Search results for: Sepulveda Juan
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 331

Search results for: Sepulveda Juan

181 Outbreak of Pulmonary Tuberculosis in Cojutepeque Military Brigade, El Salvador, July 2013

Authors: Juan Santos Garcia

Abstract:

Introduction: Tuberculosis is a chronic granulomatous disease caused by a microorganism called Mycobacterium tuberculosis, it has the capacity to spread from the lungs to other parts of the body. Globally, the rate per 100 thousand inhabitants has varied from 136 in 2007 to 122 in 2012; while in the region of the Americas has been much lower: 32 cases per 100,000 in 2007, to 29 in 2012. In El Salvador have also varied incidence rates from 2007 to 2012, from 27.4 cases per 100 000 population to 32 in the period indicated. Methods: Screening was performed with smear and chest X-ray at 80 military personnel from Military Brigade # 5 of El Salvador. Besides HIV tests were taken at the positive cases, which are also made interview, investigating demographic, clinical, laboratory and risk factors data. Frequencies, percentages and rates were calculated using Excel page. The rates were calculated for each of the 5 military bedrooms (called A, B, C, D, and E). Results: Attack rate was 18.75% in the bedroom C. the index case was identified and two secondary cases, with an exposure period of 59 days. Only the index case presented symptoms: cough, fever and weight loss. The other two cases had no symptoms. Discussion: We found a rate of tuberculosis 526 times higher than the national rate. He was also 12.5 times higher than that found in other studies in closed populations such as school facilities. It was not possible to make association analysis.

Keywords: tuberculosis, outbreak, military brigade, chronic granulomatous disease

Procedia PDF Downloads 259
180 Numerical Analysis of Wire Laser Additive Manufacturing for Low Carbon Steels+

Authors: Juan Manuel Martinez Alvarez, Michele Chiumenti

Abstract:

This work explores the benefit of the thermo-metallurgical simulation to tackle the Wire Laser Additive Manufacturing (WLAM) of low-carbon steel components. The Finite Element Analysis is calibrated by process monitoring via thermal imaging and thermocouples measurements, to study the complex thermo-metallurgical behavior inherent to the WLAM process of low carbon steel parts.A critical aspect is the analysis of the heterogeneity in the resulting microstructure. This heterogeneity depends on both the thermal history and the residual stresses experienced during the WLAM process. Because of low carbon grades are highly sensitive to quenching, a high-gradient microstructure often arises due to the layer-by-layer metal deposition in WLAM. The different phases have been identified by scanning electron microscope. A clear influence of the heterogeneities on the final mechanical performance has been established by the subsequent mechanical characterization. The thermo-metallurgical analysis has been used to determine the actual thermal history and the corresponding thermal gradients during the printing process. The correlation between the thermos-mechanical evolution, the printing parameters and scanning sequence has been established. Therefore, an enhanced printing strategy, including optimized process window has been used to minimize the microstructure heterogeneity at ArcelorMittal.

Keywords: additive manufacturing, numerical simulation, metallurgy, steel

Procedia PDF Downloads 71
179 Role of Physiotherapist: How Their Job and Working Area Could Be Known

Authors: Juan Pablo Hervas-Perez, Jesus Guodemar-Perez, Montserrat Ruiz-Lopez, Elena Sonsoles Rodriguez-Lopez, Noemi Mayoral-Gonzalo, Eduardo Cimadevilla Fernandez-Pola, Mario Caballero-Corella

Abstract:

Physiotherapy is a healthcare discipline that covers many fields of action within the recovery and prevention of health. Some are well known, but others, such as working with newborns and premature children are not so. Physical therapist functions are well defined, but the impression of the population is that there are other professionals who can develop them, and a large part are unknown. Objective: To evaluate the level of knowledge of the sample on the role of the physiotherapist in general, and more specifically in the neonatal intensive care (NICU) units, and estimate your level of notions on the development centered care (DCC). Method: A descriptive, transversal, observational and prospective study developed on a 125 participants' sample. Results: From the sample studied, 87.2% had already had contact with physiotherapy previously. An 80.9% believed that the physiotherapist intervention was decisive for the cure, and 84.0% would recommend physiotherapy treatment to others. Of the total surveyed, 98.0% felt that the physiotherapist is who should run the physiotherapeutic treatments, but shares with other professions 71.0% of votes. The field's best-known work is rehabilitation (94.0%); Neonatology is on the 4th place (66.0% of votes). Conclusions: Many areas of work of physical therapy are unknown to a big part of the population, including the own health workers. Less than half of the sample meets the DCC, and only 58% of the interviewed physiotherapists know them.

Keywords: functions of physiotherapist, neonatal intensive care, physiotherapy, prematurity

Procedia PDF Downloads 330
178 Biosurfactants Produced by Antarctic Bacteria with Hydrocarbon Cleaning Activity

Authors: Claudio Lamilla, Misael Riquelme, Victoria Saez, Fernanda Sepulveda, Monica Pavez, Leticia Barrientos

Abstract:

Biosurfactants are compounds synthesized by microorganisms that show various chemical structures, including glycolipids, lipopeptides, polysaccharide-protein complex, phospholipids, and fatty acids. These molecules have attracted attention in recent years due to the amphipathic nature of these compounds, which allows their application in various activities related to emulsification, foaming, detergency, wetting, dispersion and solubilization of hydrophobic compounds. Microorganisms that produce biosurfactants are ubiquitous, not only present in water, soil, and sediments but in extreme conditions of pH, salinity or temperature such as those present in Antarctic ecosystems. Due to this, it is of interest to study biosurfactants producing bacterial strains isolated from Antarctic environments, with the potential to be used in various biotechnological processes. The objective of this research was to characterize biosurfactants produced by bacterial strains isolated from Antarctic environments, with potential use in biotechnological processes for the cleaning of sites contaminated with hydrocarbons. The samples were collected from soils and sediments in the South Shetland Islands and the Antarctic Peninsula, during the Antarctic Research Expedition INACH 2016, from both pristine and human occupied areas (influenced). The bacteria isolation was performed from solid R2A, M1 and LB media. The selection of strains producing biosurfactants was done by hemolysis test on blood agar plates (5%) and blue agar (CTAB). From 280 isolates, it was determined that 10 bacterial strains produced biosurfactants after stimulation with different carbon sources. 16S rDNA taxonomic markers, using the universal primers 27F-1492R, were used to identify these bacterias. Biosurfactants production was carried out in 250 ml flasks using Bushnell Hass liquid culture medium enriched with different carbon sources (olive oil, glucose, glycerol, and hexadecane) during seven days under constant stirring at 20°C. Each cell-free supernatant was characterized by physicochemical parameters including drop collapse, emulsification and oil displacement, as well as stability at different temperatures, salinity, and pH. In addition, the surface tension of each supernatant was quantified using a tensiometer. The strains with the highest activity were selected, and the production of biosurfactants was stimulated in six liters of culture medium. Biosurfactants were extracted from the supernatants with chloroform methanol (2:1). These biosurfactants were tested against crude oil and motor oil, to evaluate their displacement activity (detergency). The characterization by physicochemical properties of 10 supernatants showed that 80% of them produced the drop collapse, 60% had stability at different temperatures, and 90% had detergency activity in motor and olive oil. The biosurfactants obtained from two bacterial strains showed a high activity of dispersion of crude oil and motor oil with halos superior to 10 cm. We can conclude that bacteria isolated from Antarctic soils and sediments provide biological material of high quality for the production of biosurfactants, with potential applications in the biotechnological industry, especially in hydrocarbons -contaminated areas such as petroleum.

Keywords: antarctic, bacteria, biosurfactants, hydrocarbons

Procedia PDF Downloads 279
177 Airbnb, Hotel Industry and Optimum Strategies: Evidence from European Cities, Barcelona, London and Paris

Authors: Juan Pedro Aznar Alarcon, Josep Maria Sayeras Maspera

Abstract:

Airbnb and other similar platforms are offering a near substitute to the traditional accommodation service supplied by the hotel sector. In this context, hotels can try to compete by offering higher quality and additional services, which imply the need for new investments or try to compete by reducing prices. The theoretical model presented in this paper analyzes the best response using a sequential game theory model. The main conclusion is that due to the financial constraints that small and medium hotels have these hotels have reduced prices whereas hotels that belong to international groups or have an easy access to financial resources have increased their investment to increase the quality of the service provided. To check the validity of the theoretical model financial data from Barcelona, London and Paris hotels have been used analyzing profitability, quality of the service provided, the investment propensity and the evolution of the gross profit. The model and the empirical data provide the base for some industrial policy in the hospitality industry. To address the extra cost that small hotels in Europe have to face compared by bigger firms would help to improve the level of quality provided and to some extent have positive externalities in terms of job creation and an increasing added value for the industry.

Keywords: Airbnb, profitability, hospitality industry, game theory

Procedia PDF Downloads 348
176 Power Ultrasound Application on Convective Drying of Banana (Musa paradisiaca), Mango (Mangifera indica L.) and Guava (Psidium guajava L.)

Authors: Erika K. Méndez, Carlos E. Orrego, Diana L. Manrique, Juan D. Gonzalez, Doménica Vallejo

Abstract:

High moisture content in fruits generates post-harvest problems such as mechanical, biochemical, microbial and physical losses. Dehydration, which is based on the reduction of water activity of the fruit, is a common option for overcoming such losses. However, regular hot air drying could affect negatively the quality properties of the fruit due to the long residence time at high temperature. Power ultrasound (US) application during the convective drying has been used as a novel method able to enhance drying rate and, consequently, to decrease drying time. In the present study, a new approach was tested to evaluate the effect of US on the drying time, the final antioxidant activity (AA) and the total polyphenol content (TPC) of banana slices (BS), mango slices (MS) and guava slices (GS). There were also studied the drying kinetics with nine different models from which water effective diffusivities (Deff) (with or without shrinkage corrections) were calculated. Compared with the corresponding control tests, US assisted drying for fruit slices showed reductions in drying time between 16.23 and 30.19%, 11.34 and 32.73%, and 19.25 and 47.51% for the MS, BS and GS respectively. Considering shrinkage effects, Deff calculated values ranged from 1.67*10-10 to 3.18*10-10 m2/s, 3.96*10-10 and 5.57*10-10 m2/s and 4.61*10-10 to 8.16*10-10 m2/s for the BS, MS and GS samples respectively. Reductions of TPC and AA (as DPPH) were observed compared with the original content in fresh fruit data in all kinds of drying assays.

Keywords: banana, drying, effective diffusivity, guava, mango, ultrasound

Procedia PDF Downloads 535
175 How to Improve the Environmental Performance in a HEI in Mexico, an EEA Adaptation

Authors: Stephanie Aguirre Moreno, Jesús Everardo Olguín Tiznado, Claudia Camargo Wilson, Juan Andrés López Barreras

Abstract:

This research work presents a proposal to evaluate the environmental performance of a Higher Education Institution (HEI) in Mexico in order to minimize their environmental impact. Given that public education has limited financial resources, it is necessary to conduct studies that support priorities in decision-making situations and thus obtain the best cost-benefit ratio of continuous improvement programs as part of the environmental management system implemented. The methodology employed, adapted from the Environmental Effect Analysis (EEA), weighs the environmental aspects identified in the environmental diagnosis by two characteristics. Number one, environmental priority through the perception of the stakeholders, compliance of legal requirements, and environmental impact of operations. Number two, the possibility of improvement, which depends of factors such as the exchange rate that will be made, the level of investment and the return time of it. The highest environmental priorities, or hot spots, identified in this evaluation were: electricity consumption, water consumption and recycling, and disposal of municipal solid waste. However, the possibility of improvement for the disposal of municipal solid waste is higher, followed by water consumption and recycling, in spite of having an equal possibility of improvement to the energy consumption, time of return and cost-benefit is much greater.

Keywords: environmental performance, environmental priority, possibility of improvement, continuous improvement programs

Procedia PDF Downloads 495
174 Integral Form Solutions of the Linearized Navier-Stokes Equations without Deviatoric Stress Tensor Term in the Forward Modeling for FWI

Authors: Anyeres N. Atehortua Jimenez, J. David Lambraño, Juan Carlos Muñoz

Abstract:

Navier-Stokes equations (NSE), which describe the dynamics of a fluid, have an important application on modeling waves used for data inversion techniques as full waveform inversion (FWI). In this work a linearized version of NSE and its variables, neglecting deviatoric terms of stress tensor, is presented. In order to get a theoretical modeling of pressure p(x,t) and wave velocity profile c(x,t), a wave equation of visco-acoustic medium (VAE) is written. A change of variables p(x,t)=q(x,t)h(ρ), is made on the equation for the VAE leading to a well known Klein-Gordon equation (KGE) describing waves propagating in variable density medium (ρ) with dispersive term α^2(x). KGE is reduced to a Poisson equation and solved by proposing a specific function for α^2(x) accounting for the energy dissipation and dispersion. Finally, an integral form solution is derived for p(x,t), c(x,t) and kinematics variables like particle velocity v(x,t), displacement u(x,t) and bulk modulus function k_b(x,t). Further, it is compared this visco-acoustic formulation with another form broadly used in the geophysics; it is argued that this formalism is more general and, given its integral form, it may offer several advantages from the modern parallel computing point of view. Applications to minimize the errors in modeling for FWI applied to oils resources in geophysics are discussed.

Keywords: Navier-Stokes equations, modeling, visco-acoustic, inversion FWI

Procedia PDF Downloads 520
173 The Mechanical Characteristics of Rammed Earth with Plastic Fibers

Authors: Majdi Al Shdifat, Juan Chiachio, Esther Puertas, María L. Jalón, Álvaro Blanca-Hoyos

Abstract:

In recent years, the world has begun to adopt more sustainable practices in response to today's environmental and climate challenges. The construction sector is one of the most resource-intensive among others, so researchers are testing different types of materials with different processes and methodologies to achieve more environmentally and sustainably friendly buildings. Plastic is one of the most harmful materials for the environment. The global production of plastics has increased dramatically in recent decades, and it is one of the most widely used materials. However, plastic waste is not biodegradable and has a chemical composition that is stable for many years in the environment, both on land and in water bodies. Recycled plastics have been tested to be used in construction in many ways to reduce the amount of plastic in the environment and the use of raw materials in construction. In this context, the main objective of this research is to test the use of plastic fibers with one of the most promising materials to replace cement, which is rammed earth. In fact, rammed earth is considered one of the most environmentally friendly materials due to its use of local raw materials, recyclability, and low embodied energy. In this research, three different types of plastic fibers were used. Then, the blends were evaluated by considering their mechanical properties, including compressive strength and tensile strength. In addition, the non-destructive ultrasonic wave velocity was measured. The result shows excellent potential for the use of plastic fibers in rammed earth, especially in terms of compressive strength.

Keywords: mechanical characterization, plastic fibers reinforcement, rammed earth, sustainable material

Procedia PDF Downloads 73
172 The Mechanical Properties of Rammed Earth with Plastic Fibers

Authors: Majdi Al Shdifat, Juan Chiachio, Esther Puertas, María L. Jalón, Álvaro Blanca-Hoyos

Abstract:

In recent years, the world has begun to adopt more sustainable practices in response to today's environmental and climate challenges. The construction sector is one of the most resource-intensive among others, so researchers are testing different types of materials with different processes and methodologies to achieve more environmentally and sustainably friendly buildings.Plastic is one of the most harmful materials for the environment. The global production of plastics has increased dramatically in recent decades, and it is one of the most widely used materials. However, plastic waste is not biodegradable and has a chemical composition that is stable for many years in the environment, both on land and in water bodies. Recycled plastics have been tested to be used in construction in many ways to reduce the amount of plastic in the environment and the use of raw materials in construction. In this context, the main objective of this research is to test the use of plastic fibers with one of the most promising materials to replace cement, which is rammed earth. In fact, rammed earth is considered one of the most environmentally friendly materials due to its use of local raw materials, recyclability, and low embodied energy. In this research, three different types of plastic fibers were used. Then, the blends were evaluated by considering their mechanical properties, including compressive strength and tensile strength. In addition, the non-destructive ultrasonic wave velocity was measured. The result shows excellent potential for the use of plastic fibers in rammed earth, especially in terms of compressive strength.

Keywords: mechanical characterization, plastic fibers reinforcement, rammed earth, sustainable material

Procedia PDF Downloads 69
171 A Model for Predicting Organic Compounds Concentration Change in Water Associated with Horizontal Hydraulic Fracturing

Authors: Ma Lanting, S. Eguilior, A. Hurtado, Juan F. Llamas Borrajo

Abstract:

Horizontal hydraulic fracturing is a technology to increase natural gas flow and improve productivity in the low permeability formation. During this drilling operation tons of flowback and produced water which contains many organic compounds return to the surface with a potential risk of influencing the surrounding environment and human health. A mathematical model is urgently needed to represent organic compounds in water transportation process behavior and the concentration change with time throughout the hydraulic fracturing operation life cycle. A comprehensive model combined Organic Matter Transport Dynamic Model with Two-Compartment First-order Model Constant (TFRC) Model has been established to quantify the organic compounds concentration. This algorithm model is composed of two transportation parts based on time factor. For the fast part, the curve fitting technique is applied using flowback water data from the Marcellus shale gas site fracturing and the coefficients of determination (R2) from all analyzed compounds demonstrate a high experimental feasibility of this numerical model. Furthermore, along a decade of drilling the concentration ratio curves have been estimated by the slow part of this model. The result shows that the larger value of Koc in chemicals, the later maximum concentration in water will reach, as well as all the maximum concentrations percentage would reach up to 90% of initial concentration from shale formation within a long sufficient period.

Keywords: model, shale gas, concentration, organic compounds

Procedia PDF Downloads 226
170 A Comprehensive CFD Model for Sugar-Cane Bagasse Heterogeneous Combustion in a Grate Boiler System

Authors: Daniel José de Oliveira Ferreira, Juan Harold Sosa-Arnao, Bruno Cássio Moreira, Leonardo Paes Rangel, Song Won Park

Abstract:

The comprehensive CFD models have been used to represent and study the heterogeneous combustion of biomass. In the present work, the operation of a global flue gas circuit in the sugar-cane bagasse combustion, from wind boxes below primary air grate supply, passing by bagasse insertion in swirl burners and boiler furnace, to boiler bank outlet is simulated. It uses five different meshes representing each part of this system located in sequence: wind boxes and grate, boiler furnace, swirl burners, super heaters and boiler bank. The model considers turbulence using standard k-ε, combustion using EDM, radiation heat transfer using DTM with 16 ray directions and bagasse particle tracking represented by Schiller-Naumann model. The results showed good agreement with expected behavior found in literature and equipment design. The more detailed results view in separated parts of flue gas system allows to observe some flow behaviors that cannot be represented by usual simplifications like bagasse supply under homogeneous axial and rotational vectors and others that can be represented using new considerations like the representation of 26 thousand grate orifices by 144 rectangular inlets.

Keywords: comprehensive CFD model, sugar-cane bagasse combustion, sugar-cane bagasse grate boiler, axial

Procedia PDF Downloads 472
169 Manufacturing and Characterization of Bioresorbable Self-Reinforced PLA Composites for Bone Applications

Authors: Carolina Pereira Lobato Costa, Cristina Pascual-González, Monica Echeverry, Javier LLorca, Carlos Gonzáléz, Juan Pedro Fernández-Bláquez

Abstract:

Although the potential of PLA self-reinforced composites for bone applications, not much literature addresses optimal manufacturing conditions. In this regard, this paper describes the woven self-reinforced PLA composites manufacturing processes: the commingling of yarns, weaving, and hot pressing and characterizes the manufactured laminates. Different structures and properties can be achieved by varying the hot compaction process parameters (pressure, holding time, and temperature). The specimens manufactured were characterized in terms of thermal properties (DSC), microstructure (C-scan optical microscope and SEM), strength (tensile test), and biocompatibility (MTT assays). Considering the final device, 155 ℃ for 10 min at 2 MPa act as the more appropriate hot pressing parameters. The laminate produced with these conditions has few voids/porosity, a tensile strength of 30.39 ± 1.21 MPa, and a modulus of 4.09 ± 0.24 GPa. Subsequently to the tensile testing was possible to observe fiber pullout from the fracture surfaces, confirming that this material behaves as a composite. From the results, no single laminate can fulfill all the requirements, being necessary to compromise in function of the priority property. Further investigation is required to improve materials' mechanical performance. Subsequently, process parameters and materials configuration can be adjusted depending on the place and type of implant to suit its function.

Keywords: woven fabric, self-reinforced polymer composite, poly(lactic acid), biodegradable

Procedia PDF Downloads 195
168 Procedure for Impact Testing of Fused Recycled Glass

Authors: David Halley, Tyra Oseng-Rees, Luca Pagano, Juan A Ferriz-Papi

Abstract:

Recycled glass material is made from 100% recycled bottle glass and consumes less energy than re-melt technology. It also uses no additives in the manufacturing process allowing the recycled glass material, in principal, to go back to the recycling stream after end-of-use, contributing to the circular economy with a low ecological impact. The aim of this paper is to investigate the procedure for testing the recycled glass material for impact resistance, so it can be applied to pavements and other surfaces which are at risk of impact during service. A review of different impact test procedures for construction materials was undertaken, comparing methodologies and international standards applied to other materials such as natural stone, ceramics and glass. A drop weight impact testing machine was designed and manufactured in-house to perform these tests. As a case study, samples of the recycled glass material were manufactured with two different thicknesses and tested. The impact energy was calculated theoretically, obtaining results with 5 and 10 J. The results on the material were subsequently discussed. Improvements on the procedure can be made using high speed video technology to calculate velocity just before and immediately after the impact to know the absorbed energy. The initial results obtained in this procedure were positive although repeatability needs to be developed to obtain a correlation of results and finally be able to validate the procedure. The experiment with samples showed the practicality of this procedure and application to the recycled glass material impact testing although further research needs to be developed.

Keywords: construction materials, drop weight impact, impact testing, recycled glass

Procedia PDF Downloads 296
167 Management Software for the Elaboration of an Electronic File in the Pharmaceutical Industry Following Mexican Regulations

Authors: M. Peña Aguilar Juan, Ríos Hernández Ezequiel, R. Valencia Luis

Abstract:

For certification, certain goods of public interest, such as medicines and food, it is required the preparation and delivery of a dossier. For its elaboration, legal and administrative knowledge must be taken, as well as organization of the documents of the process, and an order that allows the file verification. Therefore, a virtual platform was developed to support the process of management and elaboration of the dossier, providing accessibility to the information and interfaces that allow the user to know the status of projects. The development of dossier system on the cloud allows the inclusion of the technical requirements for the software management, including the validation and the manufacturing in the field industry. The platform guides and facilitates the dossier elaboration (report, file or history), considering Mexican legislation and regulations, it also has auxiliary tools for its management. This technological alternative provides organization support for documents and accessibility to the information required to specify the successful development of a dossier. The platform divides into the following modules: System control, catalog, dossier and enterprise management. The modules are designed per the structure required in a dossier in those areas. However, the structure allows for flexibility, as its goal is to become a tool that facilitates and does not obstruct processes. The architecture and development of the software allows flexibility for future work expansion to other fields, this would imply feeding the system with new regulations.

Keywords: electronic dossier, cloud management software, pharmaceutical industry, sanitary registration

Procedia PDF Downloads 296
166 The Transcriptome of Carnation (Dianthus Caryophyllus) of Elicited Cells with Fusarium Oxysporum f.sp. Dianthi

Authors: Juan Jose Filgueira, Daniela Londono-Serna, Liliana Maria Hoyos

Abstract:

Carnation (Dianthus caryophyllus) is one of the most important products of exportation in the floriculture industry worldwide. Fusariosis is the disease that causes the highest losses on farms, in particular the one produced by Fusarium oxysporum f.sp. dianthi, called vascular wilt. Gene identification and metabolic routes of the genes that participate in the building of the plant response to Fusarium are some of the current targets in the carnation breeding industry. The techniques for the identifying of resistant genes in the plants, is the analysis of the transcriptome obtained during the host-pathogen interaction. In this work, we report the cell transcriptome of different varieties of carnation that present differential response from Fusarium oxysporum f.sp. dianthi attack. The cells of the different hybrids produced in the outbreeding program were cultured in vitro and elicited with the parasite in a dual culture. The isolation and purification of mRNA was achieved by using affinity chromatography Oligo dT columns and the transcriptomes were obtained by using Illumina NGS techniques. A total of 85,669 unigenes were detected in all the transcriptomes analyzed and 31,000 annotations were found in databases, which correspond to 36.2%. The library construction of genic expression techniques used, allowed to recognize the variation in the expression of genes such as Germin-like protein, Glycosyl hydrolase family and Cinnamate 4-hydroxylase. These have been reported in this study for the first time as part of the response mechanism to the presence of Fusarium oxysporum.

Keywords: Carnation, Fusarium, vascular wilt, transcriptome

Procedia PDF Downloads 150
165 Maker-Based Learning in Secondary Mathematics: Investigating Students’ Proportional Reasoning Understanding through Digital Making

Authors: Juan Torralba

Abstract:

Student digital artifacts were investigated, utilizing a qualitative exploratory research design to understand the ways in which students represented their knowledge of seventh-grade proportionality concepts as they participated in maker-based activities that culminated in the creation of digital 3-dimensional models of their dream homes. Representations of the geometric and numeric dimensions of proportionality were analyzed in the written, verbal, and visual data collected from the students. A directed content analysis approach was utilized in the data analysis, as this work aimed to build upon existing research in the field of maker-based STEAM Education. The results from this work show that students can represent their understanding of proportional reasoning through open-ended written responses more accurately than through verbal descriptions or digital artifacts. The geometric and numeric dimensions of proportionality and their respective components of attributes of similarity representation and percents, rates, and ratios representations were the most represented by the students than any other across the data, suggesting a maker-based instructional approach to teaching proportionality in the middle grades may be promising in helping students gain a solid foundation in those components. Recommendations for practice and research are discussed.

Keywords: learning through making, maker-based education, maker education in the middle grades, making in mathematics, the maker movement

Procedia PDF Downloads 71
164 External Noise Distillation in Quantum Holography with Undetected Light

Authors: Sebastian Töpfer, Jorge Fuenzalida, Marta Gilaberte Basset, Juan P. Torres, Markus Gräfe

Abstract:

This work presents an experimental and theoretical study about the noise resilience of quantum holography with undetected photons. Quantum imaging has become an important research topic in the recent years after its first publication in 2014. Following this research, advances towards different spectral ranges in detection and different optical geometries have been made. Especially an interest in the field of near infrared to mid infrared measurements has developed, because of the unique characteristic, that allows to sample a probe with photons in a different wavelength than the photons arriving at the detector. This promising effect can be used for medical applications, to measure in the so-called molecule fingerprint region, while using broadly available detectors for the visible spectral range. Further advance the development of quantum imaging methods have been made by new measurement and detection schemes. One of which is quantum holography with undetected light. It combines digital phase shifting holography with quantum imaging to extent the obtainable sample information, by measuring not only the object transmission, but also its influence on the phase shift experienced by the transmitted light. This work will present extended research for the quantum holography with undetected light scheme regarding the influence of external noise. It is shown experimentally and theoretically that the samples information can still be at noise levels of 250 times higher than the signal level, because of its information being transmitted by the interferometric pattern. A detailed theoretic explanation is also provided.

Keywords: distillation, quantum holography, quantum imaging, quantum metrology

Procedia PDF Downloads 75
163 Degradation of Amitriptyline Hydrochloride, Methyl Salicylate and 2-Phenoxyethanol in Water Systems by the Combination UV/Cl2

Authors: F. Javier Benitez, Francisco J. Real, Juan Luis Acero, Francisco Casas

Abstract:

Three emerging contaminants (amitriptyline hydrochloride, methyl salicylate and 2-phenoxyethanol) frequently found in waste-waters were selected to be individually degraded in ultra-pure water by the combined advanced oxidation process constituted by UV radiation and chlorine. The influence of pH, initial chlorine concentration and nature of the contaminants was firstly explored. The trend for the reactivity of the selected compounds was deduced: amitriptyline hydrochloride > methyl salicylate > 2-phenoxyethanol. A later kinetic study was carried out and focused on the specific evaluation of the first-order rate constants and the determination of the partial contribution to the global reaction of the direct photochemical pathway and the radical pathway. A comparison between the rate constant values among photochemical experiments without and with the presence of Cl2 reveals a clear increase in the oxidation efficiency of the combined process with respect to the photochemical reaction alone. In a second stage, the simultaneous oxidation of mixtures of the selected contaminants in several types of water (ultrapure water, surface water from a reservoir, and two secondary effluents) was also performed by the same combination UV/Cl2 under more realistic operating conditions. The efficiency of this combined system UV/Cl2 was compared to other oxidants such as the UV/S2O82- and UV/H2O2 AOPs. Results confirmed that the UV/Cl2 system provides higher elimination efficiencies among the AOPs tested.

Keywords: emerging contaminants, UV/chlorine advanced oxidation process, amitriptyline, methyl salicylate, 2-phenoxyethanol, chlorination, photolysis

Procedia PDF Downloads 333
162 Recycled Aggregates from Construction and Demolition Waste in the Production of Concrete Blocks

Authors: Juan A. Ferriz-Papi, Simon Thomas

Abstract:

The construction industry generates large amounts of waste, usually mixed, which can be composed of different origin materials, most of them catalogued as non-hazardous. The European Union targets for this waste for 2020 have been already achieved by the UK, but it is mainly developed in downcycling processes (backfilling) whereas upcycling (such as recycle in new concrete batches) still keeps at a low percentage. The aim of this paper is to explore further in the use of recycled aggregates from construction and demolition waste (CDW) in concrete mixes so as to improve upcycling. A review of most recent research and legislation applied in the UK is developed regarding the production of concrete blocks. As a case study, initial tests were developed with a CDW recycled aggregate sample from a CDW plant in Swansea. Composition by visual inspection and sieving tests of two samples were developed and compared to original aggregates. More than 70% was formed by soil waste from excavation, and the rest was a mix of waste from mortar, concrete, and ceramics with small traces of plaster, glass and organic matter. Two concrete mixes were made with 80% replacement of recycled aggregates and different water/cement ratio. Tests were carried out for slump, absorption, density and compression strength. The results were compared to a reference sample and showed a substantial reduction of quality in both mixes. Despite that, the discussion brings to identify different aspects to solve, such as heterogeneity or composition, and analyze them for the successful use of these recycled aggregates in the production of concrete blocks. The conclusions obtained can help increase upcycling processes ratio with mixed CDW as recycled aggregates in concrete mixes.

Keywords: aggregates, concrete, concrete block, construction and demolition waste, recycling

Procedia PDF Downloads 299
161 Numerical Investigation of Tsunami Flow Characteristics and Energy Reduction through Flexible Vegetation

Authors: Abhishek Mukherjee, Juan C. Cajas, Jenny Suckale, Guillaume Houzeaux, Oriol Lehmkuhl, Simone Marras

Abstract:

The investigation of tsunami flow characteristics and the quantification of tsunami energy reduction through the coastal vegetation is important to understand the protective benefits of nature-based mitigation parks. In the present study, a three-dimensional non-hydrostatic incompressible Computational Fluid Dynamics model with a two-way coupling enabled fluid-structure interaction approach (FSI) is used. After validating the numerical model against experimental data, tsunami flow characteristics have been investigated by varying vegetation density, modulus of elasticity, the gap between stems, and arrangement or distribution of vegetation patches. Streamwise depth average velocity profiles, turbulent kinetic energy, energy flux reflection, and dissipation extracted by the numerical study will be presented in this study. These diagnostics are essential to assess the importance of different parameters to design the proper coastal defense systems. When a tsunami wave reaches the shore, it transforms into undular bores, which induce scour around offshore structures and sediment transport. The bed shear stress, instantaneous turbulent kinetic energy, and the vorticity near-bed will be presented to estimate the importance of vegetation to prevent tsunami-induced scour and sediment transport.

Keywords: coastal defense, energy flux, fluid-structure interaction, natural hazards, sediment transport, tsunami mitigation

Procedia PDF Downloads 150
160 Bioinformatic Screening of Metagenomic Fosmid Libraries for Identification of Biosynthetic Pathways Derived from the Colombian Soils

Authors: María Fernanda Quiceno Vallejo, Patricia del Portillo, María Mercedes Zambrano, Jeisson Alejandro Triana, Dayana Calderon, Juan Manuel Anzola

Abstract:

Microorganisms from tropical ecosystems can be novel in terms of adaptations and conservation. Given the macrodiversity of Colombian ecosystems, it is possible that this diversity is also present in Colombian soils. Tropical soil bacteria could offer a potentially novel source of bioactive compounds. In this study we analyzed a metagenomic fosmid library constructed with tropical bacterial DNAs with the aim of understanding its underlying diversity and functional potential. 8640 clones from the fosmid library were sequenced by NANOPORE MiniOn technology, then analyzed with bioinformatic tools such as Prokka, AntiSMASH and Bagel4 in order to identify functional biosynthetic pathways in the sequences. The strains showed ample difference when it comes to biosynthetic pathways. In total we identified 4 pathways related to aryl polyene synthesis, 12 related to terpenes, 22 related to NRPs (Non ribosomal peptides), 11 related PKs (Polyketide synthases) and 7 related to RiPPs (bacteriocins). We designed primers for the metagenomic clones with the most BGCs (sample 6 and sample 2). Results show the biotechnological / pharmacological potential of tropical ecosystems. Overall, this work provides an overview of the genomic and functional potential of Colombian soil and sets the groundwork for additional exploration of tropical metagenomic sequencing.

Keywords: bioactives, biosyntethic pathways, bioinformatic, bacterial gene clusters, secondary metabolites

Procedia PDF Downloads 165
159 Tomato-Weed Classification by RetinaNet One-Step Neural Network

Authors: Dionisio Andujar, Juan lópez-Correa, Hugo Moreno, Angela Ri

Abstract:

The increased number of weeds in tomato crops highly lower yields. Weed identification with the aim of machine learning is important to carry out site-specific control. The last advances in computer vision are a powerful tool to face the problem. The analysis of RGB (Red, Green, Blue) images through Artificial Neural Networks had been rapidly developed in the past few years, providing new methods for weed classification. The development of the algorithms for crop and weed species classification looks for a real-time classification system using Object Detection algorithms based on Convolutional Neural Networks. The site study was located in commercial corn fields. The classification system has been tested. The procedure can detect and classify weed seedlings in tomato fields. The input to the Neural Network was a set of 10,000 RGB images with a natural infestation of Cyperus rotundus l., Echinochloa crus galli L., Setaria italica L., Portulaca oeracea L., and Solanum nigrum L. The validation process was done with a random selection of RGB images containing the aforementioned species. The mean average precision (mAP) was established as the metric for object detection. The results showed agreements higher than 95 %. The system will provide the input for an online spraying system. Thus, this work plays an important role in Site Specific Weed Management by reducing herbicide use in a single step.

Keywords: deep learning, object detection, cnn, tomato, weeds

Procedia PDF Downloads 103
158 Physicochemical and Sensorial Evaluation of Astringency Reduction in Cashew Apple (Annacardium occidentale L.) Powder Processing in Cookie Elaboration

Authors: Elida Gastelum-Martinez, Neith A. Pacheco-Lopez, Juan L. Morales-Landa

Abstract:

Cashew agroindustry obtained from cashew apple crop (Anacardium occidentale L.) generates large amounts of unused waste in Campeche, Mexico. Despite having a high content of nutritional compounds such as ascorbic acid, carotenoids, fiber, carbohydrates, and minerals, it is not consumed due to its astringent sensation. The aim of this work was to develop a processing method for cashew apple waste in order to obtain a powder with reduced astringency able to be used as an additive in the food industry. The processing method consisted first in reducing astringency by inducing tannins from cashew apple peel to react and form precipitating complexes with a colloid rich in proline and histidine. Then cashew apples were processed to obtain a dry powder. Astringency reduction was determined by total phenolic content and evaluated by sensorial analysis in cashew-apple-powder based cookies. Total phenolic content in processed powders showed up to 72% lower concentration compared to control samples. The sensorial evaluation indicated that cookies baked using cashew apple powder with reduced astringency were 96.8% preferred. Sensorial characteristics like texture, color and taste were also well-accepted attributes. In conclusion, the method applied for astringency reduction is a viable tool to produce cashew apple powder with desirable sensorial properties to be used in the development of food products.

Keywords: astringency reduction, cashew apple waste, food industry, sensorial evaluation

Procedia PDF Downloads 351
157 Replica-Exchange Metadynamics Simulations of G-Quadruplex DNA Structures Under Substitution of K+ by Na+ Ions

Authors: Juan Antonio Mondragon Sanchez, Ruben Santamaria

Abstract:

The DNA G-quadruplex is a four-stranded DNA structure conformed by stacked planes of four base paired guanines (G-quartet). The guanine rich DNA sequences are present in many sites of genomic DNA and can potentially lead to the formation of G-quadruplexes, especially at the 3'-terminus of the human telomeric DNA with many TTAGGG repeats. The formation and stabilization of a G-quadruplex by small ligands at the telomeric region can inhibit the telomerase activity. In turn, the ligands can be used to regulate oncogene expression making the G-quadruplex an attractive target for anticancer therapy. Clearly, the G-quadruplex structured in the telomeric DNA is of fundamental importance for rational drug design. In this context, we investigate two G-quadruplex structures, the first follows from the sequence TTAGGG(TTAGGG)3TT (HUT1), and the second from AAAGGG(TTAGGG)3AA (HUT2), both in a K+ solution. We determine the free energy surfaces of the HUT1 and HUT2 structures and investigate their conformations using replica-exchange metadynamics simulations. The carbonyl-carbonyl distances belonging to different guanines residues are selected as the main collective variables to determine the free energy surfaces. The surfaces exhibit two main local minima, compatible with experiments on the conformational transformations of HUT1 and HUT2 under substitution of the K+ ions by the Na+ ions. The conformational transitions are not observed in short MD simulations without the use of the metadynamics approach. The results of this work should be of help to understand the formation and stability of human telomeric G-quadruplex in environments including the presence of K+ and Na+ ions.

Keywords: g-quadruplex, metadynamics, molecular dynamics, replica-exchange

Procedia PDF Downloads 346
156 Revisiting the Historical Narratives of the Old Churches in Albay, Bikol Region, Philippines

Authors: Ruby Ann L. Ayo

Abstract:

As cultural heritage reflects the historical origin of a certain group of people, it reveals their customs, traits, beliefs, practices and even values they hold on for years. One of the tangible examples of cultural heritage is the physical structures including the old churches. The study looked-into the existing historical narratives of the century Old Catholic churches in the Province of Albay, Bikol Region, Philippines: NuestraSeñora de Salvacion in Joroan, Tiwi, Albay; the Our Lady of the Gate in Daraga, Albay; the San Juan de Bautista in Tabaco City and the St. John the Baptist in Camalig, Albay. The historical narratives were analysed in terms of validity and reliability of the secondary documents with reference to the elements of history revealing consistency and adequacy of historical facts. The contents were examined using a modified Checklist of Historical Documents. The historical narratives were likewise submitted to the content expert for validation as regards historical authenticity and accuracy. The contents of the narratives were scrutinized according to the following codes: (1.1) the Patron Saints;(1.2) factors that paved to their constructions; (1.3) the people responsible for their constructions; (1.4) the misconceptions about their constructions; and (1.5) their contributions to Bikol heritage. Based on the codes, themes were identified as: (2.1) Marian Devotees and Christ-centered Patron Saints; (2.2) geographical, socio-political and cultural factors; (2.3) church and government officials; (2.4) misconceptions on the dates of constructions and original sites; and (2.5) popular pilgrim sites and well-admired architectural designs.

Keywords: historical narratives, old churches, cultural heritage, historical validity and reliability, elements of history

Procedia PDF Downloads 294
155 The Role of Cognitive Impairment in Asthma Self-Management Behaviors and Outcomes in Older Adults

Authors: Gali Moritz, Jacqueline H. Becker, Jyoti V. Ankam, Kimberly Arcoleo, Matthew Wysocki, Roee Holtzer, Juan Wisnivesky, Paula J. Busse, Alex D. Federman, Sunit P. Jariwala, Jonathan M. Feldman

Abstract:

Objective: Cognitive impairment (CI), whose incidence is greater among ethnic/racial minorities, is a significant barrier to asthma self-management (SM) behaviors and outcomes in older adults. The aim of this study was to examine the relationships between CI, assessed using the Montreal Cognitive Assessment (MoCA), and asthma SM behaviors and outcomes in a sample of predominantly Black and Hispanic participants. Additionally, we evaluated whether using two different MoCA cutoff scores influenced the association between CI and study outcomes. Methods: Baseline cross-sectional data were extracted from a longitudinal study of older adults with asthma (N=165) age≥ 60 years and used for analysis. Cognition was assessed using the MoCA. Asthma control, asthma-related quality of life (QOL), inhaled corticosteroid (ICS) dosing, and ICS adherence were assessed using self-report. The inhaler technique was observed and rated. Results: Using established MoCA cutoff scores of 23 and 26 yielded 45% and 74% CI rates, respectively. CI, defined using the 23 cutoff score, was significantly associated with worse asthma control (p=.04) and worse ICS adherence (p=.01). With a cutoff score of 26, only asthma-related QOL was significantly associated with CI (p=.03). Race/ethnicity and education did not moderate the relationships between CI and asthma SM behaviors and outcomes. Conclusions: CI in older adults with asthma is associated with important clinical outcomes, but this relationship is influenced by the cutoff score used to define CI.

Keywords: cognition, respiratory, elderly, testing, adherence, validity

Procedia PDF Downloads 80
154 5-HT2CR Deficiency Causes Affective Disorders by Impairing E/I Balance through Augmenting Hippocampal nNOS-CAPON Coupling

Authors: Hu-Jiang Shi, Li-Juan Zhu

Abstract:

The implication of 5-hydroxytryptamine 2C receptor (5-HT2CR) in affective behaviors is a topic of debate, and the underlying mechanisms remain largely unclear. Here, we elucidate that the interaction between hippocampal neuronal nitric oxide synthase (nNOS) and carboxy-terminal PDZ ligand of nNOS (CAPON) contributes to the disruption of hippocampal excitation-inhibition (E/I) balance, which is responsible for the anxiety- and depressive-like behaviors caused by chronic stress-related 5-HT2CR signaling deficiency. In detail, activation or inhibition of 5-HT2CR by CP809101 or SB242084 modulates nNOS-CAPON interaction by influencing intracellular Ca²⁺ release. Notably, the dissociation of nNOS-CAPON abolishes SB242084-induced anxiety- and depressive-like behaviors, as well as the reduction in extracellular signal-regulated kinase (ERK)/cAMP-response element binding protein (CREB)/synapsin signaling and SNARE complex assembly. Furthermore, nNOS-CAPON blockers restore the impairments caused by SB242084, including the reduction in SNARE assembly-mediated γ-aminobutyric acid (GABA) vesicle release and a consequent shift of the E/I balance toward excitation in CA3 pyramidal neurons. Conclusively, our findings disclose the regulatory role of 5-HT2CR in anxiety- and depressive-like behaviors and highlight the hippocampal nNOS-CAPON coupling-triggered E/I imbalance as a pivotal cellular event underpinning the behavioral consequences of 5-HT2CR inhibition.

Keywords: 5-HT2CR, anxiety, depression, nNOS-CAPON coupling, excitation-inhibition balance, neurotransmitter release

Procedia PDF Downloads 65
153 Wear Resistance and Mechanical Performance of Ultra-High Molecular Weight Polyethylene Influenced by Temperature Change

Authors: Juan Carlos Baena, Zhongxiao Peng

Abstract:

Ultra-high molecular weight polyethylene (UHMWPE) is extensively used in industrial and biomedical fields. The slippery nature of UHMWPE makes this material suitable for surface bearing applications, however, the operational conditions limit the lubrication efficiency, inducing boundary and mixed lubrication in the tribological system. The lack of lubrication in a tribological system intensifies friction, contact stress and consequently, operating temperature. With temperature increase, the material’s mechanical properties are affected, and the lifespan of the component is reduced. The understanding of how mechanical properties and wear performance of UHMWPE change when the temperature is increased has not been clearly identified. The understanding of the wear and mechanical performance of UHMWPE at different temperature is important to predict and further improve the lifespan of these components. This study evaluates the effects of temperature variation in a range of 20 °C to 60 °C on the hardness and the wear resistance of UHMWPE. A reduction of the hardness and wear resistance was observed with the increase in temperature. The variation of the wear rate increased 94.8% when the temperature changed from 20 °C to 50 °C. Although hardness is regarded to be an indicator of the material wear resistance, this study found that wear resistance decreased more rapidly than hardness with the temperature increase, evidencing a low material stability of this component in a short temperature interval. The reduction of the hardness was reflected by the plastic deformation and abrasion intensity, resulting in a significant wear rate increase.

Keywords: hardness, surface bearing, tribological system, UHMWPE, wear

Procedia PDF Downloads 271
152 Engineering of E-Learning Content Creation: Case Study for African Countries

Authors: María-Dolores Afonso-Suárez, Nayra Pumar-Carreras, Juan Ruiz-Alzola

Abstract:

This research addresses the use of an e-Learning creation methodology for learning objects. Throughout the process, indicators are being gathered, to determine if it responds to the main objectives of an engineering discipline. These parameters will also indicate if it is necessary to review the creation cycle and readjust any phase. Within the project developed for this study, apart from the use of structured methods, there has been a central objective: the establishment of a learning atmosphere. A place where all the professionals involved are able to collaborate, plan, solve problems and determine guides to follow in order to develop creative and innovative solutions. It has been outlined as a blended learning program with an assessment plan that proposes face to face lessons, coaching, collaboration, multimedia and web based learning objects as well as support resources. The project has been drawn as a long term task, the pilot teaching actions designed provide the preliminary results object of study. This methodology is been used in the creation of learning content for the African countries of Senegal, Mauritania and Cape Verde. It has been developed within the framework of the MACbioIDi, an Interreg European project for the International cooperation and development. The educational area of this project is focused in the training and advice of professionals of the medicine as well as engineers in the use of applications of medical imaging technology, specifically the 3DSlicer application and the Open Anatomy Browser.

Keywords: teaching contents engineering, e-learning, blended learning, international cooperation, 3dslicer, open anatomy browser

Procedia PDF Downloads 172