Search results for: polymer mixed with bitumen (PMB)
1461 Gas-Liquid Flow Regimes in Vertical Venturi Downstream of Horizontal Blind-Tee
Authors: Muhammad Alif Bin Razali, Cheng-Gang Xie, Wai Lam Loh
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A venturi device is commonly used as an integral part of a multiphase flowmeter (MPFM) in real-time oil-gas production monitoring. For an accurate determination of individual phase fraction and flowrate, a gas-liquid flow ideally needs to be well mixed in the venturi measurement section. Partial flow mixing is achieved by installing a venturi vertically downstream of the blind-tee pipework that ‘homogenizes’ the incoming horizontal gas-liquid flow. In order to study in-depth the flow-mixing effect of the blind-tee, gas-liquid flows are captured at blind-tee and venturi sections by using a high-speed video camera and a purpose-built transparent test rig, over a wide range of superficial liquid velocities (0.3 to 2.4m/s) and gas volume fractions (10 to 95%). Electrical capacitance sensors are built to measure the instantaneous holdup (of oil-gas flows) at the venturi inlet and throat. Flow regimes and flow (a)symmetry are investigated based on analyzing the statistical features of capacitance sensors’ holdup time-series data and of the high-speed video time-stacked images. The perceived homogenization effect of the blind-tee on the incoming intermittent horizontal flow regimes is found to be relatively small across the tested flow conditions. A horizontal (blind-tee) to vertical (venturi) flow-pattern transition map is proposed based on gas and liquid mass fluxes (weighted by the Baker parameters).Keywords: blind-tee, flow visualization, gas-liquid two-phase flow, MPFM
Procedia PDF Downloads 1281460 Bioactive Compounds and Antioxidant Capacity of Instant Fruit Green Tea Powders
Authors: Akanit Pisalwadcharin, Komate Satayawut, Virachnee Lohachoompol
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Green tea, mangosteen and pomegranate contain high levels of bioactive compounds which have antioxidant effects and great potential in food applications. The aim of this study was to produce and determine catechin contents, total phenolic contents, antioxidant activity and phenolic compounds of two instant fruit green tea powders which were green tea fortified with mangosteen juice and green tea fortified with pomegranate juice. Seventy percent of hot water extract of green tea was mixed with 30% of mangosteen juice or pomegranate juice, and then spray-dried using a spray dryer. The results showed that the drying conditions optimized for the highest total phenolic contents, catechin contents and antioxidant activity of both powders were the inlet air temperature of 170°C, outlet air temperatures of 90°C and maltodextrin concentration of 30%. The instant green tea with mangosteen powder had total phenolic contents, catechin contents and antioxidant activity of 19.18 (mg gallic acid/kg), 85.44 (mg/kg) and 4,334 (µmoles TE/100 g), respectively. The instant green tea with pomegranate powder had total phenolic contents, catechin contents and antioxidant activity of 32.72 (mg gallic acid/kg), 156.36 (mg/kg) and 6,283 (µmoles TE/100 g), respectively. The phenolic compounds in instant green tea with mangosteen powder comprised of tannic acid (2,156.87 mg/kg), epigallocatechin-3-gallate (898.23 mg/kg) and rutin (13.74 mg/kg). Also, the phenolic compounds in instant green tea with pomegranate powder comprised of tannic acid (2,275.82 mg/kg), epigallocatechin-3-gallate (981.23 mg/kg), rutin (14.97 mg/kg) and i-quercetin (5.86 mg/kg).Keywords: green tea, mangosteen, pomegranate, antioxidant activity
Procedia PDF Downloads 3661459 Magnetic Structure and Transitions in 45% Mn Substituted HoFeO₃: A Neutron Diffraction Study
Authors: Karthika Chandran, Pulkit Prakash, Amitabh Das, Santhosh P. N.
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Rare earth orthoferrites (RFeO₃) exhibit interesting and useful magnetic properties like multiferroicity, magnetodielectric coupling, spin reorientation (SR) and exchange bias. B site doped RFeO₃ are attracting attention due to the complex and tuneable magnetic transitions. In this work, 45% Mn-doped HoFeO₃ polycrystalline sample (HoFe₀.₅₅Mn₀.₄₅O₃) was synthesized by a solid-state reaction method. The magnetic structure and transitions were studied by magnetization measurements and neutron powder diffraction methods. The neutron diffraction patterns were taken at 13 different temperatures from 7°K to 300°K (7°K and 25°K to 300°K in 25°K intervals). The Rietveld refinement was carried out by using a FULLPROF suite. The magnetic space groups and the irreducible representations were obtained by SARAh module. The room temperature neutron diffraction refinement results indicate that the sample crystallizes in an orthorhombic perovskite structure with Pnma space group with lattice parameters a = 5.6626(3) Ǻ, b = 7.5241(3) Ǻ and c = 5.2704(2) Ǻ. The temperature dependent magnetization (M-T) studies indicate the presence of two magnetic transitions in the system ( TN Fe/Mn~330°K and TSR Fe/Mn ~290°K). The inverse susceptibility vs. temperature curve shows a linear behavior above 330°K. The Curie-Weiss fit in this region gives negative Curie constant (-34.9°K) indicating the antiferromagnetic nature of the transition. The neutron diffraction refinement results indicate the presence of mixed magnetic phases Γ₄(AₓFᵧGKeywords: neutron powder diffraction, rare earth orthoferrites, Rietveld analysis, spin reorientation
Procedia PDF Downloads 1481458 The Study and the Use of the Bifunctional Catalyst Pt/Re for Obtaining High Octane Number of the Gasoline
Authors: Menouar Hanafi
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The original function of the process of platforming is to develop heavy naphtha (HSRN), coming from the atmospheric unit of distillation with a weak octane number (NO=44), to obtain a mixture of fuels â number octane raised by catalytically supporting specific groups of chemical reactions. The installation is divided into two sections: Section hydrobon. Section platforming. The rafinat coming from the bottom of column 12C2 to feed the section platforming, is divided into two parts whose flows are controlled and mixed with gas rich in hydrogen. Bottom of the column, we obtain stabilized reformat which is aspired by there pump to ensure the heating of the column whereas a part is sent towards storage after being cooled by the air cooler and the condenser. In catalytic catalyst of reforming, there is voluntarily associated a hydrogenating function-dehydrogenating, brought by platinum deposited, with an acid function brought by the alumina support (Al 2 0 3). The mechanism of action of this bifunctional catalyst depends on the severity of the operation, of the quality of the load and the type of catalyst. The catalyst used in the catalytic process of reforming is a very elaborate bifunctional catalyst whose performances are constantly improved thanks to the experimental research supported on an increasingly large comprehension of the phenomena. The American company Universel 0i1 petroleum (UOP) marketed several series of bimetallic catalysts such as R16, R20, R30, and R62 consisted Platinum/Rhenium on an acid support consisted the alumina added with a halogenous compound (chlorine).Keywords: platforming, amelioration, octane number, catalyst
Procedia PDF Downloads 3861457 Spiritual Symbols of African Fruits as Responsive Catalysts for Naturopathy
Authors: Orogun Daniel Oghenekevhwe
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Africa being an agrarian continent has an abundance of fruits that are both nutritional and medicinal. Regardless of the abundance of these healing elements, Africa leads the statistics of poor healthcare globally. Among others, there are two noticeable challenges in the healthcare system which are ‘Poor access and high cost of medical healthcare’. The effects of both the access and economic implications are (1) Low responsiveness and (2) High mortality rate. While the United Nations and the global health community continue to work towards reduced mortality rates and poor responsiveness to healthcare and wellness, this paper investigates how some Africans use the spiritual symbols of African fruits as responsive catalysts to embrace naturopathy thereby reducing the effects and impacts of poor healthcare challenges in Africa. The main argument is whether there are links between spiritual symbols and fruits that influence Africans' response to naturopathy and low-cost healthcare. Following that is the question of how medical healthcare responds to such development. Bitter Kola (Garcinia) is the case study fruit, and Sunnyside in Pretoria, South Africa, has been spotted as one of the high-traffic selling points of herbal fruits. A mixed research method is applicable with an expected 20 Quantitative data respondents among sellers and nutritionists and 50 Qualitative Data respondents among consumers. Based on the results, it should be clear how spirituality contributes to alternative healthcare and how it can be further encouraged to bridge the gap between the high demand and low supply of healthcare in Africa and beyond.Keywords: spiritual symbols, naturopathy, African fruits, spirituality, healthcare
Procedia PDF Downloads 711456 Influence of Aluminium on Grain Refinement in As-Rolled Vanadium-Microalloyed Steels
Authors: Kevin Mark Banks, Dannis Rorisang Nkarapa Maubane, Carel Coetzee
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The influence of aluminium content, reheating temperature, and sizing (final) strain on the as-rolled microstructure was systematically investigated in vanadium-microalloyed and C-Mn plate steels. Reheating, followed by hot rolling and air cooling simulations were performed on steels containing a range of aluminium and nitrogen contents. Natural air cooling profiles, corresponding to 6 and 20mm thick plates, were applied. The austenite and ferrite/pearlite microstructures were examined using light optical microscopy. Precipitate species and volume fraction were determined on selected specimens. No influence of aluminium content was found below 0.08% on the as-rolled grain size in all steels studied. A low Al-V-steel produced the coarsest initial austenite grain size due to AlN dissolution at low temperatures leading to abnormal grain growth. An Al-free V-N steel had the finest initial microstructure. Although the as-rolled grain size for 20mm plate was similar in all steels tested, the grain distribution was relatively mixed. The final grain size in 6mm plate was similar for most compositions; the exception was an as-cast V low N steel, where the size of the second phase was inversely proportional to the sizing strain. This was attributed to both segregation and a low VN volume fraction available for effective pinning of austenite grain boundaries during cooling. Increasing the sizing strain refined the microstructure significantly in all steels.Keywords: aluminium, grain size, nitrogen, reheating, sizing strain, steel, vanadium
Procedia PDF Downloads 1521455 Offline Parameter Identification and State-of-Charge Estimation for Healthy and Aged Electric Vehicle Batteries Based on the Combined Model
Authors: Xiaowei Zhang, Min Xu, Saeid Habibi, Fengjun Yan, Ryan Ahmed
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Recently, Electric Vehicles (EVs) have received extensive consideration since they offer a more sustainable and greener transportation alternative compared to fossil-fuel propelled vehicles. Lithium-Ion (Li-ion) batteries are increasingly being deployed in EVs because of their high energy density, high cell-level voltage, and low rate of self-discharge. Since Li-ion batteries represent the most expensive component in the EV powertrain, accurate monitoring and control strategies must be executed to ensure their prolonged lifespan. The Battery Management System (BMS) has to accurately estimate parameters such as the battery State-of-Charge (SOC), State-of-Health (SOH), and Remaining Useful Life (RUL). In order for the BMS to estimate these parameters, an accurate and control-oriented battery model has to work collaboratively with a robust state and parameter estimation strategy. Since battery physical parameters, such as the internal resistance and diffusion coefficient change depending on the battery state-of-life (SOL), the BMS has to be adaptive to accommodate for this change. In this paper, an extensive battery aging study has been conducted over 12-months period on 5.4 Ah, 3.7 V Lithium polymer cells. Instead of using fixed charging/discharging aging cycles at fixed C-rate, a set of real-world driving scenarios have been used to age the cells. The test has been interrupted every 5% capacity degradation by a set of reference performance tests to assess the battery degradation and track model parameters. As battery ages, the combined model parameters are optimized and tracked in an offline mode over the entire batteries lifespan. Based on the optimized model, a state and parameter estimation strategy based on the Extended Kalman Filter (EKF) and the relatively new Smooth Variable Structure Filter (SVSF) have been applied to estimate the SOC at various states of life.Keywords: lithium-ion batteries, genetic algorithm optimization, battery aging test, parameter identification
Procedia PDF Downloads 2681454 Potentiality of Biohythane Process for the Gaseous Energy Recovery from Organic Wastes
Authors: Debabrata Das, Preeti Mishra
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A two-phase anaerobic process combining biohydrogen followed by biomethane (biohythane technology) serves as an environment-friendly and economically sustainable approach for the improved valorization of organic wastes. Suitability of the pure cultures like Klebsiela pneumonia, C. freundii, B. coagulan, etc. and mixed acidogenic cultures for the biohydrogen production was already studied. The characteristics of organic wastes play a critical role in biohydrogen production. The choice of an appropriate combination of complementary organic wastes can vastly improve the bioenergy generation besides achieving the significant cost reduction. Suitability and economic viability of using the groundnut deoiled cake (GDOC), mustard deoiled cake (MDOC), distillers’ dried grain with soluble (DDGS) and algal biomass (AB) as a co-substrate were studied for a biohythane production. Results show that maximum gaseous energy of 20.7, 9.3, 16.7 and 15.6 % was recovered using GDOC, MDOC, DDGS and AB in the two stage biohythane production, respectively. Both GDOC and DDGS were found to be better co-substrates as compared to MDOC and AB in terms of hythane production, respectively. The maximum cumulative hydrogen and methane production of 150 and 64 mmol/L were achieved using GDOC. Further, 98 % reduction in substrate input cost (SIC) was achieved using the co-supplementation procedure.Keywords: Biohythane, algal biomass, distillers’ dried grain with soluble (DDGS), groundnut deoiled cake (GDOC), mustard deoiled cake (MDOC)
Procedia PDF Downloads 2001453 Caged in Concrete Jungles: Reasserting Cultural Identity and Environmental Sustainability through Material Choice and Design Expression in Architecture
Authors: Ikenna Michael Onuorah
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The relentless march of globalization in architecture has led to a homogenization of built environments, often characterized by an overreliance on imported, resource-intensive materials and a disregard for local cultural contexts. This research posits that such practices pose significant environmental and cultural perils, trapping communities in "caged concrete jungles" devoid of both ecological sustainability and a meaningful connection to their heritage. Through a mixed-method approach encompassing quantitative and qualitative data analysis, the study investigated the impacts of neglecting local materials and cultural expression in architectural design. The research is anticipated to yield significant insights into the multifaceted consequences of neglecting locally available materials and cultural expression in architecture. It creates a compelling case for reasserting local materials and cultural expression in architectural design. Based on the anticipated research findings, the study proposed series of actionable recommendations for architects, policymakers, and communities to promote sustainable and culturally sensitive built environments. This will serve as a wake-up call, urging architects, policymakers, and communities to break free from the confines of "caged concrete jungles" and embrace a more sustainable and culturally sensitive approach to design.Keywords: sustainability, cultural identity, building materials, sustainable dsigns
Procedia PDF Downloads 561452 Co-Precipitation Method for the Fabrication of Charge-Transfer Molecular Crystal Nanocapsules
Authors: Rabih Al-Kaysi
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When quasi-stable solutions of 9-methylanthracene (pi-electron donor, 0.0005 M) and 1,2,4,5-Tetracyanobenzene (pi-electron acceptor, 0.0005 M) in aqueous sodium dodecyl sulfate (SDS, 0.025 M) were gently mixed, uniform-shaped rectangular charge-transfer nanocrystals precipitated out. These red colored charge-transfer (CT) crystals were composed of a 1:1-mole ratio of acceptor/ donor and are highly insoluble in water/SDS solution. The rectangular crystals morphology is semi hollow with symmetrical twin pockets reminiscent of nanocapsules. For a typical crop of nanocapsules, the dimensions are 21 x 6 x 0.5 microns with an approximate hollow volume of 1.5 x 105 nm3. By varying the concentration of aqueous SDS, mixing duration and incubation temperature, we can control the size and volume of the nanocapsules. The initial number of CT seed nanoparticles, formed by mixing the D and A solutions, determined the number and dimensions of the obtained nanocapsules formed after several hours of incubation under still conditions. Prolonged mixing of the donor and acceptor solutions resulted in plenty of initial seeds hence smaller nanocapsules. Short mixing times yields less seed formation and larger micron-sized capsules. The addition of Doxorubicin in situ with the quasi-stable solutions while mixing leads to the formation of CT nanocapsules with Doxorubicin sealed inside. The Doxorubicin can be liberated from the nanocapsules by cracking them using ultrasonication. This method can be extended to other binary CT complex crystals as well.Keywords: charge-transfer, nanocapsules, nanocrystals, doxorubicin
Procedia PDF Downloads 2141451 Dual Thermoresponsive Polyzwitterionic Core-Shell Microgels and Study of Their Anti-Fouling Effect
Authors: P. Saha, R. Ganguly, N. K .Singha, A. Pich
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Microgel, a smart class of material, has drawn attention in the past few years due to its response to external stimuli like temperature, pH, and ionic strength of the solution. Among them, one type of polymer becomes soluble, and the other becomes insoluble in water upon heating displaying upper critical solution temperature (UCST) (e.g., polysulfobetaine, PSB) and lower critical solution temperature (LCST) (e.g., poly(N-vinylcaprolactam, PVCL)) respectively. Polyzwitterions, electrically neutral polymers are biocompatible, biodegradable, and non-cytotoxic in nature, and presence of zwitterionic pendant group in the main backbone makes them stable against temperature and pH variations and strong hydration capability in salt solution promotes them to be used as interfacial bio-adhesion resistance material. Majority of zwitterionic microgels have been synthesized in mini- emulsion technique using free radical polymerization approach. Here, a new route to synthesize dual thermo-responsive PVCL microgels decorated with appreciable amount of zwitterionic PSB chains was developed by a purely water-based surfactant-free reversible addition–fragmentation chain transfer (RAFT) precipitation polymerization. PSB macro-RAFTs having different molecular weights were synthesized and utilized for surface-grafting with PVCL microgels varying the macro-RAFT concentration using N,N′-methylenebis(acrylamide) (BIS) as cross-linker. Increasing the PSB concentration in the PVCL microgels resulted in a linear increase in UCST but decrease in hydrodynamic radius due to strong intrachain coulombic attraction forces acting between the opposite charges present in the zwitterionic groups. Anti- fouling effect was observed on addition of BSA protein solution on the microgel-coated membrane surfaces as studied by fluorescence spectrophotoscopy.Keywords: microgels, polyzwitterions, upper critical solution temperature-lower critical solution temperature, UCST-LCST, ionic crosslinking
Procedia PDF Downloads 1161450 Diagnosis of the Heart Rhythm Disorders by Using Hybrid Classifiers
Authors: Sule Yucelbas, Gulay Tezel, Cuneyt Yucelbas, Seral Ozsen
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In this study, it was tried to identify some heart rhythm disorders by electrocardiography (ECG) data that is taken from MIT-BIH arrhythmia database by subtracting the required features, presenting to artificial neural networks (ANN), artificial immune systems (AIS), artificial neural network based on artificial immune system (AIS-ANN) and particle swarm optimization based artificial neural network (PSO-NN) classifier systems. The main purpose of this study is to evaluate the performance of hybrid AIS-ANN and PSO-ANN classifiers with regard to the ANN and AIS. For this purpose, the normal sinus rhythm (NSR), atrial premature contraction (APC), sinus arrhythmia (SA), ventricular trigeminy (VTI), ventricular tachycardia (VTK) and atrial fibrillation (AF) data for each of the RR intervals were found. Then these data in the form of pairs (NSR-APC, NSR-SA, NSR-VTI, NSR-VTK and NSR-AF) is created by combining discrete wavelet transform which is applied to each of these two groups of data and two different data sets with 9 and 27 features were obtained from each of them after data reduction. Afterwards, the data randomly was firstly mixed within themselves, and then 4-fold cross validation method was applied to create the training and testing data. The training and testing accuracy rates and training time are compared with each other. As a result, performances of the hybrid classification systems, AIS-ANN and PSO-ANN were seen to be close to the performance of the ANN system. Also, the results of the hybrid systems were much better than AIS, too. However, ANN had much shorter period of training time than other systems. In terms of training times, ANN was followed by PSO-ANN, AIS-ANN and AIS systems respectively. Also, the features that extracted from the data affected the classification results significantly.Keywords: AIS, ANN, ECG, hybrid classifiers, PSO
Procedia PDF Downloads 4421449 Life Stage Customer Segmentation by Fine-Tuning Large Language Models
Authors: Nikita Katyal, Shaurya Uppal
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This paper tackles the significant challenge of accurately classifying customers within a retailer’s customer base. Accurate classification is essential for developing targeted marketing strategies that effectively engage this important demographic. To address this issue, we propose a method that utilizes Large Language Models (LLMs). By employing LLMs, we analyze the metadata associated with product purchases derived from historical data to identify key product categories that act as distinguishing factors. These categories, such as baby food, eldercare products, or family-sized packages, offer valuable insights into the likely household composition of customers, including families with babies, families with kids/teenagers, families with pets, households caring for elders, or mixed households. We segment high-confidence customers into distinct categories by integrating historical purchase behavior with LLM-powered product classification. This paper asserts that life stage segmentation can significantly enhance e-commerce businesses’ ability to target the appropriate customers with tailored products and campaigns, thereby augmenting sales and improving customer retention. Additionally, the paper details the data sources, model architecture, and evaluation metrics employed for the segmentation task.Keywords: LLMs, segmentation, product tags, fine-tuning, target segments, marketing communication
Procedia PDF Downloads 241448 Fostering Resilience in Early Adolescents: A Canadian Evaluation of the HEROES Program
Authors: Patricia L. Fontanilla, David Nordstokke
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Introduction: Today’s children and youth face increasing social and behavioural challenges, leading to delays in social development and greater mental health needs. Early adolescents (aged 9 to 14) are experiencing a rise in mental health symptoms and diagnoses. This study examines the impact of HEROES, a social-emotional learning (SEL) program, on resilience and academic outcomes in early adolescents. The HEROES program is designed to enhance resilience the ability to adapt and thrive in the face of adversity, equipping youth to navigate developmental transitions and challenges. This study’s objective was to evaluate the program’s long-term effectiveness by measuring changes in resilience and academic resilience across 10 months. Methodology: This study collected data from 21 middle school students (grades 7 to 9) in a rural Canadian school. Quantitative data were gathered at four intervals: pre-intervention, post-intervention, and at 2- and 4-month follow-ups. Data were analyzed with linear mixed models (LMM). Results: Findings showed statistically significant increases in academic resilience over time and significant increases in resilience from pre-intervention to 2 and 4 months later. Limitations included a small sample size, which may affect generalizability. Conclusion: The HEROES program demonstrates promise in increasing resilience and academic resilience among early adolescents through SEL skill development.Keywords: academic resilience, early adolescence, resilience, SEL, social-emotional learning program
Procedia PDF Downloads 111447 Patients' Interpretation of Prescribed Medication Instructions: A Pilot Study among Diabetes Mellitus Patients at Makanye Clinic in Limpopo Province, South Africa
Authors: Charity Ngoatle, Tebogo M. Mothiba, Mahlapahlapana J. Themane
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Misapprehension of medications instructions due to poor health literacy is common in diabetic patients, predominantly leading to suboptimal medication therapy caused by taking less than expected, or getting inadequate medication concentration. Globally, 50% of adults have been reported to have misunderstood medication instructions which could be the cause of not using medication as prescribed. Reading material has been found not to improve people’s knowledge to the extent where they would be informed and knowledgeable about their health. This, therefore, depicts that instructive materials alone cannot improve health literacy but further patient education is still needed to explain what the information really mean. The aim of this study was to investigate patients’ interpretation of prescribed medication instructions at Makanye Clinic in Limpopo Province, South Africa. The study used a mixed method approach. A non-probability purposive and simple random sampling strategies will be used to select ten (10) participants for the pilot study. Semi-structured interviews with a guide and self- administered structured questionnaires will be used to collect data. Tesch’s eight steps for qualitative data analysis and SPSS version 24 with descriptive statistics will be adopted. The preliminary findings from other studies show that: (a) poor health literacy negatively affect medication adherence, (b) general literacy influence health literacy, and (c) there are poor health outcomes and medication adverse effects due to poor medication comprehension.Keywords: instructions, diabetes mellitus, patients, prescribed medication
Procedia PDF Downloads 1371446 Household Water Source Substitution and Demand for Water Connections
Authors: Elizabeth Spink
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The United Nations' Sustainable Development Goal 6 sets a target for safe and affordable drinking water for all. Developing country governments aiming to achieve this goal often face significant challenges when trying to service last mile customers, particularly those in peri-urban and rural areas. Expansion of water networks often requires high connection fees from households, and demand for connections may be low if there are cheaper substitute sources of water available. This research studies the effect of the availability of substitute sources of water on demand for individual water connections in Livingstone, Zambia, using an event study analysis of metering campaigns. Metering campaigns reduce the share of a household's neighbors that can provide free water to the household if their water connection becomes disconnected due to nonpayment. The results show that household payments in newly metered regions increase by 10 percentage points in the months following metering events, with a decrease in disconnections of 6 percentage points for low-income households. To isolate the effect of changes in a household's substitution possibilities, a similar analysis is conducted among households that neighbor the metered region. These results show mixed evidence of the impact of substitutes on payment behavior and disconnections. The results suggest that metering may be effective in increasing household demand for individual water connections primarily through a lower monthly cost burden for newly metered households.Keywords: piped-water access, water demand, water utilities, water sharing
Procedia PDF Downloads 1981445 Vitrification and Devitrification of Chromium Containing Tannery Ash
Authors: Savvas Varitis, Panagiotis Kavouras, George Kaimakamis, Eleni Pavlidou, George Vourlias, Konstantinos Chrysafis, Philomela Komninou, Theodoros Karakostas
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Tannery industry produces high quantities of chromium containing waste which also have high organic content. Processing of this waste is important since the organic content is above the disposal limits and the containing trivalent chromium could be potentially oxidized to hexavalent in the environment. This work aims to fabricate new vitreous and glass ceramic materials which could incorporate the tannery waste in stabilized form either for safe disposal or for the production of useful materials. Tannery waste was incinerated at 500oC in anoxic conditions so most of the organic content would be removed and the chromium remained trivalent. Glass forming agents SiO2, Na2O and CaO were mixed with the resulting ash in different proportions with decreasing ash content. Considering the low solubility of Cr in silicate melts, the mixtures were melted at 1400oC and/or 1500oC for 2h and then casted on a refractory steel plate. The resulting vitreous products were characterized by X-Ray Diffraction (XRD), Differential Thermal Analysis (DTA), Scanning and Transmission Electron Microscopy (SEM and TEM). XRD reveals the existence of Cr2O3 (eskolaite) crystallites embedded in a glassy amorphous matrix. Such crystallites are not formed under a certain proportion of the waste in the ash-vitrified material. Reduction of the ash proportion increases chromium content in the silicate matrix. From these glassy products, glass-ceramics were produced via different regimes of thermal treatment.Keywords: chromium containing tannery ash, glass ceramic materials, thermal processing, vitrification
Procedia PDF Downloads 3671444 Studies on Some Aspects of Sub Clinical Mastitis in Cattle
Authors: Kavita Jaidiya, Anju Chahar, Chitra Jaidiya
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The present study was conducted on 200 quarters from 50 apparently healthy cows. Samples are subjected to California Mastitis Test (CMT), cultural examination, and mPCR. Milk samples were also subjected to changes in composition Viz. fat, protein, and lactose. The prevalence of subclinical mastitis based on culture examination was 30(60/200), 36 (72/200), and 40 percent (93/200) based on CMT, culture examination, and mPCR on a quarterly basis. The prevalence of subclinical mastitis on animal basis was 40 (20/50), 46 (23/50), and 52 percent (26/50) based on CMT, Culture examination, and mPCR. The highest prevalence was observed in IVth parity on a quarterly basis and in Vth parity on cow basis. On culture examination, Staphylococcus aureus was the most prevalent organism (50.56%), followed by Streptococcus dysaglactiae (11.33%), E. coli (7.8 %), Staphylococcus agalactiae (13.48 %), Staphylococcus epidermidis (2.2 %), Streptococcus hyicus (6.94%), Streptococcus uberis (5.16%), Klebsiella pneumonia (6.74%). On isolation by bacterial mPCR, Staphylococcus spp. (42%) was the major pathogen. Organisms isolated in mixed infections are Streptococcus spp., Klebsiella pneumonia, E.coli and Pseudomonas aeruginous. The average mean value of fat, protein, and lactose content in subclinically affected milk samples were 3.40 ± 0.101, 3.009 ± 0.033, and 4.48 ± 0.03, and the mean value of fat, protein, and lactose content in normal milk were 4.13 ± 0.035, 3.39 ± 0.021, and 5.10 ± 0.016. The mean blood level of reduced glutathione in subclinical mastitis (30.44 ± 1.87 ng/ml) was lower than healthy cows (47.98 ± 4.04ng/ml). The concentration of malondialdehyde (10.026 ± 0.21mmol/L) in subclinical mastitis was significantly higher as compared to healthy group cows (2.19 ± 0.23mmol/L).Keywords: cow, subclinical mastitis, mPCR, California Mastitis test
Procedia PDF Downloads 1491443 The Prognostic Value of Dynamic Changes of Hematological Indices in Oropharyngeal Cancer Patients Treated with Radiotherapy
Authors: Yao Song, Danni Cheng, Jianjun Ren
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Objectives: We aimed to explore the prognostic effects of absolute values and dynamic changes of common hematological indices on oropharynx squamous cell carcinoma (OPSCC) patients treated with radiation. Methods and materials: The absolute values of white blood cell (WBC), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), hemoglobin (Hb), platelet (Plt), albumin (Alb), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at baseline (within 45 days before radiation), 1-, 3-, 6- and 12-months after the start of radiotherapy were retrospectively collected. Locally-estimated smoothing scatterplots were used to describe the smooth trajectory of each index. A mixed-effect model with a random slope was fitted to describe the changing rate and trend of indices over time. Cox proportional hazard analysis was conducted to assess the correlation between hematological indices and treatment outcomes. Results: Of the enrolled 85 OPSCC patients, inflammatory indices, such as WBC and ALC, dropped rapidly during acute treatment and gradually recovered, while NLR and PLR increased at first three months and subsequently declined within 3-12 months. Higher absolute value or increasing trend of nutritional indices (Alb and Hb) was associated with better prognosis (all p<0.05). In contrast, patients with higher absolute value or upward trend of inflammatory indices (WBC, ANC, Plt, PLR and NLR) had worse survival (all p<0.05). Conclusions: The absolute values and dynamic changes of hematological indices were valuable prognostic factors for OPSCC patients who underwent radiotherapy.Keywords: hematological indices, oropharyngeal cancer, radiotherapy, NLR, PLR
Procedia PDF Downloads 1841442 In vitro Comparison Study of Biologically Synthesized Cupper-Disulfiram Nanoparticles with Its Free Corresponding Complex as Therapeutic Approach for Breast and Liver Cancer
Authors: Marwa M. Abu-Serie, Marwa M. Eltarahony
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The search for reliable, effective, and safe nanoparticles (NPs) as a treatment for cancer is a pressing priority. In this study, Cu-NPs were fabricated by Streptomyces cyaneofuscatus through simultaneous bioreduction strategy of copper nitrate salt. The as-prepared Cu-NPs subjected to structural analysis; energy-dispersive X-ray spectroscopy, elemental mapping, X-ray diffraction, transmission electron microscopy, and ζ-potential. These biological synthesized Cu-NPs were mixed with disulfiram (DS), forming a nanocomplex of Cu-DS with a size of ~135 nm. The prepared nanocomplex (nanoCu-DS) exhibited higher anticancer activity than that of free complex of DS-Cu, Cu-NPs, and DS alone. This was illustrated by the lowest IC50 of nanoCu-DS (< 4 µM) against human breast and liver cancer cell lines comparing with DS-Cu, Cu-NPs, and DS (~8, 22.98-33.51 and 11.95-14.86, respectively). Moreover, flow cytometric analysis confirmed that higher apoptosis percentage range of nanoCu-DS-treated in MDA-MB 231, MCF-7, Huh-7, and HepG-2 cells (51.24-65.28%) than free complex of Cu-DS ( < 4.5%). Regarding inhibition potency of liver and breast cancer cell migration, no significant difference was recorded between free and nanocomplex. Furthermore, nanoCu-DS suppressed gene expression of β-catenine, Akt, and NF-κB and upregulated p53 expression (> 3, >15, > 5 and ≥ 3 folds, respectively) more efficiently than free complex (all ~ 1 fold) in MDA-MB 231 and Huh-7 cells. Our finding proved this prepared nano complex has a powerful anticancer activity relative to free complex, thereby offering a promising cancer treatment.Keywords: biologically prepared Cu-NPs, breast cancer cell lines, liver cancer cell lines, nanoCu- disulfiram
Procedia PDF Downloads 1891441 Online Foreign Language Learning Motivation for Tunisian Students of English
Authors: Leila Najeh
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This study investigates the motivational factors influencing Tunisian university students learning English through online platforms. Using a mixed-methods approach, data were collected from 112 undergraduate students of English across universities in Tunisia. The study employed an online questionnaire to measure intrinsic and extrinsic motivation, incorporating the Learning Motivation Questionnaire (FFLLM-Q) developed by Gonzales in 2001 and semi-structured interviews to explore students’ perspectives on their online learning experiences. Quantitative analysis revealed a significant correlation between intrinsic motivation and interactive features such as gamification and adaptive content delivery, while extrinsic motivation was strongly linked to career aspirations and academic requirements. Qualitative findings highlighted challenges such as limited interaction with peers and teachers, technical constraints, and a lack of immediate feedback as demotivating factors. Participants expressed a preference for blended learning models, combining the flexibility of online education with the collaborative environment of traditional classrooms. This study underscores the need for tailored online learning solutions to enhance the motivational landscape for Tunisian students, emphasizing the importance of culturally relevant content, accessible platforms, and supportive learning communities. Further research is recommended to evaluate the long-term impact of these interventions on language proficiency and learner autonomy.Keywords: motivational factor, online foreign language learnig, tunsian students of english, online learning platforms
Procedia PDF Downloads 71440 Modification of Titanium Surfaces with Micro/Nanospheres for Local Antibiotic Release
Authors: Burcu Doymus, Fatma N. Kok, Sakip Onder
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Titanium and titanium-based materials are commonly used to replace or regenerate the injured or lost tissues because of accidents or illnesses. Hospital infections and strong bond formation at the implant-tissue interface are directly affecting the success of the implantation as weak bonding with the native tissue and hospital infections lead to revision surgery. The purpose of the presented study is to modify the surface of the titanium substrates with nano/microspheres for local drug delivery and to prevent hospital infections. Firstly, titanium surfaces were silanized with APTES (3-Triethoxysilylpropylamine) following the negatively charged oxide layer formation. Then characterization studies using Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were done on the modified surfaces. Secondly, microspheres/nanospheres were prepared with chitosan that is a natural polymer and having valuable properties such as non-toxicity, high biocompatibility, low allergen city and biodegradability for biomedical applications. Antibiotic (ciprofloxacin) loaded micro/nanospheres have been fabricated using emulsion cross-linking method and have been immobilized onto the titanium surfaces with different immobilization techniques such as covalent bond and entrapment. Optimization studies on size and drug loading capacities of micro/nanospheres were conducted before the immobilization process. Light microscopy and SEM were used to visualize and measure the size of the produced micro/nanospheres. Loaded and released drug amounts were determined by using UV- spectrophotometer at 278 nm. Finally, SEM analysis and drug release studies on the micro/nanospheres coated Ti surfaces were done. As a conclusion, it was shown that micro/nanospheres were immobilized onto the surfaces successfully and drug release from these surfaces was in a controlled manner. Moreover, the density of the micro/nanospheres after the drug release studies was higher on the surfaces where the entrapment technique was used for immobilization. Acknowledgement: This work is financially supported by The Scientific and Technological Research Council Of Turkey (Project # 217M220)Keywords: chitosan, controlled drug release, nanosphere, nosocomial infections, titanium
Procedia PDF Downloads 1251439 Teachers’ and Parents’ Perceptions of School and Family Partnership Practices of Schools in Mogadishu
Authors: Mohamed Abdullahi Gure, Farhia Ali Abdi
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There is almost a complete certainty among educators that parental involvement is the remedy for many of the problems facing schools. It is also widely acknowledged that school administrators and teachers have important roles in promoting parental involvement in children’s education. This work aims at examining the views of parents and teachers on school-partnership practices for promoting parental involvement in education in selected primary schools in Mogadishu-Somalia. The method, which has been employed in this study, is a mixed-method approach; data were collected from parents as well as from teachers of the selected schools using survey questionnaires and interviews. A sample size of 377 parents and 214 teachers participated in this study. This study used an instrument that has been developed by Epstein and Salinas (1993) to assess the perceptions of parents and teachers about parental involvement. Furthermore, data was collected qualitatively through interviews with parents and teachers of the selected schools. The findings of this study show that parents and teachers had similar positive perceptions towards school practices for parental involvement. This study is significant for several reasons. It contributes to the limited information on parental involvement in Somalia and therefore, filling a gap in the existing empirical literature. It offers information to educators as well as to parents, which will help them understand the issues that relate to parental involvement in education. It is hoped that information from this study will facilitate parents and teachers to understand each other’s ideas on parental involvement and develop positive working relations to support children to become successful in their education.Keywords: Mogadishu, parents, school-partnership, practices, teachers
Procedia PDF Downloads 1531438 Comparison of Depth of Cure and Degree of Conversion between Opus Bulk Fill and X-Tra Fill Bulk Fill Composites
Authors: Yasaman Samani, Ali Golmohammadi
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Introduction: The degree of conversion and depth of cure affects the clinical success of resin composite restorations directly. One of the main challenges in achieving a successful composite restoration is the achievement of sufficient depth of cure. The insufficient polymerization may lead to a decrease in the physical/mechanical and biological properties of resin composites and, as a result of that, unsuccessful composite restoration. Thus, because of the importance of studying and evaluating the depth of cure and degree of conversion in bulk-fill composites, we decided to evaluate and compare the degree of conversion and depth of cure in two bulk-fill composites; x-tra fill (Voco, Germany) and Opus Bulk fill APS (FGM, Brazil). Materials and Methods: Composite resin specimens (n=10) per group were prepared as cylinder blocks (4×8 mm) with bulk-fill composites, x-tra fil (Voco, Germany) designated as Group A, and Opus Bulk fill APS (FGM, Brazil) designated as Group B. Depth of cure was determined according to “ISO 4049; Depth of Cure” method, In which each specimen were cured (iLED, Woodpecker, China) 40 seconds and FTIR spectroscopy method was used to estimate the degree of conversion of both the bulk-fill composites. The degree of conversion of monomer to polymer was estimated individually in the coronal half (Group A1 and B1) and pulpal half (Group A2 and Group B2) by dividing each specimen into two halves. The data were analyzed using a Student’s t-test and one-way ANOVA at a 5% level of significance. Results: The mean depth of cure in x-tra fil (Voco, Germany) was 3.99 (±0.16), and for Opus Bulk fill, APS (FGM, Brazil) was 2.14 (±0.3). The degree of conversion percentage in Group A1 was 82.7 (±6.1), in group A2 was 73.4 (±5.2), in group B1 was 63.3 (±4.7) and in Group B2 was 56.5 (±7.7). Statistical analysis revealed a significant difference in the depth of cure between the two bulk-fill composites with x-tra fil (Voco, Germany) higher than Opus Bulk fill APS (FGM, Brazil) (P<0.001). The degree of conversion percentage also showed a significant difference, Group A1 being higher than A2 (P=0.0085), B1, and B2 (P<0.001). Group A2 was also higher than B1 (P=0.003) and B2 (P<0.001). There was no significant difference between B1 and B2 (P=0.072). Conclusion: The results indicate that x-tra fill has more depth of cure and a higher percentage of the degree of conversion than Opus Bulk fill APS. The coronal half of x-tra fil had the highest depth of cure percentage (82.66%), and the pulpal half of Opus Bulk fill APS had the lowest percentage (56.45%). Even though both bulk-fill composite materials had an acceptable degree of conversion (55% and higher), x-tra fill has shown better results.Keywords: depth of cure, degree of conversion, bulk-fill composite, FTIR
Procedia PDF Downloads 1021437 Bio Based Agro Textiles
Authors: K. Sakthivel
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With the continuous increase in population worldwide, stress increased among agricultural peoples, so it is necessary to increase the yield of agro-products. But it is not possible to meet fully with the traditionally adopted ways of using pesticides and herbicides. Today, agriculture and horticulture has realized the need of tomorrow and opting for various technologies to get higher overall yield, quality agro-products. Most of today’s synthetic polymers are produced from petrochemical bi-products and are not biodegradable. Persistent polymers generate significant sources of environmental pollution, harming wildlife when they are disposed in nature. The disposal of non degradable plastic bags adversely affects human and wild life. Moreover incineration of plastic waste presents environmental issues as well, since it yields toxic emissions. Material incineration is also limited due to the difficulties to find accurate and economically viable outlets. In addition plastic recycling shows a negative eco balance due to the necessity in nearly all cases to wash the plastic waste as well as the energy consumption during the recycling process phases. As plastics represent a large part of the waste collection at the local regional and national levels institutions are aware of the significant savings that compostable or biodegradable materials would generate. Polylactic acid (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and wheat, has attracted much attention for automotive parts and also can be applied in agro textiles. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the stereo complex PLA, we developed by the four unit processes, fermentation, separation, lactide conversion, and polymerization. Then the polymer is converted into mulching film and applied in agriculture field. PLA agro textiles have better tensile strength, tearing strength and with stand from UV rays than polyester agro textile and polypropylene-based products.Keywords: biodegradation, environment, mulching film, PLA, technical textiles
Procedia PDF Downloads 3861436 Biogas Production from Pistachio (Pistacia vera L.) Processing Waste
Authors: İ. Çelik, Goksel Demirer
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Turkey is the third largest producer of pistachio (Pistacia vera L.) after Iran and United States. Harvested pistachio nuts are covered with organic hull which is removed by de-hulling process. Most of the pistachio by-products which are produced during de-hulling process are considered as agricultural waste and often mixed with soil, to a lesser extent are used as feedstuff by local livestock farmers and a small portion is used as herbal medicine. Due to its high organic and phenolic content as well as high solids concentration, pistachio processing wastes create significant waste management problems unless they are properly managed. However, there is not a well-established waste management method compensating the waste generated during the processing of pistachios. This study investigated the anaerobic treatability and biogas generation potential of pistachio hull waste. The effect of pre-treatment on biogas generation potential was investigated. For this purpose, Biochemical Methane Potential (BMP) Assays were conducted for two Chemical Oxygen Demand (COD) concentrations of 22 and 33 g tCOD l-1 at the absence and presence of chemical and thermal pre-treatment methods. The results revealed anaerobic digestion of the pistachio de-hulling wastes and subsequent biogas production as a renewable energy source are possible. The observed percent COD removal and methane yield values of the pre-treated pistachio de-hulling waste samples were significantly higher than the raw pistachio de-hulling waste. The highest methane yield was observed as 213.4 ml CH4/g COD.Keywords: pistachio de-hulling waste, biogas, renewable energy, pre-treatment
Procedia PDF Downloads 2151435 Thermal and Hydraulic Design of Shell and Tube Heat Exchangers
Authors: Ahmed R. Ballil
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Heat exchangers are devices used to transfer heat between two fluids. These devices are utilized in many engineering and industrial applications such as heating, cooling, condensation and boiling processes. The fluids might be in direct contact (mixed), or they separated by a solid wall to avoid mixing. In the present paper, interactive computer-aided design of shell and tube heat exchangers is developed using Visual Basic computer code as a framework. This design is based on the Bell-Delaware method, which is one of the very well known methods reported in the literature for the design of shell and tube heat exchangers. Physical properties for either the tube or the shell side fluids are internally evaluated by calling on an enormous data bank composed of more than a hundred fluid compounds. This contributes to increase the accuracy of the present design. The international system of units is considered in the developed computer program. The present design has an added feature of being capable of performing modification based upon a preset design criterion, such that an optimum design is obtained at satisfying constraints set either by the user or by the method itself. Also, the present code is capable of giving an estimate of the approximate cost of the heat exchanger based on the predicted surface area of the exchanger evaluated by the program. Finally, the present thermal and hydraulic design code is tested for accuracy and consistency against some of existed and approved designs of shell and tube heat exchangers.Keywords: bell-delaware method, heat exchangers, shell and tube, thermal and hydraulic design
Procedia PDF Downloads 1481434 An Experimental Study of Low Concentration CO₂ Capture from Regenerative Thermal Oxidation Tail Gas in Rotating Packed Bed
Authors: Dang HuynhMinhTam, Kuang-Cong Lu, Yi-Hung Chen, Zhung-Yu Lin, Cheng-Siang Cheng
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Carbon capture, utilization, and storage (CCUS) technology become a predominant technique to mitigate carbon dioxide and achieve net-zero emissions goals. This research targets to continuously capture the low concentration CO₂ from the tail gas of the regenerative thermal oxidizer (RTO) in the high technology industry. A rotating packed bed (RPB) reactor is investigated to capture the efficiency of CO₂ using a mixture of NaOH/Na₂CO₃ solutions to simulate the real absorbed solution. On a lab scale, semi-batch experiments of continuous gas flow and circulating absorbent solution are conducted to find the optimal parameters and are then examined in a continuous operation. In the semi-batch tests, the carbon capture efficiency and pH variation in the conditions of a low concentration CO₂ (about 1.13 vol%), the NaOH concentration of 1 wt% or 2 wt% mixed with 14 wt% Na₂CO₃, the rotating speed (600, 900, 1200 rpm), the gas-liquid ratio (100, 200, and 400), and the temperature of absorbent solution of 40 ºC are studied. The CO₂ capture efficiency significantly increases with higher rotating speed and smaller gas-liquid ratio, respectively, while the difference between the NaOH concentration of 1 wt% and 2 wt% is relatively small. The maximum capture efficiency is close to 80% in the conditions of the NaOH concentration of 1 wt%, the G/L ratio of 100, and the rotating speed of 1200 rpm within the first 5 minutes. Furthermore, the continuous operation based on similar conditions also demonstrates the steady efficiency of the carbon capture of around 80%.Keywords: carbon dioxide capture, regenerative thermal oxidizer, rotating packed bed, sodium hydroxide
Procedia PDF Downloads 611433 The Effect of Heart Rate and Valence of Emotions on Perceived Intensity of Emotion
Authors: Madeleine Nicole G. Bernardo, Katrina T. Feliciano, Marcelo Nonato A. Nacionales III, Diane Frances M. Peralta, Denise Nicole V. Profeta
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This study aims to find out if heart rate variability and valence of emotion have an effect on perceived intensity of emotion. Psychology undergraduates (N = 60) from the University of the Philippines Diliman were shown 10 photographs from the Japanese Female Facial Expression (JAFFE) Database, along with a corresponding questionnaire with a Likert scale on perceived intensity of emotion. In this 3 x 2 mixed subjects factorial design, each group was either made to do a simple exercise prior to answering the questionnaire in order to increase the heart rate, listen to a heart rate of 120 bpm, or colour a drawing to keep the heart rate stable. After doing the activity, the participants then answered the questionnaire, providing a rating of the faces according to the participants’ perceived emotional intensity on the photographs. The photographs presented were either of positive or negative emotional valence. The results of the experiment showed that neither an induced fast heart rate or perceived fast heart rate had any significant effect on the participants’ perceived intensity of emotion. There was also no interaction effect of heart rate variability and valence of emotion. The insignificance of results was explained by the Philippines’ high context culture, accompanied by the prevalence of both intensely valenced positive and negative emotions in Philippine society. Insignificance in the effects were also attributed to the Cannon-Bard theory, Schachter-Singer theory and various methodological limitations.Keywords: heart rate variability, perceived intensity of emotion, Philippines , valence of emotion
Procedia PDF Downloads 2531432 Effect of Chemical Modification of Functional Groups on Copper(II) Biosorption by Brown Marine Macroalgae Ascophyllum nodosum
Authors: Luciana P. Mazur, Tatiana A. Pozdniakova, Rui A. R. Boaventura, Vitor J. P. Vilar
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The principal mechanism of metal ions sequestration by brown algae involves the formation of complexes between the metal ion and functional groups present on the cell wall of the biological material. To understand the role of functional groups on copper(II) uptake by Ascophyllum nodosum, some functional groups were chemically modified. The esterification of carboxylic groups was carried out by suspending the biomass in a methanol/HCl solution under stirring for 48 h and the blocking of the sulfonic groups was performed by repeating the same procedure for 4 cycles of 48 h. The methylation of amines was conducted by suspending the biomass in a formaldehyde/formic acid solution under shaking for 6 h and the chemical modification of sulfhydryl groups on the biomass surface was achieved using dithiodipyridine for 1 h. Equilibrium sorption studies for Cu2+ using the raw and esterified algae were performed at pH 2.0 and 4.0. The experiments were performed using an initial copper concentration of 300 mg/L and algae dose of 1.0 g/L. After reaching the equilibrium, the metal in solution was quantified by atomic absorption spectrometry. The biological material was analyzed by Fourier Transform Infrared Spectroscopy and Potentiometric Titration techniques for functional groups identification and quantification, respectively. The results using unmodified algae showed that the maximum copper uptake capacity at pH 4.0 and 2.0 was 1.17 and 0.52 mmol/g, respectively. At acidic pH values most carboxyl groups are protonated and copper sorption suffered a significant reduction of 56%. Blocking the carboxylic, sulfonic, amines and sulfhydryl functional groups, copper uptake decreased by 24/26%, 69/81%, 1/23% and 40/27% at pH 2.0/4.0, respectively, when compared to the unmodified biomass. It was possible to conclude that the carboxylic and sulfonic groups are the main functional groups responsible for copper binding (>80%). This result is supported by the fact that the adsorption capacity is directly related to the presence of carboxylic groups of the alginate polymer, and the second most abundant acidic functional group in brown algae is the sulfonic acid of fucoidan that contributes, to a lower extent, to heavy metal binding, particularly at low pH.Keywords: biosorption, brown marine macroalgae, copper, ion-exchange
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