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Portland cement is a crucial mineral chemical that is globally produced in large quantities. It has been reported that in 2011, approximately 3.6 billion tons of Portland cement were produced, and its demand continues to grow. However, this industry's expansion has resulted in increased environmental risks. Therefore, it is important to conduct research to enhance the sustainability of this product. The utilization of nanomaterials in cement and concrete materials has received significant attention in recent years. Employing nanotechnology to modify cement-based materials can significantly enhance the efficacy of this inorganic binder. Primarily, nanoparticles possess the capability to fill the porosity within the cement structure and exhibit pozzolanic properties that reinforce concrete. Additionally, the high specific surface area of nanomaterials facilitates increased reactivity at the nanoscale, thereby enhancing cement hydration and subsequently improving its mechanical properties.Despite cement and concrete being known for their strength, they are also inherently brittle, which hinders their mechanical performance. In recent years, various nanomaterials have been utilized to address this weakness due to their high specific surface area and strengthening capability in different matrices, including cement. This study aims to evaluate the impact of incorporating a binary nanocomposite of titanium dioxide nanoparticles and graphene oxide to enhance the mechanical properties of the Portland cement.For hybridization, electrostatic adsorption mechanism was used to connect TiO2 nanoparticles on graphene sheets and synthesize TiO2–GO nanocomposite. In this work, TiO2 powder was processed in nitric acid to accumulate protons in the form of H+ functional group on the surface of nanoparticles and make it positively charged. On the other hand, chemically produced GO suspension has an intrinsic negative charge due to the formation and presence of hydroxyl groups (OH–) on its surface. Therefore, the combination of these two charged substances with the opposite charge under several hours of stirring causes them to be connected and attracted to each other through electrostatics.Cement paste with a water-to-cement ratio of 0.38 was prepared and hydrated for different durations (7, 14, and 28 days). Nanostructured reinforcement with a fixed concentration of 0.05 wt.% GO and varying concentrations of 0.5, 1, and 1.5 wt.% TiO2 were added to the cement. The resulting cement paste samples were analyzed for compressive strength, porosity, and microstructure. The study revealed that the sample containing 1 wt.% TiO2–0.05 wt.% GO exhibited the best mechanical behavior, with a 55% higher compressive strength compared to the unreinforced cement sample. Furthermore, this sample had the lowest porosity. Microstructural analyses indicated that the reinforced sample had a reduced porosity, improved hydration acceleration, and enhanced overall integrity of the structure, leading to the significant improvements in its mechanical properties.

Nowadays, energy storage has become a crucial challenge for humanity. Supercapacitors have emerged as a promising option for energy storage due to their numerous advantages. In this study, Co3O4/RGO nanocomposite electrode materials with high specific capacity and favorable electrochemical performance and cycling stability for electrochemical applications were synthesized via a one-step hydrothermal method on a nickel foam substrate and compared with cobalt oxide nanoparticles. The synthesized samples were characterized using various techniques, including X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. For electrochemical evaluation, the synthesized nanostructures were examined in a three-electrode system with a 6 M KOH electrolyte. Cyclic voltammetry and galvanostatic charge-discharge tests were performed. The obtained specific capacity for the hybrid sample was 634.8 F/g at a current density of 1.5 A/g. In contrast, the specific capacity for the cobalt oxide nanoparticle sample was obtained to be 206.1 F/g, indicating a significant capacity enhancement for the hybrid sample. The demonstrated favorable electrochemical performance could be attributed to the nanoscale morphology and hybrid composition.

In tunnel drilling operations using tunnel boring machine (TBM), a relatively large concentrated load is applied by the device jacks to the prefabricated parts or segments of the tunnel cover. This load leads to significant tensile stresses in the segments. One of the most important parameters affecting the tensile stresses in the segments is the geometry of the loading plates of the trust jacks. In this study, with the aim of reduction of the values of tensile stresses in the segments, the innovative changes in the geometry of the loading plates of the propulsion jacks have been evaluated experimentally and numerically.

Death is a vital necessity and an undeniable phenomenon. Death is a concept in contrast with life and inevitable. Confrontation with death has a lifespan as old as humanity itself. Humanity's constant confrontation with death has made man make peace with its inevitability. Therefore, the desire to know more about the phenomenon of death has been one of human’s oldest pastimes. The way of dealing with this process has different patterns in different cultures and traditions. But since mankind have always been looking for a way to commend the deceased, monuments and tombs have been one of the most obvious ways of showing and symbolizing the deceased person, and tombstones are important in this process. The construction of tombs has long been important for honoring the status of the dead, so that in the ancient times of Iran we come across tombs and graves that show us the traditions of the past regarding the deceased. After Islam, according to the Islamic tradition, the deceased is buried in the soil during a ceremony. In line with historical eras, tombs were structurally influenced and conformed to the various cultural factors of each era and changes in rituals and beliefs.In Islamic Iran, tomb buildings became prevalent from the 4th century A.H. and the construction of tombs for important people became popular and gradually widespread, and as evidenced by history, since then the tombs of the elders and important figures always continued to be significant during following eras. Tombs are a place to display history, art, culture and even philosophy and life style of the people of a society. The common feature of tombs and mausoleums, either for important figures or ordinary people, is the existence of a tombstone that is designed with special specifications. By observing the graves and studying them and the concepts, themes and motifs of their carvings, beliefs, history of the people of a region, and even their art can be understood. Inscriptions, names, decorations and forms are the factors that give life to the stone, and become guides and take us somewhere in-between existence and non-existence; where there is no name, but only commemoration. Patterns that are a testament to the art history of Iranian civilization and their main source are mystical in nature.The history of using tombstones in Iran dates back to Islam. Although there is no sign and proof of the onset of placing the stone on the grave of the deceased, it can be said that the way of burial and marking the grave (stone) after forty days in Shia jurisprudence can be the beginning of this tradition. By the passage of time the tombstones, like other works of the Islamic period, were decorated by symbols that implied many characteristics, ranging from the introduction of the deceased to the historical period and identity signs. The application of a boxed tombstones on the grave of the deceased does not have a precise and specific date, but their first well known examples can be found in the Timurid period. Tombstones in various types and special styles, which are rooted in the religious foundations of the Islamic periods, are used in all cemeteries and are considered an important feature of the cemetery. Engraved motifs in the Islamic period can be seen in various parts of religious texts, one example of which is tombstones engraved with plant themes, ethnic beliefs, pure sculptural forms and inscriptions with various forms of calligraphy.Since far past, ever since the burial of the holy body of the 8th Imam of Shiites, Imam Reza’s (pbuh) holy shrine has been the focus of attention of various groups of people, and many people, in their wills, requested to be buried next to the shrine of this noble Imam. Also with the development of the Holy Shrine for the welfare of pilgrims and the growing trend of urbanization, a number of tombstones around the Holy Shrine were transferred to the Astan Quds Razavi Museum. Astan Quds Razavi has a great treasure of art works, many of which have not yet been introduced to researchers. The tombstones preserved in this large collection are among the works that are considered significant, due to the reading of their themes and the study of their motifs. This research intends to study the symbolic concepts of this type of tombstones with various decorations and examine their form and content. The tombstones of the Astan Quds Razavi Museum include the Timurid and Safavid periods. About 15 tombstones are on display in this museum. In this research, 7 samples of tombstones from the tombs of Mahfouz in Astan Quds Razavi Museum have been studied. Two of them have recently been found in the excavations of the Holy Shrine of Razavi and are introduced for the first time in this study. They belong to Khanka Bibi, the daughter of Amir Afzaluddin Mohammad Al Mousavi and Goharshad Khatun, the daughter of Sultan Farrokh Yasar.The purpose of this research is to study the structure, inscriptions and motifs carved on the tombstones. The question of this research is what concepts do the inscriptions and decorative motifs of the box tombstones of Astan Quds Razavi Museum refer to?The research method is based on analytical and descriptive method, and data collection is conducted via field studies and documents and library resources in parallel. The statistical population of the research includes 7 examples of tombstones in Astan Quds Razavi Museum, which have the maximum amount of information and the minimum percentage of degradation.The results of the research show that the decorations of the studied tombstones were decorated with inscriptions, geometric designs, Mihrabi and Moqransi motifs with carvings of plant foliage such as lotus flower and Eslimi designs. The texts engraved on the tombstones include verses of the Quran, prayers, names of God, poems, and also the details of the deceased, which can be seen on the body of the tombstone. What can be said concerning the selected tombstones is that two types of inscriptions and motifs can be detected on them. In addition to introducing the deceased with prayers, the verses of the Quran and the names of the Innocents, the inscriptions reflect the whole view of the religious beliefs of the people of that era, who fully understood the relationship between the form and the meaning of the motifs. Especially mentioning the name of Hazrat Ali due to the recognition of the Shia as the official religion of Iran during the Safavid era is one of the noteworthy cases. These inscriptions are engraved on the top most part, body and the margins of the tombstone. The type of writing style in the inscriptions is of significan importance in the work of artists on tombstones. In the selected examples, the Kufic script of Banai, Naskh, and Tholut have been used. In transforming the shape of tombstones from cradle to boxed, the altar-shaped design at the top of the box is quite clear a replacement for the upper prominent part of the cradle tombstone. The design of the altar contains decorations such as inscriptions and motifs. In connection with the motifs, the use of geometric, Eslimi and Moqrans motifs is prominent. Geometric motifs are used along with plant motifs and inscriptions, among which circle is one of the most widely used shapes. These motifs are formed by regular repetition and reproduction of a pattern in all directions of the shape to fill the entire surface and the empty space between the shapes. These geometric motifs can also be seen in the form of decorative flowers, the varieties of which are four-petal, eight-petal, and lotus flowers. Sometimes these flowers are centrally located in the upper frame, or they connect a series of surrounding inscriptions as a chain, or they are carved to fill empty spaces. The juxtaposition of these motifs and inscriptions shows symbolic meanings. Also, in the four corners of some tombstones,  column-shaped designs can be seen that have a decorative purpose and hold a Muqrans design at their upper part which creates a sense of balance. These carved capitals on the four sides of the stone create balance and symmetry between the elements and motifs used in the stone. Eslimi plant motifs and spiral movements and their continuous repetition evoke the multiplicity in unity and the immortality of the world with continuous birth.

In recent years, a new type of fiber-reinforced concrete, consisting of several different types of fibers, known as hybrid fibers reinforced concrete, has attracted the attention of researchers. The aim of this paper for experimental evaluation of the effect of replacement ratio of recycled aggregates with natural aggregates on the mechanical properties of reinforced concrete with hybrid fibers (steel and polypropylene fibers). To this end, reinforced concrete with hybrid fibers with volume fractions of "0.0%" , "0.5%" , and "1%" of steel fibers and "0.0%" and "0.4%" of polypropylene fibers and replacement ratios of "0.0%" , "25%" , and "50%" recycled coarse aggregate of natural coarse aggregates were tested for compressive strength, Brazilian tensile strength, and flexural strength by four-point bending tests. The results show that increasing the replacement ratio of recycled aggregate leads to a decrease in compressive, tensile, and flexural strength. If polypropylene and steel fibers are added to concrete containing recycled aggregates, the compressive, tensile, and flexural strengths of concrete increase, whose steel fibers are more efficient in improving the tensile and flexural strength of concrete than polypropylene fibers. The combination of polypropylene fibers with steel fibers increases energy absorption and increases the flexural toughness of concrete containing recycled aggregates. Moreover, reinforced concrete with hybrid fibers does not disintegrate after breaking, and hybrid fibers play an important role in maintaining the cohesion of concrete.

Since ancient times, the inscription has been one of the arts that have been popular in Iran and have been performed in different forms on other materials. Inscriptions represent valuable information from their time. One type of inscriptions is the designs and inscriptions on tombstones that have a considerable variety belonging to different centuries. It can find unique examples of them in all parts of Iran. In this research, using the descriptive-analytical method and library and field studies, the authors seek to answer these questions that the tombstones of Shiekh ‘ᾼli mausoleum belong to what period and personalities? What are the themes of the inscriptions on the gravestones? What are the appearance characteristics of tombstones? Studies have shown that the gravestones are related to the fifth to fourteenth centuries AH and belong to great Fārs and Islamic world scholars and mystics. All existing tombstones are made of limestone and are classified into two main groups: table tombs and simple. Tombstones are simple and without engravings, and their inscriptions’ themes include Qur’anic verses, prayers, poems and names, nicknames and characteristics of the deceased, and the date of their departure. The calligraphy used on these tombstones includes Kufic, Thuluth, Naskh, and Nasta’līq inscriptions.

In this research, the effects of graphene oxide (GO) as an additive to Kevlar fabric impregnated with nanosilica/PEG shear thickening fluid (STF) on the ballistic performance were investigated. In order to understand the influence of STF, pull-out tests were accomplished to assess the friction between yarns. The energy absorption in the high-impact ballistic test for the fabric impregnated with STF increased by 25.8% compared to that for the neat Kevlar fabric. This parameter for the fabric impregnated with STF-0.2 wt.% GO was 23.3% as compared with that of the neat fabric, demonstrating the deteriorating effect of graphene oxide additive. The results of the pull-up tests were in agreement with ballistic tests, meaning that the increase or decrease in the maximum forces in pull-up tests was followed by the increase or decrease in the energy absorption in ballistic tests. Compared to the sample impregnated with STF, adding graphene oxide causes the decrease in the maximum force in the pull-up test, resulting in a reduction in restriction of yarns movement, consequently facilitating their movement inside the fabric.

The mirror work is an Iranian art and it is subset of architectural decoration. The history of this art in Iran dates back to Safavid era, and afterward it turned to one of the most popular arts in Qajar period. As a result, Mashhad became one of the mirror work sites very soon due to the Shrine of Imam Reza (A.S.). In the Shrine of Imam Reza (A.S.) numerous places and porticos are decorated with beautiful and various mirrors. Dāral-Sīyādah is one of the porticoes that have been mirrored as well as using fresco and tile work. In this descriptive-analytical article, the author seeks to answer the questions that when the mirror works of Shrine of Imam Reza (A.S.), and in particular, the Dāral-Sīyādah portico was done? Who and with what roles have been involved in Dāral-Sīyādah mirror works? What styles and patterns have been used in Dāral-Sīyādah mirror works? The findings indicate that the use of mirror works in the Shrine of Imam Reza (A.S.) goes back to the late Safavid and early Qajar periods and one of the earliest documents related to the mirror works of Dāral-Sīyādah belongs to the late thirteenth century AH. Along with the artists, officials have been involved in performing the mirror works of Imam Reza's (A.S.)shrine and have used plaster works, sandblasting (Jīvitarāshī), colored glass, Qur'anic inscriptions, traditions, God's and Imams' names, paintings , Candlestick, vase, flower and leaf designs, and geometric patterns, especially strap work, for decorating the Dāral-Sīyādah mirrors.

In parts of constructing east-west t lot of line 7 Tehran subway, the excavating machine (EPB-TBM) passes from the top of the Abouzar’s wastewater conveyance tunnel with clear distance of 2.25 m. The FLAC 3D has been used to model this problem and find the deformations and forces of ground and linings. The modeling results show that after excavating subway tunnel, lining of Abouzar tunnel will be moving upward due to the increasing plastic zones and stress relaxation. This rate of displacement induced the internal force more than allowable designed amount in concrete lining of Abouzar tunnel. Generally, excavation a tunnel near another tunnel may lead to significant interaction effects, which mainly dependent on tunnels position relative to each other (parallel or cross), the distance between two tunnels, tunnel dimensions, lining rigidity, stress and boring environment condition as well as the method of tunnel boring. The interaction between adjacent tunnels have been investigated by different researchers using methods such as analytical and empirical, field observation, physical modeling and numerical modeling. In the current project, the tunnel of Tehran metro line 7 passes with a distance of 2.25 meters from the top of the Abuzar tunnel. Because of the nature of three-dimensional problem of interaction between underground spaces, numerical modeling is an appropriate tool for the analysis of these complicated problems. Therefore, FLAC3D software have been used in order to investigate into the interaction analysis. The purpose of modeling is study on stability of support system of Abuzar tunnel during tunnel excavation of Tehran metro line 7. Methodology and Approaches: In this paper, the finite difference method (FDM) is used for modeling and solving the problem. FLAC 3D program which uses FDM was selected in order to study the interaction between the two tunnels, in construction stage. For this purpose, at first Abouzar tunnel modeled and excavated, then impact of stepwise excavating of line 7 Tehran subway on lining system of Abouzar tunnel is investigated numerically. History of Internal forces, bending moments and structural displacement of Abouzar’s tunnel lining have been provided and studied. Engineering recommendations have been proposed in different-leveled intersecting tunnels. Results and Conclusions: The results of modeling show that after excavation of metro tunnel, the support system of Abuzar tunnel will be uplifted because of increasing the plastic zone and stress relaxation. This displacement causes internal forces in Abuzar tunnel lining which are more than allowed values.

When an underground space is drilled, the state of stresses is changed and a disturbance is created in the mechanical behavior of the surrounding Area. Stability of an underground space is provided by support systems. One of the most important loads in designing tunnel support system is environmental rock/soil loads. So far different methods have been represented to estimate the rock load such as empirical, analytical and numerical method that is based on engineering classification of rock. The aim of this study was to evaluate empirical and numerical methods of estimation of rock load on the segmental tunnel support system according to instrumentation data in the tunnel to transfer water from the Zayanderood dam to the city of Kashan. The results of numerical simulations, shows nearer results to field data.
In order to estimate the Rock load on tunnels, empirically, analytically or numerically methods those are useable for tunnel design engineers. Empirical methods are based on local observations, the required parameters in the project, comparing them with past experience and at last are based on the conclusions and determine the forces. In numerical method based on analysis stress, displacement and plastic zone is determined and rock load calculated. The most important advantage of this method for the simultaneous determination of the load on support system and deformation occurred in the rock mass. In estimating the Rock load for each of these methods sometimes large differences can be observed between the results from different methods.
Methodology and Approaches : In this research, all experimental methods available in the literature were evaluated. The SAP2000 and PLAXIS-2D software numerical modeling has been done. The results of empirical and numerical methods are compared with the results of field work and instrumentation and its results have been analyzed and interpreted. The results of the internal forces in the lining of software PLAXIS analysis and the results of the internal forces in the software SAP2000 (based on the rock of experimental methods) were compared and interpreted.
Results and Based on the results of numerical simulations, estimates of the analysis in Plaxis software for all host rock mass conditions, shows nearer results to field data. According to the analysis, the results of Goel & Jethwa and Goel et al. that based on RMR classification system using RMR Basic values as the closest approximation to field data to estimation of rock load have been introduced.

Social assessment is process of preparing framework to prioritize, collecting, social information analyzing and classifying, participation in design and provision of urban development operations. Unforeseen consequences of urban development projects can greatly reduce the project benefits, so from this point, social impact assessment is important. Since this issue has been less attention in the country development projects, in present study evaluating social impact of Hakim Highway Twin Tunnels construction projects in Tehran metropolitan, studied by quick matrix method. In this method according to each plan, consequences and their impact on the social environment have been rated and finally, assessment is done on the basis of rates. The results show that most negative consequences in construction phase activities of project on social and cultural is related to traffic by low intensity. Consequences in operation phase of the project, on the social and cultural tasks, are . The most positive effect is related to reducing traffic with high intensity.

Form plays a major role in Iranian architecture. Chahārtāqy is a type of common forms in Iranian architecture with an ancient history that by studying its structure and formation process and development, the course of development and continuity of architecture in various eras in Iran can be understood. From a number of researcher's view, Khorasan is the origin of Chahārtāqy architecture, Chalipaee form (cruciform), and Chahar Eyvani (four-porch) plan. The authors of the paper, according to this approach have studied the evolution and continuity of Chahartaqy form from Sassanid era in the North East Iran until the end of the fourth century AH. So, in this article we are going to make it clear that how was the distribution of Chahartaqys in North East of Iran and how was their applied categorization? In addition, what was the relationship between the location of Chahartaqys and their application? And what has influenced their form and structure? Finally what was the impact of Chahartaqyhays of Sasanian in North East of Iran on Islamic architecture of the region in that period? This research has been carried out with the descriptive-analytical method and by means of compilation of information, field studies, and library studies. The results suggest that both religion and politics have played a major role in the formation and development of this type of architecture. The Location of Chahartaqys also has had a direct effect on the type of construction, and similarly, the Islamic period architecture of the region of North-Eastern Iran, especially in such edifices as mausoleums, mosques, palaces, mansions, and fortresses has been influenced by the Sassanid Chahārtāqy plan and the general form of construction of that period.

O‌n‌e o‌f t‌h‌e m‌o‌s‌t i‌m‌p‌o‌r‌t‌a‌n‌t d‌e‌f‌e‌c‌t‌s o‌c‌c‌u‌r‌r‌i‌n‌g i‌n r‌e‌i‌n‌f‌o‌r‌c‌e‌d c‌o‌n‌c‌r‌e‌t‌e s‌t‌r‌u‌c‌t‌u‌r‌e‌s i‌s t‌h‌e c‌o‌r‌r‌o‌s‌i‌o‌n o‌f r‌e‌i‌n‌f‌o‌r‌c‌e‌m‌e‌n‌t‌s u‌n‌d‌e‌r u‌n‌d‌e‌s‌i‌r‌a‌b‌l‌e e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t‌a‌l c‌o‌n‌d‌i‌t‌i‌o‌n‌s. V‌a‌r‌i‌o‌u‌s i‌n‌n‌o‌v‌a‌t‌i‌v‌e m‌e‌t‌h‌o‌d‌s h‌a‌v‌e b‌e‌e‌n s‌t‌u‌d‌i‌e‌d b‌y d‌i‌f‌f‌e‌r‌e‌n‌t ‌e‌s‌e‌a‌r‌c‌h‌e‌r‌s t‌o p‌r‌e‌v‌e‌n‌t c‌o‌r‌r‌o‌s‌i‌o‌n. I‌f a t‌y‌p‌i‌c‌a‌l c‌o‌n‌c‌r‌e‌t‌e s‌t‌r‌u‌c‌t‌u‌r‌e, r‌e‌i‌n‌f‌o‌r‌c‌e‌d b‌y s‌t‌e‌e‌l r‌o‌d‌s, e‌n‌c‌o‌u‌n‌t‌e‌r‌s c‌o‌r‌r‌o‌s‌i‌v‌e e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t‌s l‌i‌k‌e s‌a‌l‌t‌s, a‌c‌i‌d‌s a‌n‌d c‌h‌l‌o‌r‌i‌d‌e‌s f‌o‌r a l‌e‌n‌g‌t‌h o‌f t‌i‌m‌e, i‌t w‌i‌l‌l l‌o‌s‌e s‌t‌r‌e‌n‌g‌t‌h t‌o s‌o‌m‌e e‌x‌t‌e‌n‌t. I‌n a‌d‌d‌i‌t‌i‌o‌n, t‌h‌e c‌o‌r‌r‌o‌s‌i‌o‌n o‌f t‌h‌e s‌t‌e‌e‌l, w‌h‌i‌c‌h i‌s l‌o‌c‌a‌t‌e‌d i‌n‌s‌i‌d‌e t‌h‌e c‌o‌n‌c‌r‌e‌t‌e, m‌i‌g‌h‌t e‌x‌p‌a‌n‌d a‌n‌d d‌a‌m‌a‌g‌e i‌t. L‌o‌n‌g‌i‌t‌u‌d‌i‌n‌a‌l r‌o‌d‌s h‌a‌v‌e l‌a‌r‌g‌e‌r d‌i‌a‌m‌e‌t‌e‌r‌s c‌o‌m‌p‌a‌r‌e‌d t‌o s‌t‌i‌r‌r‌u‌p‌s a‌n‌d, t‌h‌e‌r‌e‌f‌o‌r‌e, t‌h‌e‌y d‌e‌m‌o‌n‌s‌t‌r‌a‌t‌e l‌o‌w‌e‌r c‌o‌r‌r‌o‌s‌i‌o‌n e‌f‌f‌e‌c‌t‌s a‌n‌d a‌r‌e a b‌e‌t‌t‌e‌r a‌l‌t‌e‌r‌n‌a‌t‌i‌v‌e. S‌t‌i‌r‌r‌u‌p‌s w‌i‌t‌h l‌o‌w‌e‌r d‌i‌a‌m‌e‌t‌e‌r‌s a‌n‌d m‌o‌r‌e p‌r‌o‌x‌i‌m‌i‌t‌y t‌o t‌h‌e e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t a‌r‌e s‌u‌b‌j‌e‌c‌t t‌o c‌o‌r‌r‌o‌s‌i‌o‌n a‌n‌d, t‌h‌e‌r‌e‌f‌o‌r‌e, i‌t i‌s b‌e‌t‌t‌e‌r t‌o u‌s‌e F‌R‌P s‌t‌i‌r‌r‌u‌p‌s, w‌h‌i‌c‌h a‌r‌e r‌e‌s‌i‌s‌t‌a‌n‌t t‌o c‌o‌r‌r‌o‌s‌i‌o‌n. P‌r‌e‌c‌a‌s‌t s‌t‌i‌r‌r‌u‌p‌s h‌a‌v‌e a s‌p‌e‌c‌i‌a‌l m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌i‌n‌g p‌r‌o‌c‌e‌s‌s a‌n‌d a‌r‌e a‌l‌s‌o e‌x‌p‌e‌n‌s‌i‌v‌e a‌n‌d r‌a‌r‌e. S‌o, u‌s‌i‌n‌g t‌h‌e‌m i‌n s‌m‌a‌l‌l s‌c‌a‌l‌e ‌r‌o‌j‌e‌c‌t‌s i‌s n‌o‌t e‌c‌o‌n‌o‌m‌i‌c. H‌e‌n‌c‌e, i‌t s‌e‌e‌m‌s n‌e‌c‌e‌s‌s‌a‌r‌y t‌o f‌i‌n‌d a n‌e‌w m‌e‌t‌h‌o‌d f‌o‌r m‌a‌n‌u‌f‌a‌c‌t‌u‌r‌i‌n‌g F‌R‌P s‌t‌i‌r‌r‌u‌p‌s t‌h‌a‌t i‌s e‌c‌o‌n‌o‌m‌i‌c‌a‌l‌l‌y v‌i‌a‌b‌l‌e a‌s w‌e‌l‌l a‌s s‌h‌o‌w‌i‌n‌g a g‌o‌o‌d p‌e‌r‌f‌o‌r‌m‌a‌n‌c‌e u‌n‌d‌e‌r e‌x‌t‌e‌r‌n‌a‌l f‌o‌r‌c‌e‌s. T‌h‌e p‌r‌e‌s‌e‌n‌t r‌e‌s‌e‌a‌r‌c‌h e‌x‌p‌e‌r‌i‌m‌e‌n‌t‌a‌l‌l‌y i‌n‌v‌e‌s‌t‌i‌g‌a‌t‌e‌s r‌e‌p‌l‌a‌c‌i‌n‌g s‌t‌e‌e‌l s‌t‌i‌r‌r‌u‌p‌s w‌i‌t‌h s‌t‌i‌r‌r‌u‌p‌s m‌a‌d‌e b‌y F‌R‌P f‌i‌l‌a‌m‌e‌n‌t‌s u‌n‌d‌e‌r c‌y‌c‌l‌i‌c l‌o‌a‌d‌s. S‌o, t‌h‌r‌e‌e c‌o‌n‌c‌r‌e‌t‌e c‌o‌n‌n‌e‌c‌t‌i‌o‌n‌s w‌e‌r‌e m‌a‌d‌e a‌n‌d t‌e‌s‌t‌e‌d. A l‌o‌n‌g‌i‌t‌u‌d‌i‌n‌a‌l r‌e‌i‌n‌f‌o‌r‌c‌e‌m‌e‌n‌t w‌i‌t‌h s‌t‌e‌e‌l s‌t‌i‌r‌r‌u‌p‌s w‌a‌s d‌e‌s‌i‌g‌n‌e‌d a‌s t‌h‌e r‌e‌f‌e‌r‌e‌n‌c‌e c‌o‌n‌n‌e‌c‌t‌i‌o‌n. S‌t‌e‌e‌l l‌o‌n‌g‌i‌t‌u‌d‌i‌n‌a‌l r‌e‌i‌n‌f‌o‌r‌c‌e‌m‌e‌n‌t‌s w‌e‌r‌e u‌s‌e‌d i‌n a‌l‌l t‌h‌r‌e‌e c‌o‌n‌n‌e‌c‌t‌i‌o‌n‌s. O‌n‌e s‌p‌e‌c‌i‌m‌e‌n o‌f F‌R‌P s‌t‌i‌r‌r‌u‌p c‌o‌n‌n‌e‌c‌t‌i‌o‌n‌s i‌s e‌x‌a‌c‌t‌l‌y s‌i‌m‌i‌l‌a‌r t‌o t‌h‌e r‌e‌f‌e‌r‌e‌n‌c‌e. A‌s w‌i‌t‌h t‌h‌e o‌t‌h‌e‌r t‌w‌o F‌R‌P s‌t‌i‌r‌r‌u‌p c‌o‌n‌n‌e‌c‌t‌i‌o‌n‌s, t‌h‌e s‌p‌a‌c‌e b‌e‌t‌w‌e‌e‌n t‌h‌e s‌t‌i‌r‌r‌u‌p‌s i‌s t‌w‌i‌c‌e t‌h‌a‌t o‌f t‌h‌e r‌e‌f‌e‌r‌e‌n‌c‌e s‌p‌e‌c‌i‌m‌e‌n. T‌h‌e s‌t‌i‌r‌r‌u‌p‌s i‌n t‌h‌e l‌a‌s‌t t‌w‌o s‌p‌e‌c‌i‌m‌e‌n‌s w‌e‌r‌e m‌a‌d‌e o‌f F‌R‌P f‌i‌l‌a‌m‌e‌n‌t‌s, i‌n t‌h‌e l‌a‌b‌o‌r‌a‌t‌o‌r‌y. T‌h‌e d‌i‌a‌g‌r‌a‌m‌s o‌f m‌o‌m‌e‌n‌t-d‌r‌i‌f‌t, m‌o‌m‌e‌n‌t-c‌u‌r‌v‌a‌t‌u‌r‌e a‌n‌d m‌o‌m‌e‌n‌t-s‌t‌r‌a‌i‌n h‌a‌v‌e b‌e‌e‌n o‌b‌t‌a‌i‌n‌e‌d f‌o‌r s‌t‌e‌e‌l a‌n‌d F‌R‌P s‌t‌i‌r‌r‌u‌p‌s. E‌n‌e‌r‌g‌y a‌b‌s‌o‌r‌p‌t‌i‌o‌n a‌n‌d h‌a‌r‌d‌n‌e‌s‌s c‌h‌a‌n‌g‌e‌s h‌a‌v‌e b‌e‌e‌n c‌a‌l‌c‌u‌l‌a‌t‌e‌d f‌o‌r a‌l‌l t‌h‌r‌e‌e s‌p‌e‌c‌i‌m‌e‌n‌s. A‌l‌l t‌h‌r‌e‌e s‌t‌i‌r‌r‌u‌p‌s w‌e‌n‌t u‌n‌d‌e‌r c‌y‌c‌l‌i‌c l‌o‌a‌d‌s, a‌n‌d F‌R‌P s‌t‌i‌r‌r‌u‌p‌s s‌h‌o‌w‌e‌d a b‌e‌t‌t‌e‌r p‌e‌r‌f‌o‌r‌m‌a‌n‌c‌e c‌o‌m‌p‌a‌r‌e‌d t‌o s‌t‌e‌e‌l s‌t‌i‌r‌r‌u‌p‌s.

Golden tiles are among the exquisite assets and one of the evidences concerning the history and antiquity of the Holy Shrine of Imam al-Riḍā (A.S.) and the city of Mashhad. A major part of these tiles date back to the 6th/12th to 8th/15th centuries. A large number of these tiles are still preserved in their original places and a number of others, including the niches (miḥrābs), have been transferred to the AQR Museum. This article briefly introduces the golden tiles of the Holy Shrine, their origin and place of manufacture, the tile workers, the tiles themes, the tourists and the historians who have described them, and the present condition of the tiles.

This experimental study is intended to evaluate the effectiveness of a Near Surface Mounted (NSM) technique using bars made of carbon fabrics (BMCF) for strengthening of RC beams. When the amount of NSM reinforcement in strengthening of RC beams is low، the failure is likely to be due to debonding of individual reinforcing rod and in this case improved bond properties as well as proper anchoring of the BMCF rods are likely to delay the failure of the beam. BMCF provide a larger perimeter to cross sectional area ratio with respect to conventional rods for the same amount of fibre used، providing potentially higher bond strength. In addition، the circular shape of BMCF is not only convenient for production but also suitable for NSM strengthening as noted by previous researchers. Another key advantage of introducing the BMCF is that it allows the incorporation of a different anchor system that can be used to improve the performance of NSM BMCF reinforcement for strengthening of RC beams in applications with low strengthening reinforcement percentage. A distinguished benefit of the proposed anchor system is that it only requires the access to the beam sides for installation. This means that the proposed anchorage system can be conveniently applied to beams whose top and/or bottom face is inaccessible. A set of deficient beam specimens were designed. All specimens had the same internal reinforcement arrangements. They were 300 mm wide، 350 mm high and 2050 mm long. One half of each beam was designed to be weak in load bearing as the test span while the other half was designed as the strong span. Only the test span was strengthened in with NSM BMCF. The amount of steel reinforcement in the two sides was designed to ensure that shear failure would occur in the test span. All beams were simply supported at the ends and tested under a concentrated monotonic load applied at the mid-span. Test results presented in this paper have confirmed that the use of BMCF is an effective technique for improving the shear capacity of RC beams. The increase in the shear capacity was between 18 to 55% for beams strengthened with BMCF، compared with the reference beam. The load–deflection response of beams is presented. The capacity of specimens for energy absorption are also presented and discussed in this paper. In order to predict the contribution of NSM-BMCF strengthening method، an analytical study is presented in this paper. The analytical procedure is evaluated by experimental findings. It is concluded that the analytical formulation can reasonably estimates the contribution of NSM-BMCF strengthening reinforcement and as a safe design point of view; it is advisable for engineering application aims.

This article is excerpted from the fieldwork library research outcomes in the field of stone objects of AQR Museum. With respect to the form and content of the stone inscriptions, the article proceeds to analyze the information concerning the material of the stone, type of calligraphy and the style used in ornamenting the stones, identification of the artists who have created these inscriptions, the sponsors of the buildings of the Holy Shrine, and the thematic examination of the stones.

What is displayed today in AQR Museum represents a small part of the Iranians’ art and devotion to Imam al-Riḍā (A.S.). In this respect, the remnants of a ḍarīḥ that Shāh Ṭahmāsb ordered to be built about 500 years ago, has a significant status. In the course of history, of course, greedy people have frequently attempted to take possession of this exquisite artifact; however, it was not destined so.At present, a major part of the inscriptions belonging to this ḍarīḥ are displayed to public in AQR Museum. In this article, the writer introduces this ḍarīḥ and its existing remnants.

Carbide layer produced by thermal reactive diffusion (TRD) technique onto metals and alloys has characteristic properties including wear, oxidation and corrosion resistance as well as relatively high surface hardness. In the present work, kinetics of formation of chromium carbide layer on carburized AISI 1020 steel at temperatures of 900, 1000 and 1100 ºC for 3 to 9 hours was studied. The presence of Cr7C3 phase formed on the surface of specimens was confirmed by X-ray diffraction analysis. Cross-sectional observations of optical and SEM micrographs showed that chromium carbide layer formed on the steel surface were continuous and relatively uniform. The surface microhardness values for the coated steel samples were between 530 and 1321 HV (under 200g load). The evaluation of kinetics of chromium carbide layer formed using salt bath method showed that there is a parabolic relationship between the layer thickness and the soaking time. In addition, the activation energy for chromium carbide formation on carburized AISI 1020 steel in borax salt bath was obtained to be 97.781 KJ/mol. Moreover, the contour diagrams were suggested for prediction of thickness of carbide layer and surface microhardness. The possibility of using a series of mathematical equations for predicting carbide thickness and surface microhardness was also investigated.