The 3D printing technology allows the production of parts with complex geometry quickly. However, the printed parts have poor mechanical properties due to the nature of their layers and the presence of defects such as cavities and poor adhesion between the layers. This paper investigates the use of ultrasonic vibrations to improve the mechanical properties of ACRYLONITRILE-butadiene-styrene printed components. Samples were fabricated with standard geometry of tensile test using a desktop 3D FDM printer. Process parameters are layer thickness and infill. Also, the time of ultrasonic imposing was selected as a variable parameter. The thickness of the print layers are 0.15, 0.2, and 0.30 mm, and the infill is 60, 80, and 100%. The design of the experiment was performed by the response level method. Then the uniaxial tensile test was performed on the samples, and the data were analyzed by analysis of variance (ANOVA). The results showed that the application of ultrasonic vibrations significantly improves the tensile strength of printed parts, which is greater in lower thickness. Also, with increasing the infill, the effect of ultrasonic vibrations increases, which can be due to better bonding of the print layers due to ultrasonic vibrations and reducing the number of pores in the low infill values. Therefore, it is found that by applying ultrasonic vibrations to the 3D printed samples, their mechanical properties were improved and could be used in performance evaluation.

Suspension polymerization of styrene-ACRYLONITRILE at 75oCunder atmospheric pressure was studied. To have copolymer with azeotropic composition, it was found that 30%AN in feed is needed. Different grades based on different average molecular weights were synthesized and relative procedures discussed. Mixed initiators of lauryl peroxide and benzoylperoxide were used in presence of n-dodecylmercaptane (n-ddm) as chain transfer agent. It was found that for isothermal copolymerization the optimum concentration of n-ddm is 0.1%.

Sandwich structures are widely used in aerospace, automobile, high speed train and civil applications. Sandwich structures consist of two thin and stiff skins and a thick and light weight core. In this study, the obligatory mandate of a sandwich plate contact constitutes a flexible FOAM core and composite skins with a hemispherical rigid punch has been studied by an analytical/empirical method. In sandwich structures, calculation of force distribution under the punch nose is complicated, because the core is flexible and the difference between the modulus of elasticity of skin and core is large. In the present study, an exponential correlation between the contact force and indentation is proposed. The coefficient and numerical exponent were calculated using the experimental indentation results. A model based on a highorder sandwich panel theory was used to study the bending behavior of sandwich plate under hemispherical punch load. In the first method, the force distribution under the punch nose was calculated by the proposed method and multiplied to deformation of related point in the loading area to calculate the potential energy of the external loads.In the second method, the punch load was modeled as a point force and multiplied to deformation of maximum indented point. The results obtained from the two methods were compared with the experimental results. Indentation and bending tests were carried out on sandwich plates with glass/epoxy skins and a styrene/ACRYLONITRILE FOAM core. In the bending test, a simply support condition was set and in the indentation test the sandwich specimens were put on a rigid support. Indeed, in this position the punch movement was equal the indentation. The comparison between the analytical and experimental results showed that the proposed method significantly improved the accuracy of analysis.

The aim of this study is to provide a method of making ultralight open cell copper FOAM with high surface area using chemical procedures. Among the various methods of making open-cell metal FOAMs, electrodeposition method is selected because it can be done in a clean way and is cheaper than other methods. In this method, an open cell polyurethane sponge was used as substrate. Then by choosing appropriate chemical solutions with specific technical knowledge, first polyurethane surface has activated and then by electroless-deposition method, polyurethane activated surface covered with a thin layer of copper. In the final stage, with the aid of electrodeposition the thickness of copper layer was increased to the desired thickness with a minimum required strength. The results show that electrodeposition can increase the thickness of copper layer from 3-5 microns that is obtained in electroless-deposition method to above100 to 150 microns. SEM results show that the micro structure of the deposited layer is globular. By controlling the thickness of deposited copper in electroplating, the surface area of the copper FOAM can be increased. According to results optimum time for electroless-deposition is between 5 to 7 minutes and for electrodeposition is 1 hour. The open-cell copper FOAM that is produced in this research is ultralight and due to it high surface can transfer heat with high rates.

Abstract In the design and construction of structures, especially water structures, and contact with any problematic soils, many issues and problems may arise during construction or operation, eventually leading to local destruction or destruction of the structure. Iran is one of the countries that, due to its special arid and semi-arid climatic conditions as well as its geology, many types of problematic soils are found in it, so the existence of this category of soils has been the source of many destructions and damages caused in There have been all kinds of structures, especially water structures in the country. To achieve the goals of the present research, tests were conducted on the soils of the construction site of Ramhormoz canals in three sections to identify the mineral type and morphology of the tested samples and to investigate the effect of different additives on the mechanical properties of the soil samples. The results of the research show that there are changes in the paste limit for all related samples, the lowest value for the sample with 5% lime is an increase of 3.58 and the highest value for the sample with 7% cement is an increase of 9.65. The changes in internal friction angle for all samples show that the lowest value related to the sample with 7% cement is equal to 0.1% increase and the highest value related to the sample with 7% cement is equal to 24.9% increase. INTRODUCTION In the design and construction of structures, especially water structures, and contact with any problematic soils, many issues and problems may arise during construction or operation, eventually leading to local destruction or destruction of the structure. Iran is one of the countries that, due to its special arid and semi-arid climatic conditions as well as its geology, many types of problematic soils are found in it, so the existence of this category of soils has been the source of many destructions and damages caused in There have been all kinds of structures, especially water structures in the country. METHOD AND MATERIAL To achieve the objectives of the present research, field sampling was done after studying the previous research, and then relevant laboratory studies were carried out by transferring the prepared samples to the laboratory. Laboratory studies of the current research in three sections: mineralogy of samples with XRD device, morphology of samples with SEM device; and Granulation of the samples was done by LPSA method. For sampling for the present research, data collection was done from the Ramhormoz region located in Khuzestan province, which has chalk soils and is the place where various water transfer structures are implemented. In this research, manual boreholes were dug from a depth of -30 (minus 30 cm) from the base level to a depth of -60 (minus 60 cm) and the information about the state of the soil layer was obtained by sampling the mentioned boreholes by performing the necessary tests. From the soil composition that was sampled from the mentioned places with 3 types of solid materials including: a- The combination of soil with type 2 cement with a combination of 2, 5%, and 7% by volume. b- Mixing the soil with slaked lime with a combination of 5% and 7% by volume. C - Mixing the soil with slag with 3 with a combination of 5% and 7% by volume. Results The results of this research show that the changes in the paste limit for all the samples show that the lowest value for the sample with 5% lime is a 3.58% increase and the highest value for the sample with 8% cement is a 9.65% increase. Also, the changes in the dry density of compaction show that the lowest value of the sample with 7% cement is equal to a 22% decrease and the highest value of the sample with 7% slag is equal to a 6% increase. The changes in adhesion coefficient show that the lowest value of the sample with 5% cement is a 15.4% decrease and the highest value of the sample with 5% slag is a 450% increase. The changes in the internal friction angle show that the lowest value corresponding to the sample with 5% and 7% lime, 5% and 7% slag, and the highest value corresponding to the sample with 5% cement is equal to a 5.8% increase. DISCUSSION AND CONCLUSION In general, the most important reactions of lime with soil can be divided into four categories: a) flocculation, b) carbonation, 3) ion exchange, and d) pozzolanic reactions, and each of these changes can be Even in a short period observed in the soil. In the event of any of the presented reactions, changes can be observed in the optimum moisture content, specific weight, reduction in plasticity indices, and increase in unconfined compressive strength. The mixture of lime and clay with the cation exchange reaction of clay minerals and as a result, coagulation of its fine particles, provides suitable conditions by which the flocculated clay particles together cause the formation of larger particles. This process involves the hydration reaction of quicklime. After this initial rapid reaction, more permanent reactions begin, such as the pozzolanic reaction in which materials impregnated with cement are used, the best performance of the samples is expected in a longer time. Hydration reactions are effective at temperatures above 20 degrees Celsius, at higher stages this reaction causes an increase in resistance through the formation of hydrated calcium silicate and hydrated calcium aluminate silicate from hydration and pozzolanic reactions. The formation of these compounds increases resistance.   Considering that the soil of the study area is gypsum, therefore, among the mechanical parameters of the soil, the coefficient of adhesion can be considered as the most important parameter. Therefore, based on the above explanation and based on the results obtained, mineral slag is added to the soil of the study area. It can be a suitable solution to solve the mentioned soil problem. ACKNOWLEDGEMENT The authors of the article express their gratitude to Khorramshahr University of Marine Sciences and Technology and Khuzestan Water and Power Organization for their financial and spiritual support of this research.

Copolymerization of ACRYLONITRILE (AN) with acrylic acid (AA) carried out by solvent (DMF)-water suspension method, at 60 oC, using azobisisobutyronitrile (AIBN) as an initiator. The effects of mole fraction variation of acrylic acid and concentration variation of water in reaction medium, on the properties of synthesized copolymers were investigated by FTIR, viscometry, and DSC techniques. The reactivity ratios were calculated using Fineman-Ross and Kelen-Tudos methods. The results obtained show that by increasing the mole fraction of acrylic acid in the feed up to 0.0756, the conversion percentage decreases. However, the molecular weight increases in this range of feed ratio. In the samples prepared by keeping the feed ratio of comonomers constant and varying the ratio of the solvent/nonsolvent, the molecular weight increases by increasing nonsolvent amount. The reactivity ratio of AA is 6.5 times greater than that of AN. DSC Exothermic peak of homopolymer shows a single peak whereas, in copolymers it appears as doublets, due to more distinction of dehydrogenation, oxidation, and cyclization reactions.

Background and Aim: ACRYLONITRILE (ACN) is widely used as a main raw material in the ACRYLONITRILE-Butadiene-Styrene (ABS) resin-manufacturing units and other industrial and commercial processes. ACN, due to its toxicity, is not easily decomposed by microorganisms. The discharge of improperly treated ACN-containing wastewater into a natural water body may cause serious environmental problems and severe adverse impact on the aquatic ecology. This study attempts to isolate and identify bacteria which utilize ACN as the sole source of carbon and nitrogen from the activated sludge of petrochemical wastewater treatment system. The performance of the isolated strains in treating different initial ACN concentrations was also investigated under aerobic conditions. In addition, the performance of biodegradation and the metabolic intermediates and end-products in the process were determined.Materials and Methods: Experiments were conducted with three batch reactors, the volume of each one being 250mL. The activated sludge samples as a microbial seeding were taken from the return sludge line of the aeration tank of the wastewater treatment facility in Tabriz Petrochemical Complex. Phosphate-buffered medium (PBM) was used to make available minerals and trace elements, and ACN was used as the sole carbon and nitrogen source for microbial growth. R2A medium was used to obtain pure colonies, and to identify the isolated strain, Gram staining and microscopic examination followed by biochemical and physiologic analyses using selective media such as O-F glucose, MacConkey agar, TSI agar, EMB and SS agar, nitrate reduction, gelatin liquefaction, lactose fermentation, oxidase, catalase and SIM were used. In the final stage, the performance of biological systems in degrading different initial concentrations of ACN and its intermediate and end-products were investigated. Results: The findings indicated that when the ACN concentration was 500mg/L, the average removal efficiency after 46 and 70 h reached 46% and 98%, respectively. But at an initial concentration of 700mg/L, the removal efficiency of the ACN in the biological system was 50% after 46 h and 98.6% after 94h. However, when the ACN concentration was increased to 1000mg/L, the removal efficiency after 46 and 94 h was only 30% and 40%, respectively, and after 118 h of reaction, the remaining concentration of ACN was about 580mg/L. Furthermore, the results of isolation and identification experiments revealed that at the optimum operation of the biological system the strain belonging to the gamma group of Proteobacteria as Pseudomonas putida had the best ability to degrade ACN.Conclusion: Biological processes can degrade ACN and the abilities of different bacterial strains in this degradation vary. The rod-shaped Gram-negative P. putida could easily adapt to ACN concentrations up to 700mg/L and utiliz ACN and its intermediate- and end-products as a carbon and nitrogen source for growth in the process. Thus, this strain is expected to play an important role in aeration tanks for treating ABS resin-manufacturing wastewater.