Showing papers by "Beijing Institute of Petrochemical Technology published in 2008"

Densities and Viscosities of 1-Butyl-3-methylimidazolium Trifluoromethanesulfonate + H2O Binary Mixtures at T = (303.15 to 343.15) K

Abstract: Densities and viscosities for the binary mixtures of H2O (1) + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM][CF3SO3]) (2) were measured over the entire mole fraction range from (303.15 to 343.15) K at atmospheric pressure. Excess molar volumes and viscosity deviations as a function of mole fraction average were derived, and the results were fitted to the Redlich−Kister equation using a multiparametric nonlinear regression method. Estimated coefficients of the Redlich−Kister equation and standard error calculated from the Redlich−Kister equation to the experimental data are also presented. The results show that the densities and viscosities are dependent on water content and temperature.

Highly Active La1-xKxCoO3 Perovskite-type Complex Oxide Catalysts for the Simultaneous Removal of Diesel Soot and Nitrogen Oxides Under Loose Contact Conditions

Abstract: The nanometric La1−x K x CoO3 (x = 0–0.30) perovskite-type oxides were prepared by a citric acid-ligated method. The catalysts were characterized by means of XRD, IR, BET, XPS and SEM. The catalytic activity for the simultaneous removal of soot and nitrogen oxides was evaluated by a technique of the temperature-programmed oxidation reaction. In the LaCoO3 catalyst, the partial substitution of La3+ at A-site by alkali metal K+ enhanced the catalytic activity for the oxidation of soot particle and reduction of NO x . The La0.70K0.30CoO3 oxides are good candidate catalysts for the simultaneous removal of soot particle and NO x . The combustion temperatures for soot particles over the La0.70K0.30CoO3 catalyst are in the range from 289 to 461 °C, the selectivity of CO2 is 98.4% and the conversion of NO to N2 is 34.6% under loose contact conditions. The possible reasons that can lead to the activity enhancement for the K-substitution samples compared to the unsubstituted sample (LaCoO3) were given. The particle size has a large effect on its catalytic performance for the simultaneous removal of diesel soot and nitrogen oxides.

GIS and ANN coupling model: an innovative approach to evaluate vulnerability of karst water inrush in coalmines of north China

Abstract: In northern China, coal mining is often affected by groundwater inrushes from the underlying karst aquifers. Water inrush is controlled by geomorphology, regional geologic structure, and hydrogeologic conditions of the coalmines. A geographic information system (GIS) was constructed to evaluate the vulnerability of the water inrush for coalmines in north China. An artificial neural network (ANN) is used to determine the weight coefficient for each factor that affects the water inrush. The developed coupling technique can be used to forecast karst water inrushes and perform the sensitivity analysis for each factor.

Zeolite beta monoliths with hierarchical porosity by the transformation of bimodal pore silica gel

Abstract: Zeolite beta monoliths with hierarchical porosity were prepared by the steam-assisted conversion of pre-seeded bimodal pore silica gel using the Layer-by-Layer process. The bimodal pore silica gel acts as both macrotemplates and silica source. The zeolite beta monoliths were characterized by X-ray diffraction, scanning electron microscopy, IR absorption spectra and nitrogen adsorption measurements. This zeolite beta monolith had hierarchical porosity: the unique micropores within the zeolite, the small macropores generated by aggregation of crystallites and three dimensionally interconnected macropores formed by template of silica gel. It is believed that the hierarchical structured zeolite monoliths will show good properties and potential applications the fields of catalyst, ion exchange, and adsorption.

Development of a 3D GIS and its application to karst areas

Abstract: There is a growing interest in modeling and analyzing karst phenomena in three dimensions. This paper integrates geology, groundwater hydrology, geographic information system (GIS), database management system (DBMS), visualization and data mining to study karst features in Huaibei, China. The 3D geo-objects retrieved from the karst area are analyzed and mapped into different abstract levels. The spatial relationships among the objects are constructed by a dual-linker. The shapes of the 3D objects and the topological models with attributes are stored and maintained in the DBMS. Spatial analysis was then used to integrate the data in the DBMS and the 3D model to form a virtual reality (VR) to provide analytical functions such as distribution analysis, correlation query, and probability assessment. The research successfully implements 3D modeling and analyses in the karst area, and meanwhile provides an efficient tool for government policy-makers to set out restrictions on water resource development in the area.

Homogeneous Fluidization Characteristics of Vibrating Fluidized Beds

Abstract: n recent years, there has been growing interest in utilizing mechani-cal vibration to improve the performance of a fl uidized bed in the processing of relatively large particles. The advantages of vibrating fl uidized beds (VFB) over conventional fl uidized beds include reduced minimal fl uidization velocity and fl uidization pressure drops, increased effi ciency of gas-solid contact and improved homogeneity and stability of the fl uidized bed layers. These advantages can be used in drying, cooling, heating, separating, mixing process, etc. In conventional fl uidized beds, the possibility for arising of homo- or heterogeneous fl uidization is connected directly with the so-called stability of the fl uidized system. Moreover, the theories dealing the stability often examine the behavior of their density micro-fl uctuation. The stability of the bed density is a subject of focus in the segregation of granular solids. Any large fl uctuation in the bed density will result in a failure of separation in some regions and this leads to a decrease in the total separation effi ciency. In developing better separation technology, a greater stability of bed layers will be required. A method for the classifi cation of granular materials in vibrating fl uidized beds has already been suggested (Zhang et al., 1996; Chen et al., 1993), which is useful in the separation of fi ne coal and the segregation of waste coke-slag mixture. All these technologies use vibration energy to improve bed homogeneity. The effects of vibration on fl uidization quality are important for separation in fl uidized beds. However, there have been only few studies of the effect of vibration on fl uidization homogeneity in the literature. By analyzing capacitance charts, Morse (1955) suggests that homogeneity and stability exist only for beds of smaller particles (1 –70 µm) and high frequencies of vibration (l0 – 50 Hz). By measuring the fl uctuations of voidage in space and in time using a capacitance probe, Mushtaev (1979) showed that the bed homogeneity begins to deterio-rate with severe fountain action of the particle beds when the vibration acceleration exceeds 4 g, namely aω

Properties and influence of hydrophobically associating polyacrylamide modified with 2-phenoxylethylacrylate

Abstract: The properties of hydrophobically associating copolymer P(acrylamide (AM)/2-phenoxylethylacrylate (POEA)), composed of acrylamide and a small amount of POEA (⩽1.0 mol.%) as hydrophobe, were investigated in aqueous solution under various conditions. The results showed that the solution properties were strongly affected by the microstructure of copolymer. The copolymers (BP series) with hydrophobic microblocky structure exhibited large viscosity enhancement due to the intermolecular hydrophobic association, while that did not occur for the random copolymers (RP series). The hydrophobic association thickening behaviors were also remarkably dependent on the number and length of the hydrophobic block in polymer chain. Nonlinear viscosity relationship was found as increasing hydrophobe content and SMR (surfactant/hydrophobic monomer molar ratio), and a maximum appeared at the middle position as a result of the competitive effect between inter- and intra- molecular hydrophobic associations. Solution properties were further studied as a function of the polymer concentration, salinity, temperature and shear rate. The block copolymers show high salt tolerance and shear thinning as well as recovery after shear.

Study on Process of Ion Implantation on AZ31 Magnesium Alloy

Abstract: Ti ion and C ion is implanted into AZ31 magnesium alloy surface by metal vapor vacuum arc (MEVVA) implanter operating with a modified cathode. This metal arc ion source has a broad beam and high current capabilities. Implantation energy is fixed at 45K eV and dose is 9×1017 cm-2 and 3×1017 cm-2 respectively. Through ion implantation, Ti ion implantation layer approximately 1000nm thick is directly formed on the surface of AZ31 magnesium alloy, by which its surface property is greatly improved. Microstructure, the component distribution and phase composition are analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The property of hardness of the ion implantation layer was studied by HMV-1T Vickers micro hardness tester. The results show that Ti ion implantation layer of a magnesium alloy surface is mainly composed of TiO2, MgO and a little of TiO. The Ti-C double ions implantation layer is composed of MgO, TiC. The hardness of ion implantation layer is improved.

Analysis and Removal of Organic Pollutants in Biologically Treated Landfill Leachate by an Inorganic Flocculent Composite of Al(III)‐Mg(II)

Abstract: A novel inorganic flocculent composite of Al(III)-Mg(II) poly-magnesium-aluminum-sulfate (PMAS) is used to remove organic matter from biologically treated leachate in some landfills in Beijing, China. Jar-test experiments are employed to determine the optimum conditions for the removal of organic matter, which is represented as UV(254). Under optimum conditions, the removal of COD, BOD(5), and color is also determined. Moreover, gas chromatography coupled with mass spectrometry (GC-MS) is used to analyze the organic matter in the biologically treated leachate before and after treatment by the coagulant. The experimental results indicate that the removal of COD, BOD(5), UV(254), and color by coagulation with PMAS can reach above 65%, 60%, 85%, and 85%, respectively, under optimal conditions. This greatly weakens its pollution extent and improves its visual appeal. Forty-one kinds of organic pollutants in the biologically treated leachate were determined. Some of them belong to the Black List of water environmental preferred controlled pollutants, as judged by the United States and China. The species of alkyl, alkene, acyclic alcohol, and acyclic acyl amines are about 85% removed, some of them are removed completely, while the species of acids, esters, and ketones are removed at about 65%. Those contaminants with benzene rings, such as aromatic hydrocarbons, hydroxybenzene, aromatic alcohol, and aromatic acyl amine, are about 50% partially removed.

A Feature Selection Algorithm Based on Boosting for Road Detection

Abstract: Feature selection is very important for road detection. Generally, optimal feature set is very hard to be determined manually by prior-knowledge. In this paper, a feature selection algorithm based on boosting is proposed. To fully utilize potential feature correlations, the features are combined. The feature vector is enlarged by the combined features, and the new feature vector is called raw feature vector. In this paper, the classify power of each feature is evaluated by the error rate and converge speed of boosting classifier which is based on single feature. After that, the features are selected according to itpsilas classify power. The selected features are reassembled to B-feature vector. Then features are weighted according to its power in classification. The weighted B-feature vector is called B-W-Feature Vector. Three classifiers are used to evaluate the raw feature vector, the B-Feature and the B-W-Feature. The experiment results show selected and weighted feature vector can improve the classification performance.

Synthesis, characterization and hydrotreating performance of supported tungsten phosphide catalysts

Abstract: Supported tungsten phosphide catalysts were prepared by temperature-programmed reduction of their precursors (supported phospho-tungstate catalysts) in H2 and characterized by X-ray diffraction (XRD), BET, temperature-programmed desorption of ammonia (NH3-TPD) and X-ray photoelectron spectroscopy (XPS). The reduction-phosphiding processes of the precursors were investigated by thermogravimetry and differential thermal analysis (TG-DTA) and the suitable phosphiding temperatures were defined. The hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities of the catalysts were tested by using thiophene, pyridine, dibenzothiophene, carbazole and diesel oil as the feedstock. The TiO2, γ-Al2O3 supports and the Ni, Co promoters could remarkably increase and stabilize active W species on the catalyst surface. A suitable amount of Ni (3%–5%), Co (5%–7%) and V (1%–3%) could increase dispersivity of the W species and the BET surface area of the WP/γ-Al2O3 catalyst. The WP/γ-Al2O3 catalyst possesses much higher thiophene HDS and carbazole HDN activities and the WP/TiO2 catalyst has much higher dibenzothiophene (DBT) HDS and pyridine HDN activities. The Ni, Co and V can obviously promote the HDS activity and inhibit the HDN activity of the WP/γ-Al2O3 catalyst. The G-Ni5 catalyst possesses a much higher diesel oil HDS activity than the sulphided industrial NiW/γ-Al2O3 catalyst. In general, a support or promoter in the WP/γ-Al2O3 catalyst which can increase the amount and dispersivity of the active W species can promote its HDS and HDN activities.

Histogram Specification-based Audio Watermarking Technology against Filtering Attacks in Time Domain

Abstract: Filtering processing is a kind of typical and serious attack on the audio watermarking algorithm. Based on the computation in time domain before and after attacking on the audio, the mean and the standard deviation show good invariant statistical feature. The relation of four consecutive bins in a histogram can keep the change within plusmn5%. A data range selection approach, which meets the demands of normal distribution, is created generally for the watermark hiding. Based on segmenting idea, an audio watermarking algorithm is designed with statistical features by the stable relation of four consecutive bins. Experimental results show that the algorithm can resist on the attack of low pass filtering with large hiding bandwidth up to 17 bit/s. It shows much better than the existed histogram approach with relations of three consecutive bins.

Flocculation Process Optimization of a Novel Coagulant for Landfill Leachate Pretreatment

Abstract: Sanitary landfill leachates are considered as heavily polluted industrial wastewaters, so special care is required for their efficient treatment and disposal. The most popular biological treatments are mostly the secondary stage in a combination with additional physical-chemical pre-process. A novel inorganic polymer flocculants, poly-ferric(III)-magnesium(II)-aluminum(III)-sulfate (PFMAS in brief) is used to pretreat landfill leachate. Jar-test experiments are employed to investigate the effect of flocculation conditions such as PFMAS dosage, leachate pH, leachate temperature, and sedimentation time to organics removal. It is demonstrated that the removals of COD, BOD5 and color by coagulation with PFAMS can reach 67%, 56% and 90% respectively under the optimum conditions (including PFMAS dosage at 3.3 g/L (Fe+Al+Mg), the leachate pH at 8.0, the leachate temperature at 20degC, and the sedimentation time at 50 min, respectively), which greatly weakens its pollution extent and improves its visual appeal. Flocculation with PFMAS may be used as a useful pretreatment step for landfill leachate.

Catalytic properties of a (A=Ba, Ca, Sr and Y) modified lanthanum hexaaluminates for catalytic combustion of methane

Abstract: A series of hexaaluminates, La0.8A0.2MnAl11O19−δ samples (A = Ba, Ca, Sr and Y) as new catalysts were prepared by carbonate precipitation and calcined at high temperature. The structure and properties of these samples were characterized by XRD, BET and XPS techniques. Upon calcination at 1200°C, the hexaaluminate structure was formed and it retained the specific surface area of 17∼20 m2g−1. The La0.8Ca0.2MnAl11O19−δ catalyst has a surface area of 19.3 m2g−1 and shows a good activity in CH4 combustion.

Segmenting Histogram-based Robust Audio Watermarking Approach

Abstract: Based on the invariant features and data distribution in time domain before and after attacking on the audio, it is clearly that the standard variance shows good invariant statistical feature. The relation of four consecutive bins in a histogram maintains change less than 5%. Then, a general data selection approach, which meets the demands of normal distribution and other distributions, is created for the watermark hiding. Based on segmenting idea, an audio watermarking algorithm of embedding and extracting is designed with statistical features by the stable relation of four consecutive bins. Experimental results show that the algorithm can resist on attack of low-pass filtering with large hiding bandwidth up to 17 bit/s. It shows much better than the existed histogram approach with relations of three consecutive bins. The algorithm can also resist on the attacks of TSM and other common attacks.

CFD simulation of flow field in standard orifice plate flow meter

Abstract: The utilization of CFD numerical simulation in standard orifice flow meter provides a new method on the estimation and optimization of discharge coefficientThis paper complemented numerical simulation onto the flow field of incompressible flow under different flow rate,diameter ratio,orifice thickness and flow media,by comparing and analyzing the discharge coefficient achieved from numerical simulation and the ISO empirical formulaIt is indicated that,with the variation of structural parameters and working condition,the discharge coefficient will change correspondently,but ISO formula is not very sensitive to the thickness of orifice plateThe CFD numerical simulation can be adopted as a complementary design and certification tool in standard orifice flow meter,to enhance its measurement accuracy further more

New Approach for Sensitive Association Rule Hiding

Abstract: A new sensitive rule hiding algorithm, including two processes of weak association transaction adding and strong association transaction removing, is presented based on the devotion degree of transactions to the discovered association rules. The approach and algorithm are stated in detail aiming to hide simple rules,including two types of single rule and composed rule.Four item modification methods are designed for the updating of selected weak association transactions. Only a small number of transactions are required in updating to keep the original features in the mined dataset. When the modification factor is set above 0.05, the hiding rate can be reached to 100%, and the side effects of the lost rules and new created rules are very small with rate less than 10%. Finally, after the hiding detection to the new database, the robustness to the support attack is satisfying with suitable hiding rate.

Preparation of a Fibrous Catalyst Containing Palladium Nanoparticles and Its Application in Hydrogenation of Olefins

Abstract: A novel fibrous catalyst containing palladium nanoparticles was produced via electrospinning technique. The fibrous catalyst was characterized by scanning electron microscopy and transmission electron microscopy respectively, the results show that the diameter of fiber was about 200 nm and the palladium (Pd) nanoparticles was in the range of 30–40 nm. The size and shape of Pd particles on the fiber can be adjusted by changing the concentration of polymer or amount of PdCl2 in the electrospun solution. The catalyst was tested in hydrogenation of α-hexene and α-octene in ethanol at room temperature. The catalytic experimental results show that the activity of the titled catalyst was 4.7 times higher than that of PdCl2/γ-Al2O3 and higher than that of PdCl2 on poly(styrene-divinylbenzene) resin catalyst (Zharmagambetov et al., J Mol Catal A: Chemical, 177, 165 (2001)). POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

The Overview of the Technique of Solar Energy Generating Electricity

Abstract: This article discusses solar energy's application,the point discussion is the technique of the solar energy generating electricity.And then introduces all kinds of techniques in and out of nation,as technique of solar energy tower hot air flow to generate electricity,technique of solar energy hot to generate electricity and technique of solar energy light bring voltaic electricity etc,at the foundation of discussion of techniques and advantage and disadvantage,inquiries into the prospect of the technique of solar energy application.At the same time,briefly introduces development status of the technique of the solar energy generating electricity in our nation,points out advantage and natural space of exploiture system of the solar energy generating electricity energetically.

Robust Audio Watermarking Algorithm Based on Histogram Specification

Abstract: It is very important to resist on the typical attacks for the watermarking algorithms. From the data distribution analysis in time domain before and after attacking on the audio, the relation of four consecutive bins in a data histogram can keep its change within plusmn 5%. A data range selection approach, which meets the demands of normal distribution, is created generally for the watermark hiding. Based on segmenting idea, an audio watermarking algorithm is designed with statistical features by the stable relation of four consecutive bins. Experimental results show that the algorithm can resist on the attack of low pass filtering effectively. It shows much better than the existed histogram approach with relations of three consecutive bins. The algorithm can also resist on the attacks of time-scale modification, volume change of plusmn 50%, along with strong robustness to the common attacks of MP3 compression, re-sampling and re-quantization.

A Needle-Holding Robot for Ultrasound Guided Percutaneous Hepatic Microwave Ablation and Initial Experiments

Abstract: A needle-holding robot for percutaneous hepatic microwave ablation is developed. The overall architecture of the robot is introduced first with the explanation of the mechanism of 3D motion tracking. Two experiments were conducted, one to quantify the force required for motion tracking, the other to assess the performance of motion tracking. The result of force-measuring experiment shows that the force required for rotation and radial translation motion tracking are less than 15 grams, which indicates the high sensitivity of the holding robot. The result of in-vivo animal trial performed on a swine shows that the holding robot is accurate enough in tracking the 3D motion of the ablation needle, which allows for stable and precise holding of the needle compared to that of freehand holding.

Operating state monitoring and fault diagnosis on traction power supply system

Abstract: How to extract fault feature and divide pattern space is very important for the fault diagnosis. The traveling wave signal characteristic of over-head contact system is analyzed on the base of electromagnetic field theory; the eigenvector is constructed by the wavelet packet energy spectrum. The tests prove that the method in which the traveling wave feature is extracted in terms of wavelet packet energy spectrum is very available. The arithmetic of the pattern recognition is simplified using the method and the accuracy of the fault diagnosis is improved obviously.

Weld Seam Edge Extraction Algorithm Based on Beamlet Transform

Abstract: We present a novel algorithm based on Beamlet Transform for extracting seam edges from noisy welding images. Taking into account of some special characteristics of welding image processing, we introduce an orientation-thresholding step as well as a two-scan method to the standard beamlet-based line detection algorithm. Experiments are conducted to extract edge features from noisy welding images at different scales and to test the anti-noising performance of our algorithm. The result of experiments show that our algorithm is capable of directly extracting weld seam edges from highly noisy welding images without any pre-processing or post-processing steps, thus is characterized by its high efficiency and its prominent anti-noising performance. The orientation threshold can not only reduce the calculation load, expedite its running speed, but also it can help to improve the anti-noising performance of the algorithm. The two-scan method is particularly helpful when coping with low SNR welding images.

Vibration Analysis and Rebuilding for Superhigh Pressure Reciprocating Compressor

Abstract: In a petrochemical plastics factory,a superhigh pressure reciprocating compressor had serious vibration and noise pollution.In order to solve the problem,the finite element analysis software ANSYS was used to build vibration analysis models,to have structure modal and harmonic analysis. Thereby the compressor vibration causes were found,and an effective rebuilding program was designed,After the implementation of the program,the vibration was significantly lowered,the biggest drop is more than 76.8%.The method provides a reference for reducing vibration and noise of other superhigh pressure devices.