PARTITION-EQUIVALENT n-POINTS CONFIGURATIONS WITH TWO DISTANCES

In this paper we define an equivalence relation on the set of all possible geometrical models of M(n, k) containing n points in 3D Euclidean space having k distinct distances. We investigate the number of geometrical model for M(4,2), M(5,2) and M(6,2) up to the mentioned equivalence relation

Cofibrations in the Category of Noncommutative CW Complexes

Cofibration in the category of noncommutative CW complexes is defined. The C*-algebraic counterparts of topological mapping Cylinder and mapping cone are presented as examples of noncommutative CW complex cofibres. As a generalization, the concepts of noncommutative mapping cylindrical and conical telescope are introduced to provide more examples of NCCW complex cofibres. Their properties and K-theoretic behavior are also studied in detail. We will see that they carry the properties similar to the topological properties of their CW complex counterparts

High surface area vanadium phosphate catalysts for n-butane oxidation

Vanadium phosphorus oxide (VPO) was prepared using the precipitation procedure and tested for potential use in the partial oxidation reaction of n-butane to maleic anhydride. In particular, the effect of reducing agents such as the isobutanol, 1-butanol, and glycol, subsequent water treatment, and microwave heating were investigated in detail. The optimum synthesis conditions were identified with respect to catalyst activity for the oxidation of n-butane. The activity and selectivity of VPO prepared catalysts have been evaluated in a fixed bed microreactor and in situ gas chromatography (GC) was used to evaluate the system efficiency and analyze the product effluent stream. The different catalysts exhibited a range of activities and selectivities under the same reaction conditions. The range in catalyst performance may be attributed to the crystal size as well as particle size of catalyst. The results were interpreted in terms of surface area and catalyst nanostructure, and it has been generally concluded that the catalyst surface area is enhanced by the employment of glycol as the reducing agent, followed refluxing by distilled water and drying by microwave irradiation. The catalyst produced using this method is the most active and selective catalyst for partial oxidation of n-butane to maleic anhydride. The catalyst lifetime was tested under the optimum reaction conditions, and the catalyst was found to be highly stable for more than 70 h. The characterization of both precursors and calcined catalysts was carried out using X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometer (ICP-AES), Brunauer−Emmer−Teller (BET) surface area measurement, temperature programmed reduction (H2-TPR), and scanning electron microscopy (SEM)

Influence of rare-earth and bimetallic promoters on various VPO catalysts for partial oxidation of n-butane

Vanadium phosphorous oxide (VPO) catalyst was prepared using dihydrate method and tested for the potential use in selective oxidation of n-butane to maleic anhydride. The catalysts were doped by La, Ce and combined components Ce + Co and Ce + Bi through impregnation. The effect of promoters on catalyst morphology and the development of acid and redox sites were studied through XRD, BET, SEM, H2-TPR and TPRn reaction of n-butane/He. Addition of rare-earth element to VPO formulation and drying of catalyst precursor by microwave irradiation increased the fall width at half maximum (FWHM) and reduced the crystallite size of the Vanadyl hydrogen phosphate hemihydrate (VOHPO4 · 1/2 H2O, VHP) precursor phase and thus led to the production of final catalysts with larger surface area. The Ce doped VPO catalyst which, assisted by the microwave heating method, exhibited the highest surface area. Moreover, the addition of promoters significantly increased catalyst activity and selectivity as compared to undoped VPO catalyst in the oxidation reaction of n-butane. The H2-TPR and TPRn reaction profiles showed that the highest amount of active oxygen species, i.e., the V4+–O− pair, was removed from the bimetallic (Ce + Bi) promoted catalyst. This pair is responsible for n-butane activation. Furthermore, based on catalytic test results, it was demonstrated that the catalyst promoted with Ce and Bi (VPOD1) was the most active and selective catalyst among the produced catalysts with 52% reaction yield. This suggests that the rare earth metal promoted vanadium phosphate catalyst is a promising method to improve the catalytic properties of VPO for the partial oxidation of n-butane to maleic anhydride

Solvothermal synthesis of vanadium phosphate catalysts for n-butane oxidation

In this paper, we have developed a simple, low-cost, template-free and surfactant-free solvothermal process for synthesis of vanadyl hydrogen phosphate hemihydrate (VOHPO4·0.5H2O) with well defined crystal size. The synthesis was performed by reaction of VPO4·2H2O with an aliphatic alcohol (isobutyl alcohol, 1-pentanol, 1-hexanol, 1-heptanol or 1-decanol). This afforded well crystallized VOHPO4·0.5H2O by solvothermal methods at 120 °C temperature. This new method significantly reduced the preparation time and lowered production temperature (50%) of catalyst precursor (VOHPO4·0.5H2O) when compared to conventional hydrothermal synthesis methods. By varying the reducing agent, the solvothermal evolution process from layered tetragonal phase VOPO4·2H2O to orthorhombic phase VOHPO4·0.5H2O was observed. It was found that the length of carbon chain in an alcohol in the solvothermal condition had a great impact on chemical and physical properties of resulting catalysts. Interestingly, there was no trace of VO(H2PO4)2 an impurity noted to be readily formed under solvothermal preparation condition. Therefore, this study introduces a more facile synthetic pathway to V(III) compounds. In addition, the microwave-synthesized catalysts exhibited some properties superior to those of conventionally synthesized catalyst such as better stability, crystallinity, and catalytic activity in the production of maleic anhydride. The characterization of both precursors and calcined catalysts was carried out using X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometer (ICP-AES), N2 physisorption, temperature programmed reduction (H2-TPR) and scanning electron microscopy (SEM). The XRD pattern of the active catalyst prepared by this solvothermal method confirmed the presence of smaller crystal size (between 6 and 13 nm along 0 2 0 planes) of vanadium phosphate catalyst with higher specific surface area. Finally, the yield of maleic anhydride was significantly increased from 29% for conventional catalyst to 44% for the new solvothermal catalyst

Prediction of Optimum Gas Mixture for Highest SXR Intensity Emitted by A 4kj Plasma Focus Device Using Artificial Neural Network

In this study, artificial neural network (ANN) is investigated to predict the optimum gas mixture for highest soft X-ray (SXR) intensity emitted by a 4kJ plasma focus device. To do this multi-layer perceptron (MLP) neural network is used for developing the ANN model in MATLAB 7.0.4 software. In this model, the input parameters are voltage, Percentage of nitrogen in admixture and pressure and the output is SXR intensity. The obtained results show that the proposed ANN model has achieved good agreement with the experimental data and has a small error between the estimated and experimental values. Therefore, this model is a useful, reliable, fast and cheap tool to predict the optimum gas mixture for highest SXR intensity emitted by plasma focus devices

Effect of Slope Position on Soil Properties and Types Along an Elevation Gradient of Arasbaran Forest, Iran

Sustainable development by forest managing need to identify forest ecosystem elements. Forest soil is the most important element of forest ecosystem that has key roles in forest managing. Therefore, studying of soil properties and evolution under different environmental conditions is necessary for sustainable management of forest ecosystems. Spatial variation of soil properties is significantly influenced by some environmental factors that slope position is one of them. The aim of this study was evaluating effects of slope position on forest soil change which was carried out in Arasbaran forest, North-West of Iran. Nine soil profiles were dug, described and sampled in three different parts of an altitudinal transect with same environmental conditions and different slope positions. Then soil samples were analysed physicaly and chemicaly and so classified based on Soil Taxonomy 2014. Also according to obtained results One-way analysis of variance was used to test relations of soil properties and slope positions. This results revealed significant effect of slope positions on thickness of the soil profile and solum, clay, organic carbon and total nitrogen percentages and cation exchange capacity at 5% level of confidence which lead to change of type, depth and sequence of soil horizons along altitudinal transect. Finally, it has found that slope position not only has important role in soil properties changes and soil evolution but also it can't be refused the various role and influence of same forest stand in different slope positions. Therefore various soils such as Inceptisols, Alfisols and Molisols were observed under different slope positions. Then it can be achieved that, because of special forest vegetation, soil evolution along altitudinal transect of forest ecosystems are differing from other ecosystems. Thus, for forest soil management program it is necessary to consider both of topography and vegetation effect over the area, even if one of them is constant

A Study on the Relationship between Proprietorship Concentration and Profit Management in the Companies Listed in Tehran Stock Exchange

The presence of institutional investors may change the behaviors of companies. The impact of institutional investors on management decisions on financial affairs have been proven in other studies; yet, the present study aims to investigate the relationship between lack of information symmetry an concentration of proprietorship with profit management in the companies listed in Tehran Stock Exchange. The period under study included years 2004 to 2009. Rahavard Novin Computer application was utilized to collect the data; then they were calculated using Microsoft Excel.  SPSS computer application was used to test research hypothesis and conduct other statistical analysis using statistical methods like descriptive statistics, correlation (correlation coefficient, coefficient of determination), regression analysis and testing its coefficients, correlation analysis and test of coefficients and significance of the difference between two correlation coefficients. A total of 109 active companies in the stock exchange were selected as the sample of the study. Results on the first hypothesis revealed that the relationship between concentration of proprietorship and lack of information symmetry. In case of the second hypothesis, it is predicted that there is a significant relationship between profit management with lack of information symmetry and concentration of proprietorship. According to research results, investors and analysts ought to pay attention to factors like proprietorship composition, the level of information symmetry along with the figures published by the companies when making short and long-term decisions

Immunogenic Properties of Sonicated Multivalent Antigen of Pseudomonas Aeruginosa

Objective: Pseudomonas aeruginosa is one of the opportunistic pathogens that takes the advantage of patient"s immunodeficiency and is one of the major causes of nosocomial infections. Multivalent vaccines such as those using the collection of secretory antigens and inactivated or killed whole-cell can be effective in preventing the infections. This study intended to evaluate the protective effect of P. aeruginosa whole-cell antigen in preventing the infections. Materials and Methods: In this study, sonicated multivalent antigen was provided and active immunization of female BALB/c mice aged 6-8 weeks (4 groups each with 7 mice) was carried out by subcutaneous, intraperitoneal and intramuscular administrations on days 0, 14 and 28. The fourth group was selected as the control group of the study. One week after each injection, on days 7, 21 and 35 blood samples were taken from mice and after isolating the serum, indirect ELISA was carried out to evaluate the produced IgG antibody against sonicated multivalent antigen of P. aeruginosa. Results: According to the results, due to the complexity of P. aeruginosa pathogenicity, using the multivalent vaccines such as the collection of somatic and secretory antigens, can be effective in the prevention of infections. ELISA results showed significant antibody production in subcutaneously, intraperitoneally and intramuscularly injected groups compared to the control group. Comparing the immunization of antigen based on the route of injection showed that there was no significant difference in induced immunization between the groups (subcutaneous, intraperitoneal and intramuscular injections). Moreover, immunized mice showed significant protection against intraperitoneal challenge with 7.5 × 107 CFU (2× LD50) P. aeruginosa. Conclusion: The sonicated antigens can have a more effective role in immunization and the prevention of mortality among mice infected with Pseudomonas