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Torre, Fernando Torres de la,Torres de la Torre, Fernando 한국외국어대학 서반아어과 1986 AULA Vol.4 No.1

First-principles calculation of volatile organic compound adsorption on carbon nanotubes: Furan as case of study

Torres Ana M.,Correa J. D. 한국탄소학회 2021 Carbon Letters Vol.31 No.5

Sensing of volatile organic compounds (VOCs) is a growing research topic because of the concern about their hazard for the environment and health. Furan is a VOC produced during food processing, and it has been classifed as a risk molecule for human health and a possible biomarker of prostate cancer. The use of carbon nanotubes for VOCs sensing systems design could be a good alternative. In this work, a theoretical evaluation of the interactions between furan and zigzag single-wall carbon nanotubes takes into account diferent positions and orientations of the furan molecule, within a density-functional theory frst-principles approach. The van der Waals interactions are considered using diferent exchange-correlation functionals (BH,C09, DRSLL and KBM). The results indicate that vdW-functionals do not signifcantly afect geometry; however, the binding energy and the distance between furan and nanotube are strongly dependent on the selected exchange-correlation functional. On the other hand, the efects of single and double vacancies on carbon nanotube are considered. It was found that the redistribution of charge around the single-vacancy afects the bandgap, magnetic moment, and binding energy of the complex, while furan interaction with a double-vacancy does not considerably change the electronic structure of the system. Our results suggest that to induce changes in the electronic properties of carbon nanotubes by furan, it is necessary to change the nanotube surface, for example, by means of structural defects.

Hospitality Service Innovation: KLEEDing an Outstanding Guest Experience

Torres, Arnelyn Manaluz,말런 사이프 차세대컨버전스정보서비스학회 2020 차세대컨버전스정보서비스기술논문지 Vol.9 No.2

The paper proposes to innovate service strategies following the KLEED model that expands to the attributes for the outstanding guest experience. The study is based on a review of academic literature, business news reports and online resources regarding human touch and technology the hotel industry is using. The suggestions were drawn from the authors’ guest journey experience while staying in different hotels. Human touch or personal interaction is an integral part of the hospitality service business, and should never be set aside. In the same way for technology, adopting it contributes to the value creation of the hospitality business resulting in greater guest satisfaction. Thus, a blend of human touch and technology turns out to be the main ingredients for the outstanding guest experience. This paper used the authors’ experience as hotel guests and other business reports to draw suggestions on how a blended service will create outstanding guest experience.

Technology Convergence in Tourism Education: Modelling a Multimedia Technology Inclusive Academic Instruction

Torres, Arnelyn Manaluz 차세대컨버전스정보서비스학회 2022 디지털예술공학멀티미디어논문지 Vol.9 No.2

COVID-19 laid the groundwork for the transition from traditional to digital classrooms during its peak period. In the digital classroom, various technologies enhance teachings, such as hardware (PCs, laptops, tablets, and smartphones) and software (social media sites, videos, slides, sounds, and narrations). To illustrate how digital technologies enhance, innovate, and keep up with tourism education, this paper describes how convergences of digital technologies enhance, innovate, and update tourism education. The author selected a hybrid classroom setting as a case study for International Tourism and Culture, a course offered during the Fall 2021 semester. In designing and implementing the course, the facilitator employed content, pedagogical, and technological knowledge. As part of the course management plan, both the facilitator and students will utilize technology. The study concludes that incorporating multimedia technology in teaching tourism courses provides numerous advantages, such as 1) time and space flexibility, 2) development and practice of technical competencies, 3) positive effect on students' engagement, and 4) promotion of soft skills development. Integrating multimedia technology into the teaching of courses and throughout the curriculum contributes to the development of strategies for transforming Tourism Education.

Wild mushroom consumption in the P’urhépecha Plateau at Michoacán, México: social, ethnomycological and nutritional issues

Torres-Gómez Mariano,Gómez-Peralta Marlene,Vázquez-Marrufo Gerardo 한국식품연구원 2023 Journal of Ethnic Foods Vol.10 No.4

Among Mesoamerican cultures, P’urhépecha settlers inhabiting Michoacán State in Central Mexico preserve ancestral tradition on mushrooms eating. Most mycological knowledge available for this ethnical group has been addressed in the Pátzcuaro’s Lake zone, whereas P’urhépecha communities in other cultural and ecological relevant geographic areas remain unstudied. Thus, this work describes the ethnomycological knowledge of a scarcely analyzed Arantepacua P’urhépecha community at Michoacán Plateau region. Through structured interviews and field collections, data on the use, knowledge, biomass extraction and nomenclature of wild mushrooms were obtained. A list of P’urhépecha names to design 16 wild mushrooms species and 11 fruitbody components is documented and studied community used Spanish popular names to describe 21 wild mushrooms species and 11 fruitbody structures. Most valuable consumed mushroom species for Arantepacua settlers belong to the Amanita, Boletus, Hypomyces and Ramaria genera. Gender roles on mushrooms collect and cooking, new terms in P’urhépecha dialect to refer the parts of a fruitbody and vegetative mycelium, as well as local recipes and nutritional relevance of the mushroom species consumed by studied community are addressed and discussed. The ethnomycological knowledge documented contributes new terms in P’urhépecha to name the parts of an agarical fruitbody, the mycelium and empirical knowledge about mycorrhizal associations. This was the first P’urhépecha ethnomycological study made outside the Lake Pátzcuaro basin.

Micro-computed tomographic evaluation of the flow and filling ability of endodontic materials using different test models

Torres Fernanda Ferrari Esteves,Guerreiro-Tanomaru Juliane Maria,Chavez-Andrade Gisselle Moraima,Pinto Jader Camilo,Berbert Fábio Luiz Camargo Villela,Tanomaru-Filho Mario 대한치과보존학회 2020 Restorative Dentistry & Endodontics Vol.45 No.2

Objectives: This study compared the flow and filling of several retrograde filling materials using new different test models. Materials and Methods: Glass plates were manufactured with a central cavity and 4 grooves in the horizontal and vertical directions. Grooves with the dimensions used in the previous study (1 × 1 × 2 mm; length, width, and height respectively) were compared with grooves measuring 1 × 1 × 1 and 1 × 2 × 1 mm. Biodentine, intermediate restorative material (IRM), and mineral trioxide aggregate (MTA) were evaluated. Each material was placed in the central cavity, and then another glass plate and a metal weight were placed over the cement. The glass plate/material set was scanned using micro-computed tomography. Flow was calculated by linear measurements in the grooves. Central filling was calculated in the central cavity (mm3 ) and lateral filling was measured up to 2 mm from the central cavity. Results: Biodentine presented the least flow and better filling than IRM when evaluated in the 1 × 1 × 2 model. In a comparison of the test models, MTA had the most flow in the 1 × 1 × 2 model. All materials had lower lateral filling when the 1 × 1 × 2 model was used. Conclusions: Flow and filling were affected by the size of the test models. Higher grooves and materials with greater flow resulted in lower filling capacity. The test model measuring 1 × 1 × 2 mm showed a better ability to differentiate among the materials.

CO₂ absorption enhancement by nanoabsorbents in Taylor-Couette absorber

Torres Pineda, I.,Kang, Y.T. Pergamon Press ; Elsevier Science Ltd 2016 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.100 No.-

CO<SUB>2</SUB> gas is physically absorbed in liquid methanol in bubbly Taylor-Couette absorber. The experiments are performed in the turbulent regime with rotational Reynolds numbers ranging from 1.9x10<SUP>4</SUP> to 19.2x10<SUP>4</SUP>. The volumetric mass transfer coefficients are obtained for the counter-current operation. Methanol is utilized as the base absorbent. In addition, with the purpose of enhancing CO<SUB>2</SUB> absorption performance, Al<SUB>2</SUB>O<SUB>3</SUB> nanoparticles are combined with methanol to produce the absorbent. The results show an increase in the volumetric mass transfer coefficient that reaches a maximum value at 4x10<SUP>4</SUP> rotational Reynolds number for both pure methanol and the nanoabsorbents, after which the absorption rate declines almost linearly with the rotational speed. The reasons for the reduction in the absorption performance are discussed. The maximum enhancement in the volumetric mass transfer coefficient is estimated at 20% for 4x10<SUP>4</SUP> rotational Reynolds number and up to 27% for methanol and Al<SUB>2</SUB>O<SUB>3</SUB> nanoparticles at a concentration of 0.1vol%.

A micro-computed tomographic study using a novel test model to assess the filling ability and volumetric changes of bioceramic root repair materials

Torres Fernanda Ferrari Esteves,Pinto Jader Camilo,Figueira Gabriella Oliveira,Guerreiro-Tanomaru Juliane Maria,Tanomaru-Filho Mario 대한치과보존학회 2021 Restorative Dentistry & Endodontics Vol.46 No.1

Objectives: New premixed bioceramic root repair materials require moisture for setting. Using micro-computed tomography (micro-CT), this study evaluated the filling ability and volumetric changes of calcium silicate-based repair materials (mineral trioxide aggregate repair high-plasticity [MTA HP] and Bio-C Repair, Angelus), in comparison with a zinc oxide and eugenol-based material (intermediate restorative material [IRM]; Dentsply DeTrey). Materials and Methods: Gypsum models with cavities 3 mm deep and 1 mm in diameter were manufactured and scanned using micro-CT (SkyScan 1272. Bruker). The cavities were filled with the cements and scanned again to evaluate their filling capacity. Another scan was performed after immersing the samples in distilled water for 7 days to assess the volumetric changes of the cements. The statistical significance of differences in the data was evaluated using analysis of variance and the Tukey test with a 5% significance level. Results: Bio-C Repair had a greater filling ability than MTA HP (p < 0.05). IRM was similar to Bio-C and MTA HP (p > 0.05). MTA HP presented the largest volumetric change (p < 0.05), showing more volume loss than Bio-C and IRM, which were similar (p > 0.05). Conclusions: Bio-C Repair is a new endodontic material with excellent filling capacity and low volumetric change. The gypsum model proposed for evaluating filling ability and volumetric changes by micro-CT had appropriate and reproducible results. This model may enhance the physicochemical evaluation of premixed bioceramic materials, which need moisture for setting.

How do imaging protocols affect the assessment of root-end fillings?

Torres Fernanda Ferrari Esteves,Jacobs Reinhilde,EzEldeen Mostafa,de Faria-Vasconcelos Karla,Guerreiro-Tanomaru Juliane Maria,dos Santos Bernardo Camargo,Tanomaru-Filho Mário 대한치과보존학회 2022 Restorative Dentistry & Endodontics Vol.47 No.1

Objectives This study investigated the impact of micro-computed tomography (micro-CT)-based voxel size on the analysis of material/dentin interface voids and thickness of different endodontic cements. Materials and Methods Following root-end resection and apical preparation, maxillary premolars were filled with mineral trioxide aggregate (MTA), Biodentine, and intermediate restorative material (IRM) (n = 24). The samples were scanned using micro-CT (SkyScan 1272; Bruker) and the cement/dentin interface and thickness of materials were evaluated at voxel sizes of 5, 10, and 20 µm. Analysis of variance and the Tukey test were conducted, and the degree of agreement between different voxel sizes was evaluated using the Bland and Altman method (p < 0.05). Results All materials showed an increase in thickness from 5 to 10 and 20 µm (p < 0.05). When evaluating the interface voids, materials were similar at 5 µm (p > 0.05), while at 10 and 20 µm Biodentine showed the lowest percentage of voids (p < 0.05). A decrease in the interface voids was observed for MTA and IRM at 20 µm, while Biodentine showed differences among all voxel sizes (p < 0.05). The Bland-Altman plots for comparisons among voxel sizes showed the largest deviations when comparing images between 5 and 20 µm. Conclusions Voxel size had an impact on the micro-CT evaluation of thickness and interface voids of endodontic materials. All cements exhibited an increase in thickness and a decrease in the void percentage as the voxel size increased, especially when evaluating images at 20 µm.

Mass transfer analysis for CO₂ bubble absorption in methanol/Al₂O₃ nanoabsorbents

Torres Pineda, Israel,Kim, Dongmin,Kang, Yong Tae Elsevier 2017 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.114 No.-

<P><B>Abstract</B></P> <P>In this paper computational fluid dynamics (CFD) analysis is carried out to investigate CO<SUB>2</SUB> bubble absorption characteristics in methanol/Al₂O<SUB>3</SUB> nanoabsorbents. Bubble size, rising velocity and mass transfer rate are compared to the previous experimental results for validation. It is found that the distance traveled for each CO<SUB>2</SUB> bubble increases as the concentration of Al<SUB>2</SUB>O<SUB>3</SUB> increases, which, in consequence, increases the residence time between liquid and gas phases resulting in higher interfacial mass transfer rates. For the case of a bubble rising in the gap between walls, the wall shear stress has a major effect on the bubble diameter and rising velocity which in consequence affects the mass transfer coefficient. It is concluded that the mass transfer coefficient enhances by about 40% by adding Al₂O<SUB>3</SUB> nanoparticles (0.01vol%) compared with pure methanol absorbent from the experimental and simulation results. It is also concluded that the use of nanoparticles has a higher impact on mass transfer rate than it does on mass transfer amount, which depends on the residence time and travel distance of CO<SUB>2</SUB> bubbles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mass transfer analysis is carried out for CO<SUB>2</SUB> bubble absorption in nanoabsorbents. </LI> <LI> CO<SUB>2</SUB> absorption enhancement by nanoabsorbents is evaluated. </LI> <LI> Mass transfer coefficient enhances by about 40% by adding Al₂O<SUB>3</SUB> nanoparticles (0.01vol%). </LI> <LI> The use of nanoparticles has a higher impact on mass transfer rate than it does on mass transfer amount. </LI> </UL> </P>