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  1 - Cheese whey recycling, the right approach to prevent environmental damage
  Zahra  Katabehei Moradi Maryam  Haghighi khomami Hamed Kioumarsi hooshang dehghanzadeh saeed tamadoni jahromi
  10.29252/.5.7.91
  Today, with increasing in production and diversity expansion of dairy products in factories and production of whey products, this food product has become very important. Whey is a water-soluble part of milk that is obtained by adding acid, heating, and coagulating the c More

  Today, with increasing in production and diversity expansion of dairy products in factories and production of whey products, this food product has become very important. Whey is a water-soluble part of milk that is obtained by adding acid, heating, and coagulating the cheese. This yellow liquid contains a lot of lactose and mineral compounds such as calcium and phosphorus, which is important to achieve in order to use as a food source and prevent environmental pollution. Since the wastewaters of the dairy industry have the highest levels of contamination, if the untreated wastewaters of this industry are discharged, serious environmental problems will be inevitable. On the other hand, a reduction in existing reserves and environmental problems followed by increasing use of fossil fuels has prompted researchers to produce new sources of renewable energy, and it can be said that new biological technologies, such as the use of whey as a way to produce biofuels, reduces the environmental problems of dischrging this kind of wastewaters into nature. Today, using biological technology, these compounds can be used to produce biofuels such as hydrogen, methane, and ethanol. So far, various methods and tests have been performed to produce these fuel sources and in this study, the effective strategies for recycling whey and preventing environmental damages are investigated. Manuscript profile
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  2 - جنبه های اقتصادی فرآوری پسماندهای شهری با نگرشی بر کشورهای پیشروی جهان (مطالعه موردی: کلان شهر اراک)
   
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  3 - Double Recycling Folded Cascode Op-Amp Using Feed-Forward Capacitor Coupling Driving
  Mohammad R. Ali Ali Khamesi Naeini
  A double recycling Op-Amp based on a simple recycling folded cascode Op-Amp is presented. The proposed Op-Amp has significantly improved performance compared to a recycling folded cascode. In the proposed Op-Amp, those cascode output current sources of recycling folde More

  A double recycling Op-Amp based on a simple recycling folded cascode Op-Amp is presented. The proposed Op-Amp has significantly improved performance compared to a recycling folded cascode. In the proposed Op-Amp, those cascode output current sources of recycling folded cascode that still have a constant value have been considered and have taken on a dynamic state through capacitive couplings in the path created between the input and output of the amplifier. DC gain, unity-gain bandwidth, and slew rate have been improved compared to the previous amplifier at the same power consumption. Simulation results using the 0.18μm CMOS technology show a DC gain enhancement of 6dB, 35% improvement in slew rate, and almost a 30% increase the bandwidth compared to the traditional recycling folded cascode Op-Amp. Also, smaller input-referred noise is achieved. Simulated results of proposed circuit show the values of SR, power consumption and DC gain are about 93.5 V/µs, 1.02mW and 68.3 dB respectively. Manuscript profile
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  4 - A Review of Mechanical Recycling of Polylactic Acid: Challenges and Recent Achievements
  Farzane Tabatabaee
  The growing use of polylactic acid (PLA) encourages technologists to conduct extensive research into valorization of PLA waste with best quality. In general, mechanical recycling of PLA is one of the most cost-effective recycling methods. However, recycled materials are More

  The growing use of polylactic acid (PLA) encourages technologists to conduct extensive research into valorization of PLA waste with best quality. In general, mechanical recycling of PLA is one of the most cost-effective recycling methods. However, recycled materials are commonly used for minor applications due to the inherent thermo-mechanical degradation of the polymer during recycling, which mainly results in chain scissions and intramolecular and intermolecular transesterification reactions. Therefore, it has a negative effect on the molar mass distribution and consequently on the mechanical, thermal and rheological properties of recycled PLA. In this article, a review of recent research on the effects of mechanical recycling on the properties of PLA including structural, morphological, mechanical, rheological and thermal changes was done. Furthermore, a review of three main ways of valorization of recycled PLA including thermal modification, chemical modifications in the presence of stabilizers, chain extenders, branching agents and finally mixing with nanoadditives or with other polymers was done in order to improve the properties of recycled PLA. Moreover, due to the widespread use of natural fibers to improve the performance of PLA, the recyclability of natural fiber-reinforced PLA biocomposites was investigated. Finally, two important applications of recycled PLA in the food packaging and the 3D printing industries were discussed. Manuscript profile
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  5 - Participation at Source Separation of Waste in Tehran City
  bizhan zare RAMIN KARIMI
  Nowadays management of discharged materials is considered as one of the factors influencing sustainable urban development plans and recycling waste materials is very important in the areas of environment and urban management, and source separation of waste itself is the More

  Nowadays management of discharged materials is considered as one of the factors influencing sustainable urban development plans and recycling waste materials is very important in the areas of environment and urban management, and source separation of waste itself is the main pillar of recycling.The purpose of this study is to identify and examine social factors and practical conditions for participation in source separation of waste. The study also is going to determine the roles of each factor and the ratio of their share portions. The methodology used for this research is cross-sectional surveying. The society of the research is composed of 15-75 years old Tehranian citizens. The statistical sample also includes 384 persons. Multi-stage clustered random sampling is used and data were collected by questionnaire. The general framework of the research model includes three groups of variables including social factors (social capital, socio-economic status, satisfaction of the municipality), practical conditions and economic benefits of source separation of waste. Results showed that trust in the Municipal Organizations, economic benefits of source separation of waste and practical conditions are associated with participation in source separation of waste. Multivariate regression analysis showed that 47% of the variance of participation at source separation of waste is explained by the model. Results showed that practical conditions have an important role in participation in source separation of waste in Tehran city. Manuscript profile
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  6 - The effect of additives and masterbatch to improve the properties of recycled polyolefins
  Hamidreza Haydari marziyeh hosseini
  Although the recycling of polymer products is beneficial for the environment and economy, the main goal is to achieve the efficiency of raw (intact) polymers in recycled polymers. The best type of recycling to have maximum energy efficiency and minimum environmental con More

  Although the recycling of polymer products is beneficial for the environment and economy, the main goal is to achieve the efficiency of raw (intact) polymers in recycled polymers. The best type of recycling to have maximum energy efficiency and minimum environmental consequences is mechanical recycling. However, there are a number of differences between virgin and recycled polymers. Due to the structural changes and the presence of impurities in the polymer, it is difficult to achieve a quality recycling. Whether the recycled polymer is suitable for obtaining new applications or not is measured by mechanical tests (such as tensile test, impact test), physical tests (such as hydraulic stability, surface roughness) and operational tests (extrusion and molding) under standard conditions. When these tests are performed, most recycled polymers do not meet the requirements required for various applications, unless we use additives that improve their properties. These additives may include coupling agents, impact improvers, metal deactivators, melt flow regulators, antioxidants, masterbatches, etc., and each is used in some way to improve specific properties of the polymers. Although the recycling of polymer products is beneficial for the environment and economy, the main goal is to achieve the efficiency of raw (intact) polymers in recycled polymers. Manuscript profile