this study aims to serve as a guideline for the refining and asphalt industries facing the stage of selecting the optimum processing parameters.     

电池用变性淀粉的工艺研究

本文用交联、氧化二种化学方法加工玉米淀粉，制取了复合变性淀粉，并重点研究、筛选了反应体系中催化剂、淀粉浓度、交联剂、氧化剂、反应温度及碱量等工艺条件．