Search results for: Aura Gutierrez
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 78

Search results for: Aura Gutierrez

48 Pharmacokinetics of Oral Controlled-Release Formulation of Doxycycline Hyclate with Polymethacrylate and Acrylic Acid for Dogs

Authors: S. M. Arciniegas, D. Vargas, L. Gutierrez

Abstract:

The aim of this study was to develop oral drug presentation of doxycycline hyclate that maintains longer therapeutic levels than conventional forms. A polymethacrylate and acrylic acid based matrix were used in different proportions to obtain controlled-release formulations; DOX1 (1:0.25:0.0035), DOX2 (1:2:0.0225) and DOX-C (without excipients). All were tested in vivo in healthy dogs and their serum concentrations vs. time profile was investigated after its oral administration in this species. DOX1 and DOX2 show therapeutic concentrations for 60 hours, while DOX-C only for 24 hours. The pharmacokinetics values tested were K½el, Cmax, Tmax, AUC, AUC∞, AUCt, AUMC, RT, Kel, Vdss, Clb and Frel. DOX1 does not differ significantly from DOX-C, but shows significant differences in all variables with DOX2 (p<0.05). In conclusion, DOX1 presents best pharmacokinetics for time-dependent drug and longer release time of 60 hours, thereby reducing the frequency of administration, the patient's stress, the occurrence of adverse effects and the cost of treatment.

Keywords: tetracyclines, long-acting, sustained-release, carbopol, eudragit, canine

Procedia PDF Downloads 583
47 Synchronization of Two Mobile Robots

Authors: R. M. López-Gutiérrez, J. A. Michel-Macarty, H. Cervantes-De Avila, J. I. Nieto-Hipólito, C. Cruz-Hernández, L. Cardoza-Avendaño, S. Cortiant-Velez

Abstract:

It is well know that mankind benefits from the application of robot control by virtual handlers in industrial environments. In recent years, great interest has emerged in the control of multiple robots in order to carry out collective tasks. One main trend is to copy the natural organization that some organisms have, such as, ants, bees, school of fish, birds’ migration, etc. Surely, this collaborative work, results in better outcomes than those obtain in an isolated or individual effort. This topic has a great drive because collaboration between several robots has the potential capability of carrying out more complicated tasks, doing so, with better efficiency, resiliency and fault tolerance, in cases such as: coordinate navigation towards a target, terrain exploration, and search-rescue operations. In this work, synchronization of multiple autonomous robots is shown over a variety of coupling topologies: star, ring, chain, and global. In all cases, collective synchronous behavior is achieved, in the complex networks formed with mobile robots. Nodes of these networks are modeled by a mass using Matlab to simulate them.

Keywords: robots, synchronization, bidirectional, coordinate navigation

Procedia PDF Downloads 328
46 Flocculation on the Treatment of Olive Oil Mill Wastewater: Pre-Treatment

Authors: G. Hodaifa, J. A. Páez, C. Agabo, E. Ramos, J. C. Gutiérrez, A. Rosal

Abstract:

Currently, the continuous two-phase decanter process used for olive oil production is the more internationally widespread. The wastewaters generated from this industry (OMW) is a real environmental problem because of its high organic load. Among proposed treatments for these wastewaters, the advanced oxidation technologies (Fenton process, ozone, photoFenton, etc.) are the most favourable. The direct application of these processes is somewhat expensive. Therefore, the application of a previous stage based on a flocculation-sedimentation operation is of high importance. In this research five commercial flocculants (three cationic, and two anionic) have been used to achieve the separation of phases (liquid clarified-sludge). For each flocculant, different concentrations (0-1000 mg/L) have been studied. In these experiments, sludge volume formed over time and the final water quality were determined. The final removal percentages of total phenols (11.3-25.1%), COD (5.6-20.4%), total carbon (2.3-26.5%), total organic carbon (1.50-23.8%), total nitrogen (1.45-24.8%), and turbidity (27.9-61.4%) were obtained. Also, the variation on the electric conductivity reduction percentage (1-8%) was determined. Finally, the best flocculants with highest removal percentages have been determined (QG2001 and Flocudex CS49).

Keywords: flocculants, flocculation, olive oil mill wastewater, water quality

Procedia PDF Downloads 511
45 Analysis of the Optical Behavior of Diffuse Reflectance in Polycrystalline Yttrium–Iron Garnet Synthesized by Different Methods and its Effect to Estimate Eg by Tauc Plot

Authors: Lis Tamayo-Rivera, Anette Lopez-Sierra, Diana Salvador-Garcia, Joel E. Valdivieso-Villegas, María del Pilar Gutiérrez-Amador, Ariadna Sánchez-Castillo.

Abstract:

Due to fast progress in communication systems development, garnets are an attractive material due to their unique optical and magnetic properties. The band gap energy (Eg) of Yttrium- Iron Garnet (Y3Fe5O12, YIG) is a key parameter to determine its potential technological applications; however, band gap values can be strongly influenced by the synthesis route and processing method. Electronic features of polycrystalline Yttrium-Iron Garnet samples were obtained through optical diffuse reflectance spectroscopy. Optical characterization of polycrystalline YIG samples allowed to observe a clear difference in the amplitude and position of the high and low reflectivity bands around the fundamental absorption energy edge, thus, a review of different criteria to estimate Eg by Tauc plot method is also discussed. The differences observed in the optical properties agree with differences in the structural and microstructural characteristics.

Keywords: diffuse reflectance, energy gap, polycrystal, tauc plot, yttrium-iron garnet

Procedia PDF Downloads 43
44 Factors Motivating Experienced Secondary Teachers to Remain in the Teaching Profession

Authors: Joselito Castro Gutierrez, Herbert Orteza, Jervie Boligon, Kenneth Esteves, Edrick Kevin Ferrer, Mark Kevin Torres, Patrick Vergara

Abstract:

Teaching is a noble profession that involves an effective imparting of holistic learning. Consequently, it requires a driving force called motivation. This research aims to determine the motivating factors, problems encountered, solutions made by experienced secondary school teachers to remain in the teaching profession. A mixed unstructured/structured questionnaire was used for gathering data among public secondary school teachers. The researchers have arrived to a conclusion that the dominant motivating factors of teachers to stay in the profession are altruism, extrinsic factors, and self-efficacy. Meanwhile, the prevalent problems these experienced secondary teachers experienced are mutual dilemma, work overload, and personal issues. Teachers have varied methods on solving the problem which are: a) Direct Solution; b) Indirect Solution; and c) Pseudo-Solutions. Lastly, the factors, problems, and solutions, have influential effects on how long a teacher would sustain in teaching which would manifest as positive, negative and neutral effects.

Keywords: motivation, common problems of teachers, strategies in solving problems, teaching profession

Procedia PDF Downloads 412
43 Studying the Linguistics of Hungarian Luxurious Brands: Analysing the Sound Effects from a non-Hungarian Consumer’s Perspective

Authors: Syrine Bassi

Abstract:

Sound symbolism has been able to give us an exciting new tool to target consumers’ brand perception. It acts on a subconscious level making them less likely to reject the implicit message delivered by the sound of the brand name. Most of the research conducted in the field was focused on the English language as it is the language used for international branding campaigns and global companies. However, more research is examining the sound symbolism in other languages and comparing it to the English language findings. Besides, researchers have been able to study luxury brand names and spot out the patterns used in them to provoke luxury and sophistication. It stands to a reason to connect the luxury brand names and the local language’s sound effects since a considerable number of these brands are promoting the origin of the Maison, therefore, have names in foreign languages. This study was established around the Hungarian luxury brand names. It aims to spot out the patterns used in these names that connect to the previous findings of luxury sound effects and also the differences. We worked with a non-Hungarian speaking sample who had some basic knowledge of the language just to make sure they were able to correctly pronounce the names. The results have shown both similarities and differences when it comes to perceiving luxury based on the brand name. As the Hungarian language can be qualified as a saturated language, consonant wise, it was easy to feed the luxury feeling only by using designers' names, however, some complicated names were too difficult and repulsive to consider as luxurious. On the other hand, oversimplifying some names did not convey the desired image as it was too simple and easy. Overall, some sounds have been proved to be linked to luxury as the literature suggests, the difficulty of pronunciation has also proved effective since it highlights the distant feeling consumers crave when looking for luxury. These results suggest that sound symbolism can set up an aura of luxury when used properly, leveraging each languages’ convenient assets.

Keywords: hungarian language, linguistics, luxury brands, sound symbolism

Procedia PDF Downloads 87
42 Synthesis of Biofuels of New Generation

Authors: Selena Gutiérrez, Araceli Martínez

Abstract:

One of the most important challenges worldwide, scientific and technological, is to have a sustainable energy source; friendly to the environment and widely available. Currently, the 85% of the energy used comes from the fossil sources. Another important environmental problem is that several rubber products (tires, gloves, hoses, among others) are discarded practically without any treatment. In nature, the degradation of such products will take at least 500 years. In 2009, the worldwide rubber production was about 23.6 million tons. In order to solve this problems, our research focus in an alternative synthesis of biofuels in a two-step approach: The metathesis degradation of industrial rubber (models of rubber waste), and the oligomers transesterification. Thus, cis-1,4-polybutadiene (Mn= 9.1x105, Mw/Mn= 2.2) and styrene-butadiene block copolymers with 30% (Mn= 1.61x105; Mw/Mn= 1.3) and 21% wt styrene (Mn= 1.92x105; Mw/Mn= 1.4) were degraded via metathesis with soybean oil as chain transfer agent (CTA) and green solvent; using [(PCy3)2Cl2Ru=CHPh] and [(1,3-diphenyl-4,5-dihydroimidazol-2-ylidene)(PCy3)Ru=CHPh] catalysts. Afterwards, the products were transesterified by basic homogeneous catalysis. Before transesterification, the polystyrene microblocks (Mn= 16,761; Mw/Mn= 1.2) were isolated. Finally, the biofuels obtained (BO) were purified, characterized and showed similar properties to standards biodiesel (SB) (Norms: EN 14214-03 and ASTM D6751-02), i.e. (SB / BO): molecular weight [Daltons] (570 / 543-596), density [g/cm3] (0.86-0.90 / 0.88), kinematic viscosity [mm2/s] (1.90-6.0 / 3.5-4.5), iodine (97 / 97-98) and cetane number (Min.47 / 56-58).

Keywords: biofuels, industrial rubber, metathesis, vegetable oils

Procedia PDF Downloads 232
41 Parameters Adjustment of the Modified UBCSand Constitutive Model for the Potentially Liquefiable Sands of Santiago de Cali-Colombia

Authors: Daniel Rosero, Johan S. Arana, Sebastian Arango, Alejandro Cruz, Isabel Gomez-Gutierrez, Peter Thomson

Abstract:

Santiago de Cali is located in the southwestern Colombia in a high seismic hazard zone. About 50% of the city is on the banks of the Cauca River, which is the second most important hydric affluent in the country and whose alluvial deposits contain potentially liquefiable sands. Among the methods used to study a site's liquefaction potential is the finite elements method which use constitutive models to simulate the soil response for different load types. Among the different constitutive models, the Modified UBCSand stands out to study the seismic behavior of sands, and especially the liquefaction phenomenon. In this paper, the dynamic behavior of a potentially liquefiable sand of Santiago de Cali is studied by cyclic triaxial and CPTu tests. Subsequently, the behavior of the sand is simulated using the Modified UBCSand constitutive model, whose parameters are calibrated using the results of cyclic triaxial and CPTu tests. The above with the aim of analyze the constitutive model applicability for studying the geotechnical problems associated to liquefaction in the city.

Keywords: constitutive model, cyclic triaxial test, dynamic behavior, liquefiable sand, modified ubcsand

Procedia PDF Downloads 242
40 A Dialectical Behavioral Therapy Adaptation in Reducing Depression, Anxiety, and Self-Harm in Older Adults

Authors: Valerie Alexander, Amanda Gutierrez, Veronica Campbell, Dara Schwartz, B. Charles Tatum

Abstract:

It has long been assumed that personality disorders (PD) originate in adolescence or early adulthood and that the maladaptive behaviors significantly attenuate over time. The Diagnostic and Statistical Manual of Mental Disorders-5 supports early onset of PD and views the pattern of behaviors as enduring and stable. The premise of this study is that PD may not always begin early in life, that behaviors may change over the lifespan, and that current treatment modalities may be beneficial in seniors. Self-injurious behaviors (SIB) exhibited earlier in life may, in older adults, be manifested in less overt high-risk behaviors but by refusal to take medication and get necessary medical treatment. Dialectical Behavioral Therapy is a well-known treatment modality for teaching emotional regulation and distress tolerance and thus reducing self-injurious behaviors yet very little has been studied about SIB and treatment in older adults. The population for this study was older adults, with a history of SIB, a PD, and depression and/or anxiety. Participants learned an adapted version of Dialectical Behavioral Therapy (DBT) as developed by DBT trained therapists. The results provided clinical potentials for the efficacy of DBT to reduce SIB, decrease depression and anxiety in the older adult population.

Keywords: anxiety, depression, dialectical behavioral therapy, personality disorders, self-harm behavior, treatment in older adults

Procedia PDF Downloads 278
39 An Adaptive Application of Emotionally Focused Couple Therapy with Trans and Nonbinary Couples

Authors: Reihaneh Mahdavishahri, Dumayi Gutierrez

Abstract:

Emotionally focused couple therapy (EFCT) is one of the most effective and evidence-based approaches to couple therapy. Yet, literature is scarce of its effective application with trans and non-binary couples. It is estimated that 1.4 million trans adults live in the United Stated, with about 40% of these individuals experiencing serious psychological distress within the past month. Trans and nonbinary adults are significantly likely to experience discrimination, harassment, family rejection, and relationship challenges throughout the course of their lives. As systemic therapists, applying an informed lens when working with trans and nonbinary couples can contribute to providing effective mental health care to these individuals. This paper aims to provide a comprehensive, intersectional, and culturally informed application of EFCT with trans and nonbinary couples. We will address the current literature on applications of EFCT with diverse couples, EFCT’s strengths and limitations on cultural humility, and the gaps within current systems of care for trans and nonbinary couples. We will then provide an adaptive application of EFCT to help trans, and nonbinary couples recover from potential attachment injuries in their relationships, intersecting gender minority stressors, and achieve healing and restoration in their interpersonal dynamics.

Keywords: attachment, culturally informed care, emotionally focused couple therapy, trans and nonbinary couples

Procedia PDF Downloads 48
38 Correlations between Wear Rate and Energy Dissipation Mechanisms in a Ti6Al4V–WC/Co Sliding Pair

Authors: J. S. Rudas, J. M. Gutiérrez Cabeza, A. Corz Rodríguez, L. M. Gómez, A. O. Toro

Abstract:

The prediction of the wear rate of rubbing pairs has attracted the interest of many researchers for years. It has been recently proposed that the sliding wear rate can be inferred from the calculation of the energy rate dissipated by the tribological pair. In this paper some of the dissipative mechanisms present in a pin-on-disc configuration are discussed and both analytical and numerical calculations are carried out. Three dissipative mechanisms were studied: First, the energy release due to temperature gradients within the solid; second, the heat flow from the solid to the environment, and third, the energy loss due to abrasive damage of the surface. The Finite Element Method was used to calculate the dynamics of heat transfer within the solid, with the aid of commercial software. Validation the FEM model was assisted by virtual and laboratory experimentation using different operating points (sliding velocity and geometry contact). The materials for the experiments were Ti6Al4V alloy and Tungsten Carbide (WC-Co). The results showed that the sliding wear rate has a linear relationship with the energy dissipation flow. It was also found that energy loss due to micro-cutting is relevant for the system. This mechanism changes if the sliding velocity and pin geometry are modified though the degradation coefficient continues to present a linear behavior. We found that the less relevant dissipation mechanism for all the cases studied is the energy release by temperature gradients in the solid.

Keywords: degradation, dissipative mechanism, dry sliding, entropy, friction, wear

Procedia PDF Downloads 474
37 An Anthropological Reading of the Italian Shockumentary Mondo Cane: Whiteness Made Visible and Racial Discourses

Authors: Claudia Pisano

Abstract:

The Italian shockumentary Mondo cane (1962), directed by Gualtiero Jacopetti, Paolo Cavara, and Franco Prosperi, has often been criticized for its supposed racist and colonialist stances. Several critics consider it a film that proclaims, without explicitly mentioning it, the superiority of the white Euro-American individual over the people who do not belong to white-western societies. This paper proposes a different interpretation of the way in which Mondo cane engages with the discourse of race. Through an analysis of crucial scenes and of the relationship between images and voice-over, and through a comparison between the representation of non-white societies in Mondo cane and in some popular Italian newsreels of the 50s-60s, such as 'La Settimana Incom' and 'Mondo Libero,' the paper argues that Mondo cane debunks the western-white superiority that, according to some critics, the film would promote. The continuous and rapid alternance of scenes set in the western world, for example in Europe or in the United States, and scenes set in exotic countries inhabited by non-white peoples highlights the commonalities between these far-away realities, rather than pointing out the superiority of the white-western one. In addition, the subtle irony employed by the voice-over distances Mondo cane from the newsreels that it much resembles for its documentary style. Mondo cane’s treatment and representation of race is analyzed in the light of the work of Australian Aboriginal anthropologist Aileen Moreton-Robinson, which is based on key concepts such as whiteness and whiteness invisibility. Whiteness is defined as the invisible and omnipresent norm based on which everything that does not belong to the white world is labeled as an odd and inferior 'other.' To overcome racial discrimination, it is necessary to make whiteness visible; that is to say, to deprive it of that aura of normalcy and unquestionable righteousness that surrounds it. This essay argues that Mondo cane participates in the process of making whiteness visible through the confrontation of the white people with the visible 'other'. Because the film shows that the common features on which this confrontation is based are violence and bestiality, the paper suggests that the film does not support the idea of the white world being superior to the non-white; on the contrary, it underlines that the entire world is characterized by the same shocking savagery.

Keywords: irony, race, shockumentary, whiteness, whiteness invisibility

Procedia PDF Downloads 100
36 Co-Alignment of Comfort and Energy Saving Objectives for U.S. Office Buildings and Restaurants

Authors: Lourdes Gutierrez, Eric Williams

Abstract:

Post-occupancy research shows that only 11% of commercial buildings met the ASHRAE thermal comfort standard. Many buildings are too warm in winter and/or too cool in summer, wasting energy and not providing comfort. In this paper, potential energy savings in U.S. offices and restaurants if thermostat settings are calculated according the updated ASHRAE 55-2013 comfort model that accounts for outdoor temperature and clothing choice for different climate zones. eQUEST building models are calibrated to reproduce aggregate energy consumption as reported in the U.S. Commercial Building Energy Consumption Survey. Changes in energy consumption due to the new settings are analyzed for 14 cities in different climate zones and then the results are extrapolated to estimate potential national savings. It is found that, depending on the climate zone, each degree increase in the summer saves 0.6 to 1.0% of total building electricity consumption. Each degree the winter setting is lowered saves 1.2% to 8.7% of total building natural gas consumption. With new thermostat settings, national savings are 2.5% of the total consumed in all office buildings and restaurants, summing up to national savings of 69.6 million GJ annually, comparable to all 2015 total solar PV generation in US. The goals of improved comfort and energy/economic savings are thus co-aligned, raising the importance of thermostat management as an energy efficiency strategy.

Keywords: energy savings quantifications, commercial building stocks, dynamic clothing insulation model, operation-focused interventions, energy management, thermal comfort, thermostat settings

Procedia PDF Downloads 278
35 Effect of Brown Algae, Ecklonia arborea and Silvetia compressa, in Lipidemic and Hepatic Metabolism in Wistar Rats

Authors: Laura Acevedo-Pacheco, Janet Alejandra Gutierrez-Uribe, Lucia Elizabeth Cruz-Suarez, Segio Othon Serna-Saldivar

Abstract:

Seaweeds can generate changes in the metabolism of lipids; as a consequence, this may diminish cholesterol and other lipids in the blood. However, the consumption of marine algae may also alter the functions of other organs. Therefore, the objective of this research was to study the effect of two different sorts of algae (Ecklonia arborea and Silvetia compressa) in the metabolism of lipids, as well as, in the physiology of the liver. Wistar male rats were fed for two months with independent diets composed of 20% of fat and 2.5% of E. arborea and S. compressa each. Blood parameters (cholesterol, lipoproteins, triglycerides, hepatic enzymes) and triglycerides in the liver were quantified, and also hepatic histology analyses were performed. While S. compressa reduced 18% total cholesterol compared to the positive control, E. arborea increased it 5.8%. Animals fed with S. compressa presented a decrement, compared to the positive control, not only in low density lipoproteins levels (53%) but also in triglycerides (67%). The presence of steatosis in the histologies and the high levels of triglycerides showed an evident lipid accumulation in hepatic tissues of rats fed with both algae. These results indicate that even though S. compressa showed a promising resource to decrease total cholesterol and low-density lipoproteins in blood, a detrimental effect was observed in liver physiology. Further investigations should be made to find out if toxic compounds associated with these seaweeds may cause liver damage especially in terms of heavy metals.

Keywords: brown algae, Eisenia arborea, hepatic metabolism, lipidemic metabolism, Pelvetia compressa, steatosis

Procedia PDF Downloads 105
34 Comparison of Low Velocity Impact Test on Coir Fiber Reinforced Polyester Composites

Authors: Ricardo Mendoza, Jason Briceño, Juan F. Santa, Gabriel Peluffo, Mauricio Márquez, Beatriz Cardozo, Carlos Gutiérrez

Abstract:

The most common controlled method to obtain impact strength of composites materials is performing a Charpy Impact Test which consists of a pendulum with calibrated mass and length released from a known height. In fact, composites components experience impact events in normal operations such as when a tool drops or a foreign object strikes it. These events are categorized into low velocity impact (LVI) which typically occurs at velocities below 10m/s. In this study, the major aim was to calculate the absorbed energy during the impact. Tests were performed on three types of composite panels: fiberglass laminated panels, coir fiber reinforced polyester and coir fiber reinforced polyester subjected to water immersion for 48 hours. Coir fibers were obtained in local plantations of the Caribbean coast of Colombia. They were alkali treated in 5% aqueous NaOH solution for 2h periods. Three type of shape impactors were used on drop-weight impact test including hemispherical, ogive and pointed. Failure mechanisms and failure modes of specimens were examined using an optical microscope. Results demonstrate a reduction in absorbed energy correlated with the increment of water absorption of the panels. For each level of absorbed energy, it was possible to associate a different fracture state. This study compares results of energy absorbed obtained from two impact test methods.

Keywords: coir fiber, polyester composites, low velocity impact, Charpy impact test, drop-weight impact test

Procedia PDF Downloads 429
33 Network Conditioning and Transfer Learning for Peripheral Nerve Segmentation in Ultrasound Images

Authors: Harold Mauricio Díaz-Vargas, Cristian Alfonso Jimenez-Castaño, David Augusto Cárdenas-Peña, Guillermo Alberto Ortiz-Gómez, Alvaro Angel Orozco-Gutierrez

Abstract:

Precise identification of the nerves is a crucial task performed by anesthesiologists for an effective Peripheral Nerve Blocking (PNB). Now, anesthesiologists use ultrasound imaging equipment to guide the PNB and detect nervous structures. However, visual identification of the nerves from ultrasound images is difficult, even for trained specialists, due to artifacts and low contrast. The recent advances in deep learning make neural networks a potential tool for accurate nerve segmentation systems, so addressing the above issues from raw data. The most widely spread U-Net network yields pixel-by-pixel segmentation by encoding the input image and decoding the attained feature vector into a semantic image. This work proposes a conditioning approach and encoder pre-training to enhance the nerve segmentation of traditional U-Nets. Conditioning is achieved by the one-hot encoding of the kind of target nerve a the network input, while the pre-training considers five well-known deep networks for image classification. The proposed approach is tested in a collection of 619 US images, where the best C-UNet architecture yields an 81% Dice coefficient, outperforming the 74% of the best traditional U-Net. Results prove that pre-trained models with the conditional approach outperform their equivalent baseline by supporting learning new features and enriching the discriminant capability of the tested networks.

Keywords: nerve segmentation, U-Net, deep learning, ultrasound imaging, peripheral nerve blocking

Procedia PDF Downloads 76
32 Effect of Segregation on the Reaction Rate of Sewage Sludge Pyrolysis in a Bubbling Fluidized Bed

Authors: A. Soria-Verdugo, A. Morato-Godino, L. M. García-Gutiérrez, N. García-Hernando

Abstract:

The evolution of the pyrolysis of sewage sludge in a fixed and a fluidized bed was analyzed using a novel measuring technique. This original measuring technique consists of installing the whole reactor over a precision scale, capable of measuring the mass of the complete reactor with enough precision to detect the mass released by the sewage sludge sample during its pyrolysis. The inert conditions required for the pyrolysis process were obtained supplying the bed with a nitrogen flowrate, and the bed temperature was adjusted to either 500 ºC or 600 ºC using a group of three electric resistors. The sewage sludge sample was supplied through the top of the bed in a batch of 10 g. The measurement of the mass released by the sewage sludge sample was employed to determine the evolution of the reaction rate during the pyrolysis, the total amount of volatile matter released, and the pyrolysis time. The pyrolysis tests of sewage sludge in the fluidized bed were conducted using two different bed materials of the same size but different densities: silica sand and sepiolite particles. The higher density of silica sand particles induces a flotsam behavior for the sewage sludge particles which move close to the bed surface. In contrast, the lower density of sepiolite produces a neutrally-buoyant behavior for the sewage sludge particles, which shows a proper circulation throughout the whole bed in this case. The analysis of the evolution of the pyrolysis process in both fluidized beds show that the pyrolysis is faster when buoyancy effects are negligible, i.e. in the bed conformed by sepiolite particles. Moreover, sepiolite was found to show an absorbent capability for the volatile matter released during the pyrolysis of sewage sludge.

Keywords: bubbling fluidized bed, pyrolysis, reaction rate, segregation effects, sewage sludge

Procedia PDF Downloads 326
31 Lessons of Passive Environmental Design in the Sarabhai and Shodan Houses by Le Corbusier

Authors: Juan Sebastián Rivera Soriano, Rosa Urbano Gutiérrez

Abstract:

The Shodan House and the Sarabhai House (Ahmedabad, India, 1954 and 1955, respectively) are considered some of the most important works of Le Corbusier produced in the last stage of his career. There are some academic publications that study the compositional and formal aspects of their architectural design, but there is no in-depth investigation into how the climatic conditions of this region were a determining factor in the design decisions implemented in these projects. This paper argues that Le Corbusier developed a specific architectural design strategy for these buildings based on scientific research on climate in the Indian context. This new language was informed by a pioneering study and interpretation of climatic data as a design methodology that would even involve the development of new design tools. This study investigated whether their use of climatic data meets values and levels of accuracy obtained with contemporary instruments and tools, such as Energy Plus weather data files and Climate Consultant. It also intended to find out if Le Corbusier's office’s intentions and decisions were indeed appropriate and efficient for those climate conditions by assessing these projects using BIM models and energy performance simulations from Design Builder. Accurate models were built using original historical data through archival research. The outcome is to provide a new understanding of the environment of these houses through the combination of modern building science and architectural history. The results confirm that in these houses, it was achieved a model of low energy consumption. This paper contributes new evidence not only on exemplary modern architecture concerned with environmental performance but also on how it developed progressive thinking in this direction.

Keywords: bioclimatic architecture, Le Corbusier, Shodan, Sarabhai Houses

Procedia PDF Downloads 36
30 Effects of Accelerated Environment Aging on the Mechanical Properties of a Coir Fiber Reinforced Polyester Composite

Authors: Ricardo Mendoza, Jason Briceño, Juan F. Santa, Gabriel Peluffo, Mauricio Márquez, Beatriz Cardozo, Carlos Gutiérrez

Abstract:

Coir natural fiber reinforced polyester composites were exposed to an accelerated environment aging in order to study the influence on the mechanical properties. Coir fibers were obtained in local plantations of the Caribbean coast of Colombia. A physical and mechanical characterization was necessary to found the best behavior between three types of coconut. Composites were fabricated by hand lay-up technique and samples were cut by water jet technique. An accelerated aging test simulates environmental climate conditions in a hygrothermal and ultraviolet chamber. Samples were exposed to the UV/moisture rich environment for 500 and 1000 hours. The tests were performed in accordance with ASTM G154. An additional water absorption test was carried out by immersing specimens in a water bath. Mechanical behaviors of the composites were tested by tensile, flexural and impact test according to ASTM standards, after aging and compared with unaged composite specimens. It was found that accelerated environment aging affects mechanical properties in comparison with unaged ones. Tensile and flexural strength were lower after aging, meantime elongation at break and flexural deflection increased. Impact strength was found that reduced after aging. Other result revealed that the percentage of moisture uptake increased with aging. This results showed that composite materials reinforced with natural fibers required an improvement adding a protective barrier to reduce water absorption and increase UV resistance.

Keywords: coir fiber, polyester composites, environmental aging, mechanical properties

Procedia PDF Downloads 250
29 TutorBot+: Automatic Programming Assistant with Positive Feedback based on LLMs

Authors: Claudia Martínez-Araneda, Mariella Gutiérrez, Pedro Gómez, Diego Maldonado, Alejandra Segura, Christian Vidal-Castro

Abstract:

The purpose of this document is to showcase the preliminary work in developing an EduChatbot-type tool and measuring the effects of its use aimed at providing effective feedback to students in programming courses. This bot, hereinafter referred to as tutorBot+, was constructed based on chatGPT and is tasked with assisting and delivering timely positive feedback to students in the field of computer science at the Universidad Católica de Concepción. The proposed working method consists of four stages: (1) Immersion in the domain of Large Language Models (LLMs), (2) Development of the tutorBot+ prototype and integration, (3) Experiment design, and (4) Intervention. The first stage involves a literature review on the use of artificial intelligence in education and the evaluation of intelligent tutors, as well as research on types of feedback for learning and the domain of chatGPT. The second stage encompasses the development of tutorBot+, and the final stage involves a quasi-experimental study with students from the Programming and Database labs, where the learning outcome involves the development of computational thinking skills, enabling the use and measurement of the tool's effects. The preliminary results of this work are promising, as a functional chatBot prototype has been developed in both conversational and non-conversational versions integrated into an open-source online judge and programming contest platform system. There is also an exploration of the possibility of generating a custom model based on a pre-trained one tailored to the domain of programming. This includes the integration of the created tool and the design of the experiment to measure its utility.

Keywords: assessment, chatGPT, learning strategies, LLMs, timely feedback

Procedia PDF Downloads 35
28 Characterization of Chest Pain in Patients Consulting to the Emergency Department of a Health Institution High Level of Complexity during 2014-2015, Medellin, Colombia

Authors: Jorge Iván Bañol-Betancur, Lina María Martínez-Sánchez, María de los Ángeles Rodríguez-Gázquez, Estefanía Bahamonde-Olaya, Ana María Gutiérrez-Tamayo, Laura Isabel Jaramillo-Jaramillo, Camilo Ruiz-Mejía, Natalia Morales-Quintero

Abstract:

Acute chest pain is a distressing sensation between the diaphragm and the base of the neck and it represents a diagnostic challenge for any physician in the emergency department. Objective: To establish the main clinical and epidemiological characteristics of patients who present with chest pain to the emergency department in a private clinic from the city of Medellin, during 2014-2015. Methods: Cross-sectional retrospective observational study. Population and sample were patients who consulted for chest pain in the emergency department who met the eligibility criteria. The information was analyzed in SPSS program vr.21; qualitative variables were described through relative frequencies, and the quantitative through mean and standard deviation ‬or medians according to their distribution in the study population. Results: A total of 231 patients were evaluated, the mean age was 49.5 ± 19.9 years, 56.7% were females. The most frequent pathological antecedents were hypertension 35.5%, diabetes 10,8%, dyslipidemia 10.4% and coronary disease 5.2%. Regarding pain features, in 40.3% of the patients the pain began abruptly, in 38.2% it had a precordial location, for 20% of the cases physical activity acted as a trigger, and 60.6% was oppressive. Costochondritis was the most common cause of chest pain among patients with an established etiologic diagnosis, representing the 18.2%. Conclusions: Although the clinical features of pain reported coincide with the clinical presentation of an acute coronary syndrome, the most common cause of chest pain in study population was costochondritis instead, indicating that it is a differential diagnostic in the approach of patients with pain acute chest.

Keywords: acute coronary syndrome, chest pain, epidemiology, osteochondritis

Procedia PDF Downloads 311
27 First Approximation to Congenital Anomalies in Kemp's Ridley Sea Turtle (Lepidochelys kempii) in Veracruz, Mexico

Authors: Judith Correa-Gomez, Cristina Garcia-De la Pena, Veronica Avila-Rodriguez, David R. Aguillon-Gutierrez

Abstract:

Kemp's ridley (Lepidochelys kempii) is the smallest species of sea turtle. It nests on the beaches of the Gulf of Mexico during summer. To date, there is no information about congenital anomalies in this species, which could be an important factor to be considered as a survival threat. The aim of this study was to determine congenital anomalies in dead embryos and hatchlings of Kemp's ridley sea turtle during 2020 nesting season. Fieldwork was conducted at the 'Campamento Tortugero Barra Norte', on the shores of Tuxpan, Veracruz, Mexico. A total of 95 nests were evaluated, from which 223 dead embryos and hatchlings were collected. Anomalies were detected by detailed physical examinations. Photographs of each anomaly were taken. From the 223 dead turtles, 213 (95%) showed a congenital anomaly. A total of 53 types of congenital anomalies were found: 22 types on the head region, 21 on the carapace region, 6 on the flipper region, and 4 regarding the entire body. The most prevalent anomaly in the head region was the presence of prefrontal supernumerary scales (42%, 93 occurrences). On the carapace region, the most common anomaly was the presence of supernumerary gular scales (59%, 131 occurrences). The two most common anomalies on the flipper region were amelia in fore flippers and rear bifurcation of flippers (0.9%, 2 occurrences each). The most common anomaly involving the entire body was hypomelanism (35%, 79 occurrences). These results agree with the recent studies on congenital malformations on sea turtles, being the head and the carapace regions the ones with the highest number of congenital anomalies. It is unknown whether the reported anomalies can be related to the death of these individuals. However, it is necessary to develop embryological studies in this species. To our best knowledge, this is the first worldwide report on Kemp’s ridley sea turtle anomalies.

Keywords: Amelia, hypomelanism, morphology, supernumerary scales

Procedia PDF Downloads 132
26 Generic Competences, the Great Forgotten: Teamwork in the Undergraduate Degree in Translation and Interpretation

Authors: María-Dolores Olvera-Lobo, Bryan John Robinson, Juncal Gutierrez-Artacho

Abstract:

Graduates are equipped with a wide range of generic competencies which complement solid curricular competencies and facilitate their access to the labour market in diverse fields and careers. However, some generic competencies such as instrumental, personal and systemic competencies related to teamwork and interpersonal communication skills, decision-making and organization skills are seldom taught explicitly and even less often assessed. In this context, translator training has embraced a broad range of competencies specified in the undergraduate program currently taught at universities and opens up the learning experience to cover areas often ignored due to the difficulties inherent in both teaching and assessment. In practice, translator training combines two well-established approaches to teaching/learning: project-based learning and genuinely cooperative – or merely collaborative – learning. Our professional approach to translator training is a model focused on and adapted to the teleworking context of professional translation and presented through the medium of blended e-learning. Teamwork-related competencies are extremely relevant, and they require explicit and implicit teaching so that graduates can be confident about their capacity to make their way in professional contexts. In order to highlight the importance of teamwork and intra-team relationships beyond the classroom, we aim to raise awareness of teamwork processes so as to empower translation students in managing their interaction and ensure that they gain valuable pre-professional experience. With these objectives, at the University of Granada (Spain) we have developed a range of classroom activities and assessment tools. The results of their application are summarized in this study.

Keywords: blended learning, collaborative teamwork, cross-curricular competencies, higher education, intra-team relationships, students’ perceptions, translator training

Procedia PDF Downloads 141
25 Assesment of Quality of Life among Iranian Male Amateur Athletes via WHOQOL-Brief

Authors: Shirko Ahmadi, Ahmad Fallahi, Marco C. Uchida, Gustavo L. Gutierrez

Abstract:

The aims of the present study are to assess and compare the health habits and quality of life (QoL) of Iranian amateur athletes in different sports. A total of 120 male amateur athletes between 17 and 31 years, engaged in 16 kinds of sports which include team (n=44), individual (n=40) and combat sports (n=36) from sports clubs in the west cities of Iran; and also those not involved in any competition in the past. Additionally, this is a cross-sectional, descriptive observational study, which the subjects completed the WHOQOL-brief questionnaire to evaluate QoL. The questionnaire is composed of 26 questions in four domains (physical health, psychological, social and environmental domains), that was applied in the Persian language. Information on the frequency and duration of training sessions were also collected. The Shapiro-Wilk test was used to verify normal distribution, followed by the chi-squared test for proportions and simple analysis of variance for comparisons between groups of sports. Pearson’s correlation was used to assess the relationships between the variables analyzed. According to the findings, those from individual sports obtained highest points in the all domains of QoL; physical domains (87.1 ± 8.1 point), psychological domains (87.6 ± 9.6 point), social domains (89.7 ± 9.2 point), environmental domains (75.5± 10.7 point) and overall QoL score (84.9 ± 9.4 point). Generally, social domains were the highest QoL index (84.3 ± 7.2 points), and environmental domains were the lowest QoL index (68.1 ± 10.8 points), in all of the sports. No correlations were found between QoL domains and time engaged in the sport (r = 0.01; p = 0.93), number of weekly training sessions (r = 0.09; p = 0.37) and session duration (r = -0.06; p= 0.58). Comparison of QoL results with those of the general population revealed higher levels in the physical and psychological components of amateur athletes. In the present study, engaging in sports was associated with higher QoL levels in amateur athletes, particularly in the physical and psychological domains. Moreover, correlations were found between the overall score and domains of QoL.

Keywords: amateur, domains, Iranian, quality of life

Procedia PDF Downloads 128
24 Accumulation of Pollutants, Self-Purification and Impact on Peripheral Urban Areas: A Case Study in Shantytowns in Argentina

Authors: N. Porzionato, M. Mantiñan, E. Bussi, S. Grinberg, R. Gutierrez, G. Curutchet

Abstract:

This work sets out to debate the tensions involved in the processes of contamination and self-purification in the urban space, particularly in the streams that run through the Buenos Aires metropolitan area. For much of their course, those streams are piped; their waters do not come into contact with the outdoors until they have reached deeply impoverished urban areas with high levels of environmental contamination. These are peripheral zones that, until thirty years ago, were marshlands and fields. They are now densely populated areas largely lacking in urban infrastructure. The Cárcova neighborhood, where this project is underway, is in the José León Suárez section of General San Martín country, Buenos Aires province. A stretch of José León Suarez canal crosses the neighborhood. Starting upstream, this canal carries pollutants due to the sewage and industrial waste released into it. Further downstream, in the neighborhood, domestic drainage is poured into the stream. In this paper, we formulate a hypothesis diametrical to the one that holds that these neighborhoods are the primary source of contamination, suggesting instead that in the stretch of the canal that runs through the neighborhood the stream’s waters are actually cleaned and the sediments accumulate pollutants. Indeed, the stretches of water that runs through these neighborhoods act as water processing plants for the metropolis. This project has studied the different organic-load polluting contributions to the water in a certain stretch of the canal, the reduction of that load over the course of the canal, and the incorporation of pollutants into the sediments. We have found that the surface water has considerable ability to self-purify, mostly due to processes of sedimentation and adsorption. The polluting load is accumulated in the sediments where that load stabilizes slowly by means of anaerobic processes. In this study, we also investigated the risks of sediment management and the use of the processes studied here in controlled conditions as tools of environmental restoration.

Keywords: bioremediation, pollutants, sediments, urban streams

Procedia PDF Downloads 411
23 A Microcosm Study on the Response of Phytoplankton and Bacterial Community of the Subarctic Northeast Atlantic Ocean to Oil Pollution under Projected Atmospheric CO₂ Conditions

Authors: Afiq Mohd Fahmi, Tony Gutierrez, Sebastian Hennige

Abstract:

Increasing amounts of CO₂ entering the marine environment, also known as ocean acidification, is documented as having harmful impacts on a variety of marine organisms. When considering the future risk of hydrocarbon pollution, which is generally detrimental to marine life as well, this needs to consider how OA-induced changes to microbial communities will compound this since hydrocarbon degradation is influenced by the community-level microbial response. This study aims to evaluate the effects of increased atmospheric CO₂ conditions and oil enrichment on the phytoplankton-associated bacterial communities. Faroe Shetland Channel (FSC) is a subarctic region in the northeast Atlantic where crude oil extraction has recently been expanded. In the event of a major oil spill in this region, it is vital that we understand the response of the bacterial community and its consequence on primary production within this region—some phytoplankton communities found in the ocean harbor hydrocarbon-degrading bacteria that are associated with its psychosphere. Surface water containing phytoplankton and bacteria from FSC were cultured in ambient and elevated atmospheric CO₂ conditions for 4 days of acclimation in microcosms before introducing 1% (v/v) of crude oil into the microcosms to simulate oil spill conditions at sea. It was found that elevated CO₂ conditions do not significantly affect the chl a concentration, and exposure to crude oil detrimentally affected chl a concentration up to 10 days after exposure to crude oil. The diversity and richness of the bacterial community were not significantly affected by both CO₂ treatment and oil enrichment. The increase in the relative abundance of known hydrocarbon degraders such as Oleispira, Marinobacter and Halomonas indicates potential for biodegradation of crude oil, while the resilience of dominant taxa Colwellia, unclassified Gammaproteobacteria, unclassified Rnodobacteria and unclassified Halomonadaceae could be associated with the recovery of microalgal community 13 days after oil exposure. Therefore, the microbial community from the subsurface of FSC has the potential to recover from crude oil pollution even under elevated CO₂ (750 ppm) conditions.

Keywords: phytoplankton, bacteria, crude oil, ocean acidification

Procedia PDF Downloads 201
22 Reflections of Narrative Architecture in Transformational Representations on the Architectural Design Studio

Authors: M. Mortas, H. Asar, P. Dursun Cebi

Abstract:

The visionary works of architectural representation in the 21st century's present situation, are practiced through the methodologies which try to expose the intellectual and theoretical essences of futurologist positions that are revealed with this era's interactions. Expansions of conceptual and contextual inputs related to one architectural design representation, depend on its deepness of critical attitudes, its interactions with the concepts such as experience, meaning, affection, psychology, perception and aura, as well as its communication with spatial, cultural and environmental factors. The purpose of this research study is to be able to offer methodological application areas for the design dimensions of experiential practices into architectural design studios, by focusing on the architectural representative narrations of 'transformation,' 'metamorphosis,' 'morphogenesis,' 'in-betweenness', 'superposition' and 'intertwine’ in which they affect and are affected by the today’s spatiotemporal hybridizations of architecture. The narrative representations and the visual theory paradigms of the designers are chosen under the main title of 'transformation' for the investigation of these visionary and critical representations' dismantlings and decodings. Case studies of this research area are chosen from Neil Spiller, Bryan Cantley, Perry Kulper and Dan Slavinsky’s transformative, morphogenetic representations. The theoretical dismantlings and decodings which are obtained from these artists’ contemporary architectural representations are tried to utilize and practice in the structural design studios as alternative methodologies when to approach architectural design processes, for enriching, differentiating, diversifying and 'transforming' the applications of so far used design process precedents. The research aims to indicate architectural students about how they can reproduce, rethink and reimagine their own representative lexicons and so languages of their architectural imaginations, regarding the newly perceived tectonics of prosthetic, biotechnology, synchronicity, nanotechnology or machinery into various experiential design workshops. The methodology of this work can be thought as revealing the technical and theoretical tools, lexicons and meanings of contemporary-visionary architectural representations of our decade, with the essential contents and components of hermeneutics, etymology, existentialism, post-humanism, phenomenology and avant-gardism disciplines to re-give meanings the architectural visual theorists’ transformative representations of our decade. The value of this study may be to emerge the superposed and overlapped atmospheres of futurologist architectural representations for the students who need to rethink on the transcultural, deterritorialized and post-humanist critical theories to create and use the representative visual lexicons of themselves for their architectural soft machines and beings by criticizing the now, to be imaginative for the future of architecture.

Keywords: architectural design studio, visionary lexicon, narrative architecture, transformative representation

Procedia PDF Downloads 115
21 Modern Pilgrimage Narratives and India’s Heterogeneity

Authors: Alan Johnson

Abstract:

This paper focuses on modern pilgrimage narratives about sites affiliated with Indian religious expressions located both within and outside India. The paper uses a multidisciplinary approach to examine poetry, personal essays, and online attestations of pilgrimage to illustrate how non-religious ideas coexist with outwardly religious ones, exemplifying a characteristically Indian form of syncretism that pre-dates Western ideas of pluralism. The paper argues that the syncretism on display in these modern creative works refutes the current exclusionary vision of India as a primordially Hindu-nationalist realm. A crucial premise of this argument is that the narrative’s intrinsic heteroglossia, so evident in India’s historically rich variety of stories and symbols, belies this reactionary version of Hindu nationalism. Equally important to this argument, therefore, is the vibrancy of Hindu sites outside India, such as the Batu Caves temple complex in Kuala Lumpur, Malaysia. The literary texts examined in this paper include, first, Arun Kolatkar’s famous 1976 collection of poems, titled Jejuri, about a visit to the pilgrimage site of the same name in Maharashtra. Here, the modern, secularized visitor from Bombay (Mumbai) contemplates the effect of the temple complex on himself and on the other, more worshipful visitors. Kolatkar’s modernist poems reflect the narrator’s typically modern-Indian ambivalence for holy ruins, for although they do not evoke a conventionally religious feeling in him, they nevertheless possess an aura of timelessness that questions the narrator’s time-conscious sensibility. The paper bookends Kolatkar’s Jejuri with considerations of an early-twentieth-century text, online accounts by visitors to the Batu Caves, and a recent, more conventional Hindu account of pilgrimage. For example, the pioneering graphic artist Mukul Chandra Dey published in 1917, My Pilgrimages to Ajanta and Bagh, in which he devotes an entire chapter to the life of the Buddha as a means of illustrating the layering of stories that is a characteristic feature of sacred sites in India. In a different but still syncretic register, Jawaharlal Nehru, India’s first prime minister, and a committed secularist proffers India’s ancient pilgrimage network as a template for national unity in his classic 1946 autobiography The Discovery of India. Narrative is the perfect vehicle for highlighting this layering of sensibilities, for a single text can juxtapose the pilgrim-narrator’s description with that of a far older pilgrimage, a juxtaposition that establishes an imaginative connection between otherwise distanced actors, and between them and the reader.

Keywords: India, literature, narrative, syncretism

Procedia PDF Downloads 130
20 Effector and Memory Immune Responses Induced by Total Extracts of Naegleria fowleri Co-Administered with Cholera Toxin

Authors: Q. B. Maria de la Luz Ortega Juárez, Saúl Rojas Hernández, Itzel Berenice Rodríguez Mera, María Maricela Carrasco Yépez, Mara Gutierrez Sánchez

Abstract:

Naegleria fowleri is a free-living amoeba found mainly in temperate freshwater and is the etiologic agent of primary amebic meningoencephalitis (PAM), a fatal acute disease with a mortality rate greater than 95%. At present, there are no treatments available for MAP, and the development of effective vaccines that generate long-term immunological memory allowing protection against MAP would be of great importance. The objective of this work was to analyze the effector and memory immune response in BALB/c mice immunized with total extract of N. fowleri co-administered with cholera toxin. In this study, BALB/c mice were immunized four times intranasally with ET of N. fowleri adjuvanted with CT with or without booster at three months and were challenged or not with the lethal dose of N. fowleri, determining survival, the humoral, effector and memory response, by ELISA and flow cytometry techniques. The results obtained showed that the survival of mice immunized with booster had 60% protection compared to the group without booster, which obtained 20% protection. Evaluating the humoral response, it was found that both IgG and IgA levels were higher in sera than in nasal washes in both treatments. In the cellular response, the increase in the percentage of positive cells was found for effector T and B lymphocytes in the nasal passages (NP) in the group with boost and nasopharynx-associated lymphoid tissue (NALT) in the group without boost and lymphocytes only. B in both treatments, as well as in memory cells treatment with boost T lymphocytes in PN and NALT and without boost in cervical lymph nodes (CG) with respect to B lymphocytes, in PN, GC and NALT in treatment with boost and NALT in treatment without booster. Therefore, the involvement of the effector immune response and memory play a fundamental role for protection against N. fowleri and for the development of vaccine candidates.

Keywords: immune response, immunological memory, naegleria fowleri, primary amebic meningoencephalitis

Procedia PDF Downloads 48
19 Assessment of the Performance of the Sonoreactors Operated at Different Ultrasound Frequencies, to Remove Pollutants from Aqueous Media

Authors: Gabriela Rivadeneyra-Romero, Claudia del C. Gutierrez Torres, Sergio A. Martinez-Delgadillo, Victor X. Mendoza-Escamilla, Alejandro Alonzo-Garcia

Abstract:

Ultrasonic degradation is currently being used in sonochemical reactors to degrade pollutant compounds from aqueous media, as emerging contaminants (e.g. pharmaceuticals, drugs and personal care products.) because they can produce possible ecological impacts on the environment. For this reason, it is important to develop appropriate water and wastewater treatments able to reduce pollution and increase reuse. Pollutants such as textile dyes, aromatic and phenolic compounds, cholorobenzene, bisphenol-A and carboxylic acid and other organic pollutants, can be removed from wastewaters by sonochemical oxidation. The effect on the removal of pollutants depends on the type of the ultrasonic frequency used; however, not much studies have been done related to the behavior of the fluid into the sonoreactors operated at different ultrasonic frequencies. Based on the above, it is necessary to study the hydrodynamic behavior of the liquid generated by the ultrasonic irradiation to design efficient sonoreactors to reduce treatment times and costs. In this work, it was studied the hydrodynamic behavior of the fluid in sonochemical reactors at different frequencies (250 kHz, 500 kHz and 1000 kHz). The performances of the sonoreactors at those frequencies were simulated using computational fluid dynamics (CFD). Due to there is great sound speed gradient between piezoelectric and fluid, k-e models were used. Piezoelectric was defined as a vibration surface, to evaluate the different frequencies effect on the fluid into sonochemical reactor. Structured hexahedral cells were used to mesh the computational liquid domain, and fine triangular cells were used to mesh the piezoelectric transducers. Unsteady state conditions were used in the solver. Estimation of the dissipation rate, flow field velocities, Reynolds stress and turbulent quantities were evaluated by CFD and 2D-PIV measurements. Test results show that there is no necessary correlation between an increase of the ultrasonic frequency and the pollutant degradation, moreover, the reactor geometry and power density are important factors that should be considered in the sonochemical reactor design.

Keywords: CFD, reactor, ultrasound, wastewater

Procedia PDF Downloads 169