@misc{rico_mazabel_egurrola_pulido_barrios_marquez_garcia_2024, title={Meta-Analysis and Analytical Methods in Cosmetics Formulation: A Review}, volume={11}, ISSN={["2079-9284"]}, url={https://www.mdpi.com/2079-9284/11/1/1}, DOI={10.3390/cosmetics11010001}, abstractNote={The ever-evolving cosmetic industry requires advanced analytical techniques to explore, understand, and optimize product performance at nano, micro, and macroscopic levels. Nowadays, these insights are crucial for translating microstructure behavior into macroscopic properties. This knowledge is essential to formulate products with a lower carbon footprint and a higher sustainability profile, incorporating, at the same time, natural or biobased raw materials. These raw materials may present challenges for formulators and analytical scientists due to either an inferior performance when compared to their fossil-derived counterparts or higher costs. This comprehensive review covers a spectrum of analytical methodologies employed in cosmetic formulation, including chromatographic analyses, olfactometry, and electronic nose technology. The characterization of product stability involving assessing parameters such as droplet size, zeta potential, viscosity, analytical centrifugation, surface tension, and interfacial tension are also explored. The discussion in this paper extends to the role of rheology in understanding the molecular structure and behavioral dynamics of cosmetic samples. This review concludes with an overview of colorimetric analysis, a crucial aspect related to consumer perception, followed by a discussion on the challenges and opportunities associated with using meta-analysis methodologies in cosmetics. The formulation of cosmetics employing biobased feedstocks is included, highlighting the evolving landscape of cosmetic science and the integration of sustainable practices. This review stands at the interface between a meta-analysis of cosmetics and product performance, which is attained through a detailed examination of each analytical method. The know-how shared serves as a valuable resource for formulators, researchers, and industry professionals for real-world applications in the analytical field of cosmetics formulation.}, number={1}, journal={COSMETICS}, author={Rico, Felipe and Mazabel, Angela and Egurrola, Greciel and Pulido, Juanita and Barrios, Nelson and Marquez, Ronald and Garcia, Johnbrynner}, year={2024}, month={Feb} }
 @article{mittal_terpilowski_grady_marquez_2023, title={23rd International symposium on Surfactants in Solution (SIS-2022)}, ISSN={["1558-9293"]}, DOI={10.1002/jsde.12720}, abstractNote={Journal of Surfactants and DetergentsEarly View EDITORIAL 23rd International symposium on Surfactants in Solution (SIS-2022) Kash Mittal, Kash Mittal ConsultantSearch for more papers by this authorKonrad Terpilowski, Konrad Terpilowski orcid.org/0000-0002-8078-3644 Department of Chemistry, Maria Curie-Sklodowska University, Lublin, PolandSearch for more papers by this authorBrian Grady, Corresponding Author Brian Grady [email protected] orcid.org/0000-0002-4975-8029 Sustainable Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma, USA Correspondence Brian Grady, Sustainable Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK, USA. Email: [email protected]Search for more papers by this authorRonald Marquez, Ronald Marquez orcid.org/0000-0001-6003-7487 Department of Forest Biomaterials, North Carolina State University, Raleigh, North Carolina, USASearch for more papers by this author Kash Mittal, Kash Mittal ConsultantSearch for more papers by this authorKonrad Terpilowski, Konrad Terpilowski orcid.org/0000-0002-8078-3644 Department of Chemistry, Maria Curie-Sklodowska University, Lublin, PolandSearch for more papers by this authorBrian Grady, Corresponding Author Brian Grady [email protected] orcid.org/0000-0002-4975-8029 Sustainable Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma, USA Correspondence Brian Grady, Sustainable Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK, USA. Email: [email protected]Search for more papers by this authorRonald Marquez, Ronald Marquez orcid.org/0000-0001-6003-7487 Department of Forest Biomaterials, North Carolina State University, Raleigh, North Carolina, USASearch for more papers by this author First published: 06 October 2023 https://doi.org/10.1002/jsde.12720Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Early ViewOnline Version of Record before inclusion in an issue RelatedInformation}, journal={JOURNAL OF SURFACTANTS AND DETERGENTS}, author={Mittal, Kash and Terpilowski, Konrad and Grady, Brian and Marquez, Ronald}, year={2023}, month={Oct} }
 @article{marquez_barrios_vera_mendez_tolosa_zambrano_li_2023, title={A Perspective on The Synergistic Potential of Artificial Intelligence and Product-Based Learning Strategies in Biobased Materials Education}, volume={44}, ISSN={1749-7728}, url={http://dx.doi.org/10.1016/j.ece.2023.05.005}, DOI={10.1016/j.ece.2023.05.005}, abstractNote={The integration of product-based learning strategies in Materials in Chemical Engineering education is crucial for students to gain the skills and competencies required to thrive in the emerging circular bioeconomy. Traditional materials engineering education has often relied on a transmission teaching approach, in which students are expected to passively receive information from instructors. However, this approach has shown to be inadequate under the current circumstances, in which information is readily available and innovative tools such as artificial intelligence and virtual reality environments are becoming widespread (e.g., metaverse). Instead, we consider that a critical goal of education should be to develop aptitudes and abilities that enable students to generate solutions and products that address societal demands. In this work, we propose innovative strategies, such as product-based learning methods and GPT (Generative Pre-trained Transformer) artificial intelligence text generation models, to modify the focus of a Materials in Chemical Engineering course from non-sustainable materials to sustainable ones, aiming to address the critical challenges of our society. This approach aims to achieve two objectives: first to enable students to actively engage with raw materials and solve real-world challenges, and second, to foster creativity and entrepreneurship skills by providing them with the necessary tools to conduct brainstorming sessions and develop procedures following scientific methods. The incorporation of circular bioeconomy concepts, such as renewable resources, waste reduction, and resource efficiency into the curriculum provides a framework for students to understand the environmental, social, and economic implications in Chemical Engineering. It also allows them to make informed decisions within the circular bioeconomy framework, benefiting society by promoting the development and adoption of sustainable technologies and practices.}, journal={Education for Chemical Engineers}, publisher={Elsevier BV}, author={Marquez, Ronald and Barrios, Nelson and Vera, Ramon and Mendez, Maria E. and Tolosa, Laura and Zambrano, Franklin and Li, Yali}, year={2023}, month={May}, pages={164–180} }
 @article{marquez_ontiveros_barrios_tolosa_palazzo_nardello-rataj_salager_2023, title={Advantages and limitations of different methods to determine the optimum formulation in surfactant-oil-water systems: A review}, volume={9}, ISSN={["1558-9293"]}, url={https://doi.org/10.1002/jsde.12703}, DOI={10.1002/jsde.12703}, abstractNote={Abstract}, journal={JOURNAL OF SURFACTANTS AND DETERGENTS}, author={Marquez, Ronald and Ontiveros, Jesus F. and Barrios, Nelson and Tolosa, Laura and Palazzo, Gerardo and Nardello-Rataj, Veronique and Salager, Jean Louis}, year={2023}, month={Sep} }
 @article{vera_zambrano_marquez_vivas_forfora_bedard_farrell_ankeny_pal_jameel_et al._2023, title={Environmentally friendly oxidation pretreatments to produce sugar-based building blocks from dyed textile wastes via enzymatic hydrolysis}, volume={467}, ISSN={["1873-3212"]}, DOI={10.1016/j.cej.2023.143321}, abstractNote={Given the increasing concern over textile waste management and the proliferation of textile landfills, enzymatic hydrolysis of cotton represents a potential pathway to upcycle textile waste into valuable chemical building blocks. However, this pathway is challenged by the presence of persistent dyes, hindering enzyme performance. To overcome this issue, environmentally friendly and total chlorine free oxidation methods such as ozone and alkaline hydrogen peroxide were used in combination with mechanical refining pretreatment. The results showed that the enzymatic conversion of black-dyed cotton, without oxidation, resulted in a glucose yield of only 60% as compared to 95% for undyed cotton fibers. On the other hand, the inclusion of oxidation processes in the pretreatment stage resulted in a glucose yield of 90% via enzymatic hydrolysis at expense of using low oxidation chemicals and low enzyme charges. This work highlights the potential of oxidation methods, enzymatic hydrolysis, and mechanical refining as an ecofriendly pathway for generating value-added chemicals from cotton textile waste while promoting economic circularity.}, journal={CHEMICAL ENGINEERING JOURNAL}, author={Vera, Ramon E. and Zambrano, Franklin and Marquez, Ronald and Vivas, Keren A. and Forfora, Naycari and Bedard, John and Farrell, Matthew and Ankeny, Mary and Pal, Lokendra and Jameel, Hasan and et al.}, year={2023}, month={Jul} }
 @article{barrios_marquez_mcdonald_hubbe_venditti_venditti_pal_2023, title={Innovation in lignocellulosics dewatering and drying for energy sustainability and enhanced utilization of forestry, agriculture, and marine resources - A review}, volume={318}, ISSN={0001-8686}, url={http://dx.doi.org/10.1016/j.cis.2023.102936}, DOI={10.1016/j.cis.2023.102936}, abstractNote={Efficient utilization of forestry, agriculture, and marine resources in various manufacturing sectors requires optimizing fiber transformation, dewatering, and drying energy consumption. These processes play a crucial role in reducing the carbon footprint and boosting sustainability within the circular bioeconomy framework. Despite efforts made in the paper industry to enhance productivity while conserving resources and energy through lower grammage and higher machine speeds, reducing thermal energy consumption during papermaking remains a significant challenge. A key approach to address this challenge lies in increasing dewatering of the fiber web before entering the dryer section of the paper machine. Similarly, the production of high-value-added products derived from alternative lignocellulosic feedstocks, such as nanocellulose and microalgae, requires advanced dewatering techniques for techno-economic viability. This critical and systematic review aims to comprehensively explore the intricate interactions between water and lignocellulosic surfaces, as well as the leading technologies used to enhance dewatering and drying. Recent developments in technologies to reduce water content during papermaking, and advanced dewatering techniques for nanocellulosic and microalgal feedstocks are addressed. Existing research highlights several fundamental and technical challenges spanning from the nano- to macroscopic scales that must be addressed to make lignocellulosics a suitable feedstock option for industry. By identifying alternative strategies to improve water removal, this review intends to accelerate the widespread adoption of lignocellulosics as feasible manufacturing feedstocks. Moreover, this review aims to provide a fundamental understanding of the interactions, associations, and bonding mechanisms between water and cellulose fibers, nanocellulosic materials, and microalgal feedstocks. The findings of this review shed light on critical research directions necessary for advancing the efficient utilization of lignocellulosic resources and accelerating the transition towards sustainable manufacturing practices.}, journal={Advances in Colloid and Interface Science}, publisher={Elsevier BV}, author={Barrios, Nelson and Marquez, Ronald and McDonald, J. David and Hubbe, Martin A. and Venditti, Richard A. and Venditti, A. and Pal, Lokendra}, year={2023}, month={Jun}, pages={102936} }
 @article{vera_suarez_zambrano_marquez_bedard_vivas_pifano_farrell_ankeny_jameel_et al._2023, title={Upcycling cotton textile waste into bio-based building blocks through an environmentally friendly and high-yield conversion process}, volume={189}, ISSN={["1879-0658"]}, url={https://doi.org/10.1016/j.resconrec.2022.106715}, DOI={10.1016/j.resconrec.2022.106715}, abstractNote={This work presents mechanical refining as a chemical-free pretreatment of cotton textile waste to be converted into glucose via enzymatic hydrolysis. Both Cellic® CTec2 and CTec3 cellulase enzymes were evaluated to perform the enzymatic hydrolysis. Mechanical refining enabled cotton fiber fibrillation, thus increasing its specific surface area, water swellability, enzyme adsorption, and the efficiency of cotton conversion into sugars. Compared to conventional pretreatments, mechanical refining promoted sugar yields above 90% after enzymatic hydrolysis at lower enzyme usage (4–6 FPU/O.D g). From experimental data, a non-linear model was developed to predict cotton conversion. The predictive model allowed the optimization of the conversion process, which resulted in maximum yields of 89.3 and 98.3% when CTec2 and CTec3 were respectively used. Results from this work open the window to deploy mechanical refining as a promising and more sustainable transformation approach to produce sugar-based building blocks within the circular economy framework of textile waste.}, journal={RESOURCES CONSERVATION AND RECYCLING}, author={Vera, Ramon E. and Suarez, Antonio and Zambrano, Franklin and Marquez, Ronald and Bedard, John and Vivas, Keren A. and Pifano, Alonzo and Farrell, Matthew and Ankeny, Mary and Jameel, Hasan and et al.}, year={2023}, month={Feb} }
 @article{salager_graciaa_marquez_2022, title={Analyzing the surfactant classification confusion through the HLD formulation equation}, url={https://doi.org/10.1016/j.jciso.2022.100060}, DOI={10.1016/j.jciso.2022.100060}, abstractNote={The qualitative presentation from Winsor on an interfacial balance of interactions between the surfactant and the oil and water phases has been transformed into a multivariable linear equation so-called hydrophilic-lipophilic deviation (HLD). This relation involves at least 6 independent variables (surfactant head and tail specifications, water salinity, oil nature, temperature, and pressure) with a MacLaurin series first order approximation, i.e., a linear multivariable expression. After 40 years of practical experience, it can be said that the HLD relation matches well the experimental data, with only very few exceptions with complex mixtures. Herein, we clear the confusion concerning the meaning and the mathematical handling of the surfactant parameter in the HLD equation. We start with a presentation of simple surfactant systems with only 4 parameters (water salinity, oil nature, surfactant nature, and temperature) as was done 40 years ago. Later, we present a critical discussion on the surfactant term, concerning binary surfactant systems, and on strategies for applications in ternary surfactant mixtures. We have found that the surfactant parameters can only be compared in a series of surfactants with the same head group, where the surfactant parameter is a linear function of the surfactant tail length.}, journal={JCIS Open}, author={Salager, Jean-Louis and Graciaa, Alain and Marquez, Ronald}, year={2022}, month={Dec} }
 @article{patete_marquez_2022, title={Computer Animation Education Online: A Tool to Teach Control Systems Engineering throughout the COVID-19 Pandemic}, volume={12}, url={https://www.mdpi.com/2227-7102/12/4/253}, DOI={10.3390/educsci12040253}, abstractNote={The world is changing, and university education must be able to adapt to it. New technologies such as artificial intelligence and robotics are requiring tools such as simulation and process control to develop products and services. Thus, control systems engineering schools are adapting to new educational frameworks tailored to deploy promising and feasible new technologies. Herein, we have relied on computer animation-based education and its implementation as an online project-based strategy to attain the objectives and goals of the control systems engineering courses at University of Los Andes, Venezuela. The ControlAnimation library developed in Mathematica program in 2002 has been used as a tool to teach control systems engineering courses since 2008 and with greater prominence since 2020, when the stay-at-home orders due to the COVID-19 pandemic were enacted. Consequently, computer animation-based education has proven its feasibility as an online tool combined with project-based learning techniques, thus allowing students to interact with an animated control system by changing the mathematical model and the design parameters of control laws in a comfortable and somewhat playful way. This enabled new capabilities to study the dynamic behaviors of primordial control systems online. In addition, it allowed students to co-identify and relate in a more intuitive way to the mathematical models and control equations with the physical behavior of the real control systems.}, number={4}, journal={Education Sciences}, publisher={MDPI AG}, author={Patete, Anna and Marquez, Ronald}, year={2022}, month={Apr}, pages={253} }
 @article{zambrano_marquez_vera_jameel_venditti_gonzalez_2022, title={Developing Alternative, High-Absorbency Brown Fibers: Tissue Paper from Upcycled Corrugated Packaging Waste to Meet New Consumer Trends}, volume={9}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.2c03280}, DOI={10.1021/acssuschemeng.2c03280}, abstractNote={Consumers’ rising interest in brown tissue papers, perceived as sustainable, has increased the market share and selling prices of such products despite their limited performance. Meanwhile, the current excess of packaging waste in the US has created an opportunity for using old corrugated containerboard (OCC) as an alternative source of brown pulp, despite its inferior tissue-making characteristics relative to bleached fibers. Strength, water absorption capacity, and absorption rate are among the crucial properties of absorbent tissue products. Herein, we studied the feasibility of total chlorine-free treatments, namely, oxygen delignification, alkaline hydrogen peroxide, and ozonation, to improve the tissue-making quality of OCC pulp. The processes evaluated reduced the lignin content (kappa number from 89 to values as low as 55) and generated brightness gains as high as 8.8% ISO units. The strength of the sheets also improved due to the delignification and increase in fiber swelling. Chemically treated OCC resulted in sheets with higher water absorption capacity and absorption rate and fiber slurries with higher freeness compared to sheets and slurries from mechanically refined OCC. Therefore, we demonstrate the application of treatments with low environmental impact to upcycle OCC into a high-quality brown pulp suitable for manufacturing high-performance tissue paper.}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Zambrano, Franklin and Marquez, Ronald and Vera, Ramon and Jameel, Hasan and Venditti, Richard and Gonzalez, Ronalds}, year={2022}, month={Sep} }
 @article{salager_marquez_bullon_forgiarini_2022, title={Formulation in Surfactant Systems: From-Winsor-to-HLD<sub>N</sub>}, volume={2}, url={https://www.mdpi.com/2673-8392/2/2/54}, DOI={10.3390/encyclopedia2020054}, abstractNote={Formulation is an ancient concept, although the word has been used only recently. The first formulations made our civilization advance by inventing bronze, steel, and gunpowder; then, it was used in medieval alchemy. When chemistry became a science and with the golden age of organic synthesis, the second formulation period began. This made it possible to create new chemical species and new combinations “à la carte.” However, the research and developments were still carried out by trial and error. Finally, the third period of formulation history began after World War II, when the properties of a system were associated with its ingredients and the way they were assembled or combined. Therefore, the formulation and the systems’ phenomenology were related to the generation of some synergy to obtain a commercial product. Winsor’s formulation studies in the 1950s were enlightening for academy and industries that were studying empirically surfactant-oil-water (SOW) systems. One of its key characteristics was how the interfacial interaction of the adsorbed surfactant with oil and water phases could be equal by varying the physicochemical formulation of the system. Then, Hansen’s solubility parameter in the 1960s helped to reach a further understanding of the affinity of some substances to make them suitable to oil and water phases. In the 1970s, researchers such as Shinoda and Kunieda, and different groups working in Enhanced Oil Recovery (EOR), among them Schechter and Wade’s group at the University of Texas, made formulation become a science by using semiempirical correlations to attain specific characteristics in a system (e.g., low oil-water interfacial tension, formulation of a stable O/W or W/O emulsion, or high-performance solubilization in a bicontinuous microemulsion system at the so-called optimum formulation). Nowadays, over 40 years of studies with the hydrophilic-lipophilic deviation equation (HLD) have made it feasible for formulators to improve products in many different applications using surfactants to attain a target system using HLD in its original or its normalized form, i.e., HLDN. Thus, it can be said that there is still current progress being made towards an interdisciplinary applied science with numerical guidelines. In the present work, the state-of-the-art of formulation in multiphase systems containing two immiscible phases like oil and water, and therefore systems with heterogeneous or micro-heterogeneous interfaces, is discussed. Surfactants, from simple to complex or polymeric, are generally present in such systems to solve a wide variety of problems in many areas. Some significant cases are presented here as examples dealing with petroleum, foods, pharmaceutics, cosmetics, detergency, and other products occurring as dispersions, emulsions, or foams that we find in our everyday lives.}, number={2}, journal={Encyclopedia}, publisher={MDPI AG}, author={Salager, Jean-Louis and Marquez, Ronald and Bullon, Johnny and Forgiarini, Ana}, year={2022}, month={Apr}, pages={778–842} }
 @article{formulation of a eugenol-based o/w emulsion for application as a topical and oral anesthetic by low-energy emulsification_2022, url={https://publons.com/wos-op/publon/52368878/}, journal={Ciencia E Ingenieria}, year={2022} }
 @article{salager_marquez_delgado-linares_rondon_forgiarini_2022, title={Fundamental Basis for Action of a Chemical Demulsifier Revisited after 30 Years: HLDN as the Primary Criterion for Water-in-Crude Oil Emulsion Breaking}, volume={1}, url={https://doi.org/10.1021/acs.energyfuels.1c03349}, DOI={10.1021/acs.energyfuels.1c03349}, abstractNote={In the past four decades, many experimental studies have confirmed the systematic events occurring at the so-called optimum formulation of surfactant–oil–water systems. At this particular formulation, the adsorbed surfactant at the interface interacts equally with water and oil phases, which is supposed to occur according to Winsor theory to attain a three-phase behavior. A low minimum interfacial tension has been confirmed to take place at optimum in hundreds of reports on enhanced oil recovery (EOR). It also coincides with a very definite minimum in emulsion stability, which is looked after for chemical dehydration or crude oil desalting. A normalized hydrophilic–lipophilic deviation (HLDN) equation was proposed as a multivariable expression that numerically estimates the difference of the surfactant interactions with oil and water. This concept can be applied in crude oil emulsion breaking by considering asphaltenes as being in part a lipophilic surfactant whose effect must be compensated by a hydrophilic demulsifier surfactant to reach the optimum formulation. This is attained through equivalence effects by changing two or more variables, particularly asphaltenes and demulsifier type and concentration, which can be measured through different techniques. Furthermore, in recent studies, asphaltenes are found to exhibit two different lipophilicity levels depending on their self-gathering at or close to the interface, for example, as flat bidimensional nanoaggregates or as three-dimensional clusters. This review presents the know-how reached after 30 years of studying water-in-crude oil emulsion breaking (also known as chemical dehydration) using a formulation approach with the HLD multivariable expression. The first part reviews the fundamental concepts and advances on the HLD equation in relation to simple and complex mixtures. The second part presents several strategies aimed at increasing performance and decreasing demulsifier dosification using the HLDN normalized equation in a qualitative way as well as a quantitative way.}, journal={Energy & Fuels}, publisher={American Chemical Society (ACS)}, author={Salager, Jean-Louis and Marquez, Ronald and Delgado-Linares, Jose G. and Rondon, Miguel and Forgiarini, Ana}, year={2022}, month={Jan} }
 @article{li_zambrano_wang_marquez_2022, title={How China's Foreign Waste Ban Will Reshape the US Recycling Supply Chain: Economic and Environmental Considerations towards a Circular Economy Oriented Paper Recycling Industry}, volume={17}, ISSN={["1930-2126"]}, url={https://publons.com/wos-op/publon/50709352/}, DOI={10.15376/biores.17.2.3178-3201}, abstractNote={Until recently, China was the largest scrap and unsorted waste importer in the world. Chinese industries sorted the imported wastes and recovered plastic, paper, textiles, and metals, using them as raw materials for manufacturing processes. Since 2013, the Chinese government has imposed measures to ban the import of wastes, the latest one being the “National Sword” policy (fully deployed in January 2021), banning the import of unsorted and recycled wastes. As a result, collecting wastes and recyclables and sending them to China is no longer an option; this has drastically affected the recycling industry supply chain with considerable consequences. This study analyzed the development of Chinese foreign policies on the export of paper waste materials from the U.S. and their specific impact on the recovered paper recycling industry. The economic and environmental consequences of the policy on the U.S. paper recycling industry were analyzed using three scenarios: landfilling (as a baseline), incineration, and recycling. The CO2 emissions were estimated and then compared. It was found that recycling would result in the largest reduction in greenhouse gases. Although recycling was the best evaluated scenario, it has the greatest costs; therefore, possible solutions towards adding value to paper wastes were analyzed.}, number={2}, journal={BIORESOURCES}, author={Li, Yali and Zambrano, Franklin and Wang, Yuhan and Marquez, Ronald}, year={2022}, month={May}, pages={3178–3201} }
 @article{marquez_zwilling_zambrano_tolosa_marquez_venditti_jameel_gonzalez_2022, title={Nanoparticles and essential oils with antiviral activity on packaging and surfaces: An overview of their selection and application}, volume={7}, ISSN={["1558-9293"]}, url={https://doi.org/10.1002/jsde.12609}, DOI={10.1002/jsde.12609}, abstractNote={Abstract}, journal={JOURNAL OF SURFACTANTS AND DETERGENTS}, publisher={Wiley}, author={Marquez, Ronald and Zwilling, Jacob and Zambrano, Franklin and Tolosa, Laura and Marquez, Maria E. and Venditti, Richard and Jameel, Hasan and Gonzalez, Ronalds}, year={2022}, month={Jul} }
 @article{meza_alvarado_márquez_forgiarini_2022, title={Performance Evaluation of Demulsifier Using the Optimum Formulation HLD Concept: A Practical Case Using Heavy Crude Oil Diluted in Naphtha or in Synthetic Aromatic Oil}, url={https://publons.com/wos-op/publon/52160399/}, DOI={10.2118/209577-PA}, abstractNote={Summary}, journal={SPE Journal}, author={Meza, L. and Alvarado, J. G. and Márquez, R. and Forgiarini, A.}, year={2022} }
 @article{ortiz_alvarado_zambrano_marquez_2022, title={Surfactants produced from carbohydrate derivatives: A review of the biobased building blocks used in their synthesis}, volume={1}, url={https://doi.org/10.1002/jsde.12581}, DOI={10.1002/jsde.12581}, abstractNote={Abstract}, journal={Journal of Surfactants and Detergents}, publisher={Wiley}, author={Ortiz, Maria Soledad and Alvarado, Jose Gregorio and Zambrano, Franklin and Marquez, Ronald}, year={2022}, month={Mar} }
 @article{vera_zambrano_suarez_pifano_marquez_farrell_ankeny_jameel_gonzalez_2022, title={Transforming textile wastes into biobased building blocks via enzymatic hydrolysis: A review of key challenges and opportunities}, volume={9}, url={http://dx.doi.org/10.1016/j.clcb.2022.100026}, DOI={10.1016/j.clcb.2022.100026}, abstractNote={Textile waste generation in the United States represents approximately 17 million tons per year, constituting a serious environmental problem. Solutions to this situation have led to upcycling cotton-derived textile waste into value-added chemicals through enzymatic hydrolysis. Direct enzymatic treatment of cotton textile materials results in low yields given their high degree of crystallinity and the presence of dyes. Thus, several pretreatment methods have been proposed to improve performance in converting textile materials into glucose and other biobased building blocks. However, high yields are attained at the expense of high enzyme loads, energy usage, and chemical demands. This work reviews the reported literature and successful examples on pretreatment methods to transform cotton textile materials into glucose and its upcycling into biobased building blocks, focusing on the challenges when dyes are present in cotton garments. A comparison of the feasibility of such processes is overviewed from an economic and environmental standpoint. We end by discussing on the need to deploy less chemical intensive pretreatments and possible solutions for enzyme accessibility to cotton fibers.}, journal={Cleaner and Circular Bioeconomy}, publisher={Elsevier BV}, author={Vera, Ramon E. and Zambrano, Franklin and Suarez, Antonio and Pifano, Alonzo and Marquez, Ronald and Farrell, Matthew and Ankeny, Mary and Jameel, Hasan and Gonzalez, Ronalds}, year={2022}, month={Sep}, pages={100026} }
 @article{forgiarini_marquez_salager_2021, title={Formulation Improvements in the Applications of Surfactant–Oil–Water Systems Using the HLDN Approach with Extended Surfactant Structure}, volume={26}, url={https://doi.org/10.3390/molecules26123771}, DOI={10.3390/molecules26123771}, abstractNote={Soap applications for cleaning and personal care have been used for more than 4000 years, dating back to the pharaonic period, and have widely proliferated with the appearance of synthetic surfactants a century ago. Synthetic surfactants used to make macro-micro-nano-emulsions and foams are used in laundry and detergency, cosmetics and pharmaceuticals, food conditioning, emulsified paints, explosives, enhanced oil recovery, wastewater treatment, etc. The introduction of a multivariable approach such as the normalized hydrophilic–lipophilic deviation (HLD N) and of specific structures, tailored with an intramolecular extension to increase solubilization (the so-called extended surfactants), makes it possible to improve the results and performance in surfactant–oil–water systems and their applications. This article aims to present an up-to-date overview of extended surfactants. We first present an introduction regarding physicochemical formulation and its relationship with performance. The second part deals with the importance of HLD N to make a straightforward classification according to the type of surfactants and how formulation parameters can be used to understand the need for an extension of the molecule reach into the oil and water phases. Then, extended surfactant characteristics and strategies to increase performance are outlined. Finally, two specific applications, i.e., drilling fluids and crude oil dewatering, are described.}, number={12}, journal={Molecules}, publisher={MDPI AG}, author={Forgiarini, Ana M. and Marquez, Ronald and Salager, Jean-Louis}, year={2021}, month={Jun}, pages={3771} }
 @article{how to avoid the current confusion in using the sow generalized formulation expression hld=0 for optimum formulation_2021, url={https://publons.com/wos-op/publon/50043126/}, DOI={10.21748/AM21.276}, journal={Journal of the American Oil Chemists' Society}, year={2021} }
 @article{marquez_meza_alvarado_bullon_langevin_forgiarini_salager_2021, title={Interfacial Rheology Measured with a Spinning Drop Interfacial Rheometer: Particularities in More Realistic Surfactant-Oil-Water Systems Close to Optimum Formulation at HLDN=0}, volume={24}, ISSN={["1558-9293"]}, url={https://doi.org/10.1002/jsde.12502}, DOI={10.1002/jsde.12502}, abstractNote={Abstract}, number={4}, journal={JOURNAL OF SURFACTANTS AND DETERGENTS}, publisher={Wiley}, author={Marquez, Ronald and Meza, Luz and Alvarado, Jose G. and Bullon, Johnny and Langevin, Dominique and Forgiarini, Ana M. and Salager, Jean-Louis}, year={2021}, month={Jul}, pages={587–601} }
 @article{marquez_bullon_forgiarini_salager_2021, title={The Oscillatory Spinning Drop Technique. An Innovative Method to Measure Dilational Interfacial Rheological Properties of Brine-Crude Oil Systems in the Presence of Asphaltenes}, volume={5}, url={https://doi.org/10.3390/colloids5030042}, DOI={10.3390/colloids5030042}, abstractNote={The oscillatory spinning drop method has been proven recently to be an accurate technique to measure dilational interfacial rheological properties. It is the only available equipment for measuring dilational moduli in low interfacial tension systems, as it is the case in applications dealing with surfactant-oil-water three-phase behavior like enhanced oil recovery, crude oil dehydration, or extreme microemulsion solubilization. Different systems can be studied, bubble-in-liquid, oil-in-water, microemulsion-in-water, oil-in-microemulsion, and systems with the presence of complex natural surfactants like asphaltene aggregates or particles. The technique allows studying the characteristics and properties of water/oil interfaces, particularly when the oil contains asphaltenes and when surfactants are present. In this work, we present a review of the measurements of crude oil-brine interfaces with the oscillating spinning drop technique. The review is divided into four sections. First, an introduction on the oscillating spinning drop technique, fundamental and applied concepts are presented. The three sections that follow are divided according to the complexity of the systems measured with the oscillating spinning drop, starting with simple surfactant-oil-water systems. Then the complexity increases, presenting interfacial rheology properties of crude oil-brine systems, and finally, more complex surfactant-crude oil-brine systems are reviewed. We have found that using the oscillating spinning drop method to measure interfacial rheology properties can help make precise measurements in a reasonable amount of time. This is of significance when systems with long equilibration times, e.g., asphaltene or high molecular weight surfactant-containing systems are measured, or with systems formulated with a demulsifier which is generally associated with low interfacial tension.}, number={3}, journal={Colloids and Interfaces}, publisher={MDPI AG}, author={Marquez, Ronald and Bullon, Johnny and Forgiarini, Ana and Salager, Jean-Louis}, year={2021}, month={Aug}, pages={42} }
 @article{understanding covid-19 effect on the u.s. supply chain of strategic products: important factors, current situation, and future perspective_2021, url={https://publons.com/wos-op/publon/36086767/}, journal={Ciencia E Ingenieria}, year={2021} }
 @article{zambrano_marquez_jameel_venditti_gonzalez_2021, title={Upcycling strategies for old corrugated containerboard to attain high-performance tissue paper: A viable answer to the packaging waste generation dilemma}, volume={175}, ISSN={0921-3449}, url={http://dx.doi.org/10.1016/j.resconrec.2021.105854}, DOI={10.1016/J.RESCONREC.2021.105854}, abstractNote={This study evaluated the suitability of old corrugated containerboard (OCC) to be upcycled into a high-quality pulp for tissue paper manufacture. The evolution of the physicochemical properties of OCC fibers and their effect on tissue properties were tracked across each stage of two elemental chlorine free (ECF) bleaching sequences. The properties of bleached OCC were compared to those of deinked pulp (DIP), southern bleached softwood kraft (SBSK), and refined OCC unbleached. Both sequences reduced the kappa number from 89 to negligible values and increased brightness from 18.9% to ca. 75% ISO, on average 6.2% ISO units below that of DIP. Overall, bleaching significantly increased tensile index and absorbency rate while having adverse effects on bulk and softness and minor impacts on absorption capacity. The change in properties was correlated to the improved fiber bondability and fiber wettability derived from the lignin removal. Compared to DIP, bleached OCC exhibited a higher tensile index, higher freeness, and similar absorption capacity but lower softness. It also showed higher absorption capacity and similar softness than SBSK but lower freeness at a comparable tensile index. The results indicate that upgraded OCC could be used as an alternative fiber to address the forecasted shortage of high-grade recycled papers in recycled tissue grades or replace virgin fibers in producing virgin tissue grades. In addition, it was determined that refined OCC unbleached could also be suitable for use in tissue grades where high brightness is not an essential product feature.}, journal={Resources, Conservation and Recycling}, publisher={Elsevier BV}, author={Zambrano, Franklin and Marquez, Ronald and Jameel, Hasan and Venditti, Richard and Gonzalez, Ronalds}, year={2021}, month={Dec}, pages={105854} }
 @article{vera_salazar‐rodríguez_marquez_forgiarini_2020, title={How the Influence of Different Salts on Interfacial Properties of Surfactant–Oil–Water Systems at Optimum Formulation Matches the Hofmeister Series Ranking}, volume={3}, url={https://doi.org/10.1002/jsde.12406}, DOI={10.1002/jsde.12406}, abstractNote={Abstract}, number={3}, journal={Journal of Surfactants and Detergents}, publisher={Wiley}, author={Vera, Ramon E. and Salazar‐Rodríguez, Franklin and Marquez, Ronald and Forgiarini, Ana M.}, year={2020}, month={May}, pages={603–615} }
 @article{salager_antón_bullón_forgiarini_marquez_2020, title={How to Use the Normalized Hydrophilic-Lipophilic Deviation (HLDN) Concept for the Formulation of Equilibrated and Emulsified Surfactant-Oil-Water Systems for Cosmetics and Pharmaceutical Products}, volume={7}, url={https://doi.org/10.3390/cosmetics7030057}, DOI={10.3390/cosmetics7030057}, abstractNote={The effects of surfactant molecules involved in macro-, mini-, nano-, and microemulsions used in cosmetics and pharmaceuticals are related to their amphiphilic interactions with oil and water phases. Basic ideas on their behavior when they are put together in a system have resulted in the energy balance concept labeled the hydrophilic-lipophilic deviation (HLD) from optimum formulation. This semiempirical equation integrates in a simple linear relationship the effects of six to eight variables including surfactant head and tail, sometimes a cosurfactant, oil-phase nature, aqueous-phase salinity, temperature, and pressure. This is undoubtedly much more efficient than the hydrophilic-lipophilic balance (HLB) which has been used since 1950. The new HLD is quite important because it allows researchers to model and somehow predict the phase behavior, the interfacial tension between oil and water phases, their solubilization in single-phase microemulsion, as well as the corresponding properties for various kinds of macroemulsions. However, the HLD correlation, which has been developed and used in petroleum applications, is sometimes difficult to apply accurately in real cases involving ionic–nonionic surfactant mixtures and natural polar oils, as it is the case in cosmetics and pharmaceuticals. This review shows the confusion resulting from the multiple definitions of HLD and of the surfactant parameter, and proposes a “normalized” Hydrophilic-Lipophilic Deviation (HLDN) equation with a surfactant contribution parameter (SCP), to handle more exactly the effects of formulation variables on the phase behavior and the micro/macroemulsion properties.}, number={3}, journal={Cosmetics}, publisher={MDPI AG}, author={Salager, Jean-Louis and Antón, Raquel and Bullón, Johnny and Forgiarini, Ana and Marquez, Ronald}, year={2020}, month={Jul}, pages={57} }
 @article{khatib_bullón_vivas_bahsas_rosales‐oballos_marquez_forgiarini_salager_2020, title={Synthesis, Characterization, Evaluation of Interfacial Properties and Antibacterial Activities of Dicarboxylate Anacardic Acid Derivatives from Cashew Nut Shell Liquid of Anacardium occidentale L.}, volume={1}, url={https://doi.org/10.1002/jsde.12384}, DOI={10.1002/jsde.12384}, abstractNote={Abstract}, number={3}, journal={Journal of Surfactants and Detergents}, publisher={Wiley}, author={Khatib, Sonia Koteich and Bullón, Johnny and Vivas, Jesús and Bahsas, Ali and Rosales‐Oballos, Yolima and Marquez, Ronald and Forgiarini, Ana and Salager, Jean Louis}, year={2020}, month={May}, pages={503–512} }
 @article{marquez_forgiarini_langevin_salager_2019, title={Breaking of Water-In-Crude Oil Emulsions. Part 9. New Interfacial Rheology Characteristics Measured Using a Spinning Drop Rheometer at Optimum Formulation}, volume={33}, url={https://doi.org/10.1021/acs.energyfuels.9b01476}, DOI={10.1021/acs.energyfuels.9b01476}, abstractNote={Water–crude oil interfaces often exhibit a viscoelastic layer with a high mechanical resistance, consisting of natural surfactants in crude oil, mainly asphaltenes, which stabilize water-in-oil emu...}, number={9}, journal={Energy & Fuels}, publisher={American Chemical Society (ACS)}, author={Marquez, Ronald and Forgiarini, Ana M. and Langevin, Dominique and Salager, Jean-Louis}, year={2019}, month={Sep}, pages={8151–8164} }
 @article{salager_forgiarini_marquez_2019, title={Extended Surfactants Including an Alkoxylated Central Part Intermediate Producing a Gradual Polarity Transition-A Review of the Properties Used in Applications Such as Enhanced Oil Recovery and Polar Oil Solubilization in Microemulsions}, volume={22}, url={https://doi.org/10.1002/jsde.12331}, DOI={10.1002/jsde.12331}, abstractNote={Abstract}, number={5}, journal={Journal of Surfactants and Detergents}, author={Salager, Jean-Louis and Forgiarini, Ana and Marquez, Ronald}, year={2019}, month={Sep}, pages={935–972} }
 @article{marquez_antón_vejar_salager_forgiarini_2019, title={New Interfacial Rheology Characteristics Measured Using a Spinning Drop Rheometer at the Optimum Formulation. Part 2. Surfactant–Oil–Water Systems with a High Volume of Middle‐Phase Microemulsion}, volume={22}, url={https://doi.org/10.1002/jsde.12245}, DOI={10.1002/jsde.12245}, abstractNote={Abstract}, number={2}, journal={Journal of Surfactants and Detergents}, publisher={Wiley}, author={Marquez, Ronald and Antón, Raquel and Vejar, Francia and Salager, Jean‐Louis and Forgiarini, Ana M.}, year={2019}, month={Mar}, pages={177–188} }
 @article{technological use of beeswax for obtaining organic products, non-toxic for the human being_2019, url={https://publons.com/wos-op/publon/31271964/}, journal={Ciencia E Ingenieria}, year={2019} }
 @article{tolosa_marquez_rennola_sandia_bullon_2018, title={An overview of today's project-based learning and how it has been implemented in the Chemical Engineering School at Universidad de Los Andes}, url={https://doi.org/10.22201/fq.18708404e.2018.4.64701}, DOI={10.22201/fq.18708404e.2018.4.64701}, abstractNote={This paper builds on a project-based engineering learning strategy called RAIS ‘Reproducing an Innovation Environment in the Classroom’ applied in courses in the Chemical Engineering curriculum at the Universidad de Los Andes (ULA). It follows a previous investigation where the practical implementation of RAIS strategy is presented (Marquez et al., 2016), and in this occasion the theoretical fundamentals of the RAIS strategy are outlined. Authors take the common project-based learning to a new level by directly involving the students in the common start-up company practice where the final product to be formulated and manufactured is not a requirement from an external client but comes from real entrepreneurship students’ interests. In previous work it has been shown that this strategy allows interconnecting the course objectives with the development of a product. RAIS strategy has reported successful outcomes in the accomplishment of this goal for Chemical Engineering students at ULA.}, journal={Educación Química}, author={Tolosa, Laura and Marquez, Ronald and Rennola, Leonardo and Sandia, Beatriz and Bullon, Johnny}, year={2018}, month={Oct} }
 @article{marquez_forgiarini_langevin_salager_2018, title={Instability of Emulsions Made with Surfactant–Oil–Water Systems at Optimum Formulation with Ultralow Interfacial Tension}, volume={34}, url={https://publons.com/wos-op/publon/12793334/}, DOI={10.1021/acs.langmuir.8b01376}, abstractNote={We have studied emulsions made with two- and three-phase oil-water-surfactant systems in which one of the phases is a microemulsion, the other phases being water or/and oil excess phases. Such systems have been extensively studied in the 1970-1980s for applications in enhanced oil recovery. It was found at that time that the emulsions became very unstable in the three-phase systems, but so far few explanations have been proposed. In the most complete one, Kabalnov and colleagues related the emulsion stability to the probability of hole nucleation in the liquid film separating two nearby emulsion drops and associated this probability to the curvature elastic energy of the surfactant layer covering drop surfaces. We propose a different explanation, linked to another type of interfacial elastic energy, associated with compression of the surfactant layers. As found long ago, the three-phase systems are found near optimum formulation (hydrophile lipophile difference, HLD = 0), where the interfacial tension exhibits a deep minimum. The determination of interfacial elastic properties in low interfacial tension systems is not straightforward. In our present work, we used a spinning drop tensiometer with an oscillating rotation velocity. We show that the interfacial compression elastic modulus and viscosity also exhibit a minimum at optimum formulation. We propose that this minimum is related to the acceleration of the surfactant exchanges between the interface, oil and water, near the optimum formulation. Furthermore, we find that the surfactant partitions close to equally between oil and water at the optimum, as in earlier studies. The interfacial tension gradients that slow the thinning of liquid films between drops are reduced by surfactant exchanges between drops and the interface, which are fast whatever the type of drop, oil or water; film thinning is therefore very rapid, and emulsions are almost as unstable as in the absence of surfactant.}, number={31}, journal={Langmuir}, publisher={American Chemical Society (ACS)}, author={Marquez, Ronald and Forgiarini, Ana M. and Langevin, Dominique and Salager, Jean-Louis}, year={2018}, month={Jul}, pages={9252–9263} }
 @article{zamora_marquez_forgiarini_langevin_salager_2018, title={Interfacial rheology of low interfacial tension systems using a new oscillating spinning drop method}, volume={519}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85042353425&partnerID=MN8TOARS}, DOI={10.1016/j.jcis.2018.02.015}, abstractNote={When surfactants adsorb at liquid interfaces, they not only decrease the surface tension, they confer rheological properties to the interfaces. There are two types of rheological parameters associated to interfacial layers: compression and shear. The elastic response is described by a storage modulus and the dissipation by a loss modulus or equivalently a surface viscosity. Various types of instruments are available for the measurements of these coefficients, the most common being oscillating pendent drops instruments and rheometers equipped with bicones. These instruments are applicable to systems with large enough interfacial tensions, typically above a few mN/m. We use a new type of instrument based on spinning drop oscillations, allowing to extend the interfacial rheology studies to low and ultralow interfacial tension systems. We present examples of measurements with systems of high and low tension, discuss the possible artifacts and demonstrate the capability of this new technique. We emphasize that the data shown for low interfacial tensions are the first reported in the literature. The instrument is potentially interesting for instance in enhanced oil recovery or demulsification studies.}, journal={Journal of Colloid and Interface Science}, publisher={Elsevier BV}, author={Zamora, José M. and Marquez, Ronald and Forgiarini, Ana M. and Langevin, Dominique and Salager, Jean-Louis}, year={2018}, pages={27–37} }
 @article{marquez_forgiarini_fernández_langevin_salager_2018, title={New Interfacial Rheology Characteristics Measured using a Spinning-Drop Rheometer at the Optimum Formulation of a Simple Surfactant-Oil-Water System}, volume={21}, url={https://publons.com/wos-op/publon/12793335/}, DOI={10.1002/jsde.12163}, abstractNote={Abstract}, number={5}, journal={Journal of Surfactants and Detergents}, publisher={Wiley}, author={Marquez, Ronald and Forgiarini, Ana M. and Fernández, Jesús and Langevin, Dominique and Salager, Jean-Louis}, year={2018}, month={Jun}, pages={611–623} }
 @inproceedings{obtaining products in chemical engineering through reproducing an environment of innovation in the classroom_2017, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85034229541&partnerID=MN8TOARS}, booktitle={2017 Research in Engineering Education Symposium, REES 2017}, year={2017} }
 @article{dual formulation effect produced by a high content in alcohol in oil/sodium dodecyl sulfate/pentanol/water systems and resulting shift in oil eacn_2016, url={https://publons.com/wos-op/publon/12793337/}, journal={Ciencia E Ingenieria}, year={2016} }
 @article{reproducing an innovation environment in the classroom. an strategy to promote creativity in chemical engineering education,reproducción de un ambiente de innovación en el salón de clase. una estrategia para promover la creatividad en la educación en ingeniería química_2016, volume={27}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84991737662&partnerID=MN8TOARS}, DOI={10.1016/j.eq.2016.07.001}, abstractNote={El proceso enseñanza-aprendizaje en la educación universitaria tradicional utiliza estrategias que colocan al estudiante como un receptor de información transmitida por el profesor, la cual es conceptualizada como conocimiento. La realidad en que vivimos requiere generar soluciones de formación que permitan satisfacer las necesidades de los individuos en el desarrollo de competencias o saber-hacer, para dar respuestas a la sociedad, para formar individuos capaces de aprender a aprender y aprender a transferir, preparados para buscar continuamente el conocimiento y capacitados para crear e innovar. En este trabajo se presentan los resultados de la aplicación de la estrategia «Reproducción de un Ambiente de Innovación en el Salón de clase» (RAIS) en asignaturas del currículo de Ingeniería Química, de la Universidad de los Andes, Mérida-Venezuela. Esta es una estrategia de enseñanza-aprendizaje y evaluación donde el estudiante es copartícipe de la construcción y generación del conocimiento, desarrollando las competencias propuestas en la asignatura a través de la ejecución de un producto. La estrategia RAIS fue aplicada en las asignaturas Fisicoquímica para Ingenieros Químicos, Química Industrial I y Laboratorio de Química Industrial, donde los estudiantes obtuvieron con éxito un producto, utilizando el saber-hacer en el área de cada curso. Esta estrategia generó un incremento en la motivación con respecto a otros cursos basados en clases magistrales, y el desarrollo de la capacidad de desenvolverse y encontrar soluciones en ambientes de trabajo con grupos multidisciplinarios. Es importante resaltar que más de un 80% de los estudiantes indicó que la estrategia RAIS contribuye a su desarrollo personal y formación para realizar investigación aplicada.}, number={4}, journal={Educacion Quimica}, year={2016}, pages={249–256} }
 @article{rheological changes of parenteral emulsions during phase-inversion emulsification_2008, volume={29}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-41849151112&partnerID=MN8TOARS}, DOI={10.1080/01932690801945998}, abstractNote={An efficient emulsification procedure for parenteral soybean oil‐in‐water, based on current know‐how on transitional inversion, was investigated. A fine droplet size lipid emulsion was produced using much lower mechanical energy than the typical industrial process. The aqueous phase was added gradually during mixing and various rates of water addition, as well as surfactant concentration, were evaluated. It was found that as addition rate and surfactant content increased, flow behavior changed significantly at intermediate water content, becoming highly viscoelastic. This behavior was related to the formation of a liquid crystalline phase that, at later mixing stages, turned into small droplets.}, number={4}, journal={Journal of Dispersion Science and Technology}, year={2008}, pages={621–627} }
 @article{nano-emulsification of triglyceride oils for parenteral use by mean of a low-energy emulsification method_2007, url={https://publons.com/wos-op/publon/12793339/}, journal={Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia}, year={2007} }