Green Plasticizer for Poly(vinyl chloride) Re-Granulate Production: Case Study of Sustainability Concept Implementation

The increase in waste polymer recycling has helped in promoting sustainability, and together with the use of renewable raw materials, it has become a widespread concept with positive effects on both the economy and ecology. Accordingly, the aim of this study was the synthesis of “green” plasticizers, marked as LA/PG/PET/EG/LA, formed from waste poly(ethylene terephthalate) (PET) and bio-based platform chemicals propylene glycol (PG) and levulinic acid (LA). The structure of the obtained plasticizers was complex, as confirmed by results from nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) analysis. The LA/PG/PET/EG/LA plasticizers and waste poly(vinyl chloride) (PVC) were used in an optimized technology for PVC re-granulate production. The hardness of the PVC-based material with “green” plasticizers, in comparison to commercial plasticizer dioctyl terephthalate (DOTP), increased by 11.3%, while migration decreased. An improved material homogeneity and wettability of the fibers by the matrix were observed using SEM analysis of the material’s fracture surface, with a higher efficiency of intermolecular interactions leading to better mechanical performances of the newly designed materials. Thus, LA/PG/PET/EG/LA are unique materials with good compounding and plasticizing potential for PVC, as revealed by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). In that manner, the use of bio-renewable resources and recycled polymers will contribute to diminishing waste polymer generation, contributing to a lower carbon footprint

Web application security analysis using the Kali Linux operating system / Анализ безопасности веб-приложений оперционной системой Kali Linux / Analiza bezbednosti web aplikacija operativnim sistemom Kali Linux

The Kali Linux operating system is described as well as its purpose and possibilities. There are listed groups of tools that Kali Linux has together with the methods of their functioning, as well as a possibility to install and use tools that are not an integral part of Kali. The final part shows a practical testing of web applications using the tools from the Kali Linux operating system. The paper thus shows a part of the possibilities of this operating system in analysing web applications security, which presents the goal of this work. / В статье дается описание операционной системы Kali Linux, включая цели и возможности ее использования. Приведен список инструментов системы Kali Linux, способ работы ее конкретных инструментов, а также возможность установки и использования инструментов, которые не являются частью операционной системы Kali Linux. В заключительной части статьи, наглядно представлено тестирование веб-приложений с применением инструментов операционной системы Linux Кали. Таким образом, представлена часть возможностей Кали Linux операционной системы, применяемой для анализа безопасности веб-приложений, что являлось целью данной работы. / U radu je opisan operativni sistem Kali Linux , njegove namene i mogućnosti. Navedene su grupe alata kojima Kali Linux raspolaže, način rada određenih alata koje ovaj sistem sadrži, kao i mogućnost instalacije i korišćenja alata koji nisu njegov sastavni deo. U završnom delu rada praktično je prikazano testiranje web aplikacija korišćenjem alata iz operativnog sistema Kali Linux. Time je prikazan deo mogućnosti ovog operativnog sistema u analizi bezbednosti web aplikacija, što predstavlja cilj ovog rada