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Alvarado A, Baykara H, Riofrio A, Cornejo M, Merchan-Merchan W. Preparation, characterization, electrical conductivity, and life cycle assessment of carbon nanofibers-reinforced Ecuadorian natural zeolite-based geopolymer composites. Heliyon 2024; 10:e28079. [PMID: 38524539 PMCID: PMC10957430 DOI: 10.1016/j.heliyon.2024.e28079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 01/21/2024] [Accepted: 03/12/2024] [Indexed: 03/26/2024] Open
Abstract
Geopolymers are inorganic crosslinked polymers with much less carbon footprint than ordinary Portland cement. Geopolymers and geopolymer-based materials have superior mechanical and durability properties with extreme thermal and chemical resistance. Carbon nano- or microfibers-reinforced geopolymers show potential properties such as electric conductivity, enhanced mechanical and thermal stability, and multi-functionality. This study evaluated the effect of incorporating carbon nanofibers in natural zeolite-based geopolymers and their impact on the mechanical, thermal, and electric conductivity of yielded geopolymer composites. Additionally, a life cycle assessment for 1 m3 geopolymer and its carbon fiber reinforced geopolymers' production has been conducted to evaluate the environmental impact of the processes.
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Affiliation(s)
- Adriana Alvarado
- Bert S. Turner Dept. of Construction Management, Louisiana State University, Baton Rouge, LA, 70803, United States
| | - Haci Baykara
- Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica de Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil, Ecuador
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica de Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil, Ecuador
| | - Ariel Riofrio
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica de Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil, Ecuador
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, Hong Kong
| | - Mauricio Cornejo
- Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica de Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil, Ecuador
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica de Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil, Ecuador
| | - Wilson Merchan-Merchan
- School of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK, 73019, United States
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Cabrera D, Baykara H, Riofrio A, Cornejo M, Cáceres J. Preparation, characterization, and life cycle assessment of banana rachis-recycled high-density polyethylene composites. Sci Rep 2023; 13:16534. [PMID: 37783695 PMCID: PMC10545752 DOI: 10.1038/s41598-023-42613-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 09/12/2023] [Indexed: 10/04/2023] Open
Abstract
Agro-industrial wastes are sustainable resources that have advantages as a reinforcement for polymeric matrices. This study examined the use of banana rachis fiber (BRF) in reinforcing the recycled high-density polyethylene (rHDPE) matrix. For this purpose, polymer composites with 5-20 wt% of BRF were prepared by the extrusion process using a twin-screw extruder and followed a hot press method. The structure of rHDPE/BRF composites and their characteristic peaks of degradation were successfully identified by the Fourier-transformed infrared spectroscopy and thermogravimetric analysis techniques, respectively, revealing a good dispersion of BRF in rHDPE. Differential scanning calorimetry results of the composites demonstrated that melt enthalpy decreases as the amount of BRF increases. XRD diffractograms revealed a crystallinity reduction of rHDPE due to the increase of fiber within the polymer matrix, which is reflected in the characteristic peaks' intensity decrease of HDPE. Variation in thermal and chemical properties with the addition of BRF in rHDPE was successfully evaluated in this study. Life cycle assessment for 1 kg composite production has also been evaluated. The banana rachis-rHDPE composite materials reduce the overall environmental impacts when the filler concentration increases.
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Affiliation(s)
- Demis Cabrera
- Faculty of Mechanical Engineering and Production Science (FIMCP), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador
- Plastics Processing Laboratory (PPL), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador
| | - Haci Baykara
- Faculty of Mechanical Engineering and Production Science (FIMCP), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador.
- Nanotechnology Research and Development Center (CIDNA), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador.
| | - Ariel Riofrio
- Nanotechnology Research and Development Center (CIDNA), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador
| | - Mauricio Cornejo
- Faculty of Mechanical Engineering and Production Science (FIMCP), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador
- Nanotechnology Research and Development Center (CIDNA), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador
| | - Julio Cáceres
- Nanotechnology Research and Development Center (CIDNA), ESPOL Polytechnic University, P.O. Box 09-01-5863, Guayaquil, Ecuador
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Aigaje E, Riofrio A, Baykara H. Processing, Properties, Modifications, and Environmental Impact of Nanocellulose/Biopolymer Composites: A Review. Polymers (Basel) 2023; 15:polym15051219. [PMID: 36904460 PMCID: PMC10006885 DOI: 10.3390/polym15051219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
The increasing concerns about plastic pollution and climate change have encouraged research into bioderived and biodegradable materials. Much attention has been focused on nanocellulose due to its abundance, biodegradability, and excellent mechanical properties. Nanocellulose-based biocomposites are a viable option to fabricate functional and sustainable materials for important engineering applications. This review addresses the most recent advances in composites, with a particular focus on biopolymer matrices such as starch, chitosan, polylactic acid, and polyvinyl alcohol. Additionally, the effects of the processing methods, the influence of additives, and the outturn of nanocellulose surface modification on the biocomposite's properties are outlined in detail. Moreover, the change in the composites' morphological, mechanical, and other physiochemical properties due to reinforcement loading is reviewed. Further, mechanical strength, thermal resistance, and the oxygen-water vapor barrier properties are enhanced with the incorporation of nanocellulose into biopolymer matrices. Furthermore, the life cycle assessment of nanocellulose and composites were considered to analyze their environmental profile. The sustainability of this alternative material is compared through different preparation routes and options.
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Affiliation(s)
- Elizabeth Aigaje
- Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo, Km 30.5 Vía Perimetral, Guayaquil 090506, Ecuador
- Correspondence: (E.A.); (H.B.)
| | - Ariel Riofrio
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo, Km 30.5 Vía Perimetral, Guayaquil 090506, Ecuador
| | - Haci Baykara
- Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo, Km 30.5 Vía Perimetral, Guayaquil 090506, Ecuador
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo, Km 30.5 Vía Perimetral, Guayaquil 090506, Ecuador
- Correspondence: (E.A.); (H.B.)
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Garcia-Troncoso N, Acosta-Calderon S, Flores-Rada J, Baykara H, Cornejo MH, Riofrio A, Vargas-Moreno K. Effects of Recycled Rubber Particles Incorporated as Partial Sand Replacement on Fresh and Hardened Properties of Cement-Based Concrete: Mechanical, Microstructural and Life Cycle Analyses. Materials (Basel) 2022; 16:63. [PMID: 36614401 PMCID: PMC9821007 DOI: 10.3390/ma16010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Cement is one of the most valuable materials in today's society, as it is used in most construction developments known to mankind. However, the energy intensive process and significant environmental impacts related to the production of Ordinary Portland Cement have shown the importance of searching for more sustainable materials. Concrete uses different aggregates added to the cement binder to lower, not only cost, but other factors like environmental burden, while maintaining good mechanical properties. This study analyzes the properties of fresh and hardened concrete incorporating recycled rubber to replace fine aggregate. Locally sourced 2 mm diameter rubber was incorporated in a regular strength concrete matrix into three different replacement levels, i.e., 3%, 5%, and 10%. Compression, tensile, flexural, and modulus of elasticity of hardened concrete were carried out in specimens aged 7, 14, and 28 days. In addition, non-destructive ultrasonic pulse velocity and rebound number tests were only performed on specimens aged 28 days. Once the tests were carried out, the fresh and hardened concrete properties were obtained. Similarly, the compressive and flexural strengths had the exact relationship between the values obtained. On the other hand, the modulus of elasticity tends to decrease due to the presence of the rubber. Consequently, it is recommended not to develop mix designs with more than 5% rubber because it is not meaningfully affected. The fine aggregate can be partially replaced by the rubber, keeping almost the same performance compared with sand-only counterparts. In addition, the life cycle assessment showed a reduction of up to 40% in the global warming potential. In fact, the 15% recycled rubber concrete mix has a climate change indicator of approximately 245 kg of CO2 eq.
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Affiliation(s)
- Natividad Garcia-Troncoso
- Facultad de Ingeniería en Ciencias de la Tierra (FICT), Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil P.O. Box 09-01-5863, Ecuador
| | - Samantha Acosta-Calderon
- Facultad de Ingeniería en Ciencias de la Tierra (FICT), Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil P.O. Box 09-01-5863, Ecuador
| | - Jorge Flores-Rada
- Centro de Innovación Holcim, Holcim Ecuador S.A., Guayaquil 090616, Ecuador
| | - Haci Baykara
- Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil 090112, Ecuador
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil 090506, Ecuador
| | - Mauricio H. Cornejo
- Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil 090112, Ecuador
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil 090506, Ecuador
| | - Ariel Riofrio
- Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil 090112, Ecuador
- Center of Nanotechnology Research and Development (CIDNA), Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía Perimetral, Guayaquil 090506, Ecuador
| | - Katherine Vargas-Moreno
- Escuela de Ingeniería Civil, Universidad Espíritu Santo (UEES), Samborondón P.O. Box 09-01-952, Ecuador
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Riofrio A, Baykara H. Techno‐environmental and life cycle assessment of ‘oat‐milk’ production in Ecuador: A cradle‐to‐retail life cycle assessment. Int J Food Sci Technol 2022. [DOI: 10.1111/ijfs.15828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ariel Riofrio
- Facultad de Ingeniería Mecánica y Ciencias de la Producción Escuela Superior Politécnica del Litoral ESPOL Campus Gustavo Galindo Km 30.5 Vía Perimetral Guayaquil Ecuador
- Center of Nanotechnology Research and Development (CIDNA) Escuela Superior Politécnica del Litoral ESPOL Campus Gustavo Galindo Km 30.5 Vía Perimetral Guayaquil Ecuador
| | - Haci Baykara
- Facultad de Ingeniería Mecánica y Ciencias de la Producción Escuela Superior Politécnica del Litoral ESPOL Campus Gustavo Galindo Km 30.5 Vía Perimetral Guayaquil Ecuador
- Center of Nanotechnology Research and Development (CIDNA) Escuela Superior Politécnica del Litoral ESPOL Campus Gustavo Galindo Km 30.5 Vía Perimetral Guayaquil Ecuador
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Riofrio A, Alcivar T, Baykara H. Environmental and Economic Viability of Chitosan Production in Guayas-Ecuador: A Robust Investment and Life Cycle Analysis. ACS Omega 2021; 6:23038-23051. [PMID: 34549104 PMCID: PMC8444200 DOI: 10.1021/acsomega.1c01672] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/24/2021] [Indexed: 06/01/2023]
Abstract
Ecuador is a country where shrimp production is one of its primary industries. It generates annually about 72,000 tons of wastes in the form of shrimp shells. Therefore, using this waste as a raw material resource to produce chitosan, a biopolymer, is established. An environmental and economic performance study is carried out as a possible investment report, where a conceptual design of the process is defined and a financial viability report is obtained. An environmental impact report establishes the degree of harm to the environment. The economic viability study considered costs related to capital and operation to process 5000 tons of shrimp shells each year. On the other hand, a life cycle assessment was performed to obtain the environmental impact for 1 kg of chitosan produce, where a cradle-to-gate approach was established. Results showed that this new industry has a net present value of 10.38 million USD, a rate of return of 67.31%, and a payback period of 3.13 years. Additionally, it was calculated that the environmental impact with a higher normalized value was the human noncarcinogenic toxicity. It is concluded that the production of chitosan in Guayas-Ecuador is economically viable and cost-competitive in the market, and it represents an industrial activity with no considerable environmental impacts.
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Affiliation(s)
- Ariel Riofrio
- Chemical
Engineering Department, Facultad de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía
Perimetral, Guayaquil, 090112 Ecuador
- Facultad
de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía
Perimetral, Guayaquil, 090112 Ecuador
| | - Tania Alcivar
- Chemical
Engineering Department, Facultad de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía
Perimetral, Guayaquil, 090112 Ecuador
| | - Haci Baykara
- Facultad
de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo Km 30.5 Vía
Perimetral, Guayaquil, 090112 Ecuador
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Hoang JK, Riofrio A, Bashir MR, Kranz PG, Eastwood JD. High variability in radiologists' reporting practices for incidental thyroid nodules detected on CT and MRI. AJNR Am J Neuroradiol 2014; 35:1190-4. [PMID: 24407274 DOI: 10.3174/ajnr.a3834] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE There are no guidelines for reporting incidental thyroid nodules seen on CT and MR imaging. We evaluated radiologists' current reporting practices for incidental thyroid nodules detected on these imaging modalities. MATERIALS AND METHODS Radiologists were surveyed regarding their reporting practices by using 14 scenarios of incidental thyroid nodules differing in size, patient demographics, and clinical history. Scenarios were evaluated for the following: 1) radiologists' most commonly selected response, and 2) the proportion of radiologists selecting that response (degree of agreement). These measures were used to determine how the patient scenario and characteristics of the radiologists affected variability in practice. RESULTS One hundred fifty-three radiologists participated. In 8/14 scenarios, the most common response was to "recommend sonography." For the other scenarios, the most common response was to "report in only body of report." The overall mean agreement for the 14 scenarios was 53%, and agreement ranged from 36% to 75%. Smaller nodules had lower agreement: 43%-51% for 8-mm nodules compared with 64%-75% for 15-mm nodules. Agreement was poorest for the 10-mm nodule in a 60-year-old woman (36%) and for scenarios with additional history of lung cancer (39%) and multiple nodules (36%). There was no significant difference in reporting practices and agreement when radiologists were categorized by years of practice, practice type, and subspecialty (P > .55). CONCLUSIONS The reporting practice for incidental thyroid nodules on CT or MR imaging is highly variable among radiologists, especially for patients with smaller nodules (≤10 mm) and patients with multiple nodules and a history of cancer. This variability highlights the need for practice guidelines.
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Affiliation(s)
- J K Hoang
- From the Departments of Radiology, Division of Neuroradiology (J.K.H., A.R., P.G.K., J.D.E.)Radiation Oncology (J.K.H.), Duke University Medical Center, Durham North Carolina.
| | - A Riofrio
- From the Departments of Radiology, Division of Neuroradiology (J.K.H., A.R., P.G.K., J.D.E.)
| | | | - P G Kranz
- From the Departments of Radiology, Division of Neuroradiology (J.K.H., A.R., P.G.K., J.D.E.)
| | - J D Eastwood
- From the Departments of Radiology, Division of Neuroradiology (J.K.H., A.R., P.G.K., J.D.E.)
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Escobar E, Riofrio A. [Left ventricular function in pure mitral stenosis]. Rev Med Chil 1974; 102:413-6. [PMID: 4471407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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