angel Roco

Dr. angel Roco


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 March 2023 in Sustainability
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Journal Article
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HJHERBERT SINDUJA Joseph
HERBERT SINDUJA Joseph
TPThamilselvi Pachiappan
Thamilselvi Pachiappan
ASAvudaiappan Siva
Avudaiappan Siva
Nelson MaureiraNelson Maureira
Nelson Maureira
ARangel Roco
angel Roco
Pablo Fernando ParraPablo Fernando Parra
Pablo Fernando Parra
There have been efforts to use building demolition waste as an alternative aggregate in concrete to decrease the use of natural resources for construction. The World Green Building Council estimates that the construction industry is responsible for more than 50% of all material extracted globally and that construction and demolition waste makes up 35% of global landfills. As a result, incorporating recycled aggregate (RA) in concrete production is a prudent course of action to reduce the environmental impact. This study reviews prior research on using recycled aggregate instead of conventional ingredients in concrete. The composition and morphology of different types of RA, the behavior of RA in fresh and hardened states, keyword co-occurrence and evolution analysis, and the various additives used to enhance the inferior properties of RA are discussed. The RA showed different physical properties when compared with natural aggregate. However, the addition of pozzolanic materials and various pretreatment techniques is desirable for improving the inferior properties of RA. While building waste has been utilized as a substitute for fine and coarse aggregate, prior research has demonstrated that a modified mixing approach, an adequate mixing proportion, and the optimum replacement of cementitious materials are necessary. Based on the review, the recommendation is to use RA at a replacement level of up to 30% and the addition of precoated and pozzolanic materials as a treatment to provide concrete with adequate workability, strength, and durability for structural applications.

6 April 2023 in Polymers
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Journal Article
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SKS. Anne Kavitha
S. Anne Kavitha
RPR. Krishna Priya
R. Krishna Priya
Krishna Prakash ArunachalamKrishna Prakash Arunachalam
Krishna Prakash Arunachalam
SASiva Avudaiappan
Siva Avudaiappan
Nelson MaureiraNelson Maureira
Nelson Maureira
ARangel Roco
angel Roco
Today, new materials based on natural fibres have been emerging day by day to completely eradicate plastics to favour our environmental nature. In this view, the present work is based on the extraction and characterisation of the novel root fibres of the Zea mays (Zm) plant, grown by the hydroponic method. Both the dried untreated and alkali treated root fibres are investigated using a variety of structural, morphological, thermal, elemental and mechanical tests by subjecting both the samples to p-XRD, FT-IR, SEM-EDAX, TGA-DTA, CHNS and tensile strength analyses. Thermal conductivity of the untreated and treated fibres is found using Lee’s disc experiment. From p-XRD analysis, the Crystallinity Index, Percentage Crystallinity and Crystallite size of the samples are found. FT-IR studies clarify the different vibrational groups associated with the fibre samples. SEM images show that the surface roughness increases for the chemically treated samples, such that it may be effectively utilised as reinforcement for polymeric composites. The diameter of the fibre samples is found using SEM analysis. According to the EDAX spectrum, Zm fibres in both their raw and processed forms have high levels of Carbon (C) and Oxygen (O). The TGA-DTA tests revealed that the samples of natural fibre have good thermal characteristics. CHNS studies show that Carbon content is high for these samples, which is the characteristic of many natural fibres. Chemical analysis is used to ascertain the prepared samples’ chemical makeup. It reveals that both samples have significant amounts of cellulose. The density of the fibres is found to be in the range 0.3–0.6 g/cc, which is much less than any other natural fibre. Therefore, it can be used in light weight applications. From the tensile strength analysis, physical properties such as Young’s modulus and micro-fibril angle are determined. The fibres in the roots exhibit a lower tensile strength. Thus, these fibres can be used in powdered form as reinforcement for natural rubber or epoxy composites. After examining all of its properties, it could be reasonably speculated that Zea mays root fibres can be considered as an efficient reinforcement for various matrices to produce attractive bio-composites.

4 June 2021 in Engineering with Computers
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JGJianli Guo
Jianli Guo
ABAbdolrahim Baharvand
Abdolrahim Baharvand
DTDiana Tazeddinova
Diana Tazeddinova
MHMostafa Habibi
Mostafa Habibi
HSHamed Safarpour
Hamed Safarpour
OBOmrane Benjeddou
Omrane Benjeddou

23 April 2023 in Polymers
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KSKasirajan Rajam Jaya Sheeba
Kasirajan Rajam Jaya Sheeba
RPR. Krishna Priya
R. Krishna Priya
Krishna Prakash ArunachalamKrishna Prakash Arunachalam
Krishna Prakash Arunachalam
ASAvudaiappan Siva
Avudaiappan Siva
Nelson MaureiraNelson Maureira
Nelson Maureira
ARangel Roco
angel Roco
The present study concerns the physico-chemical, structural, mechanical and thermal characterization of Acacia pennata, a natural and almost inexpensive fibre, as a potential reinforcement in polymer composites. The effect of treating the fibre with sodium acetate to increase its qualities has been seen through the use of thermogravimetric analysis, scanning electron microscope (SEM) analysis, X-ray diffraction (XRD), mechanical property tester, and Fourier transform infrared spectroscopy (FTIR). According to XRD analysis, the elimination of lignin and wax-like impurities resulted in an increase in the AP fibre’s crystalline index (79.73%). The fibre’s thermal stability was also discovered to be 365 °C. Tensile strength (557.58 MPa) and elongation at break both increased by 2.9% after treatment with sodium acetate. The surface nature and quality of AP fibres improved after sodium acetate treatment. It was confirmed by the reduction of chemical compositions (such as hemicellulose, lignin and pectin). Given its density, the fibre can be suggested as a reinforcement in polymer composites for light-weight applications because its lightweight property will be more useful for composite manufacturing.

11 August 2023 in Medicina
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Journal Article
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ARangel Roco
angel Roco
CVClaudio Villota
Claudio Villota
CPCarolina Pino-Astorga
Carolina Pino-Astorga
DMDaniela Mendoza-Puga
Daniela Mendoza-Puga
MBMauricio Bittner-Ortega
Mauricio Bittner-Ortega
TCTatiana Corbeaux-Ascui
Tatiana Corbeaux-Ascui
Ulcerative colitis is an inflammatory disease that affects the colon, generating a crisis period associated with diarrhea and ulcerations. Stress plays a pivotal role in modulating the inflammatory response and aggravating progression. Different studies have shown that fasting reduces inflammation markers, and intermittent fasting decreases inflammatory markers such as IL-2, IL-6, and RCP. Goal: To evaluate the impact of intermittent fasting on a patient diagnosed with ulcerative colitis. A female patient underwent intermittent fasting (10/14) for eight weeks. Clinical tests were performed for blood count, RCP, biochemical profile, glycemia, and T4/TSH levels. Fecal calprotectin was determined. Clinical exams were assessed before and after intermittent fasting. Inflammation markers, such as CRP and calprotectin, were significantly reduced after eight weeks of intermittent fasting. The patient reported feeling better and was seizure-free during the following months when she continued fasting intermittently. Intermittent fasting allowed for a reduction in inflammation markers.

6 October 2022 in Sustainability
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SASIVAKUMAR ABURPA AVANACHARI
SIVAKUMAR ABURPA AVANACHARI
CCCristian Canales
Cristian Canales
ARangel Roco
angel Roco
MCManuel Chavez-Delgado
Manuel Chavez-Delgado
Growing environmental concerns have heightened interest in the development of environmentally friendly materials. The purpose of this study is to evaluate how the mechanical and thermal properties of thermoplastic cassava starch (TPCS) are affected by the presence of banana leaf fibre (BLF). By incorporating between 10% and 80% by weight of banana leaf fibre into the TPCS matrix, the biocomposites were created. The thermal and mechanical parameters of the samples were determined. The results revealed that the material’s flexural and tensile characteristics improved significantly, with 50% BLF content in the matrix achieving the highest strength of 20.86 MPa, a flexural strength of 32 MPa, and tensile modulus values. Thermogravimetric examination observed that the addition of BLF improved the material’s thermal stability. The Scanning Electron Microscopy (SEM) morphological tests demonstrated an even spread of banana leaf fibre and a matrix with strong adhesion, which improved the mechanical properties of the biocomposites. The Fourier Transform Infrared Spectroscopy (FT-IR) testing, which confirmed the biocomposite presence of O-H bonds, also confirmed the strong intermolecular hydrogen bonding between TPCS and banana leaf fibre.