masoud ziaei

The occurrence of fire in structures is a possible phenomenon that can significantly affect the mechanical properties of the materials of structural members. Nowadays, the use of new materials and additives in concrete construction has been considered, and it is necessary to examine the strength of concrete made with these materials during and after fires and to ensure its proper behavior. In this research, microsilica, as a very effective pozzolanic material and polypropylene fibers as a material to improve cracking resistance were used to make concrete. The behavior of concrete specimens with different values of these additives after exposure to high heat was investigated in the form of tensile and compressive strength tests. The control concrete specimen was considered for comparison with other specimens where the compressive strength of this specimen was 30 MPa. In addition to the control specimen mixing design, 11 other mixing designs were made with propylene fibers in the amount of 0.05, 0.075 and 0.1% of the weight of concrete and microsilica in the amount of 5%, 10% and 15% of the weight of cement. The specimens were placed in an oven at 600 ° C for one hour. After cooling, compressive and tensile strength tests were performed on the specimens. The results showed that the combination of polypropylene and microsilica fibers increased the tensile strength, the maximum increase was 82% compared to the control specimen. The maximum increase in compressive strength compared to the control specimen was 63.4%. After exposure to heat, the tensile strength of the proposed sample increased by 44% compared to the control specimen.

Guar (Cyamopsis tetragonoloba) is an annual plant from the legume family and tolerant to salinity and drought, which can be used as an alternative product in low water plains. Ascorbic acid is one of the antioxidants involved in the defense mechanisms of plants against various stresses, including drought, which plays a role in ROS detoxification. Calcium is also an essential element for plant growth, which, despite being immobile, has many electrochemical, structural and catalytic functions in plants. It has been reported that calcium ions can increase drought tolerance in plants by participating in the drought signal transduction process and stimulating abscisic acid synthesis. Therefore, this research was conducted with the aim of investigating the effect of foliar spraying of ascorbic acid and calcium on some morpho-physiological traits of guar under drought stress conditions. In order to investigate the morpho-physiological responses of guar to foliar application of ascorbic acid and calcium under drought stress conditions, a factorial experiment was conducted with two factors in the form of a randomized complete block design with three replications in the research greenhouse of Saravan Higher Education Complex in 2020. The experimental treatments included three levels of drought stress (70, 50 and 30% of field capacity) and three levels of foliar application (no foliar application, foliar application with calcium carbonate and ascorbic acid with a concentration of 3‰). The results showed that in 50 and 30% of the field capacity, compared to the treatment of 70% of the field capacity, plant height, number of pods per plant, number of seeds per pod, pod length, leaf dry weight and total protein showed a decreasing trend, but traits of reducing sugar, Polyphenol oxidase (PPO) enzyme activity and root length showed an increasing trend. The increase of reducing sugars is considered a mechanism to deal with drought in plants because reducing sugars are osmolytes that play a role in plant cells as regulators of the osmotic potential of the intracellular environment. Similarly, the increase in PPO activity during drought stress is justified by the increase in radical oxygen species generated during this stress, because the increase in the activity of antioxidant compounds as a defense mechanism is essential to maintain cellular processes and prevent the damaging effects of free radicals on plant physiological processes. Foliar application with ascorbic acid did not significantly change plant height and number of pods per plant compared to non-sprayed plants but increased leaf dry weight, total protein, reducing sugar and root length by 22%, 11%, and 21%, respectively. While, calcium foliar application significantly increased plant height, number of pods per plant and leaf dry weight by 16%, 24%, and 42%, respectively compared to non-foliar application and 8.5%, 12%, and 17.5% compared to foliar application with ascorbic acid, but total protein, reducing sugar, root length and dry weight of root remained statistically unchanged in calcium spraying respect to foliar application with ascorbic acid. However, both ascorbic acid and calcium application than no-foliar application showed a significant increase in the amount of total protein, reducing sugar, root length and dry weight of root and a decrease in PPO enzyme activity. The decrease in PPO activity can be considered as a result of reducing the harmful effects of drought stress caused by the application of calcium and ascorbic acid. In general, it seems that the availability of moisture in less than 70% of the field capacity has caused the formation of mechanisms to deal with drought stress in the guar, but foliar application with ascorbic acid and calcium can somewhat to be effective in modulating the effects of drought stress on this plant.

Tires and waste glass are long-lasting pollutants in nature. One of the ways to recycle waste glass and rubber is to use it in concrete, which will result in minimal extraction of natural minerals. Many engineering structures are exposed to fire hazards, and therefore it is necessary to know the mechanical properties of concrete materials at high temperatures. In this research, waste glass and rubber were used as a substitute for a part of natural fine grain (sand). The size of glass particles is between 0.2-0.85 mm and with percentages of 5%, 10% and 15% and the size of rubber particles is between 3-5 mm by volume and with percentages of 5% and 10%, replacying fine aggregates. In total, 12 mixing plans were made, and from each mixing plan, 3 cubic and cylindrical specimens were made with different percentages of glass and rubber. The compressive and tensile strength, workability, weight loss, ratio of residual compressive and tensile strength of the specimens were measured at ambient temperature and at 600 °C and the average values were evaluated. In terms of appearance, after applying heat, the color of the specimens became darker and hairline cracks were widely visible on the concrete surfaces. As expected, with increasing the rubber, the compressive strength of the speciemns decreased. After applying heat, the resistance drop of all specimens was higher than the ambient temperature state. With the increase in the rubber, the resistance decreased more, which can be attributed to the burning and destruction of rubber particles and the appearance of small holes and porosity in concrete. With increasing glass percentage, the trend of compressive strength was slightly improved. The results showed that the combined design of 5% glass and 5% rubber is the optimal design and has a more appropriate performance than other designs.

The use of low irrigation regimes by saving water consumption can help as a water management solution to increase the cultivated area and also determine the optimal cultivation pattern. The importance of oil products such as safflower has increased in recent years in the world. In general, safflower is produced in relatively dry marginal lands with low input. Efforts are being made to improve the yield and seed quality of this plant through the development of new genotypes and agricultural practices around the world. But the fact is that drought also affects the growth and performance of this plant. Zinc plays an important role in seed and biomass production, chlorophyll production, pollination process and even plant germination.

The purpose of this experiment was to investigate different levels of irrigation regime and foliar application of zinc and manganese sulfate in the research farm of Saravan Education Complex as a split plot in a randomized complete block design with three replications. The main plot included full irrigation, cut-off of irrigation at the stem stage and cut-off of irrigation at the flowering stage, and the sub-plot included three levels of foliar application with zinc sulfate (three per thousand), manganese sulfate (three per thousand) and without foliar application (control). The harvest was done manually, depending on the time of full processing, from the end of May to the beginning of June 2019. In order to evaluate the yield, the plants were harvested after removing the margins and after beating and separating the seeds, the yield was measured. The dry matter of plant leaves was also measured by collecting the leaves of three plants in each plot; Thus, by placing the collected leaves in an oven at 75°C for 48 hours and calculating the average leaf weight of three plants, the leaf dry matter was obtained. Analysis of data variance was done using SAS software (9/1 version) and mean comparisons were done at the five percent probability level using the LSD test.

The results showed that the cut-off of irrigation in the stem and flowering stages reduced number of days up to heading, number of days up to 50% flowering and the number of days up to maturity irrigation than full irrigation. Also, interruption of irrigation in stem and flowering stages compared to full irrigation conditions significantly reduced RWC and significantly increased electrolyte leakage. Foliar application with zinc sulfate compared to manganese sulfate and no foliar application caused a significant increase of 0.53 and 2.31 percent in number of days to heading, 1.71 and 2.54 percent in number of days up to 50% flowering and 0.52 and 1.64 percent number of days up to maturity, respectively. Foliar application of zinc sulfate and manganese sulfate significantly increased RWC and decreased significantly electrolyte leakage compared to no foliar application. At each level of irrigation regime, foliar application significantly increased seed yield, which was more effective in zinc sulfate treatment than manganese sulfate.

In general, full irrigation and foliar application of zinc sulfate is recommended for safflower cultivation in Saravan climate. In general, the cut-off of irrigation in the stages of stem growth and flowering caused a sharp decrease in grain yield in safflower plants compared to full irrigation conditions. Considering the high ambient temperature in the study area, it seems that the risk of under-irrigation in safflower cultivation in this area is very high and therefore it is recommended to carry out full irrigation in safflower cultivation in this area. Also, due to the alkalinity of the soil in dry areas and the non-absorbability of zinc and manganese elements by the plant and the positive effects of these elements in relation to the defense and photosynthesis system of the plant (especially zinc sulfate), foliar spraying with zinc sulfate for safflower in conditions Saravan weather is recommended.

With the advancement of technology in the world, industrial waste has become one of the most important environmental challenges. Deformation and reuse of these wastes is one of the ways to improve the sustainable state of the environment. Glass and rubber are among the most widely used materials in the world, which due to their nature have a lot of wastes. Waste tires cause a lot of environmental pollution due to their non-degradable materials. The use of waste glass and rubber in the construction industry can be a good solution in reusing waste materials. Concrete, on the other hand, is one of the most widely used materials in the construction industry, and the addition of rubber and glass crumb to concrete can improve some of its mechanical and dynamic properties. Of course, heat resistance of materials is one of the features that is effective in the type of application. Adding waste rubber and glass to concrete, of course, depending on their amount and size can increase the heat resistance of concrete to some extent.
In this research, the effect of replacing small and large aggregates with rubber and also glass powder with cement in concrete at ambient temperature and high temperature has been studied. The size of rubber used in concrete in two categories is 1 to 3 mm and 5 to 10 mm, which are replaced by fine-grained and coarse-grained, respectively, with replacement values ​​of 0, 5 and 10%. The size of the glass used is smaller than 75 microns and it can be replaced with cement with 0, 10, 15 and 20% replacement values. Shredded truck tires and powdered construction glass were used. In this study, cubic specimens were made into 15 x 15 x 15 cm specimens and cylindrical specimens with a diameter of 15 cm and a height of 30 cm were made according to the standards and processed for 28 days in optimal conditions. After processing, the number of cubic and cylindrical specimens was subjected to compressive and tensile tests. A number of other samples were placed in an electric furnace and heated to 600 ° C as standard. After removing the samples from the furnace, they were naturally placed at room temperature for 24 hours and then they were tested for the Residual compressive and tensile strength. The microstructure of concrete containing glass and rubber was examined by scanning electron microscope (SEM). The results of this study showed that adding rubber and glass to concrete causes a decreases compressive strength and increases tensile strength. The D10C10 design, which has the highest compressive strength, has a resistance reduction of about 12% compared to the reference design. The highest tensile strength of heated samples is related to D5C15 design, which is about 43% higher than the heated reference design. By comparing the sum of heated and unheated samples, it can be seen that heat at 600 ° C has reduced the compressive strength by an average of about 33%. In general, concrete made with 10% replacement of rubber instead of coarse in unheated samples and 15% glass instead of cement in heated samples showed better properties. Also, in the study of concrete microstructure, adhesion between rubber and concrete was appropriate.

One of the recycling approaches for waste materials like tires and glass is to use them in concrete. In this paper, the effect of the simultaneous use of waste rubber as partial substitution of fine aggregate and glass powder as partial substitution of cement, on workability and mechanical properties, in ambient temperature and after exposure to temperature of 600 °C, is investigated. In order to evaluate the effect of rubber particle size on workability and mechanical properties, two different rubber particle sizes of 0.15-1mm and 3-5mm were used. In total, 13 mixtures were prepared. Except for the reference mixture, the rest contained a combination of rubber particles replacing fine aggregate with the percentages of 5% and 10% by volume and glass powder replacing cement with percentages of 10%, 15% and 20%. First of all, the slump test was carried out. Moreover, compressive strength and tensile strength, before and after thermal exposure, were investigated. In order to have an understanding of waste material's behavior, scanning electron microscopy and energy-dispersive X-ray spectroscopy tests were conducted. the results indicated that 5% for rubber particles, 10% for glass powder and also rubber particle size of 3-5 mm presented the best results among mixtures containing rubber and glass powder, in terms of compressive and tensile strengths.

Reinforced concrete structures on the shores of the Persian Gulf experience a severe corrosion environment, and in the case of the structures that are in tidal conditions or some of their members are submerged in the sea, such as piers and ports, this problem is more acute due to the penetration of chloride ions. To increase the efficient life of concrete structures in the Persian Gulf, the use of self-compacting concrete along with cement substitutes has been suggested by researchers. In this paper, two powdered materials, slag and micro-silica, have been selected to replace part of the cement content in concrete. The durability test in submerged and tidal conditions has been performed on the specimens. Based on the results of experiments on 216 concrete specimens, the use of the proposed concrete on average increases the compressive strength by 22%, electrical resistance by 50% and decreases the permeability of volumetric water absorption by 12% and capillary water absorption by 30% in tidal conditions.

One of the most common complications of diabetes is diabetic foot ulcer, which exposes patients to wound infection, osteomyelitis, and lower-limb amputation if left untreated. Therefore, accurate and rapid diagnosis of wound and osteomyelitis infection is an important step in treating this debilitating complication. In this regard, the present study was aimed to determine the incidence of osteomyelitis and assess its risk factors in patients with diabetic foot ulcers during 2013 and 2016 in Birjand, Iran. This epidemiological analytical-retrospective study was conducted using numerical sampling. Demographic and clinical data were obtained by reviewing patients’ medical records and using a checklist developed by the project manager. Data analysis was performed using SPSS software (version 18). Quantitative and qualitative results were reported as mean±standard error and percentage, respectively. The obtained findings indicated a significant association between the location of foot ulcers and the risk of osteomyelitis (P=0.02); accordingly, osteomyelitis is more likely to occur in diabetic ulcers on the toes. However, no significant difference was observed between right and left foot ulcers in terms of osteomyelitis risk. Mean erythrocyte sedimentation rate was also significantly higher in diabetic patients with osteomyelitis than those of non-osteomyelitis ones (P=0.04). However, no significant difference was observed in C-reactive protein and leukocytosis. The age and gender of the patients had no significant effect on the risk of osteomyelitis. Overall, the results of the present study demonstrated a significant relationship between the location of foot ulcers and the probability of osteomyelitis. Accordingly, ulcers located on the toes are more likely to develop osteomyelitis.

Considering the increasing hostile and terroristic threats in the country, it is important to consider the passive defecncecriteria in structures. The desirable properties of steel and concrete cab be used simultaneously to increase the strength of structural members. Concrete-filled steel tube columns (CFSTs) have been proposed as an efficient system in the previous years. The main problem with using this type of column is how to connect the beam to such a column and extensive researches has been done for seismic load scenarios. Despite the excellent resistance of these types of columns to the blast load, no comprehensive investigation has yet been conducted on the performance of beam-to-column joints under blast load. In this paper, the behavior of three types of beam-to-column connections under 5 blast scenarios is investigated. ABAQUS software was used to conduct the research. Verification was first performed using the results of an experimental study and a good agreement was observed. The behavior of beam-to-column blast-loaded connections was investigated using 16 different models using explicit nonlinear dynamic analysis. The results were compared in terms of stress, strain and damage contour as well as force, energy absorption, displacement, rotation and torsion diagrams. It was observed that when the connection was carried out as an extension of the beam inside the column, all parts of the column contributed in the load carrying and energy absorption and very good behavior was observed. In this case, the plastic joint in the beam is formed away from the column face.

The walls placed in structural frames can act as a loading surface against the explosion load and significantly increase the dynamic load applied to the structural members. Therefore, the durability of the walls against the blast load and how they are connected to the structural members may have a significant effect on the dynamic response of the structures to the blast load. To investigate this subject, finite element method and Abaqus software are used. Initially, to ensure the accuracy of the predictions of finite element model, verification is performed by modeling an explosive experiment on a concrete-filled steel tube column and a good agreement is observed. Then, the effect of the presence or absence of a concrete wall in the frame and how it is connected to the beam and column is investigated using dynamic explicit analysis. The results of the study showed that in the case of no wall and in the case where the wall is attached to the column only, the highest amount of plasticity has occurred in the beam. In specimens with wall-to-column connection, the maximum plastic strain is observed at the base of the column. The existence of infill wall and the attachment to a beam or column has a significant effect on the vertical displacement of the beam.

In this study, two-dimensional pulsating unsteady flow of nanofluid through a rectangular channel with isothermal walls is investigated numerically. The finite volume approach with a staggered grid arrangement is employed to discretize the governing momentum and energy equations. The set of resultant algebraic equations is solved simultaneously using SIMPLE algorithm to obtain the velocity and pressure distribution within the channel. The results are obtained for different pulse parameters, which are Strouhal number (frequency of pulsation), Amplitude of pulsation, Reynolds number and volume fraction of nanoparticles. The results show that increasing the amplitude of pulsation has no effect on cycle period of pulsation, while it can raise the Nusselt number. The analysis also reveals that increasing the Strouhal number reduces the cycle period of pulsation significantly, while its effect on the rate of heat transfer is not more appreciable. Furthermore, it is found that the heat transfer increases, as the volume fraction of nanoparticles and Reynolds number increase. It can also be seen that the maximum value of relative Nusselt number for silver nanoparticles is more than other studied nanoparticles.

In this paper, the heat transfer enhancement by the nanoparticles in the film condensation of nanofluid over a cooled plate is studied numerically. Shooting method and modified-Euler scheme are employed to solve the condensation boundary layer equations. The effect of changes in the plate angle, nanofluid type, volume fraction of nanoparticles and Jacob number, on the velocity and temperature profiles and Nusselt number are investigated. Resulting graphs are compared and validated with the available theoretical results for the base fluid and nanofluid. The results show that the presence of nanoparticles in the liquid film of condensation increases the heat transfer from it. As the plate distances from the vertical position, the temperature change across the boundary layer is close to linear and thus, the heat transfer descends. Also it can be found that the average Nusselt number is almost constant up to the angle of 20o, and then reduces in a gradual manner, so that for instant, for water-TiO2nanofluid, by increasing the angle up to 60o, the temperature gradient is reduced by about 20 percent. Furthermore, it is seen that the relationship between the ratio of nanofluid to pure water Nusselt number and the nanoparticles volume fraction is linear, while the slope of the line for water-Cu and water-Ag is more than other studied nanofluids, i.e., these two nanofluids are more effective in heat transfer enhancement. The obtained results also confirm the fact that the Nusselt theory is only applicable in low Jacob numbers.

This paper concerns with a similarity solution for mixed-convection boundary layer copper-water nanofluid flow over a horizontal flat plate. Appropriate similarity variables are used to convert the Governing PDEs to ODEs and the resultant equations with the nanofluid properties relations are discretized and solved simultaneously using finite-difference Keller-Box method. The effects of change in plate temperature, the volume fraction of nanoparticles, and the mixed-convection parameter, on friction coefficient, Nusselt number and velocity and temperature profiles are investigated. The results show that, the Nusselt number increases as the mixed-convection parameter and the volume fraction of nanoparticles increases. This enhancement is about 10 percent for the nanofluid with 4% volume fraction of nanoparticles, compared with the pure water. In this range, moreover, the friction coefficient parameter increases about 20 percent. However, the lower the mixed-convection parameter is, the effect of nanoparticles on the friction coefficient increment is more. The results also illustrate that the effect of the surface temperature on the increment of Nusselt number and on the reduction of friction coefficient is more considerable in higher mixed-convection parameter and volume fraction of nanoparticles. Also by increasing surface temperature, the temperature of nanofluid decreases at any surface distance.

Considering passive defense in construction and rehabilitation of military and residential structures is a proper method for blast-induced damage mitigation. In this paper، the behavior of end plate bolted connections under blast is studied. To assure the accuracy of finite element models، verification is carried out using the results of an experimental test.. A 5-story structure is designed according to national steel structures code using ETABS and one of the first storey connections is studied under blast load using nonlinear dynamic analysis in ABAQUS considering the effects of high strain rates. The results show that the beam experiences significant torsion. Moreover، the critical area in moment connection is the area adjacent to lower bolt holes as well as the area between end plate and lower beam flange. It is also observed that the use of small bolts in higher number provides more desirable response in blast loading.

CRP is the main acute phase protein in humans and plays a key role in host defense against infections. This protein is increased in many infections، inflammatory arthritis، autoimmune diseases، neoplastic diseases، pregnancy and elderly this study was done on 400 serum samples that CRP was checked with 3 different kits with slide agglutination method and with photometric method for each sample. Results were compared with quantitative results in photometric method. statistical results in evaluating 400 serum samples with Anisan، Kimia pajohan and Shim enzyme kits were like below: false negative results were detected in 21، 20 and 33 samples respectively. Sensitivities were 87. 6%، 86. 2% and 80. 5% respectively. Specificities were 84%، 74. 1% and 80% respectively. Positive predictive values were 80%، 65. 4% and 74. 7% respectively. Negative predictive values were 90. 2%، 90. 5% and 84. 9% respectively. Although Anisan kits have higher sensitivity، specificity and positive predictive values among these three Iranian kits with slide agglutination method، it is advised to use quantitative methods like ImmunoturbidImetry or photometry because of high frequency of false results in agglutination method.

Abnormal loads induced by blast or impact results in local damages in structures and these local damages may propagate and affect whole structural system. Therefore, structures should be designed in a way that progressive collapse is prevented. Connections have important effect on ductility and strength of structural systems and preventing progressive collapse. Consequently, the behavior of bolted angle connection under blast load is studied in this paper using finite element method. In this study, top and seat bolted angle connection with web angles is investigated using ANSYS finite element software. The models are verified comparing the analysis results with those of experimental tests. The verified models are then exposed to blast load and their behavior is evaluated. Critical areas are determined in the connection and failure modes and applicability of mentioned connections against blast loading is investigated.