Publications by authors named "Ricardo Sosa"

6 Publications

  • Page 1 of 1

Acidic Polysaccharides as Green Alternatives for Barite Scale Dissolution.

ACS Appl Mater Interfaces 2020 Dec 24;12(49):55434-55443. Epub 2020 Nov 24.

Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204-4004, United States.

Barium sulfate (barite) scale poses significant challenges for processes ranging from water treatment to fossil fuel production. Here, we identify alginate (a polysaccharide derived from brown algae) as a potent, "green" alternative to commercial barite demineralizing agents. Unlike conventional treatments of inorganic scales that require caustic conditions, alginate polymers dissolve barite at near-neutral conditions. In this study, we benchmark the demineralizing efficacy of alginate against a commercial dissolver, diethylenetriaminepentaacetic acid (DTPA), using a combination of bulk dissolution assays, scanning probe microscopy, and molecular dynamics simulations. Time-resolved rates of dissolution measured in a microfluidic device show that demineralization is enhanced more than an order of magnitude under flow. In situ atomic force microscopy reveals that alginate and DTPA exhibit distinct mechanisms of surface dissolution; and surprisingly, their binary combination in alkaline media results in a synergistic cooperativity that enhances the overall rate of barite dissolution. These studies collectively demonstrate a unique approach to demineralization using an inexpensive and abundant biopolymer that enables environmentally friendly treatment of inorganic scales.
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http://dx.doi.org/10.1021/acsami.0c16653DOI Listing
December 2020

Recent applications of ultrasonic waves in improved oil recovery: A review of techniques and results.

Ultrasonics 2021 Feb 29;110:106288. Epub 2020 Oct 29.

School of Engineering, King's College, University of Aberdeen, Aberdeen AB24 3UE, UK.

Ultrasound technique is an inexpensive and ecofriendly technology commonly used in oil and gas industry to improve oil recovery and its applications have been successfully tested in both laboratory and field scales. In this technique, high-power ultrasonic waves are utilized downhole to improve oil recovery and reduce formation damage in near wellbore region that causes a reduction in hydrocarbon production rate due to the penetration of mud, scale deposition, etc. In most of the cases, barriers for the oil flow to the wellbore are effectively removed by using the ultrasound technique and the effect of improved oil recovery may last up to several months. The aim of this paper is to provide an overview of recent laboratory, field and mathematical studies to serve as reference for future extensive examination of ultrasound assisted improved oil recovery. As an added value to this field of study, research gaps and opportunities based on the review of recent works were identified and factors that needs to be considered to improve the outcome of future studies were recommended.
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http://dx.doi.org/10.1016/j.ultras.2020.106288DOI Listing
February 2021

A System-of-Systems Bio-Inspired Design Process: Conceptual Design and Physical Prototype of a Reconfigurable Robot Capable of Multi-Modal Locomotion.

Front Neurorobot 2019 20;13:78. Epub 2019 Sep 20.

Engineering Products Development Pillar, Singapore University of Technology and Design, Singapore, Singapore.

Modern engineering problems require solutions with multiple functionalities in order to meet their practical needs to handle a variety of applications in different scenarios. Conventional design paradigms for single design purpose may not be able to satisfy this requirement efficiently. This paper proposes a novel system-of-systems bio-inspired design method framed in a solution-driven bio-inspired design paradigm. The whole design process consists of eight steps, that is, (1) biological solutions identification, (2) biological solutions definition/champion biological solutions, (3) principle extraction from each champion biological solution, (4) merging of extracted principles, (5) solution reframing, (6) problem search, (7) problem definition, and (8) principles application & implementation. The steps are elaborated and a case study of reconfigurable robots is presented following these eight steps. The design originates from the multimodal locomotion capabilities of two species (i.e., spiders and primates) and is analyzed based on the Pugh analysis. The resulting robotic platform could be potentially used for urban patrolling purposes.
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http://dx.doi.org/10.3389/fnbot.2019.00078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6763944PMC
September 2019

A microfluidic approach for probing hydrodynamic effects in barite scale formation.

Lab Chip 2019 04;19(9):1534-1544

Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204-4004, USA.

Crystallization of mineral scale components ubiquitously plagues industrial systems for water treatment, energy production, and manufacturing. Chemical scale inhibitors and/or dissolvers are often employed to control scale formation, but their efficacy in flow conditions remains incompletely understood. We present a microfluidic platform to elucidate the time-resolved processes controlling crystallization and dissolution of barite, a highly insoluble and chemically resistant component of inorganic scale, in the presence of flow. In a growth environment, increasing the flow rate leads to a crossover from a transport-limited to a reaction-limited kinetic regime. In situ optical microscopy reveals that addition of diethylenetriaminepentaacetic acid (DTPA), a common dissolution agent, alters the morphology of barite crystals grown under flow. In a dissolution environment (i.e. alkaline solutions without barium sulfate), increasing the flux of DTPA, whether by increasing the flow rate or DTPA concentration, enhances the rate of dissolution of barite. Trends in the rate of barite dissolution with DTPA concentration and flow rate indicate an optimal combination of these parameters. The combined use of microfluidics and optical microscopy provides a robust and broadly-useful platform for capturing crystallization kinetics and morphological transformation under dynamic flow conditions.
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http://dx.doi.org/10.1039/c9lc00061eDOI Listing
April 2019

Prevalence of caries and malocclusion in an indigenous population in Chiapas, Mexico.

Int Dent J 2015 Oct 18;65(5):249-55. Epub 2015 Sep 18.

San Francisco School of Dentistry, University of California, San Francisco, CA, USA.

Objectives: To assess the prevalence of caries and malocclusion in Mayan Mexican adolescents, 14-20 years of age, living in Chiapas, Mexico.

Methods: This was a cross-sectional, population-based, quantitative, epidemiological study. Sites were chosen to capture subjects representative of the state's Mayan population. A total of 354 subjects were recruited. Caries experience was quantified, via visual inspection, using the Decayed, Missing and Filled Surface (DMFS) index. Malocclusion was quantified using the Index of Complexity, Outcome and Need (ICON).

Results: Our data showed that 99% of the population had caries experience, with a median DMFS score of 8. Of the 99% with caries experience, over half had caries affecting more than five tooth surfaces. Thirty-seven per cent of the students had unmet orthodontic treatment need, and 46.46% presented a Class II, and 39.09% a Class III, anterior-posterior relationship.

Conclusions: Less than 1% of the population had any exposure to orthodontics, demonstrating the lack of access to care. Likewise, only 1% of the population was found to have no caries experience, exhibiting a large unmet treatment need. The median DMFS score of 8 was also high in comparison with the median DMFS in the USA of 6. Our data suggest a correlation between the lack of access to care and high prevalence of caries and malocclusion in Mexican Mayans who inhabit Chiapas, Mexico.
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http://dx.doi.org/10.1111/idj.12177DOI Listing
October 2015

Natural promoters of calcium oxalate monohydrate crystallization.

J Am Chem Soc 2014 Sep 27;136(36):12648-57. Epub 2014 Aug 27.

Department of Chemical and Biomolecular Engineering, University of Houston , Houston, Texas 77204, United States.

Crystallization is often facilitated by modifiers that interact with specific crystal surfaces and mediate the anisotropic rate of growth. Natural and synthetic modifiers tend to function as growth inhibitors that hinder solute attachment and impede the advancement of layers on crystal surfaces. There are fewer examples of modifiers that operate as growth promoters, whereby modifier-crystal interactions accelerate the kinetic rate of crystallization. Here, we examine two proteins, lysozyme and lactoferrin, which are observed in the organic matrix of three types of pathological stones: renal, prostatic, and pancreatic stones. This work focuses on the role of these proteins in the crystallization of calcium oxalate monohydrate (COM), the most prominent constituent of human kidney stones. Using a combination of experimental techniques, we show that these proteins, which are rich in l-arginine and l-lysine amino acids, promote COM growth. The synthesis and testing of peptides derived from contiguous segments of lysozyme's primary amino acid sequence revealed subdomains within the protein that operate either as an inhibitor or promoter of COM growth, with the latter exhibiting efficacies that nearly match that of the protein. We observed that cationic proteins promote COM growth over a wide range of modifier concentration, which differs from calcification promoters in the literature that exhibit dual roles as promoters and inhibitors at low and high concentration, respectively. This seems to suggest a unique mechanism of action for lysozyme and lactoferrin. Possible explanations for their effects on COM growth and crystal habit are proposed on the basis of classical colloidal theories and the physicochemical properties of peptide subdomains, including the number and spatial location of charged or hydrogen-bonding moieties.
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http://dx.doi.org/10.1021/ja505402rDOI Listing
September 2014
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