h. mazaheri

Analyzing financial ratios over consecutive years is beneficial for evaluating the financial performance of construction companies. However, such an analysis can be tedious due to the vast number of the ratios. Therefore, developing an expert system based on artificial intelligence algorithms to identify and predict factors influencing the construction companies' financial performance is essential. To this end, a hybrid model based on Genetic Algorithm (GA) and Adaptive Neuro-Fuzzy Inference System (ANFIS) was introduced in this research to predict the financial performance of construction companies in Iran. This research is applied as descriptive and in terms of methodology well developed; also conducted cross-sectionally. The statistical population included all active construction companies in the construction sector in Tehran. Due to time and resource constraints, a random sampling technique was used. A questionnaire was utilized for data collection and data analysis, factor analysis methods and neuro-fuzzy system combined with GA were employed. The ANFIS combined with GA can evaluate the construction companies' financial performance with the minimum error. The findings ultimately resulted development of a model that forecasts the financial performance of Iranian construction companies, allowing them to concentrate on factors that improve financial performance.

Successful civil projects are one of the key factors in the economic development. Civil projects are always criticized for time and budget wastage. Delays in the execution of these projects sometimes not only waste national resources and cause social damages, but also may ultimately render the project economically unjustifiable, to the extent that the direct and indirect damages from delays can sometimes exceed the actual value of the project. However, despite all government efforts, projects in Iran still suffer from delays. Therefore, managing the delays in construction projects in Iran for optimal utilization and proper management is essential. This research proposes a delay management model for construction projects based on evaluating the effective factors on the delay of construction projects in Iran using system dynamics and optimization methods. Finally, a model suitable for the managerial situation in top-ranked contracting companies in Tehran province was presented. The validation and credibility assessment of the proposed model in managing the delay of construction projects in Iran indicated that, by combining these two approaches, project managers can improve project performance under dynamic system conditions. This innovation can be utilized in different industries, especially in the construction industry. In fact, this study provides an optimal response to the management of delays in construction projects by changing the planning horizon using integrated tracking methods and identifying the best strategy and planning horizon for policymakers. Through this, an optimal planning horizon for managing delays in construction projects in the real world is achieved.

The main goal of this research is to use zeolite TiO2 nanocomposite membranes in order to remove moisture from gas. For this reason, a certain TiZ-V membrane was selected and manufactured as a standard membrane, which was the result of the initial assessment of a suitable membrane for gas dehumidification, and this membrane was used as a standard to measure the effect of manufacturing parameters. The findings showed that increasing the concentration of SiO2 had greatest effect on increasing the water flux of the membrane due to the effect of increasing the reaction time of the vapor phase carrier and reducing the selectivity drop at higher pressures. Also, the experiments of changing the relative humidity of the feed have shown the improving efficiency of the membrane in relative humidities lower than 80%, so that under the conditions of lower relative humidity, the selectivity of the membrane has increased. Another positive point found is a slight change in the selectivity efficiency of the membrane with respect to different relative humidities. This case showed the stability of membrane performance under the different conditions of humidity of the feed gas. Next, in order to increase the performance of membrane as much as possible, the sweeper gas was added from the inside of membrane. Increase in the sweeper gas, which increases the water concentration gradient and decreases the gas concentration gradient on the sides of membrane wall, increases the selectivity of membrane to the highest level of 543.

In this paper, we study wavelet approximation of the Chebyshev polyno-mials of the first, second, third, and fourth kinds. We estimate the wavelet approximation of a function f having bounded first derivatives.

In this research, the synthesis process of a novel super-active catalyst, named SAC-510 is investigated at experimental scale. The authors compared the analyzed data against those derived from a popular catalyst, Finix-112, and several other available alternatives. The data indicated that SAC-510 catalyst derived the optimal activity from its spherical particles. Titanium and other chemical elements were less uniformly distributed in SAC-510 than in Finix-112 samples, with the mean particle size being slightly larger than that found in Finix-112. The pores’ dispersion and sizes in SAC-510 were not as uniformly distributed as those in Finix-112 catalyst. Lastly, both SAC-510 and Finix-112 catalysts were equally adaptable for use in high-density polyethylene pipes (grade 100). Compared to other commercially available catalysts, the major advantages of SAC-510 are the economical use of hydrogen and monomers, and low purging of its valuable gases during the polymerization process. The results obtained are as follows: the increase in oxidative induction time efficiency with SAC catalyst compared to Finix catalyst by 5.8%, activity by 35.7%, hydrogen responsibility by 24.39%, 1-butene consumption by 8.38% and triethylaluminium consumption by 27.27%.

The separation of carbon dioxide is essential for the environment. Using membranes to separate this gas is economical, but the weakness in permeability and mechanical strength has prevented their commercialization. Robeson proved that permeability and selectivity have the opposite relationship and provided an upper limit for pairs of gases. Worth to be mentioned that any membrane placed above this limit could be commercialized. Scientists proposed mixed matrix membranes to overcome this problem. These membranes contain two phases, polymer, and inorganic. This research focuused on membrane technology and aimed to prepare a membrane that has a good performance for CO2 separation and at the same time its cost is economical, so by adding a reasonable price zeolite available in the market named 4A to the Pebax1657 polymer and changing the operating conditions of the process, permeability and Selectivity was measured. Pebax polymer and 4A zeolite were selected as respectively the polymer and mineral phases for membrane fabrication. The fabricated membranes were evaluated by XRD, FT-IR, FE-SEM, BET, EDAX, TGA/DSC, and mechanical strength tests. Finally, the selectivity of CO2 compared to N2, O2, and CH4 improved by 53, 67, and 75%, respectively, and obtained a good position on the Robeson diagram.

A kind of approximation, called best coapproximation was introduced and discussed in normed linear spaces by C. Franchetti and M. Furi in 1972. Subsequently, this study was taken up by several researchers in different abstract spaces. In this paper, we define relations on best coapproximation and worst coapproximation. We show that these relations are equivalence relation. We obtain cosets sets of best coapproximation and worst approximation. We obtain some results on these sets, compactness and weakly compactness and define coqproximinal and coqremotal.

Novel catalyst called super active catalyst for the production of high density polyethylene (HDPE) pipes grade 100 was prepared and localized for the first time in Iran. The purpose of this paper is to evaluate the performance of the new catalyst and compare it with Finix-112 catalyst which is a commercial catalyst for the production of HEPE grade 100. Extensive experiments were performed on the physical and mechanical properties of the product using both catalysts including melt flow index, particle size distribution, volatility, density, bulk density, scanning electron microscope-energy dispersive x-ray analysis, charpy impact strength. Comparison of the results showed that the hydrogen responsibility performance of the product with super active catalyst is 19%, charpy impact is 16.7% and pressure condition in first reactor about 28% was better than product with Finix-112 catalyst. Home-made super active catalyst can be a good alternative to imported finix-112 catalyst and save a considerable amount of foreign currency.

The aim of this paper is to define the concepts of remotest points and approximate remotest points in G-metric spaces and obtain some existence results on these concepts. In particular, we define G-remotest points and G-ϵ-approximate remotest points by considering a cyclic map and prove some results in G-metric spaces.

In this paper, an analytical solution and a numerical simulation of the pH-sensitive hydrogel micro-valves exposed to pH variation are proposed. Case studies consist of micro-valve with homogeneous single-layer and FG hydrogel as the active part. The results of both methods are in good agreement indicating the validity of both methods. In addition, The numerical and analytical solutions were compared between two ranges of cross-linking densities of hydrogels. In order to reach a convergent solution for the finite element model of the micro-valve, the hydrogel layer is considered to have a number of different layers, and an appropriate number of layers are considered. In the next step, parameters affecting the micro-valve behavior are studied, which are the dimensionless thickness ratio, the number of acidic groups in the network, and the salt molarity of the external solution. The findings show that as the thickness ratio, number of acidic groups, and salt concentration in the external solution result increases, the hydrogel part of the micro-valve experiences a higher degree of swelling and deformation, which should be considered when designing these devices.

In this paper, we consider “Nearest points” and “Farthest points” in inner product spaces and Hilbert spaces. The convexity of Chebyshev sets in Hilbert spacse is an open problem. In this paper we define sun sets and sunrise sets in normed spaces.

Ionic Liquid(IL)now refers to fluids that are liquid at temperatures above 100°C, they are called "Green"solvents.One of their applications is in heat transfer and solar collectors.Thermophysical properties can be improved by adding nanoparticles to the IL.For this reason,spherical and rod-shaped alumina nanoparticles were added to 1-Hexyl-3-methyl imidazolium hexafluorophosphate IL with different weight percentages. The effect of adding nanoparticles on thermophysical properties of IL such as density,viscosity,thermal conductivity, and heat capacity in 0.05,0.1 and 0.5 %wt of nanoparticles at temperatures of 20, 30, and 50 °C is investigated. Increasing the concentration of nanoparticle set out an increase in density, viscosity, and thermal conductivity and a decrease in the thermal capacity of the ionic nanofluid (INF) compared to the base IL.Also, the viscosity, density, and thermal conductivity in INF with rod-shaped alumina nanoparticles are improved more than spherical alumina nanoparticles. Also the experimental viscosity and thermal conductivity data were fitted with the existing theoretical models. the viscosity of spherical alumina-IL and rod-shape alumina-IL was in unison with particles aggregation effect (Krieger-Dougherty model) and the both INF effective thermal conductivity are prognosticated by interfacial layer approach with sufficient accuracy.Eventually nonlinear equations have also been proposed for changes in the thermophysical properties of viscosity.

In recent decades, Iran has been facing severe water deficiency. In all countries, industrial plants are the most water-consuming sectors; thus, industrial wastewater treatment is always a essential subject. Nitro-Toluene derivatives are extensively used in industries, especially the military industry, which itself has an abundant share in industrial wastewater contamination. These compounds are extremely dangerous for living beings and can have irreparable effects, so eradication of them in industrial wastewater is necessary. Photocatalytic processes are one of the particular approaches in industrial wastewater treatment from the advanced oxidation processes subdivision. One of the prominent and most widely used photocatalysts in this process is Titanium Dioxide (TiO2) . This research aims at the investigations for the modification of  TiO2/Bentonite (TB) catalysts for attaining more economical saving and degradation stabilization conditions. To achieve this goal, the Bentonite and TiO2 photocatalyst was synthesized by a co-precipitation procedure, and its catalytic activity on Para Nitro-Toluene (PNT) degradation was examined. The designed TB photocatalyst is made of 5, 10 and 20 % of TB. A suspension reactor and the spectrophotometry was applied for specifying the extent of the degradation. Characterization of modified catalyst was conducted by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and energy dispersive X-ray (EDX). The results highlight that with increasing TiO2 percent, degradation rate augmented, and the highest degradation was attained for TB 20% at 59%. However, Under the same conditions, for pure TiO2, the degradation rate is 64%, but with more TiO2 consumption and time. Finally, in order to further confirm the extent of the degradation, chemical oxygen demand (COD) test was performed on the TA20 sample. The results showed that about 53% of PNT has been converted to minerals.

In this paper, the swelling of the photo-thermal sensitive cylindrical polyelectrolyte hydrogel micro-valve has been studied. For this purpose, a modified constitutive model that considers the polyelectrolyte nature of the photothermal sensitive hydrogels is used. The analytical solution for swelling of the hydrogel cylinder due to temperature and light intensity changes was presented. Then, in order to confront problems with realistic complicated boundary conditions, the finite element (FE) tool was implemented in ABAQUS software by scripting a UHYPER subroutine. Using the FE tool, the swelling of the hydrogel cylinder and contact of the micro-valve with the wall of the channel was investigated. Then, the temperature and the light intensity at which the channel was closed was obtained. Finally, opening valve parameter was studied for analyzing the geometrical influence of the under-study actuator, and the obtained results were discussed.

The main aim of this paper is to define and investigate the fuzzy quotient spaces and t-best approximation in fuzzy quotient space and prove some theorems on quotient spaces. Finally, we present an application.

In this paper, using the best proximity theorems for an extensionof Brosowski's theorem. We obtain other results on farthest points. Finally, wedene the concept of e- farthest points. We shall prove interesting relationshipbetween the -best approximation and the e-farthest points in normed linearspaces (X; ||.||). If z in W is a e-farthest point from an x in X, then z is also a-best approximation in W.

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As dentin bond strength of the materials containing resin is reduced after bleaching, a delay in bonding for at least one week after bleaching is recommended. The aim of this study was to investigate the neutralizing effect of an antioxidizing agent on the shear bond strength (sbs) of bleached dentin and compare it with a delay of one week before bonding of composite resin (CR) and resin-modified glass-ionomer (RMGI).

Exposed dentin surfaces of 96 sound human molars were divided into eight groups. Buccal dentin surfaces of the specimens in group 1 and 5 were consecutively bonded with CR and RMGI cylinders. The specimens in other groups were bleached for six hours a day for five consecutive days. For the specimens in groups 2 and 6, bonding of CR and RMGI was performed immediately after bleaching, respectively.The specimens in groups 3 and 7 were immersed in distilled water for one week and then CR and RMGI were bonded. For the specimens in groups 4 and 8, 10% sodium ascorbate gel was applied and then CR and RMGI were bonded, respectively. Shear bond strengths of the specimens were measured. Data was analyzed by ANOVA and Tukey test (α = 0.05).

The mean sbs values for groups 1 to 5, 7, and 8 in MPa were 17.055 ± 2.954, 8.19 ± 0.941, 16.406 ± 1.508, 15.640 ± 3.073, 8.893 ± 0.620, 8.162 ± 0.975, 7.584 ± 0.939, respectively. There were significant differences between the study groups. The specimens of group 6 had pretest failure.

Bleaching led to a significant decrease in sbs of CR to dentin immediately after bleaching, and RMGI did not bond in this situation. A delay of one week before bonding and application of sodium ascorbate gel significantly increased the sbs of the evaluated materials to bleached dentin. In the composite groups the delayed subgroup had significantly higher sbs than the sodium ascorbate subgroup. In glass-ionomer groups there were no significant differences in sbs values.

In this paper we introduce a new extension to Hahn-Banach Theorem and consider its relation with the linear operatres. At the end we give some applications of this theorem.