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Papers by Luis Alberto Valencia Amador

The purpose of this study was to perform for the first time a sampling in Forest Protector Cerro ... more The purpose of this study was to perform for the first time a sampling in Forest Protector Cerro Prosperina de Guayaquil to determine the presence of Ceratophrys stolzmanni , also known as Pacific Horned Frog. The samples were taken during the wet season. The observation carried increased the distributional range of this species within the Chongon Colonche Mountain range and added a new locality in the Guayas province as a new habitat area. Also the altitude range is extensive already C. stolzmanni was registered in Prosperina the forest guard to about 130 meters above sea level, since these places remain damp for a longer time.

The International Journal of the Constructed Environment, 2013

ABSTRACT

The objective of this research is to study the impact of climate change on the hazardous weather-... more The objective of this research is to study the impact of climate change on the hazardous weather-related road accidents. The New Brunswick province of Canada is considered as a case study. The study uses road accident data collected from police accident reports for the period of 1997-2007. The climate change modeling uses thirty-year weather records of seven climate zones of New Brunswick, National Centers for Environmental Prediction (NCEP) re-analysis dataset, and large-scale simulation data from the Canadian Global Circulation Model, General Climate Model, and Coupled Global Climate Model (CGCM3). The large-scale simulation data from CGCM under SRES-A2 scenario during 21st century are used to model the climate in the future. This study develops an Exposure to Weather-Accident Severity (EWAS) index and estimate the relationship between EWAS index and weather-related explanatory variables of road accidents by applying negative binomial regression and Poisson regression models. The regression models find out that surface-weather condition, weather-driver's gender, weather-driver's age, weather-driver's experience and weather-vehicle's age have strong positive correlation with EWAS index. The surface-road alignment and surface-road characteristics have negative relationship with EWAS index. The spatial pattern of EWAS index with respect to weather-related explanatory variables is examined for the fifteen census divisions of New Brunswick province, which derives similar relationships. The climate change modeling estimates that the number of rainy days may increase in all climate zones and the number of snowy days and freezing days may decrease or stay the same in most of the climate zones during three 30-year periods of 21 st century (i.e. 2011-2040, 2041-2070, 2071-2100). The findings of this study imply that more hazardous weather in future will result in increased accident severity.

Actas: XVI CEDYA …, 1999

... por Gabriel Winter Althaus, Rafael Alejandro Montenegro Armas, Gustavo Montero García, Vol. 2... more ... por Gabriel Winter Althaus, Rafael Alejandro Montenegro Armas, Gustavo Montero García, Vol. 2, 1999, ISBN 84-95286-18-1 , págs. 861-868; Recoge los contenidos presentados a: Congreso de Ecuaciones Diferenciales y Aplicaciones (16. 1999. Las Palmas de Gran Canaria) ...

Cambio industrial y …, 1995

Información del artículo Política industria y desarrollo regional.

Journal of Materials Chemistry A, 2018

This article proposes a strategy to prepare membranes that combine the network characteristics of... more This article proposes a strategy to prepare membranes that combine the network characteristics of micro/nanocellulose with grafted zwitterionic PCysMA to develop fully bio-based membranes with antifouling properties.

ACS Applied Materials & Interfaces, 2019

RSC Advances, 2020

In this work, we explore the statistical copolymerization of 1,3-butadiene with the terpenic mono... more In this work, we explore the statistical copolymerization of 1,3-butadiene with the terpenic monomers myrcene and farnesene, carried out via coordination polymerization using a neodymium-based ternary catalytic system.

Molecules, 2021

Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based d... more Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based diphenylmethyl as R groups. The utilization of this CTA in the Reversible Addition-Fragmentation chain Transfer (RAFT) process reveals an efficient control in the polymerization of methacrylic monomers and the preparation of block copolymers. The latter are obtained by the (co)polymerization of styrene or butyl acrylate using a functionalized macro-CTA polymethyl methacrylate (PMMA) previously synthesized. Data show low molecular weight dispersity values (Đ < 1.5) particularly in the polymerization of methacrylic monomers. Considering a typical RAFT mechanism, the leaving groups (R) from the fragmentation of CTA should be able to re-initiate the polymerization (formation of growth chains) allowing an efficient control of the process. Nevertheless, in the case of the polymerization of MMA in the presence of this symmetrical CTA, the polymerization process displays an atypical behavior t...

After 40 years of the discovery of metallocene catalysts, there are still several aspects that re... more After 40 years of the discovery of metallocene catalysts, there are still several aspects that remain unresolved, especially when the “conventional” alkylaluminum activators are not used. Herein, we systematically investigate the synthesis of PE via three different zirconocene catalysts, with different alkyl substituents, activated via different organoboron compounds. The polymerization behavior, as well as the properties of the materials, are evaluated. The results demonstrate that the highest catalytic activity is shown by Bis(cyclopentadienyl)dimethylzirconium activated by trityl tetra(pentafluorophenyl)borate. Also finding that toluene is the optimum solvent for these systems and at these reaction conditions. Moreover, to validate our experimental results, a comprehensive mathematical model is developed on the basis of thermodynamic and kinetic principles. The concentration of ethylene transferred to the solvent phase (toluene) in a liquid-vapor equilibrium (LVE) system is estim...

RSC Advances, 2020

This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or... more This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or polymyrcene, reinforced with surface-modified graphene oxide (GO).

RSC Advances, 2020

This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or... more This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or polymyrcene, reinforced with surface-modified graphene oxide (GO).

ACS Applied Polymer Materials, 2020

Energy & Fuels, 2020

A preliminary enhanced oil recovery (EOR) screening was completed for the Ben Nevis Formation, He... more A preliminary enhanced oil recovery (EOR) screening was completed for the Ben Nevis Formation, Hebron Field, offshore Canada. Polymer flooding was determined to be the most viable methodology based...

The purpose of this study was to perform for the first time a sampling in Forest Protector Cerro ... more The purpose of this study was to perform for the first time a sampling in Forest Protector Cerro Prosperina de Guayaquil to determine the presence of Ceratophrys stolzmanni , also known as Pacific Horned Frog. The samples were taken during the wet season. The observation carried increased the distributional range of this species within the Chongon Colonche Mountain range and added a new locality in the Guayas province as a new habitat area. Also the altitude range is extensive already C. stolzmanni was registered in Prosperina the forest guard to about 130 meters above sea level, since these places remain damp for a longer time.

The International Journal of the Constructed Environment, 2013

ABSTRACT

The objective of this research is to study the impact of climate change on the hazardous weather-... more The objective of this research is to study the impact of climate change on the hazardous weather-related road accidents. The New Brunswick province of Canada is considered as a case study. The study uses road accident data collected from police accident reports for the period of 1997-2007. The climate change modeling uses thirty-year weather records of seven climate zones of New Brunswick, National Centers for Environmental Prediction (NCEP) re-analysis dataset, and large-scale simulation data from the Canadian Global Circulation Model, General Climate Model, and Coupled Global Climate Model (CGCM3). The large-scale simulation data from CGCM under SRES-A2 scenario during 21st century are used to model the climate in the future. This study develops an Exposure to Weather-Accident Severity (EWAS) index and estimate the relationship between EWAS index and weather-related explanatory variables of road accidents by applying negative binomial regression and Poisson regression models. The regression models find out that surface-weather condition, weather-driver's gender, weather-driver's age, weather-driver's experience and weather-vehicle's age have strong positive correlation with EWAS index. The surface-road alignment and surface-road characteristics have negative relationship with EWAS index. The spatial pattern of EWAS index with respect to weather-related explanatory variables is examined for the fifteen census divisions of New Brunswick province, which derives similar relationships. The climate change modeling estimates that the number of rainy days may increase in all climate zones and the number of snowy days and freezing days may decrease or stay the same in most of the climate zones during three 30-year periods of 21 st century (i.e. 2011-2040, 2041-2070, 2071-2100). The findings of this study imply that more hazardous weather in future will result in increased accident severity.

Actas: XVI CEDYA …, 1999

... por Gabriel Winter Althaus, Rafael Alejandro Montenegro Armas, Gustavo Montero García, Vol. 2... more ... por Gabriel Winter Althaus, Rafael Alejandro Montenegro Armas, Gustavo Montero García, Vol. 2, 1999, ISBN 84-95286-18-1 , págs. 861-868; Recoge los contenidos presentados a: Congreso de Ecuaciones Diferenciales y Aplicaciones (16. 1999. Las Palmas de Gran Canaria) ...

Cambio industrial y …, 1995

Información del artículo Política industria y desarrollo regional.

Journal of Materials Chemistry A, 2018

This article proposes a strategy to prepare membranes that combine the network characteristics of... more This article proposes a strategy to prepare membranes that combine the network characteristics of micro/nanocellulose with grafted zwitterionic PCysMA to develop fully bio-based membranes with antifouling properties.

ACS Applied Materials & Interfaces, 2019

RSC Advances, 2020

In this work, we explore the statistical copolymerization of 1,3-butadiene with the terpenic mono... more In this work, we explore the statistical copolymerization of 1,3-butadiene with the terpenic monomers myrcene and farnesene, carried out via coordination polymerization using a neodymium-based ternary catalytic system.

Molecules, 2021

Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based d... more Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based diphenylmethyl as R groups. The utilization of this CTA in the Reversible Addition-Fragmentation chain Transfer (RAFT) process reveals an efficient control in the polymerization of methacrylic monomers and the preparation of block copolymers. The latter are obtained by the (co)polymerization of styrene or butyl acrylate using a functionalized macro-CTA polymethyl methacrylate (PMMA) previously synthesized. Data show low molecular weight dispersity values (Đ < 1.5) particularly in the polymerization of methacrylic monomers. Considering a typical RAFT mechanism, the leaving groups (R) from the fragmentation of CTA should be able to re-initiate the polymerization (formation of growth chains) allowing an efficient control of the process. Nevertheless, in the case of the polymerization of MMA in the presence of this symmetrical CTA, the polymerization process displays an atypical behavior t...

After 40 years of the discovery of metallocene catalysts, there are still several aspects that re... more After 40 years of the discovery of metallocene catalysts, there are still several aspects that remain unresolved, especially when the “conventional” alkylaluminum activators are not used. Herein, we systematically investigate the synthesis of PE via three different zirconocene catalysts, with different alkyl substituents, activated via different organoboron compounds. The polymerization behavior, as well as the properties of the materials, are evaluated. The results demonstrate that the highest catalytic activity is shown by Bis(cyclopentadienyl)dimethylzirconium activated by trityl tetra(pentafluorophenyl)borate. Also finding that toluene is the optimum solvent for these systems and at these reaction conditions. Moreover, to validate our experimental results, a comprehensive mathematical model is developed on the basis of thermodynamic and kinetic principles. The concentration of ethylene transferred to the solvent phase (toluene) in a liquid-vapor equilibrium (LVE) system is estim...

RSC Advances, 2020

This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or... more This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or polymyrcene, reinforced with surface-modified graphene oxide (GO).

RSC Advances, 2020

This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or... more This article proposes a method to produce bio-elastomer nanocomposites, based on polyfarnesene or polymyrcene, reinforced with surface-modified graphene oxide (GO).

ACS Applied Polymer Materials, 2020

Energy & Fuels, 2020

A preliminary enhanced oil recovery (EOR) screening was completed for the Ben Nevis Formation, He... more A preliminary enhanced oil recovery (EOR) screening was completed for the Ben Nevis Formation, Hebron Field, offshore Canada. Polymer flooding was determined to be the most viable methodology based...