Velazquez, Sergio
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Preferred name
Velazquez, Sergio
Official Name
Velázquez Rodríguez, Sergio
Alternative Name
svelazqu
Main Affiliation
ORCID
Scopus Author ID
56177465000
Researcher ID
R-6947-2018

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Spent fluid catalytic cracking catalyst for improving early strength of portland cement

2014-01-01 , Velazquez, Sergio , Borrachero, María V. , Monzó, José M. , Payá, Jordi , Vunda, Christian , Soriano, Lourdes

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Pozzolanic reaction rate of fluid catalytic cracking catalyst residue (FC3R) in cement pastes

2013 , Payá, Jordi , Monzó, José M. , Borrachero, María V. , Velazquez, Sergio

Fluid catalytic cracking catalyst residue (FC3R) is a waste material generated in the petroleum industry. Previous research has shown that FC3R exhibits excellent pozzolanic properties in Portland cement mixtures. The pozzolanic activity of FC3R was studied by means of thermogravimetric analysis (measurement of lime fixation) and cold hydrochloric acid treatment (quantification of FC3R reacted). A water/binder ratio of 0·40 was used in the study in the preparation of a control paste (without spent catalyst) and a 15% substituted FC3R paste. The selected curing temperatures were 20 and 40°C and several curing times were tested. The amount (grammes) of fixed lime by gramme of reacted catalyst indicated that approximately one part lime is chemically combined with 2·3 parts of spent catalyst. The combination of both study techniques allows determination of the optimal dosage in order to maximise use of this excellent pozzolan.

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Assessment of Pozzolanic Activity Using Methods Based on the Measurement of Electrical Conductivity of Suspensions of Portland Cement and Pozzolan

2014 , Velazquez, Sergio , José Monzó , María Borrachero , Jordi Payá

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A thermogravimetric study of the pozzolanic reactions in mixtures containing fluidized catalytic cracking catalyst, fly ash, cement and water

2004 , Velazquez, Sergio

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Housing and quality of life. Measuring the social habitat in western Mexico

2014-01-01 , Hernández, Gustavo , Velazquez, Sergio

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Chemical activation of pozzolanic reaction of fluid catalytic cracking catalyst residue (FC3R) in lime pastes: thermal analysis

2004 , J. Paya , J. Monzo , M. V. Borrachero , Velazquez, Sergio

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Evaluation of nutrients removal (NO3-N, NH3-N and PO4-P) with Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and a consortium of these microorganisms in the treatment of wastewater effluents

2017 , Abril Gómez-Guzmán , Sergio Jiménez-Magaña , A. Suggey Guerra-Rentería , César Gómez-Hermosillo , F. Javier Parra-Rodríguez , Velazquez, Sergio , Blanca Rosa Aguilar-Uscanga , Josue Solis-Pacheco , Orfil González-Reynoso

In this research removal of NH3-N, NO3-N and PO4-P nutrients from municipal wastewater was studied, using Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and an artificial consortium of them. The objective is to analyze the performance of these microorganisms and their consortium, which has not been previously studied for nutrient removal in municipal wastewater. A model wastewater was prepared simulating the physicochemical characteristics found at the wastewater plant in Chapala, Mexico. Experiments were carried out without adding an external carbon source. Results indicate that nutrient removal with Chlorella vulgaris was the most efficient with a removal of 24.03% of NO3-N, 80.62% of NH3-N and 4.30% of PO4-P. With Bacillus cereus the results were 8.40% of NO3-N, 28.80% of NH3-N and 3.80% of PO4-P. The removals with Pseudomonas putida were 2.50% of NO3-N, 41.80 of NH3-N and 4.30% of PO4-P. The consortium of Chlorella vulgaris–Bacillus cereus–Pseudomonas putida removed 29.40% of NO3-N, 4.2% of NH3-N and 8.4% of PO4-P. The highest biomass production was with Bacillus cereus (450 mg/l) followed by Pseudomonas putida (444 mg/l), the consortium (205 mg/l) and Chlorella vulgaris (88.9 mg/l). This study highlights the utility of these microorganisms for nutrient removal in wastewater treatments.

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Cement equivalence factor evaluations for fluid catalytic cracking catalyst residue

2013 , J. Payá , J. Monzó , M.V. Borrachero , Velazquez, Sergio

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Determination of the pozzolanic activity of fluid catalytic cracking residue. Thermogravimetric analysis studies on FC3R–lime pastes

2003 , J. Payá , J. Monzó , M.V. Borrachero , Velazquez, Sergio , M. Bonilla

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Monomer chain cross‐transfer constants and cross termination factor evaluations on styrene‐acrylonitrile copolymerization

1995 , E. Mendizabal , Velazquez, Sergio , V. Gonzalez , C. F. Jasso

Using low conversion bulk copolymerization experimental data and the apparent rate constant model, the monomer chain cross‐transfer rate constants and the cross‐termination coefficient were evaluated. It was found that the dependence of the cross‐termination coefficient on composition is a function of initiator efficiency and that monomer chain cross‐transfer rate constant are relevant for the theoretical estimation of the molecular weights and molecular weight distributions.

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