Review
Polymer Science
Mohamad Hassan Akhras, Joerg Fischer
Summary: Given the rapid development of plastics recycling, there is a need for guidelines on sampling and material characterization. However, there is a scarcity of methods for proper material data acquisition. This paper reviews available sampling techniques for plastics recycling and proposes a sampling plan for pretreated rigid plastic waste based on selected information. The results show that stratified random sampling combined with composite sampling is a good technique for sampling rigid plastic waste.
Article
Engineering, Environmental
Daniele Battegazzore, Fulvia Cravero, Alberto Frache
Summary: The survey conducted in Italy at the end of 2020 found that disposable face masks were the most used by the population during the Covid-19 pandemic, leading to a considerable amount of waste. It was proposed to collect and recycle these masks separately to reduce costs and simplify the sanitization process. The recycled materials from the filtering face masks showed lower viscosity but comparable toughness, superior stiffness, and strength compared to the mixed polyolefin, providing potential for industrial recycling of plastic materials.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Crystallography
S. M. Nourin Sultana, Emna Helal, Giovanna Gutierrez, Eric David, Nima Moghimian, Nicole R. R. Demarquette
Summary: This study investigates the influence of adding few-layer graphene (FLG) on the processability and mechanical properties of mixed polyolefin waste stream. The presence of FLG reinforces the composites without hindering processability. The addition of FLG concentrations higher than 4 wt.% results in higher tensile and flexural properties while preserving impact strength.
Article
Chemistry, Multidisciplinary
Galahad O'Rourke, Margot Houbrechts, Marthe Nees, Martijn Roosen, Steven De Meester, Dirk De Vos
Summary: Recycling of multilayer packaging is challenging due to the heterogeneity of plastic types that can be comingled by chemical bonding with adhesives. This study investigated the delamination of polyamide/polyolefin multilayers, glued together by polyurethane, and introduces a highly selective separation method using glycolysis-depolymerization to target the PUR adhesive.
Review
Green & Sustainable Science & Technology
Hicham Amar, Mostafa Benzaazoua, Abdellatif Elghali, Rachid Hakkou, Yassine Taha
Summary: The demand for phosphate continues to grow, leading to the depletion of high-grade ore resources and necessitating the exploitation and beneficiation of low-grade phosphate ores and phosphate mine waste rock (PMWR). This review discusses the recent advances in beneficiation technologies for reprocessing PMWR, including sorting, flotation, gravity separation, ore sorting, magnetic, electrostatic, and thermal separation, and hydrometallurgical methods. The findings suggest that ore sorting, gravity separation, flotation, and calcination are suitable methods for recovering phosphate from PMWR.
JOURNAL OF CLEANER PRODUCTION
(2022)
Review
Chemistry, Physical
Zhongwen Dong, Wenjun Chen, Keqing Xu, Yue Liu, Jing Wu, Fan Zhang
Summary: Polyolefin plastics, the most widely used commodity plastics in the world, often end up in landfills or incineration, leading to ecological crises and resource waste. Chemical upcycling of polyolefin waste to fuels and chemicals through catalytic cracking and hydrocracking is considered effective, with zeolite catalysts playing a crucial role in the process. Matching acidity and pore structure of zeolite catalysts are important for target product formation in polyolefin cracking.
Review
Engineering, Environmental
Charlotte Abdy, Yuqing Zhang, Jiawei Wang, Yang Yang, Ignacio Artamendi, Bob Allen
Summary: This paper reviews the importance of pyrolysis technology in achieving plastic waste recycling goals, focusing on the pyrolysis process and products of polyolefin plastic waste. It also discusses the potential application of pyrolysis products as a binder material in hot mix asphalt and identifies future research trends.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Polymer Science
Erdal Karaagac, Mitchell P. Jones, Thomas Koch, Vasiliki-Maria Archodoulaki
Summary: Plastic recycling aims to balance functionality and mass producibility with environmental sustainability, but faces challenges with contamination and heterogeneous properties in recycled materials. This study investigated polypropylene (PP) contamination in post-consumer low-density polyethylene (PE-LD) and mixed polyolefin (PO) regranulates, finding that PP content affects mechanical properties and can be better estimated using FT-IR band ratios. Compatibilisation with ethylene-based olefin block copolymer showed promise in improving properties of recycled materials for higher quality regranulates.
Article
Polymer Science
Dong-Jun Kwon, Kang Rae Cho, Hyoung-Seock Seo
Summary: By using waste carbon fiber and polypropylene (PP), durable recycled composites with good moldability and dimensional stability can be manufactured.
Article
Materials Science, Multidisciplinary
Vincenzo Titone, Francesco Paolo La Mantia, Luigi Botta
Summary: This paper investigates the impact of reprocessing on the rheological and mechanical properties of a biocomposite. The results reveal that increasing the number of extrusions leads to a decrease in viscosity and molecular weight of the matrix and biocomposite. Additionally, the mechanical properties, such as tensile strength and elongation, decrease with the number of extrusions for the matrix, while the biocomposite shows a temporary increase in these properties after the first extrusion, followed by a slight decrease but still higher values compared to the virgin biocomposite.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Chemistry, Applied
Haoran Yuan, Chengyu Li, Rui Shan, Jun Zhang, Yufeng Wu, Yong Che
Summary: This review summarizes the recent advancements in catalytic pyrolysis of polyolefin plastics using various zeolite-based materials. It focuses on the production of aromatic hydrocarbons from zeolite-catalyzed polyolefin plastics pyrolysis and discusses the characteristics and distribution of the pyrolysis products. Additionally, it systematically discusses the deactivation mechanism of zeolites, coking inhibition, catalyst regeneration, and the influence of impurities. The challenge and outlook in the sustainable development of catalytic pyrolysis of polyolefin plastics into high-value products are also presented.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Thermodynamics
Leilei Dai, Nan Zhou, Yuancai Lv, Kirk Cobb, Yanling Cheng, Yunpu Wang, Yuhuan Liu, Paul Chen, Rongge Zou, Hanwu Lei, Roger Ruan
Summary: This study introduces a novel technology for converting waste polyolefinic plastics into low aromatic naphtha for new plastic production, showcasing the use of tandem catalysis process. The tandem catalysis system shows high activity in cracking various waste polyolefins, highlighting the feasibility of upcycling waste plastics into high quality naphtha for virgin plastic products.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Energy & Fuels
Yumeng Chen, Dian Zhang, Junguo Li, Changning Wu, Ke Liu
Summary: This study presents a case study on scavenging combustible matter in waste coal using a self-designed collector Ksw, consisting of kerosene, span, and water. The results showed that Ksw outperformed conventional collectors in terms of floatability and economic feasibility. The superior performance of Ksw was attributed not only to the oil droplet size and number but also to its specific composition features.
Review
Medicine, General & Internal
Max A. Schumm, Joseph E. Hadaya, Nisha Mody, Bethany A. Myers, Melinda Maggard-Gibbons
Summary: Ultraviolet germicidal irradiation, moist heat, and microwave-generated steam processing are effective methods for decontamination of filtering facepiece respirators, while vaporized hydrogen peroxide is a suitable alternative with longer decontamination durations and higher costs. Ethylene oxide, although effective, may leave toxic residues and is more difficult to implement.
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
(2021)
Article
Engineering, Environmental
Lugas Raka Adrianto, Stephan Pfister
Summary: This study investigates different reprocessing pathways for copper tailings to produce secondary metals and building materials. It finds that only when all co-products are utilized, reprocessing can offer environmental benefits, saving from 25 to 930 kg CO2-eq per tonne of treated copper tailings. Recommendations are proposed to enhance the environmental performance of mine tailings reprocessing strategies for sustainable development of the metal industry.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Green & Sustainable Science & Technology
Rajkishore Nayak, Shadi Houshyar, Asis Patnaik, Long T. Nguyen, Robert A. Shanks, Rajiv Padhye, Mac Fegusson
JOURNAL OF CLEANER PRODUCTION
(2020)
Article
Materials Science, Paper & Wood
M. A. Rahman Bhuiyan, Lijing Wang, Robert A. Shanks, Zinia Anjuman Ara, Tanushree Saha
Article
Polymer Science
Kok Peng Marcian Lee, Thomas Baum, Robert Shanks, Fugen Daver
Summary: The addition of graphene enhances the properties of polyamide-6 composite materials, while maintaining processability even at high graphene concentrations. SEM imaging shows the alignment of graphene in printed materials, and the inclusion of graphene improves the dielectric properties and EMI SE of the materials in compression molded and ME test specimens.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Polymer Science
Kok Peng Marcian Lee, Milan Brandt, Robert Shanks, Fugen Daver
Article
Construction & Building Technology
Feng Shi, Shi Yin, Thong M. Pham, Rabin Tuladhar, Hong Hao
Summary: By grafting hydrophilic groups and silane groups on PP fibers, this study successfully improved the bonding behavior between PP fibers and concrete, significantly enhancing pullout forces and energy absorption capacity. Silane-grafted PP fiber reinforced UHPC exhibited excellent toughness and flexural performance.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Shadi Houshyar, G. Sathish Kumar, Rajiv Padhye, Robert A. Shanks, Amitava Bhattacharyya
Summary: Preparation and characterization of nanodiamond dispersed polyamide-based filament were studied, showing enhanced thermomechanical properties and superior tensile strength and toughness. The incorporation of nanodiamond also resulted in higher thermal stability, delaying thermal degradation, making this composite material suitable for high performance applications.
Article
Engineering, Manufacturing
Kok Peng Marcian Lee, Thomas Baum, Robert Shanks, Fugen Daver
Summary: The thickness of the sample does not have a large impact on EMI SE, while internal geometric designs can significantly improve it. The electromagnetic response of 3D-printed GC is limited by geometric accuracy and printing methods, particularly in replicating complex geometries.
ADDITIVE MANUFACTURING
(2021)
Article
Green & Sustainable Science & Technology
Hannah Porter, Abhijit Mukherjee, Rabin Tuladhar, Navdeep Kaur Dhami
Summary: Research has shown that different metabolic pathways of Microbially Induced Calcium Carbonate Precipitation (MICP) have significantly different environmental impacts, and the sustainability of engineered MICP is directly influenced by the metabolic pathways of bacteria and the purity of input chemicals. Some biotic processes are superior to the current industrial process for manufacturing calcium carbonate if laboratory-grade purity ingredients are replaced by industrial-grade products, and introducing industry by-products as nutrients may yield a greater dividend.
Review
Construction & Building Technology
Aamar Danish, Mohammad Ali Mosaberpanah, Rabin Tuladhar, Muhammad Usama Salim, Muhammad Arslan Yaqub, Naveed Ahmad
Summary: The demand for cementitious materials has increased due to industrialization and urbanization, leading to environmental concerns. The use of industrial waste, like cenospheres, as construction materials offers economic and practical advantages. Recent studies have shown that cenospheres can be used as lightweight materials for structural cementitious materials. This article discusses the properties of cenospheres and their impact on the construction sector. The study concludes that incorporating cenospheres into cementitious materials leads to significant improvements in various aspects and can replace cement and fine aggregates without major detrimental effects on engineering properties.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Ibrahim M. H. Alshaikh, B. H. Abu Bakar, Emad A. H. Alwesabi, Aref A. Abadel, Hussam Alghamdi, Ali Altheeb, Rabin Tuladhar
Summary: The efficiency of combining partial replacements of fine aggregate with waste crumb rubber and steel fiber in enhancing the deformability and structural ductility of RC frames was investigated in this study. The tested steel fiber-reinforced rubberized concrete frames showed an enhanced structural ductility compared with conventional frames, but with a further increase in deflection.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Engineering, Geological
Gideon Gipmai Yowa, Nagaratnam Sivakugan, Rabin Tuladhar, Gabriel Arpa
Summary: This paper discusses the optimization of mix designs in cemented pastefill by replacing cement with supplementary cementitious materials. Laboratory tests showed that pitchstone fines can achieve comparable strength when replacing 10-20% of the cement. These findings are important for the mining and civil industries in waste disposal and reusing it as backfill or construction material.
INTERNATIONAL JOURNAL OF GEOSYNTHETICS AND GROUND ENGINEERING
(2022)
Article
Construction & Building Technology
M. Ramadan, Mohamed Kohail, Aref A. Abadel, Yousef R. Alharbi, Rabin Tuladhar, Alaa Mohsen
Summary: In this study, commercial titanium oxide (TiO2) was incorporated in a cement matrix containing dealuminated metakaolin (DAK), and the addition of 5% TiO2 had a significant effect on improving the mechanical performance and gamma-ray shielding ability of the material. The unique properties of TiO2, such as acting as a nano-filler and active seeds for further hydration products, contributed to the improved properties of the composite material.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Article
Engineering, Civil
Aref A. Abadel, Husain Abbas, Ibrahim M. H. Alshaikh, Khaled Sennah, Rabin Tuladhar, Ali Altheeb, Mohammed Alamri
Summary: This study experimentally demonstrates that ultra-high-performance fiber-reinforced concrete (UHPFC) deep beams strengthened with carbon fiber-reinforced polymer (CFRP) sheets can improve their shear strength after exposure to high temperatures. The test results show that the post-peak behavior is significantly influenced by elevated temperatures, and the strengthening schemes greatly enhance the post-cracking behavior, shear strength, energy-based ductility index, and deflection ductility index of UHPFC deep beams.
Article
Construction & Building Technology
Ibrahim M. H. Alshaikh, Aref A. Abadel, Khaled Sennah, Moncef L. Nehdi, Rabin Tuladhar, Mohammed Alamri
Summary: This paper utilizes finite element method to numerically simulate the effects of abnormal loads on reinforced concrete structures. Results show that slabs contribute significantly to load resistance, and rubberized concrete performs well in preventing progressive collapse.
Proceedings Paper
Computer Science, Artificial Intelligence
Madhumenon Krishnamenon, Rabin Tuladhar, Mostafa Rahimi Azghadi, Jeffrey G. Loughran, Govinda Pandey
Summary: Developing digital replicas of complex systems for decision making is a new concept across various subject domains. This paper reviews the history and characteristics of these replicas, exploring their suitability for life cycle decision making of engineered assets. Opportunities for future applications in prognostic decision making are still being discovered.
2021 INTERNATIONAL CONFERENCE ON MAINTENANCE AND INTELLIGENT ASSET MANAGEMENT (ICMIAM)
(2021)
