Design,validation, and reliability determination a citing conformity instrument at three levels: normative,informational, and identification

Authors have various motivations in citing references during scientific production. The study of these motivations has led to the introduction of different theories like normative theory and social constructive theory of citing behavior. Using the social constructive approach to citing behavior, this research introduces citing conformity whereby some authors’ social, personal or non professional citing behaviors are determined by societal pressure. This is explained at three levels namely; normative, informational and identification. This paper aims to design, validate and determine the reliability of a questionnaire to measure citing conformity at these three levels. In order to devise the instrument, a questionnaire with 45 items was preliminarily designed. After face validity of the questionnaire had been determined by ten scholars, data was gathered. 150 Iranian authors with at least two articles indexed in Arts and Humanities Citation Index (AHCI) or Social Science Citation Index (SSCI) during the period 2001–2010 were selected using systematic random allocation and were asked to fill out the questionnaire. Exploratory factor analysis was used to analyze the data. Factor analysis was administered using principal components analysis (PCA) with Varimax rotation, eigenvalue more than one, and factor loading 0.45 to extract three factors. Out of 45 items, 11 were deleted by the software due to low factor loading. The remaining 34 items were retained and constitute tree factors: normative (13 items), informational (13 items), and identification (8 items). KMO coefficient test was 0.726 and Bartlett sphericity index was 2431.91 (P < 0.0001) which proved the sufficiency of sample size and the reliability of the test. Cronbach’s alpha was employed to determine the reliability of this instrument. Cronbach’s alpha coefficient for normative, informational and identification conformities was 0.86, 0.81 and 0.85 respectively. Therefore, the reliability of all the factors was acceptable with approximately high coefficients. As the Cronbach’s alpha coefficients convey, the reliability of all factors was acceptable. The development of a citing conformity instrument at normative, informational and identification levels, provides a scale to measure authors’ citing behavior in social, personal or non professional aspects according to the above mentioned psychological variables (normative, informational and identification conformities). Therefore, this instrument will be able to explain the authors’ citing behavior and motivations in a large extent of a subject area.     

Robust Tomlinson-Harashima Precoding for Two-Way Relaying

Most of the non-linear transceivers, which are based on Tomlinson-Harashima (TH) precoding and have been proposed in the literature for two-way relay systems, assume perfect channel state information (CSI). In this paper, a novel and robust TH precoding scheme has been investigated for two-way relay systems, with multiple antennas at the transceiver and relay nodes. We assume imperfect CSI and the channel uncertainty is bounded by a spherical region. The minimum mean square error at the destinations is used as the design criterion and we develop an iterative method to solve this nonconvex problem to obtain TH precoding matrices at the transmitter, linear precoding matrix at the relay and linear equalizer at the destination nodes, where each subproblem is convex. Simulations are provided to evaluate the performance and to validate the efficiency of the proposed scheme.

     

Colour dependency of textile samples on the surface texture

In this paper, the perceptual and instrumental effects of texture on colour is investigated, using 63 textile samples, in nine colour centres and seven texture structures. The effectiveness of texture is evaluated by assessing colour differences between six texture samples and a standard texture in each colour group. Experimental results show that the sample texture has a significant effect on the measured and perceived colour and its influence depends on the colour centre of the sample. The magnitude of texture effect is more dependent on the texture type than on its coarseness. A new term to evaluate texture difference of a pair of textile samples was defined using a Gabor filter (Gabor texture difference). The visual colour changes gave a good correlation with Gabor texture difference values; however, the colour of the samples affected this correlation. So the colour change, as a result of texture differences, depends on two independent variables consisting of the Gabor texture difference and the colour centre of samples.     

Study on the efficiency of ethylene scavengers on the maintenance of postharvest quality of tomato fruit

The objectives of this study were to achieve the best level of each ethylene scavenger and evaluate the effect of selected levels of treatments on some quality traits of tomato during storage. Tomato fruits were subjected to four levels of treatments: palladium-promoted nano zeolite, KMnO₄-promoted nano zeolite, 1-MCP, CaCl₂, salicylic acid (SA) and UV-C. The sampling was done at 0, 7th, 14th, 21st, 28th and 35th days of cold storage. The results showed that palladium-promoted nano zeolite 5%, KMnO₄-promoted nano zeolite 20%, 1-MCP 30 ppm, CaCl₂ 2%, SA 1% and UV-C 15 min levels had the most ethylene scavenging function. Effectiveness of the treatments in ethylene scavenging was in the order: palladium?>?KMnO₄?>?1-MCP?>?SA?=?CaCl₂?>?UV-C. The palladium-promoted nano zeolite 5% had more positive effects on phenol content, polygalacturonase activity, lycopene content, fruit firmness and weight loss, and UV-C 15 min had effect on decay severity as compared to the other treatments. Overall, palladium-promoted nano zeolite 5% could be considered not only as favorable tool in tomato shelf life extension but also in preservation of quality characteristics of tomato fruits during storage. Moreover, the UV-C 15 min treatment could be an effective method for reducing decay severity and maintaining postharvest quality of tomato fruits.     

Correlation between quality and quantity in scientific production: A case study of Iranian organizations from 1997 to 2006

In order to prevent the formation of a gap between the quality and quantity in Iranian scientific publications, this study makes an effort to analyze Iranian scientific publications indexed on the ISI Web of Science database using quantitative and qualitative scientometrics criteria over a ten year period. As a first step, all Iranian institutes were divided into three categories; universities, research institutes and other organizations. Then they were compared according to quantitative and qualitative criteria. Second, the correlation between the quality and quantity of the publications was measured. The research findings indicated that, according to qualitative criteria (citation, citation impact and percentage of cited documents) there are no meaningful differences among the three groups, while regarding quantitative criterion(number of papers), universities rank higher than the other two groups. The results also indicated that there is a positive and meaningful correlation among qualitative and quantitative criteria in the scholarly scientific publications conducted by Iranian organizations. In other words, in Iranian organizations the quality of publications increases as their quantity increases. The comparison of magnitude of correlation between these two criteria in the three categories reveals the fact that the correlation between number of papers and citations criterion in research institutes is stronger than the other two groups.     

An Investigation on the Effect of Air Swirler Vane Angle on Liquid Fuel Combustion Characteristics

This is an experimental and numerical study on the effect of air swirl vane angle on combustion characteristics of liquid fuel burners. The swirl vane angle varied in a range from 0° to 75° and the values of the dependent variables were determined. The flame temperature was measured by an S‐type thermocouple and a Testo 350 XL gas analyzer was used to determine the NO and CO pollutant concentrations. Also, sprint CFD code along with suitable models was used in analytical modeling. The results indicate that there is an optimum angle for the swirl vane (approximately 45° for the case study). At the optimum angle, the average temperature of the flame increases as much as 12.5% and 28.5% in comparison with small and large angles, respectively. Therefore, combustion efficiency reaches its maximum level and CO emission is at an extremely low level. The results also demonstrate that large swirl angles decreases NO emission.     

Simulation and optimization of ethanol amine production plant

An industrial Ethanol Amine (EA) production plant was simulated and optimized. Due to lack of accurate reaction rate information, the first step involved obtaining reliable kinetic data from the SRI (Stanford Research Institute) industrial database and calculation using error minimization method. In the next step, by implementing the obtained reaction kinetics the whole plant was simulated using Hysys software. Simulation results were compared with the SRI data and showed that there is acceptable agreement between simulation and the measured industrial data. In the next step of study by applying the gradient search (GS) optimization technique the plant was optimized using: feeding ammonia to ethylene oxide (EO) molar ratio, water flow rate in the feed stream, and reactor temperature as optimization variables. Employing process profit as objective function the optimal operating conditions were found to be: ammonia to EO ratio of 5 (mol/mol), water flow rate of 52.59 kg mol/hr and reactor temperature of 85 °C.     

Optimizing High-Velocity Oxygen Fuel-Sprayed WC–17Co Coating Using Taguchi Experimental Design to Improve Tribological Properties

High-velocity oxy-fuel (HVOF) thermal spraying is one of the best methods for depositing conventional WC–Co cermets. The aim of the present work was to optimize the WC–17Co coating deposited using HVOF spraying process. Taguchi fractional factorial experimental design (L18) and ANOVA were used to optimize the process parameters. Seven factors (spray distance, oxygen flow rate, carrier gas flow rate, powder feed rate, coating thickness, substrate preheat temperature and grit type) were selected. Grit type had two levels, and the others had three levels. The coating properties measured were wear resistance, microhardness and roughness. Pin-on-disk wear tests were used for measuring wear. Scanning electron micrographs were used to investigate the cross sections of the coatings and the morphology of the as-sprayed coatings, and their relationship between the process parameters and energy-dispersive X-ray was used to analyze the coatings. In Taguchi method, “lower the better” quality was used for optimizing roughness and “higher the better” quality was used for optimizing wear resistance and microhardness. The most influential factor on increasing wear resistance and microhardness was powder feed rate and on reducing the roughness was oxygen flow rate. In addition, the influence of grit type on wear resistance and microhardness and the influences of grit type and substrate preheat temperature on the coating roughness were negligible.     

Experimental study and modeling of the kinetics of gas hydrate formation for acetylene,ethylene, propane and propylene in the presence and absence of SDS

The kinetics of hydrate formation of the hydrocarbons acetylene, ethylene, propane, and propylene were investigated using a fully stirred batch reactor. In relation to hydrate formation, a kinetic model was used to determine the induction time, the rate of hydrate formation, the apparent hydration rate constant, water-to-hydrate conversion associated with hydrate growth as well the storage capacity. This was done for all gases investigated in this study. Experiments were performed in the temperature and pressure ranges of (273.7–280.0) K and (0.5–4.12) MPa, respectively. Furthermore, the effect of sodium dodecyl sulfate (SDS) on the gas hydrate formation rate was examined. A substantial growth in the hydrate nucleation rate was observed in the presence of SDS.     

Removal of tylosin from aqueous solution by UV/nano Ag/S2O 8 2− process : Influence of operational parameters and kinetic study

The present work deals with the photooxidative degradation of tylosin antibiotic (TYL) in the presence of potassium peroxydisulfate (K₂S₂O₈) irradiated by UV-C in the presence of immobilized nano silver. Effects of pH, temperature, peroxydisulfate concentration and immobilized nano silver dosage on the degradation efficiency of TYL were examined. Degradation efficiency was small when the oxidation was carried out in the absence of UV irradiation. Results showed that degradation of TYL increases with temperature, nano Ag and peroxydisulfate initial concentration and decreases with pH. Due to UV/nano Ag/S₂O ₈ ^2? processes, more than 90% of TYL can be degraded at room temperature in 35 min at an initial concentration of 50 mgl^?. Degradation reaction order of TYL by UV/nano Ag/S₂O ₈ ^2? process is 1.89. Meanwhile, the initial rates of degradation in UV/nano Ag/S₂O ₈ ^2? processes can be described well by the Langmuir-Hinshelwood kinetic model.