محمدرضا محمدی زاده

A control room is a place where, as a center of operations in the petrochemical industry, production processes are monitored and controlled. Two main factors must be considered in the design of control rooms. The first factor is the protection of the control room building against possible hazards and the second factor is the location of the control room and the arrangement of the panels, to ensure the effective and ergonomic operation of the control room in normal and emergency conditions, which must be designed in such a way that the danger to the residents of the control room is acceptable and be suitable for the maintenance and protection of the unit (ASCE, 2010; Association, 2014). One of the regulations for the design of blast-resistant structures is the Swedish shelter regulations, which are derived from the examination of structures destroyed in the second world war (Ekengren and räddningsverk, 1994). The Swedish Shelter Regulations regulate the design of civil defense shelters in Sweden and include the requirements specified for these protection structures. Civilian defense shelters are designed not only to withstand the effects of conventional weapons, but also to withstand radioactive radiation, chemical and biological warfare, and gases explosion. By considering these requirements, shelters should be designed with minimal risk of death or injury to those in need of shelter, and be able to withstand the effects of the shockwave generated by a 250-kg bomb at a distance of 10 meters. Also, the requirements of proper design and retrofitting of existing structures against explosion can significantly reduce costs. In view of the above, the analysis and design of refinery structures against explosion loads and the strengthening of their members has great importance. Long-distance explosions and loading of structural elements also include phenomena that are not yet well understood. In order to increase knowledge in this field, a numerical study is currently presented. For this purpose, in this study, four types of concrete columns and four models of exterior wall for the control room were designed according to Swedish regulations to withstand the pressure of an explosion of a 250kg TNT at a distance of 10 meters and then against explosions of 6000, 4000 and 8000 kilograms at a safety distance of 40 meters is evaluated by the Eulerian-Lagrangian coupling method in Autodyn software. Response limit-state are selected according to the ASCE standard (ASCE, 2010).

Principal recycling and reuse of industrial waste is one of the most important human challenges to protect the environment. In recent years, due to the unique properties of pervious concrete, the use of pervious concrete pavement as a good alternative to asphalt procedures has been considered. In this study, in order to assess a new method for the manufacture of high -environmentally friendly concrete pavements with aluminum slag replacement with 0, 5, 10, 15 and 30 % cement weight, the concrete samples were made and the tests including compressive strength, bending strength, water absorption percentage, permeability and porosity done. The results showed that aluminum slag replacement with 5 % of cement weight, compressive strength, bending resistance and water absorption percentage compared to the control sample did not change significantly. But using the replacement of aluminum slag with 10, 15 and 30 percent of the cement weight, compressive strength and bending strength comparing to the control sample were decreased by 16, 24 and 50% and by 6, 15 and 24 %, respectively. By replacing aluminum slag with 10 and 15% by weight of cement, the permeability comparing to the control sample was increased by 61 and 97%, respectively. It was also observed that due to the high porosity of the samples containing aluminum slag replacement with 30 % of the weight of the cement, water passed immediately and quickly.

The purpose of this study is to reduce the temperature of the attic of the building of department of physics in university of Tehran. To achieve this goal, eighteen natural ventilators with the area of 0.25 m2 each were installed on the roof. The natural ventilators alone did not decrease the temperature significantly. To help natural ventilation, a laminar flow of air from the floors to the attic was provided. This led to a temperature decrease around 1.5 to 2o C. In addition, a powered ventilation was resulted 3 to 8o C temperature decrease. Since the volume (4533 m3) and area (1416 m2) of the attic are too large, further tests were conducted on two small models (47×33×51 cm3) of the attic, build from the same material as the main attic. The models were used to investigate the effect of covering the roof with aluminum foil and painting the roof with a withe color as a reflector, and installation of polystyrene panels under the roof as an insulator. Covering with aluminum foil, painting in withe, and installation of polystyrene resulted in 3-5, 2-3.5, and 1-2 degrees decrease in temperature, respectively. Reason of these changes was explained by reflection spectrum of UV-Vis-NIR spectrophotometry. Finally, the attic was simulated by the COMSOL Multiphysics software. It showed that a temperature reduction of 10 degrees could be accomplished by installation of six fans as inlet in the gables, three in each gable. Each fan has to generate 4 m/sec air flow velocity.

The most important danger that threatens a petrochemical refinery is an explosion, which is followed by a fire or vice versa. In fact, the occurrence of initial events such as explosions and fires spread from one part to another like the domino effect if the distance between the storage tanks is not sufficiently considered. Therefore, the distance and arrangement of petrochemical storage tank can play an important role in reducing the damage of initial accidents. So far, due to the explosion uncertainties, no definitive solution has been offered, but a combination of active and passive techniques such as the efficient use of intelligence and security organizations, increasing the scaled distance between the detonation point and the target buildings or providing physical barriers, the use of deformable materials to absorb energy, and the use of appropriate retrofit structural techniques can reduce the effects of explosions. As it turns out, it is virtually impossible to study the propagation of blast waves experimentally on a large scale due to financial constraints and potential hazards. Therefore, to solve this problem, two solutions are proposed: the use of small-scale laboratory methods and the use of numerical methods. Three-dimensional numerical analysis is an efficient method for investigating structural weaknesses, hazard risk analysis, and evaluating of explosion hazard points. In this study, with the help of explosion simulation by Eulerian-Lagrangian coupling method, the research has been surveyed in two parts. In the first part, petrochemical tanks in different arrangements, and,at  different distances from each other are modeled in 3D on Autodyn software on the scale of  and the propagation of explosion waves and the confinement of 8g of TNT pressure in the environment between the tanks are investigated. In the second part, the effect of barrier shape on reducing the blast pressure of 1000 kg of TNT on a real scale has been investigated. The results show that the use of semi-empirical relation in UFC-0-340-02 to determine the blast pressure is applicable only to open environments, and it is not precise in closed environments due to the confinement of the blast pressure.  Moreover, the results show that it is not conservative to use the required distance between tanks considering the amounts proposed by the regulations. As a result, increasing the distance up to twice the amount proposed by the regulations, the effect of explosion pressure confinement is eliminated. The best way to position the tanks in this study is a zigzag pattern with a distance equal to twice the safe distance between the tanks in accordance with NFPA-30. In addition, the results show that by creating a barrier against the explosion, the explosion over-pressure can be greatly reduced, but the shape of the barrier does not have much effect. Although, using the Eulerian-Lagrangian coupling method requires considerable time and appropriate software to perform the calculations, it provides a comprehensive understanding of the blast wave interaction with structures. With the advancement of technology and the use of parallel processing in the cloud space, and the mapping technology it is possible to evaluate the different structures on a real scale against the explosion.

Carrageenans can be found in a group of red algae called Carrageenophytes (Gigartinaceae, Solieriaceae, Hypneaceae and Furcellariaceae); howe-ver, this substance has not been investigated in Laurencia species. In this study, two native species of Laurencia within the Persian Gulf were investigated to extract carrageenans. Therefore, the major aims of this study included extraction, optimization and purification of carrageenans from Laurencia snyderiae, a native red algae of Persian Gulf.

Laurencia snyderiae and Laurencia papillosa were identified based on their morphological characteristics. An experimental design was carried out using Design Expert Software to produce and optimize extraction of semi-refined carrageenans. The software programmed 18 treatments based on temperature, boiling time and KOH concentration. Products of the treatments were prepared for rheometric analyses (viscosity measurements). Optimization was carried out using the software based on the maximum viscosity. Refined carrageenan efficiency was assessed using four extraction methods. Moreover, Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy spectra were compared. Laurencia snyderiae was selected for further inves-tigation.

Based on the rheometric analyses, a semi-refined carrageenan solution was identified as a non-Newtonian pseudo-plastic fluid. The optimum treatment was investigated for Laurencia snyderiae at 65 °C for 35 min at KOH concentration of 7% w/v. Results of these two analyses showed that the refined carrageenans from Laurencia snyderiae included the lambda type. The highest efficiency was achieved using dialysis method (37%). Based on the abundance of the Laurencia snyderiae on the Persian Gulf coasts in all seasons, further studies on carrageenan with higher purities enable use of these substance in various industries. Broader rheological studies can precisely assess characteristics of the investigated carrageenans.

To protect citizens and infrastructures in a modern society, the safe design of structures against accidental explosion is a particular importance. In this study, the aim is to evaluate the performance of a reinforced concrete column using Incremental explosive analysis, which is inspired by the method of incremental dynamic analysis. In order to achieve this goal, the concrete moment frame is designed for dead, live, and earthquake loads based on Iranian national regulations codes in Etabs software. Then, an exterior designed column related to the RC moment frame is analyzed under different ground blast intensity (hemispherical explosions at the ground level) at stand of distance 3, 5, 7, 10, 12, 15, 17 and 20 meter. Eulerian-Lagrangian coupling method has been used to obtain the dynamic response of the structure against rapid explosion load in Autodyn. After completing the analysis and obtaining the structural response, the IEA Curve is drawn as a structural response against the explosion intensity.Fragility curve also is obtained to determine the probability of exceeding each limit states. The results show that the probability of exceeding the limit state Ls-1 for intensity measure equals to 1 approximately equals to 80%, for the Ls-2 is about 60% and for the Ls-3 is 40%. Finally, the pressure-impulse diagram on a logarithmic scale is obtained as a combination of pressures and impulses that produce the column response in the three considered limit states. The results show that fragility curves and pressure-impulse diagrams along with IEA curves provide useful information to design.

Recent earthquakes worldwide have illustrated the vulnerability of existing reinforced concrete (RC) beam-column joints to seismic loading. Inadequate shear reinforcement in the existing beam-column joints, especially exterior ones, is believed to be the prime cause of failure/collapse of many moment-resisting RC frame buildings. Hence, effective and economical strengthening techniques to upgrade joint shear resistance in existing structures are needed. Retrofitting using FRP composites has grown in popularity over the last two-decade advantages such as fast and easy installation, high strength/weight ratio, and resistance to corrosion. In this study have been conducted a numerical analysis of 11 RC beam-column joints without FRP and strengthened with FRP in a variety of configurations under cyclic loads. The analyses are performed by ABAQUS finite element program and are calibrated with the experiments. A range of issues in joints, including maximum load, initial stiffness, energy dissipation, load-displacement hysteresis loops, stiffness-displacement curves, and energy dissipation-displacement curves, are investigated. The numerical results were in good agreement with the corresponding experimental ones. The results obtained from the numerical analysis in this study, similar experimental results demonstrated that externally bonded FRP reinforcement is a viable solution towards enhancing the strength, energy dissipation, and stiffness characteristics of RC joints subjected to seismic loads.

Monitoring the amount of ultraviolet radiation from sunlight can provide a basis for assessing people's exposure, raise public awareness and warn people against this radiation. Measuring the sun's ultraviolet index over a working period is an accurate choice to achieve this goal.

In this study, the amount of solar UV index in one of the outdoor locations of Zanjan city was measured using Solarmeter model 5.6 UV index meter for one year period. Measurements were performed from 9 am to 5 pm every 30 minutes in direct sunlight in even days for one year period (2018-2019). Finally, the results were analyzed using Excel software.

The highest value of the maximum daily UV index was related to July, with an average value of 11.87 ± 0.649; while, the lowest value of the maximum daily UV index obtained in January, with an average value of 2.23 ± 0.944. In most months of the year, except for late November, December, January and cloudy days, the average value of the maximum daily UV index around noon exceeds the UV index alert threshold set by the World Health Organization (WHO). Even for the safe time period during spring and summer, the average UV index can exceed the UV index warning threshold.

Determining the intensity of the sun's hourly UV radiation is important and necessary to increase the peoples’ and workers’ awareness working in the open environment, as well as to plan for protective measures in any place, especially in Zanjan.

The shear strength of deep beams of the reinforced concrete beams depends on the mechanical and geometrical parameters properties of the beam. Accurate estimation of shear strength in deep reinforced concrete deep beams of the reinforced concrete is one of the major issues in the design of engineering structures. However, some methods proposed to determine the shear strength in deep reinforced concrete beams do not have high accuracy. One method to accurately estimate shear strength is to use artificial intelligence (AI). Artificial intelligence has many different methods, one of which is the use of artificial intelligence based on the support vector machine method. In this study, the weighted least squares support vector machine (WLS-SVM), which is a relatively new and efficient method for predicting the shear capacity of reinforced concrete beams, has been used. In this study, a database containing experimental results on deep reinforced concrete beams was first collected. Then, after determining the input and output parameters using a training process in WLS-SVM method and using a part of the collected data, a model was developed to predict the shear strength of deep reinforced concrete beams. In order to determine the accuracy of the WLS-SVM method, the results were compared with those obtained by other AI methods and different regulations. Statistical analysis showed that WLS-SVM has the best performance in terms of statistical evaluation parameters (R^2 = 0.9887, RMSE = 0.107, MAE = 0.478 and MAPE = 9.48%) compared to the other methods.

Damage detection is a topic of great importance for structural health monitoring. Many varieties of structural damage can be detected by examining changes in structural response in terms of stiffness. Wavelet transform is a powerful mathematical tool for the processing and time-frequency analysis of transient signals and has great potential to be used in structural damage detection. In FRP-strengthened reinforced concrete and steel sections, stiffness changes can be caused by cracking, yielding of steel components, crushing of concrete, or rupture of FRP panels. With the help of wavelet transform, it is possible to use the continuous measurements of the response to bend or torsional loading to estimate the capacity of the cross section corresponding to the stiffness changes. In this paper, bending of FRP-reinforced steel beams filled by concrete under bending and CFRP-reinforced concrete beams under pure torsion is evaluated. The results show that the location of the damage appears as perturbations in the diagram of discrete wavelet coefficients, which indicate the time of cracking, yielding of steel, crushing of concrete in the compression zone, and rupture of FRP. Therefore, a wavelet transform-based data processing procedure can be used to estimate the cracking and yielding capacities of the beams subjected to torsion, the yielding capacity of the steel and the ultimate capacity of the beams subjected to bending. The results demonstrate a high level of agreement between the estimates obtained from the discrete wavelet transform method and the examined experimental and numerical data.

The shear strength of reinforced concrete beams changes depending on the mechanical and geometrical parameters of the beam. Accurate estimation of shear strength in reinforced concrete beams is a fundamental issue in engineering design. However, the prediction of shear strength in these beams does not have very high accuracy. One of the strategies proposed in recent years to provide a suitable model for predicting shear strength of reinforced concrete beams is the use of artificial intelligence (AI) algorithms. In this investigation, the application of adaptive neural fuzzy inference system (ANFIS) and support vector regression (SVR) algorithms for predicting shear strength of reinforced concrete beams was studied and the results were compared with existing regulation. For this purpose, shear span, effective beam length, effective depth, cross-section width, 28-day compressive strength of concrete, yield stress of longitudinal reinforcements, yield stress of transverse reinforcements, percentage of longitudinal reinforcement and shear reinforcement percentage were selected as input parameters and shear strength of concrete beam as output. Using the k fold validation method, educational and test data were defined and based on these data, predictions were made. The results obtained from the prediction show that the mean square root error (RMSE) for ANFIS and SVR methods is 0.1514 and 0.0994, respectively. In general, it can be seen that both ANFIS and SVR algorithms predict the shear strength of reinforced concrete beams with great accuracy. Therefore, they can be a good alternative to time-consuming algorithms such as ANN and expensive laboratory methods.

Nowadays with development of urbanity, request for dwelling has increased extremely. In all the cases the steel structures as for the high speed of construction have a special status. Among the defect of steel buildings than concrete type is higher cost of construction. Hence, occasionally the fabricators with a view to imparting of advantage of both the construction speed and some deal decreasing providing cost of steel lateral bracing, use the steel buildings with reinforced concrete shear wall as lateral bearing system. Hence, study in the field of analysis and design of this structure system seems necessary. At present, one of the most important goals of earthquake engineers is predicting of the structures behavior versus future earthquakes. Today, it has become evident that structures designed on the basis of the existing regulations sustain extensive damages in under intense earthquakes. Thus, performance-oriented design as a method based on acceptance of expected displacement and ductility has been considered. In earthquake engineering, it is imperative to determine the capacity and the seismic demand of the structure in terms of performance. The performance assessment of nonlinear systems is a complex task requiring appropriate analytical methods suitable for modeling the behavior of the structure against the earthquake. The incremental dynamic analysis is an analytical tool which can be used to assess performance in earthquake engineering. This method is able to estimate the seismic demand and limit states of the capacity of a structure under seismic loading using suitable records scales to several levels. Utilizing this method, one can attain better understanding of the behavior of a structure from elastic to destruction conditions. In the present research, dynamic analysis of the time history and the robust software OpenSees have been employed considering the geometric nonlinear effects of materials for seven buildings having 3, 6, 9, and 12 stories and two plans. The structures under consideration are analyzed using incremental dynamic analysis and the robust Opensees software subsequent to the design phase and considering the designed sections, gravity loading characteristics and specifications and seismic parameters. Then, graphing the cluster curves and IDA quantiles the buildings under consideration are assessed. Although the results of this study indicate better performance of the moderate structures in comparison to the short and rise structures, it seems that the proper height of a structure with respect to the characteristics of the soil of its construction site and the parameters of the resonance and damping between the structure and the soil (the effect of soil and structure interaction) and the frequency content of the acceleration records of the first mode in the region. The seismic intensity estimation parameter (which is considered in this study, the first-mode spectral acceleration) is a determinant factor in reflecting the behavior of the earthquake acceleration record applied to the structure. In order to conduct a detailed study with the IDA analysis, it is necessary to select the severity criterion in a way that best describes the content of the selected accelerogram.

Effect of charge on the structural properties of Wurtzite ZnO doped with interstitial hydrogen was investigated using Density Function Theory. Calculation performed using Quantum Espresso package with Generalized Gradient Approximation (GGA). Calculations for formation energy showed that H is more stable than H0 and H- doping in this structure. Charge density calculation and Bader analysis showed that for all three H, H0 and H- states hydrogen due to its higher electronegativity in compared with Zn atoms, joins to oxygen and increases its charge and repulses zinc atom. Hydrogen doping affects on volume of supercells due to locating in space charge density, therefore cell parameters and volume of supercell decrease in H state, while these values increase for H0 and H- states.

Substituted isobenzofuran-1(3H)-ones and imidzoles are useful building blocks in organic synthesis due to their structural importance, chemical stability and relative accessibility. Furthermore, such structures are of important and biologically active heterocycles and they are widely present in many bioactive compounds and synthetic drugs. In this paper, a novel, one-pot and efficient procedure are introduced for the preparation of some new derivative of these compounds. At first, some of 3a,8a-dihydroxyindeno[1,2-d]imidazole-8(3H)-one derivatives were synthesized from the reaction of trichloroacetonitrile, amines and ninhydrin in ethanol. Then their corresponding isobenzofuran-1(3H)-ones were prepared by the one-pot oxidation of the synthesized diols using lead tetraacetate in acetic acid. Reaction well worked for various amine derivatives and final products were characterized using their IR, 1H-NMR and 13C-NMR spectra.

In this work structural defects were created in P25-TiO2 nanoparticles by using hydrogen DC plasma treatment in different temperatures and exposure times. X-Ray diffraction measurements show that the structure of TiO2 remains unchanged after hydrogenation. Diffuse reflectance spectroscopy measurements demonstrated band gap of TiO2 was not changed considerably by the hydrogenation. However, by applying the hydrogen plasma for 40 min at temperature of 350 °C photocatalytic activity of TiO2 nanoparticles enhances. No more change was observed in the photocatalytic activity of the samples with plasma exposure time more than 40 min. Photoluminescence analysis shows the sample prepared at 350 °C has a large amount of defects which have been created by the plasma treatment. It seems both, structural defects and hydrogen doping in the samples are important for more efficient photocatalytic behavior of TiO2 nanoparticles.

In most industrial applications, determining production quantities are one of the most key decision making. In this paper, an integer mathematical programming model for lot-sizing problem with considering set-up time, safety stock, shortage cost, and different production manners, is presented. The objective is to minimize summation of production, set up, holding, and shortage costs. To solve the model, a forward dynamic programming (DP) approach is presented and compared with classical backward DP method. Finally, different numerical illustrations with different dimension are generated. The statistical analysis on computational results showed that the proposed DP approach is more applicable than the classical DP in terms of computational time.

In the standard optical interference fringes approach, by measuring shift of the interference fringes due to step edge of thin film on substrate, thickness of the layer has already been measured. In order to improve the measurement precision of this popular method, the interference fringes intensity curve was extracted and analyzed before and after the step preparation. By this method, one can measure a few nanometers films thickness. In addition, using the interference fringes intensity curve and its fluctuations, the roughness of surface is measured within a few nanometers accuracy. Comparison of our results with some direct methods of thickness and roughness measurements, i.e. using surface profilemeter and atomic force microscopy confirms the accuracy of the suggested improvements.

In order to study some theories about nonsuperconductivity of PrBa2Cu3O7, based on the density functional theory and with APW+lo/LAPW method some calculations for PrBa2Cu3O7 (Pr123) and YBa2Cu3O7 (Y123) were performed. The LSDA+U approximation was used for Pr(4f) orbitals and the effect of changing UPr on the band structure, Pr(4f)-DOS, distribution of electrons on the planes and chains, and Pr valence were investigated. Comparison of computational results with some experiments shows that a suitable region for UPr is a number larger than 0.4 Ry. With this selection the band structures of Pr123 and Y123 near Fermi energy are coincident completely. Therefore, the theories that present the reason for nonsuperconductivity of Pr123 corresponds to the difference of holes number or character of holes in Pr123 and Y123 were found to be incorrect.

The Gd(Ba2-xPrx)Cu3O single phase polycrystalline samples with 0.00 ≤ x ≤ 1.00 were investigated for structural, electronic and flux dynamic properties. An unusual hump on the resistivity vs. temperature curve of the samples has been observed for particular values of Pr doping. We have found that the Ba atom substitution at the rare earth site could lead to superconductivity in some parts of the grains at Tm~80-90K, which appears as a hump on the (T) curve. For all the samples, the two-dimensional variable range hopping (VRH) is a dominant conduction mechanism in the normal state. The Pr doping strongly localizes the carriers in the normal state, and finally causes the suppression of superconductivity. The effect of Pr substitution in 123 structure of HTSC at R or Ba site is to increase the pseudo gap temperature Ts, although, Pr at Ba site has a stronger effect on the increase of Ts and suppression of superconductivity. We have also extracted the two dimensionality aspects of HTSC through the similarities between superconductors, two-dimensional electron gas (2D-EG) i.e., MOSFETs, and the ultra thin films of conventional superconductors. The magneto resistance of the samples have been studied within thermally activated flux creep and the Ambegaokar and Halperin phase slip models. The derived critical current density, Hc2(T), Hc2(0), and superconducting coherence length show that the Pr- doping, like weak links, decreases the vortex flux pinning energy. Our results imply that understanding the real suppression mechanism of superconductivity by Pr doping in HTSC is connected unavoidably to determination of the exact position of Pr in the structure.

UBV ligh curves together with color curves of the semi-detached eclipsing binary RZ Cas are presented. The light curves are analyzed and the spectroscopic elements and the Hipparcos information are used to compute the absolute parameters of the system. The light curve anomalies and occasional flat minima are discussed. Based on the existing evidence, a straightforward explanation for the primary minimum anomalies is presented.