Search results for: Marc Permanyer-Bosser
103 Characteristic of Ta Alloy Coating Films on Near-Net Shape with Different Current Densities Using MARC Process
Authors: Young Jun Lee, Tae Hyuk Lee, Kyoung Tae Park, Jong Hyeon Lee
Abstract:
The harsh atmosphere of the sulfur-iodine process used for producing hydrogen requires better corrosion resistance and mechanical properties that is possible to obtain with pure tantalum. Ta-W alloy is superior to pure tantalum but is difficult to alloy due to its high melting temperature. In this study, substrates of near-net shape (Swagelok® tube ISSG8UT4) were coated with Ta-W using the multi-anode reactive alloy coating (MARC) process in molten salt (LiF-NaF-K2TaF7) at different current densities (1, 2 and 4mA/cm2). Ta-4W coating films of uniform coating thicknesses, without any entrapped salt, were successfully deposited on Swagelok tube by electrodeposition at 1 mA/cm2. The resulting coated film with a corrosion rate of less than 0.011 mm/year was attained in hydriodic acid at 160°C, and hardness up to 12.9 % stronger than pure tantalum coated film. The alloy coating films also contributed to significant enhancement of corrosion resistance.Keywords: tantalum, tantalum alloy, tungsten alloy, electroplating
Procedia PDF Downloads 417102 Stability of Total Phenolic Concentration and Antioxidant Capacity of Extracts from Pomegranate Co-Products Subjected to In vitro Digestion
Authors: Olaniyi Fawole, Umezuruike Opara
Abstract:
Co-products obtained from pomegranate juice processing contain high levels of polyphenols with potential high added values. From value-addition viewpoint, the aim of this study was to evaluate the stability of polyphenolic concentrations in pomegranate fruit co-products in different solvent extracts and assess the effect on the total antioxidant capacity using the FRAP, DPPH˙ and ABTS˙+ assays during simulated in vitro digestion. Pomegranate juice, marc and peel were extracted in water, 50% ethanol (50%EtOH) and absolute ethanol (100%EtOH) and analysed for total phenolic concentration (TPC), total flavonoids concentration (TFC) and total antioxidant capacity in DPPH˙, ABST˙+ and FRAP assays before and after in vitro digestion. Total phenolic concentration (TPC) and total flavonoid concentration (TFC) were in the order of peel > marc > juice throughout the in vitro digestion irrespective of the extraction solvents used. However, 50% ethanol extracted 1.1 to 12-fold more polyphenols than water and ethanol solvents depending on co-products. TPC and TFC increased significantly in gastric digests. In contrast, after the duodenal, polyphenolic concentrations decreased significantly (p < 0.05) compared to those obtained in gastric digests. Undigested samples and gastric digests showed strong and positive relationships between polyphenols and the antioxidant activities measured in DPPH, ABTS and FRAP assays, with correlation coefficients (r2) ranging between 0.930 – 0.990 whereas, the correlation between polyphenols (TPC and TFC) and radical cation scavenging activity (in ABTS) were moderately positive in duodenal digests. Findings from this study also showed that the concentration of pomegranate polyphenols and antioxidant thereof during in vitro gastro-intestinal digestion may not reflect the pre-digested phenolic concentration. Thus, this study highlights the need to provide biologically relevant information on antioxidants by providing data reflecting their stability and activity after in vitro digestion.Keywords: by-product, DPPH, polyphenols, value addition
Procedia PDF Downloads 322101 Net Neutrality and Asymmetric Platform Competition
Authors: Romain Lestage, Marc Bourreau
Abstract:
In this paper we analyze the interplay between access to the last-mile network and net neutrality in the market for Internet access. We consider two Internet Service Providers (ISPs), which act as platforms between Internet users and Content Providers (CPs). One of the ISPs is vertically integrated and provides access to its last-mile network to the other (non-integrated) ISP. We show that a lower access price increases the integrated ISP's incentives to charge CPs positive termination fees (i.e., to deviate from net neutrality), and decreases the non-integrated ISP's incentives to charge positive termination fees.Keywords: net neutrality, access regulation, internet access, two-sided markets
Procedia PDF Downloads 370100 Processing Mild versus Strong Violations in Music: A Pilot Study Using Event-Related Potentials
Authors: Marie-Eve Joret, Marijn Van Vliet, Flavio Camarrone, Marc M. Van Hulle
Abstract:
Event-related potentials (ERPs) provide evidence that the human brain can process and understand music at a pre-attentive level. Music-specific ERPs include the Early Right Anterior Negativity (ERAN) and a late Negativity (N5). This study aims to further investigate this issue using two types of syntactic manipulations in music: mild violations, containing no out-of-key tones and strong violations, containing out-of-key tones. We will examine whether both manipulations will elicit the same ERPs.Keywords: ERAN ERPs, Music, N5, P3, ERPs, Music, N5 component, P3 component
Procedia PDF Downloads 27099 Detection and Tracking Approach Using an Automotive Radar to Increase Active Pedestrian Safety
Authors: Michael Heuer, Ayoub Al-Hamadi, Alexander Rain, Marc-Michael Meinecke
Abstract:
Vulnerable road users, e.g. pedestrians, have a high impact on fatal accident numbers. To reduce these statistics, car manufactures are intensively developing suitable safety systems. Hereby, fast and reliable environment recognition is a major challenge. In this paper we describe a tracking approach that is only based on a 24 GHz radar sensor. While common radar signal processing loses much information, we make use of a track-before-detect filter to incorporate raw measurements. It is explained how the Range-Doppler spectrum can help to indicated pedestrians and stabilize tracking even in occultation scenarios compared to sensors in series.Keywords: radar, pedestrian detection, active safety, sensor
Procedia PDF Downloads 52398 Identification of Configuration Space Singularities with Local Real Algebraic Geometry
Authors: Marc Diesse, Hochschule Heilbronn
Abstract:
We address the question of identifying the configuration space singularities of linkages, i.e., points where the configuration space is not locally a submanifold of Euclidean space. Because the configuration space cannot be smoothly parameterized at such points, these singularity types have a significantly negative impact on the kinematics of the linkage. It is known that Jacobian methods do not provide sufficient conditions for the existence of CS-singularities. Herein, we present several additional algebraic criteria that provide the sufficient conditions. Further, we use those criteria to analyze certain classes of planar linkages. These examples will also show how the presented criteria can be checked using algorithmic methods.Keywords: linkages, configuration space-singularities, real algebraic geometry, analytic geometry
Procedia PDF Downloads 14097 Assessment of Online Web-Based Learning for Enhancing Student Grades in Chemistry
Authors: Ian Marc Gealon Cabugsa, Eleanor Pastrano Corcino, Gina Lapaza Montalan
Abstract:
This study focused on the effect of Online Web-Learning (OWL) in the performance of the freshmen Civil Engineering Students of Ateneo de Davao University in their Chem 12 subject. The grades of the students that were required to use OWL were compared to students without OWL. The result of the study suggests promising result for the use of OWL in increasing the performance rate of students taking up Chem 12. Furthermore, there was a positive correlation between the final grade and OWL grade of the students that had OWL. While the majority of the students find OWL to be helpful in supporting their chemistry knowledge needs, most of them still prefer to learn using the traditional face-to-face instruction.Keywords: chemistry education, enhanced performance, engineering chemistry, online web-based learning
Procedia PDF Downloads 36796 A Quantitative Structure-Adsorption Study on Novel and Emerging Adsorbent Materials
Authors: Marc Sader, Michiel Stock, Bernard De Baets
Abstract:
Considering a large amount of adsorption data of adsorbate gases on adsorbent materials in literature, it is interesting to predict such adsorption data without experimentation. A quantitative structure-activity relationship (QSAR) is developed to correlate molecular characteristics of gases and existing knowledge of materials with their respective adsorption properties. The application of Random Forest, a machine learning method, on a set of adsorption isotherms at a wide range of partial pressures and concentrations is studied. The predicted adsorption isotherms are fitted to several adsorption equations to estimate the adsorption properties. To impute the adsorption properties of desired gases on desired materials, leave-one-out cross-validation is employed. Extensive experimental results for a range of settings are reported.Keywords: adsorption, predictive modeling, QSAR, random forest
Procedia PDF Downloads 22295 Polyphenols from Winery Wastes as Potential Source of Antioxidants
Authors: Lucia Gharwalova, Irena Kolouchova, Jan Masak
Abstract:
A large amount of waste products is generated throughout the whole winemaking process as well as during work in the vineyard. This waste is as a source of phenolic compounds, such as resveratrol and polydatin, which possess a strong antioxidant capacity. Changes in the amounts of phenols were compared depending on the growing conditions and wine variety. Wastes (grape stems, marc and shoots) from two wineries in the Czech Republic were analyzed. Phenols from these samples were extracted by 40% ethanol. The amount of polyphenols in these extracts was determined by HPLC and their antioxidant capacity by DPPH. We compared changes in the amounts of phenols depending on the type of waste and the wine variety. The most significant source of stilbenoids was waste from pruning (shoots). These results show that winery waste could be further reused thanks to their antioxidant content.Keywords: antioxidants, polyphenols, resveratrol, winery waste
Procedia PDF Downloads 39994 The World Heritage List: A Big Data Spatial Econometrics Approach to Sites Promoting the Brand
Authors: David Wuepper, Marc Patry
Abstract:
UNESCO’s World Heritage program requests the inscribed locations to promote the World Heritage brand by clearly presenting information about it on-site. Based on feedback from over 319,000 visitors at 791 locations, we create an index that shows how much the World Heritage sites actually brand themselves as such. We find great heterogeneity throughout the list and explain this econometrically mostly with the economic benefit for the sites but also with cultural brand preferences, which are highest in Asia, followed by Europe and North America. We also find a positive relationship between World Heritage branding and conservation status and a U-shaped relationship between visitor numbers and WH branding. Based on our findings, we recommend to make clear World Heritage branding mandatory for all sites.Keywords: UNESCO World Heritage, collective brand, cultural tourism, heritage conservation, brand equity, spatial econometrics
Procedia PDF Downloads 57793 Effect of Edta in the Phytoextraction of Copper by Terminalia catappa (Talisay) Linnaeus
Authors: Ian Marc G. Cabugsa, Zarine M. Hermita
Abstract:
Phytoextraction capability of T. catappa in contaminated soils was done in the improvised greenhouse. The plant samples were planted to the soil which contained different concentrations of copper. Chelating agent EDTA was added to observe the uptake and translocation of copper in the plant samples. Results showed a significant increase of copper accumulation with the addition of EDTA at 250 and 1250 mgˑkg-1 concentration of copper in the contaminated soils (p<0.05). While translocation of copper was observed in all treatments, translocation of copper is not significantly enhanced by the addition of EDTA (p>0.05). Uptake and translocation were not directly affected the presence of EDTA. Furthermore, this study suggests that the T. catappa is not a hyperaccumulator of copper, and there is no relationship observed between the length of the plant and the copper uptake in all treatments.Keywords: chelating agent EDTA, hyperaccumulator, phytoextraction, phytoremediation, terminalia catappa
Procedia PDF Downloads 37992 Cryptocurrencies: Business Students’ Awareness and Universities’ Adoption Readiness and Compatibility of Use Considering the Mediation of Attitudes
Authors: Eric S. Parilla, Marc Edward Abadilla
Abstract:
The study aims to determine the effect of awareness of business students towards cryptocurrencies and the readiness of universities and colleges to accept cryptocurrencies as a medium of exchange, considering the mediation of business students’ attitudes. The research used partial least squares structural equation modeling (PLS-SEM) and deployed a questionnaire attuned to the awareness and attitudes of business students towards cryptocurrencies and readiness and compatibility of use in universities and colleges in Ilocos Norte. The output of the investigation revealed that awareness of business students is not correlated to the readiness of universities and colleges, which means that even though students understand cryptocurrencies, it is not an assurance that universities and colleges are ready to accept them as the medium of exchange. The study proposes that training and seminars for business students and professionals should be conducted to expand understanding and acceptance of cryptocurrencies.Keywords: cryptocurrencies, awareness, readiness, attitudes
Procedia PDF Downloads 21191 Valorization of Natural Vegetable Substances from Tunisia: Purification of Two Food Additives, Anthocyanins and Locust Bean Gum
Authors: N. Bouzouita, A. Snoussi , H. Ben Haj Koubaier, I. Essaidi, M. M. Chaabouni, S. Zgoulli, P. Thonart
Abstract:
Color is one of the most important quality attributes for the food industry. Grape marc, a complex lignocellulosic material is one of the most abundant and worth less byproduct, generated after the pressing process. The development of the process of purification by micro filtration, ultra filtration, nano filtration and drying by atomization of the anthocyanins of Tunisian origin is the aim of this work. Locust bean gum is the ground endosperm of the seeds of carob fruit; owing to its remarkable water-binding properties, it is widely used to improve the texture of food and largely employed in food industry. The purification of LGB causes drastically reduced ash and proteins contents but important increase for galactomannan.Keywords: Carob, food additives, grape pomace, locust bean gum, natural colorant, nano filtration, thickener, ultra filtration
Procedia PDF Downloads 32890 Identification of Soft Faults in Branched Wire Networks by Distributed Reflectometry and Multi-Objective Genetic Algorithm
Authors: Soumaya Sallem, Marc Olivas
Abstract:
This contribution presents a method for detecting, locating, and characterizing soft faults in a complex wired network. The proposed method is based on multi-carrier reflectometry MCTDR (Multi-Carrier Time Domain Reflectometry) combined with a multi-objective genetic algorithm. In order to ensure complete network coverage and eliminate diagnosis ambiguities, the MCTDR test signal is injected at several points on the network, and the data is merged between different reflectometers (sensors) distributed on the network. An adapted multi-objective genetic algorithm is used to merge data in order to obtain more accurate faults location and characterization. The proposed method performances are evaluated from numerical and experimental results.Keywords: wired network, reflectometry, network distributed diagnosis, multi-objective genetic algorithm
Procedia PDF Downloads 18689 Towards Better Quality in Healthcare and Operations Management: A Developmental Literature Review
Authors: Marc Dorval, Marie-Hélène Jobin
Abstract:
This work presents the various perspectives, dimensions, components and definitions given to quality in the operations management (OM) and healthcare services (HCS) literature in time, highlighting gaps and learning opportunities between the two disciplines through a thorough search into their rich and distinct body of knowledge. Greater and new insights about the general nature of quality are obtained with findings such as in OM, quality has been approached in six fairly distinct paradigms (excellence, value, conformity to specifications, attributes, satisfaction and meeting or exceeding customer expectations), whereas in HCS, two approaches are prominent (Donabedian’s structure, process and outcomes model and Lohr and Schroeder’s circumscribed definition). The two disciplines views on quality seem to have progressed much in parallel with little cross-learning from each other. This work then proposes an encompassing definition of quality as a lever and suggests further research and development avenues for a better use of the concept of quality by academics and practitioners alike toward the goals of greater organizational performance and improved management in healthcare and possibly other service domains.Keywords: healthcare, management, operations, quality, services
Procedia PDF Downloads 22288 Corporate Social Responsibility Practices and Financial Performance: The Case of French Unlisted SMEs
Authors: Zineb Abidi, Marc-Arthur Diaye
Abstract:
There exists a large empirical literature concerning the relationship between corporate social responsibility (CSR) and corporate financial performance. This literature, however, applies mainly to large corporations and/or listed firms. To the best of our knowledge, the question of whether meeting CSR requirements impacts the financial performance of small and medium-sized unlisted SMEs has not so far been analyzed. This paper aims to analyze, for the first time, the effect of CSR on the financial performance of SMEs. Using an original database including 5,257 French SMEs, we show that adopting CSR practices has a positive but weak effect on a firm’s financial performance. To develop this further, we analyzed CSR practices interactions assessing the best combination of CSR components that positively influence SME financial performance. Our results show that French SMEs benefit more from their pro-social behavior when they choose a combination of CSR components best adapted to their individual characteristics.Keywords: corporate social responsibility, financial performance, unlisted firms, SMEs
Procedia PDF Downloads 16487 Improving Cyber Resilience in Mobile Field Hospitals: Towards an Assessment Model
Authors: Nasir Baba Ahmed, Nicolas Daclin, Marc Olivaux, Gilles Dusserre
Abstract:
The Mobile field hospital is critical in terms of managing emergencies in crisis. It is a sub-section of the main hospitals and the health sector, tasked with delivering responsive, immediate, and efficient medical services during a crisis. With the aim to prevent further crisis, the assessment of the cyber assets follows different methods, to distinguish its strengths and weaknesses, and in turn achieve cyber resiliency. The work focuses on assessments of cyber resilience in field hospitals with trends growing in both the field hospital and the health sector in general. This creates opportunities for the adverse attackers and the response improvement objectives for attaining cyber resilience, as the assessments allow users and stakeholders to know the level of risks with regards to its cyber assets. Thus, the purpose is to show the possible threat vectors which open up opportunities, with contrast to current trends in the assessment of the mobile field hospitals’ cyber assets.Keywords: assessment framework, cyber resilience, cyber security, mobile field hospital
Procedia PDF Downloads 15486 Development of an Efficient Algorithm for Cessna Citation X Speed Optimization in Cruise
Authors: Georges Ghazi, Marc-Henry Devillers, Ruxandra M. Botez
Abstract:
Aircraft flight trajectory optimization has been identified to be a promising solution for reducing both airline costs and the aviation net carbon footprint. Nowadays, this role has been mainly attributed to the flight management system. This system is an onboard multi-purpose computer responsible for providing the crew members with the optimized flight plan from a destination to the next. To accomplish this function, the flight management system uses a variety of look-up tables to compute the optimal speed and altitude for each flight regime instantly. Because the cruise is the longest segment of a typical flight, the proposed algorithm is focused on minimizing fuel consumption for this flight phase. In this paper, a complete methodology to estimate the aircraft performance and subsequently compute the optimal speed in cruise is presented. Results showed that the obtained performance database was accurate enough to predict the flight costs associated with the cruise phase.Keywords: Cessna Citation X, cruise speed optimization, flight cost, cost index, and golden section search
Procedia PDF Downloads 28285 Trash Dash: An Educational Android Game Application for Proper Waste Segregation
Authors: Marylene S. Eder, Dorothy M. Jao, Paolo Marc Nicolas S. Laspiñas, Pukilan A. Malim, Sarah Jean D. Raterta
Abstract:
Trash Dash is an android game application developed to serve as an alternative tool to practice proper waste segregation for children ages 3 years old and above. The researchers designed the application using Unity 3D and developed the text file that served as the database of the game application. An observation of a pre-school teacher shows that children know how to throw their garbage but they do not know yet how to segregate wastes. After launching the mobile application to K-2 pupils 4 – 5 years of age, the researchers have noticed that children within this age are active and motivated to learn the difference between biodegradable and non-biodegradable. Based on the result of usability test conducted, it was concluded that the game is easy to use and children will most likely use this application frequently. Furthermore, the children may need assistance from their parents and teachers when playing the game. An actual testing of the application has been conducted to different devices as well as functionality test by Thwack Application and it can be concluded that the mobile application can be launched and installed on a device with a minimum API requirement of Gingerbread (2.3.1).Keywords: waste segregation, android application, biodegradable, non-biodegradable
Procedia PDF Downloads 43084 Sensitivity Studies for a Pin Homojunction a-Si:H Solar Cell
Authors: Leila Ayat, Afak Meftah
Abstract:
Amorphous-silicon alloys have great promise as low cost solar cell materials. They have excellent photo-conductivity and high optical absorption to sunlight. Now PIN a-Si:H based solar cells are widely used in power generation modules. However, to improve the performance of these cells further, a better fundamental under-standing of the factors limiting cell performance in the homo junction PIN structure is necessary. In this paper we discuss the sensitivity of light J-V characteristics to various device and material parameters in PIN homo junction solar cells. This work is a numerical simulation of the output parameters of a PIN a-Si:H solar cell under AM1.5 spectrum. These parameters are the short circuit current (Jsc), the open circuit voltage (Voc), the fill factor (FF), the conversion efficiency. The simulation was performed with SCAPS-1D software version 3.3 developed at ELIS in Belgium by Marc Burgelman et al. The obtained results are in agreement with experiment. In addition, the effect of the thickness, doping density, capture cross sections of the gap states and the band microscopic mobilities on the output parameters of the cell are also presented.Keywords: amorphous silicon p-i-n junctions, thin film, solar cells, sensitivity
Procedia PDF Downloads 51683 Equivalent Electrical Model of a Shielded Pulse Planar Transformer in Isolated Gate Drivers for SiC MOSFETs
Authors: Loreine Makki, Marc Anthony Mannah, Christophe Batard, Nicolas Ginot, Julien Weckbrodt
Abstract:
Planar transformers are extensively utilized in high-frequency, high power density power electronic converters. The breakthrough of wide-bandgap technology compelled power electronic system miniaturization while inducing pivotal effects on system modeling and manufacturing within the power electronics industry. A significant consideration to simulate and model the unanticipated parasitic parameters emerges with the requirement to mitigate electromagnetic disturbances. This paper will present an equivalent circuit model of a shielded pulse planar transformer quantifying leakage inductance and resistance in addition to the interwinding capacitance of the primary and secondary windings. ANSYS Q3D Extractor was utilized to model and simulate the transformer, intending to study the immunity of the simulated equivalent model to high dv/dt occurrences. A convenient correlation between simulation and experimental results is presented.Keywords: Planar transformers, wide-band gap, equivalent circuit model, shielded, ANSYS Q3D Extractor, dv/dt
Procedia PDF Downloads 20282 Enhancing Human Mobility Exoskeleton Comfort Using Admittance Controller
Authors: Alexandre Rabaseda, Emelie Seguin, Marc Doumit
Abstract:
Human mobility exoskeletons have been in development for several years and are becoming increasingly efficient. Unfortunately, user comfort was not always a priority design criterion throughout their development. To further improve this technology, exoskeletons should operate and deliver assistance without causing discomfort to the user. For this, improvements are necessary from an ergonomic point of view. The device’s control method is important when endeavoring to enhance user comfort. Exoskeleton or rehabilitation device controllers use methods of control called interaction controls (admittance and impedance controls). This paper proposes an extended version of an admittance controller to enhance user comfort. The control method used consists of adding an inner loop that is controlled by a proportional-integral-derivative (PID) controller. This allows the interaction force to be kept as close as possible to the desired force trajectory. The force-tracking admittance controller modifies the actuation force of the system in order to follow both the desired motion trajectory and the desired relative force between the user and the exoskeleton.Keywords: mobility assistive device, exoskeleton, force-tracking admittance controller, user comfort
Procedia PDF Downloads 14881 Homing of B Cells via Afferent Lymphatics
Authors: Sara Pereira-Nogueira, Tim Worbs, Marc Permanyer-Bosser, Reinhold Förster
Abstract:
While the entry mechanism of lymphocytes into the lymph node via the blood are well described, it is still largely unknown how cells enter lymph nodes that arrive via afferent lymphatics. In order to address this, our group has established a micro-injection technique in mice through which cells are delivered directly into the lymphatic vessel immediately afferent to the popliteal lymph node. Injected cells can then be tracked via multi-colour fluorescence or 2-photon microscopy, and their localization can be analysed within the popliteal or downstream lymph nodes by immunohistology. Since naïve B cells express the chemokine receptor CXCR5 we intra-lymphatically co-injected B cells derived from wildtype and Cxcr5-deficient mice. While CXCR5 does not play a role in guiding B cells out of the subcapsular sinus, it affects their positioning within the lymph node parenchyma, since CXCR5-deficient B cells are impaired in migrating into the B cell follicle. The knowledge obtained by studying B-cell migration may prove beneficial in clinical settings regarding tumor metastasis or autoimmune diseases.Keywords: afferent lymphatics, B cell migration, chemokine, intra-lymphatic injection
Procedia PDF Downloads 25680 Anthropomorphic Interfaces For User Trust in a Highly Automated Driving
Authors: Clarisse Lawson-Guidigbe, Nicolas Louveton, Kahina Amokrane-Ferka, Jean-Marc Andre
Abstract:
Trust in automated driving systems is receiving growing attention in the research community. Anthropomorphism has been identified by past research as a trust-building factor. In this paper, we consider three anthropomorphic interfaces integrating three versions of a virtual assistant. We attempt to measure the impact of each of these interfaces on trust in the automated driving system. An experiment following a between-subject design was conducted in a driving simulator (N = 36) to evaluate participants’ performance and experience in two handover situations (a simple one and a critical one). Perception of anthropomorphism and trust was measured using scales, while participants’ experience was measured during elicitation interviews. We found no significant difference between the three interfaces regarding the perception of anthropomorphism, trust levels, or experience. However, regarding participants’ performance, we found a significant difference between the three interfaces in the simple handover situations but not the critical one. Learnings from anthropomorphism and trust measurement scales are discussed and suggestions for further research are proposed.Keywords: highly automated driving, trust, anthropomorphic design, mindful anthropomorphism, mindless anthropomorphism
Procedia PDF Downloads 13979 Optimized Simultaneous Determination of Theobromine and Caffeine in Fermented and Unfermented Cacao Beans and in Cocoa Products Using Step Gradient Solvent System in Reverse Phase HPLC
Authors: Ian Marc G. Cabugsa, Kim Ryan A. Won
Abstract:
Fast, reliable and simultaneous HPLC analysis of theobromine and caffeine in cacao and cocoa products was optimized in this study. The samples tested were raw, fermented, and roasted cacao beans as well as commercially available cocoa products. The HPLC analysis was carried out using step gradient solvent system with acetonitrile and water buffered with H3PO4 as the mobile phase. The HPLC system was optimized using 273 nm wavelength at 35 °C for the column temperature with a flow rate of 1.0 mL/min. Using this method, the theobromine percent recovery mean, Limit of Detection (LOD) and Limit of Quantification (LOQ) is 118.68(±3.38)%, 0.727 and 1.05 respectively. The percent recovery mean, LOD and LOQ for caffeine is 105.53(±3.25)%, 2.42 and 3.50 respectively. The inter-day and intra-day precision for theobromine is 4.31% and 4.48% respectively, while 7.02% and 7.03% was for caffeine respectively. Compared to the standard method in AOAC using methanol in isocratic solvent system, the results of the study produced lesser chromatogram noise with emphasis on theobromine and caffeine. The method is readily usable for cacao and cocoa substances analyses using HPLC with step gradient capability.Keywords: cacao, caffeine, HPLC, step gradient solvent system, theobromine
Procedia PDF Downloads 27578 Development of Tools for Multi Vehicles Simulation with Robot Operating System and ArduPilot
Authors: Pierre Kancir, Jean-Philippe Diguet, Marc Sevaux
Abstract:
One of the main difficulties in developing multi-robot systems (MRS) is related to the simulation and testing tools available. Indeed, if the differences between simulations and real robots are too significant, the transition from the simulation to the robot won’t be possible without another long development phase and won’t permit to validate the simulation. Moreover, the testing of different algorithmic solutions or modifications of robots requires a strong knowledge of current tools and a significant development time. Therefore, the availability of tools for MRS, mainly with flying drones, is crucial to enable the industrial emergence of these systems. This research aims to present the most commonly used tools for MRS simulations and their main shortcomings and presents complementary tools to improve the productivity of designers in the development of multi-vehicle solutions focused on a fast learning curve and rapid transition from simulations to real usage. The proposed contributions are based on existing open source tools as Gazebo simulator combined with ROS (Robot Operating System) and the open-source multi-platform autopilot ArduPilot to bring them to a broad audience.Keywords: ROS, ArduPilot, MRS, simulation, drones, Gazebo
Procedia PDF Downloads 20277 Portfolio Selection with Active Risk Monitoring
Authors: Marc S. Paolella, Pawel Polak
Abstract:
The paper proposes a framework for large-scale portfolio optimization which accounts for all the major stylized facts of multivariate financial returns, including volatility clustering, dynamics in the dependency structure, asymmetry, heavy tails, and non-ellipticity. It introduces a so-called risk fear portfolio strategy which combines portfolio optimization with active risk monitoring. The former selects optimal portfolio weights. The latter, independently, initiates market exit in case of excessive risks. The strategy agrees with the stylized fact of stock market major sell-offs during the initial stage of market downturns. The advantages of the new framework are illustrated with an extensive empirical study. It leads to superior multivariate density and Value-at-Risk forecasting, and better portfolio performance. The proposed risk fear portfolio strategy outperforms various competing types of optimal portfolios, even in the presence of conservative transaction costs and frequent rebalancing. The risk monitoring of the optimal portfolio can serve as an early warning system against large market risks. In particular, the new strategy avoids all the losses during the 2008 financial crisis, and it profits from the subsequent market recovery.Keywords: comfort, financial crises, portfolio optimization, risk monitoring
Procedia PDF Downloads 51876 A Comparative Analysis on the Perspectives of Secular and Non-Secular Male Groups on Female Masturbation
Authors: Marc Angelo C. Balon, Maxine Joy A. Yongoyong
Abstract:
Female masturbation has been an age-old controversy. In fact, it is not widely talked about specifically in the Philippines since the Filipino culture still preserves the space for conservativeness. Although, considering the numerous and emerging studies on female masturbation, this study will focus on the perspectives of secular and non-secular male groups with regard to female masturbation. The objectives of this study is to identify the perceptions of these male groups and their taking on considering women who masturbate as their sexual partner, as a sexual object, and as a life partner and lastly, to have a comparative analysis of the perceptions of these male groups drawing out their sense of meaning on the masturbation of women. The researchers made use of purposive sampling technique and interview guide questionnaire. The secular male group were psychology students while the non-secular male group was drawn from a Catholic Church seminary in Tagaytay City, Cavite. Results showed that the secular male group had scientific perspectives such as exploring the genitals, contradicting moral perspectives on masturbation as a regular practice, while the non-secular male groups had theological perspectives in accordance with the fundamental moral theology, moral perspectives and perspectives on masturbation as a regular practice. Moreover, men who came from the non-secular group highly believe that masturbation is immoral. Otherwise, men who came from the secular group noted that masturbation is primary physiological need.Keywords: secular, non-secular, masturbation, comparative analysis
Procedia PDF Downloads 26875 Optimization of Cacao Fermentation in Davao Philippines Using Sustainable Method
Authors: Ian Marc G. Cabugsa, Kim Ryan Won, Kareem Mamac, Manuel Dee, Merlita Garcia
Abstract:
An optimized cacao fermentation technique was developed for the cacao farmers of Davao City Philippines. Cacao samples with weights ranging from 150-250 kilograms were collected from various cacao farms in Davao City and Zamboanga City Philippines. Different fermentation techniques were used starting with design of the sweat box, prefermentation conditionings, number of days for fermentation and number of turns. As the beans are being fermented, its temperature was regularly monitored using a digital thermometer. The resultant cacao beans were assessed using physical and chemical means. For the physical assessment, the bean cut test, bean count tests, and sensory test were used. Quantification of theobromine, caffeine, and antioxidants in the form of equivalent quercetin was used for chemical assessment. Both the theobromine and caffeine were analyzed using HPLC method while the antioxidant was analyzed spectrometrically. To come up with the best fermentation procedure, the different assessment were given priority coefficients wherein the physical tests – taste test, cut, and bean count tests were given priority over the results of the chemical test. The result of the study was an optimized fermentation protocol that is readily adaptable and transferable to any cacao cooperatives or groups in Mindanao or even Philippines as a whole.Keywords: cacao, fermentation, HPLC, optimization, Philippines
Procedia PDF Downloads 44474 Meningeal Hemangiopericytoma in an HIV-Positive Patient: A Case Report and Review of Literature
Authors: Roland Benedict Reyes, Marc Edsel Ayes, Regina Berba, Cybele Lara Abad
Abstract:
Background: Three AIDS-defining malignancies have been associated with the human immunodeficiency virus (HIV): Kaposi’s sarcoma, non-Hodgkin’s lymphoma, and cervical carcinoma. However, new cases of non-AIDS defining malignancies also have been increasingly associated with HIV. One of these is a rare intracranial malignancy, meningeal hemangiopericyotma. Case Description: A 32-year old HIV-positive male, not on highly active antiretroviral therapy, was admitted to our hospital due to generalized weakness and sudden onset hearing loss. Cranial MRI was done, which revealed a temporal nodule with the following considerations: granuloma, meningioma or metastases. A craniotomy was performed and the mass excised. Results from the biopsy showed meningeal hemangiopericytoma. The patient was then started on antiretroviral therapy (Lamivudine, Tenofovir, and Efavirenz) and was discharged for radiation therapy and metastatic work-up as an outpatient. On follow-up seven months later, metastatic work up revealed multiple hepatic foci not previously documented suggestive of metastasis short of biopsy sampling. Conclusions: This case of an intracranial hemangiopericytoma in an HIV-positive patient is the second case thus far presented, based on our systematic and extensive search of the literature.Keywords: Hemangiopericytoma, Human Immunodeficiency Virus, Meningeal hemangiopericytoma, Neoplasm
Procedia PDF Downloads 457