Search results for: Water level rise
4880 CFD Modeling of PROX Microreactor for Fuel Processing
Authors: M. Vahabi, M. H. Akbari
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In order to investigate a PROX microreactor performance, two-dimensional modeling of the reacting flow between two parallel plates is performed through a finite volume method using an improved SIMPLE algorithm. A three-step surface kinetics including hydrogen oxidation, carbon monoxide oxidation and water-gas shift reaction is applied for a Pt-Fe/γ-Al2O3 catalyst and operating temperatures of about 100ºC. Flow pattern, pressure field, temperature distribution, and mole fractions of species are found in the whole domain for all cases. Also, the required reactive length for removing carbon monoxide from about 2% to less than 10 ppm is found. Furthermore, effects of hydraulic diameter, wall temperature, and inlet mole fraction of air and water are investigated by considering carbon monoxide selectivity and conversion. It is found that air and water addition may improve the performance of the microreactor in carbon monoxide removal in such operating conditions; this is in agreement with the pervious published results.Keywords: CFD, Fuel Processing, PROX, Reacting Flow, SIMPLE algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14424879 Fuzzy Control of Thermally Isolated Greenhouse Building by Utilizing Underground Heat Exchanger and Outside Weather Conditions
Authors: Raghad Alhusari, Farag Omar, Moustafa Fadel
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A traditional greenhouse is a metal frame agricultural building used for cultivation plants in a controlled environment isolated from external climatic changes. Using greenhouses in agriculture is an efficient way to reduce the water consumption, where agriculture field is considered the biggest water consumer world widely. Controlling greenhouse environment yields better productivity of plants but demands an increase of electric power. Although various control approaches have been used towards greenhouse automation, most of them are applied to traditional greenhouses with ventilation fans and/or evaporation cooling system. Such approaches are still demanding high energy and water consumption. The aim of this research is to develop a fuzzy control system that minimizes water and energy consumption by utilizing outside weather conditions and underground heat exchanger to maintain the optimum climate of the greenhouse. The proposed control system is implemented on an experimental model of thermally isolated greenhouse structure with dimensions of 6x5x2.8 meters. It uses fans for extracting heat from the ground heat exchanger system, motors for automatic open/close of the greenhouse windows and LED as lighting system. The controller is integrated also with environmental condition sensors. It was found that using the air-to-air horizontal ground heat exchanger with 90 mm diameter and 2 mm thickness placed 2.5 m below the ground surface results in decreasing the greenhouse temperature of 3.28 ˚C which saves around 3 kW of consumed energy. It also eliminated the water consumption needed in evaporation cooling systems which are traditionally used for cooling the greenhouse environment.Keywords: Automation, earth-to-air heat exchangers, fuzzy control, greenhouse, sustainable buildings.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6964878 Simulations of Laminar Liquid Flows through Superhydrophobic Micro-Pipes
Authors: Mohamed E. Eleshaky
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This paper investigates the dynamic behavior of laminar water flows inside superhydrophobic micro-pipes patterned with square micro-posts features under different operating conditions. It also investigates the effects of air fraction and Reynolds number on the frictional performance of these pipes. Rather than modeling the air-water interfaces of superhydrophobic as a flat inflexible surface, a transient, incompressible, three-dimensional, volume-of-fluid (VOF) methodology has been employed to continuously track the air–water interface shape inside micro-pipes. Also, the entrance effects on the flow field have been taken into consideration. The results revealed the strong dependency of the frictional performance on the air fractions and Reynolds number. The frictional resistance reduction becomes increasingly more significant at large air fractions and low Reynolds numbers. Increasing Reynolds number has an adverse effect on the frictional resistance reduction.
Keywords: Drag reduction, laminar flow in micropipes, numerical simulation, superhyrophobic surfaces, microposts.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19504877 Traditional Grocery Stores and Business Management in Bangkok
Authors: Suppara Charoenpoom
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This paper was aimed to survey the level of awareness of traditional grocery stores in Bangkok in these categories: location, service quality, risk, shopping, worthwhile, shopping satisfaction, and future shopping intention. The paper was also aimed to survey factors influencing the decision to shop at traditional grocery stores in Bangkok in the future. The findings revealed that consumers had a high level of awareness of traditional grocery stores in Bangkok. Consumers were aware that the price was higher and it was riskier to buy goods and services at traditional grocery stores but they still had a high level of preference to patronage traditional grocery stores. This was due to the reasons that there was a high level of satisfaction from the factors of the friendliness of the owner, the ability to negotiate the price, the ability to buy on credit, free delivery, and the enjoyment to meet with other customers in the same neighborhood.Keywords: Business Management, Thai Economy, Traditional Grocery Store.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25304876 Initial Experiences of the First Version of Slovene Sustainable Building Indicators That Are Based on Level(s)
Authors: Sabina Jordan, Miha Tomšič, Friderik Knez, Marjana Šijanec Zavrl
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To determine the possibilities for the implementation of sustainable building indicators in Slovenia, testing of the first version of the indicators, developed in the CARE4CLIMATE project and based on the EU Level(s) framework, was carried out in 2022. Invited and interested stakeholders of the construction process were provided with video content and instructions on the Slovenian e-platform of sustainable building indicators. In addition, workshops and lectures with individual subjects were also performed. The final phase of the training and testing procedure included a questionnaire, which was used to obtain information about the participants' opinions regarding the indicators. The analysis of the results of the testing, which was focused on level 2, confirmed the key preliminary finding of the development group, namely that currently, due to the lack of certain knowledge, data, and tools, all indicators for this level are not yet feasible in practice. The research also highlighted the greater need for training and specialization of experts in this field. At the same time, it showed that the testing of the first version itself was a big challenge: only 30 experts fully participated and filled out the online questionnaire. This number seems alarmingly low at first glance, but compared to level(s) testing in the EU member states, it is much more than 50 times higher. However, for the further execution of the indicators in Slovenia, it will therefore be necessary to invest a lot of effort and engagement. It is likely that state support will also be needed, for example, in the form of financial mechanisms or incentives and/or legislative background.
Keywords: Sustainability, building indicator, project CARE4CLIMATE, alpha version SLO kTG, Level(s), sustainable construction stakeholders.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2024875 Removal of Pharmaceutical Compounds by a Sequential Treatment of Ozonation Followed by Fenton Process: Influence of the Water Matrix
Authors: Almudena Aguinaco, Olga Gimeno, Fernando J. Beltrán, Juan José P. Sagasti
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A sequential treatment of ozonation followed by a Fenton or photo-Fenton process, using black light lamps (365 nm) in this latter case, has been applied to remove a mixture of pharmaceutical compounds and the generated by-products both in ultrapure and secondary treated wastewater. The scientifictechnological innovation of this study stems from the in situ generation of hydrogen peroxide from the direct ozonation of pharmaceuticals, and can later be used in the application of Fenton and photo-Fenton processes. The compounds selected as models were sulfamethoxazol and acetaminophen. It should be remarked that the use of a second process is necessary as a result of the low mineralization yield reached by the exclusive application of ozone. Therefore, the influence of the water matrix has been studied in terms of hydrogen peroxide concentration, individual compound concentration and total organic carbon removed. Moreover, the concentration of different iron species in solution has been measured.Keywords: Fenton, photo-Fenton, ozone, pharmaceutical compounds, hydrogen peroxide, water treatment
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18444874 Weight Functions for Signal Reconstruction Based On Level Crossings
Authors: Nagesha, G. Hemantha Kumar
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Although the level crossing concept has been the subject of intensive investigation over the last few years, certain problems of great interest remain unsolved. One of these concern is distribution of threshold levels. This paper presents a new threshold level allocation schemes for level crossing based on nonuniform sampling. Intuitively, it is more reasonable if the information rich regions of the signal are sampled finer and those with sparse information are sampled coarser. To achieve this objective, we propose non-linear quantization functions which dynamically assign the number of quantization levels depending on the importance of the given amplitude range. Two new approaches to determine the importance of the given amplitude segment are presented. The proposed methods are based on exponential and logarithmic functions. Various aspects of proposed techniques are discussed and experimentally validated. Its efficacy is investigated by comparison with uniform sampling.
Keywords: speech signals, sampling, signal reconstruction, asynchronousdelta modulation, non-linear quantization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16514873 Genetic Diversity Based Population Study of Freshwater Mud Eel (Monopterus cuchia) in Bangladesh
Authors: M. F. Miah, K. M. A. Zinnah, M. J. Raihan, H. Ali, M. N. Naser
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As genetic diversity is most important for existing, breeding and production of any fish; this study was undertaken for investigating genetic diversity of freshwater mud eel, Monopterus cuchia at population level where three ecological populations such as flooded area of Sylhet (P1), open water of Moulvibazar (P2) and open water of Sunamganj (P3) districts of Bangladesh were considered. Four arbitrary RAPD primers (OPB-12, C0-4, B-03 and OPB-08) were screened and RAPD banding patterns were analyzed among the populations considering 15 individuals of each population. In total 174, 138 and 149 bands were detected in the populations of P1, P2 and P3 respectively; however, each primer revealed less number of bands in each population. 100% polymorphic loci were recorded in P2 and P3 whereas only one monomorphic locus was observed in P1, recorded 97.5% polymorphism. Different genetic parameters such as inter-individual pairwise similarity, genetic distance, Nei genetic similarity, linkage distances, cluster analysis and allelic information, etc. were considered for measuring genetic diversity. The average inter-individual pairwise similarity was recorded 2.98, 1.47 and 1.35 in P1, P2 and P3 respectively. Considering genetic distance analysis, the highest distance 1 was recorded in P2 and P3 and the lowest genetic distance 0.444 was found in P2. The average Nei genetic similarity was observed 0.19, 0.16 and 0.13 in P1, P2 and P3, respectively; however, the average linkage distance was recorded 24.92, 17.14 and 15.28 in P1, P3 and P2 respectively. Based on linkage distance, genetic clusters were generated in three populations where 6 clades and 7 clusters were found in P1, 3 clades and 5 clusters were observed in P2 and 4 clades and 7 clusters were detected in P3. In addition, allelic information was observed where the frequency of p and q alleles were observed 0.093 and 0.907 in P1, 0.076 and 0.924 in P2, 0.074 and 0.926 in P3 respectively. The average gene diversity was observed highest in P2 (0.132) followed by P3 (0.131) and P1 (0.121) respectively.
Keywords: Genetic diversity, Monopterus cuchia, population, RAPD, Bangladesh.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18324872 Health Risk Assessment of PET Bottles in GCC
Authors: M. M. Mortula
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Bottle water is getting very popular all through the world; especially in the gulf countries as the main source of drinking water. However, concerns over leaching of toxic chemicals are increasing. In this study, a health risk assessment was conducted in accordance with the guidelines indicated by United States Environmental Protection Agency (USEPA). It is conducted based on leaching of Diethyl Phthalate (DEP) from Polyethylene terephthalate (PET). The toxicity and exposure assessment of diethyl phthalate was conducted to characterize its risk on human health. Risk management is also discussed.Keywords: Toxicity, diethyl phthalate, PET, risk Assessment.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 41524871 Blackout on Outdoor Light
Authors: A. Castillo, A. Gutiérrez, J.M. Gutiérrez, J.M. Gómez, E. García-López
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The continued growth of the cities is causing an increase of the amount of surface to illuminate. However, this rise into lighting brings some unintended consequences such as increased of energy consumption or the light pollution. To make these effects less intrusive as possible some councils have chosen to perform a part-night lighting in some areas. Nonetheless, this kind of shutdown may cause serious problems which we intend to highlight in this paper.Keywords: Energy saving, part-night lighting, switch off, vial security
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14274870 Contextual Variables Affecting Frustration Level in Reading: An Integral Inquiry
Authors: Mae C. Pavilario
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This study employs a sequential explanatory mixed method. Quantitatively it investigated the profile of grade VII students. Qualitatively, the prevailing contextual variables that affect their frustration-level were sought based on their perspective and that of their parents and teachers. These students were categorized as frustration-level in reading based on the data on word list of the Philippine Informal Reading Inventory (Phil-IRI). The researcher-made reading factor instrument translated to local dialect (Hiligaynon) was subjected to cross-cultural translation to address content, semantic, technical, criterion, or conceptual equivalence, the open-ended questions, and one unstructured interview was utilized. In the profile of the 26 participants, the 12 males are categorized as grade II and grade III frustration-levels. The prevailing contextual variables are personal-“having no interest in reading”, “being ashamed and fear of having to read in front of others” for extremely high frustration level; social environmental-“having no regular reading schedule at home” for very high frustration level and personal- “having no interest in reading” for high frustration level. Kendall Tau inferential statistical tool was used to test the significant relationship in the prevailing contextual variables that affect frustration-level readers when grouped according to perspective. Result showed that significant relationship exists between students-parents perspectives; however, there is no significant relationship between students’ and teachers’, and parents’ and teachers’ perspectives. The themes in the narratives of the participants on frustration-level readers are existence of speech defects, undesirable attitude, insufficient amount of reading materials, lack of close supervision from parents, and losing time and focus on task. Intervention was designed.
Keywords: Contextual variables, frustration-level readers, perspective, inquiry.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11294869 DTC-SVM Scheme for Induction Motors Fedwith a Three-level Inverter
Authors: Ehsan Hassankhan, Davood A. Khaburi
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Direct Torque Control is a control technique in AC drive systems to obtain high performance torque control. The conventional DTC drive contains a pair of hysteresis comparators. DTC drives utilizing hysteresis comparators suffer from high torque ripple and variable switching frequency. The most common solution to those problems is to use the space vector depends on the reference torque and flux. In this Paper The space vector modulation technique (SVPWM) is applied to 2 level inverter control in the proposed DTC-based induction motor drive system, thereby dramatically reducing the torque ripple. Then the controller based on space vector modulation is designed to be applied in the control of Induction Motor (IM) with a three-level Inverter. This type of Inverter has several advantages over the standard two-level VSI, such as a greater number of levels in the output voltage waveforms, Lower dV/dt, less harmonic distortion in voltage and current waveforms and lower switching frequencies. This paper proposes a general SVPWM algorithm for three-level based on standard two-level SVPWM. The proposed scheme is described clearly and simulation results are reported to demonstrate its effectiveness. The entire control scheme is implemented with Matlab/Simulink.Keywords: Direct torque control, space vector Pulsewidthmodulation(SVPWM), neutral point clamped(NPC), two-levelinverter.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 43964868 Soybean and Fermented Soybean Extract Antioxidant Activities
Authors: W. Samruan, A. Oonsivilai, R. Oonsivilai
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Today, people are more interested in the foods beneficial on their health. However, there are still lacks of accurate knowledge in the field of biological properties, functional properties, including the application of legume in foods. This study focused on antioxidant activity of soybean (SB) and fermented soybean (FSB) crude extracts evaluating to have more information in fortification SB and FSB crude extracts in food products and/or dietary supplement. SB and FSB crude extracts were prepared by infusion with water and ethanol. The antioxidant activity of crude extracts was studied with DPPH and ABTS assay including commercial standard. From both DPPH and ABTS assay, the antioxidant activity of SB and FSB water crude extract showed higher antioxidant activity than ethanol crude extract, and FSB crude extract showed higher antioxidant activity than SB crude extract. In DPPH assay, BHT and vitamin C showed IC50 values at 0.241, 0.039 mg/ml, in ABTS assay. In addition, Trolox showed IC50 at 0.058 mg/ml respectively. FSB water crude extract showed high antioxidant activity. Finally, the functional properties study of both water and ethanol crude extracts should be done for beneficial in application of these extracts in food products and dietary supplement in the near future.Keywords: Antioxidant activity, Fermented soybean (FSB) crude extracts, soybean (SB) crude extracts.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 43764867 Improving the Voltage Level in High Voltage Direct Current Systems by Using Modular Multilevel Converter
Authors: G. Kishor Babu, B. Madhu Kiran
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This paper presented an intend scheme of Modular-Multilevel-Converter (MMC) levels for move towering the practical conciliation flanked by the precision and divisional competence. The whole process is standard by a Thevenin-equivalent 133-level MMC model. Firstly the computation scheme of the fundamental limit imitation time step is offered to faithfully represent each voltage level of waveforms. Secondly the earlier industrial Improved Analytic Hierarchy Process (IAHP) is adopted to integrate the relative errors of all the input electrical factors interested in one complete virtual fault on each converter level. Thirdly the stable AC and DC ephemeral condition in virtual faults effects of all the forms stabilize and curve integral stand on the standard form. Finally the optimal MMC level will be obtained by the drown curves and it will give individual weights allowing for the precision and efficiency. And the competence and potency of the scheme are validated by model on MATLAB Simulink.
Keywords: Modular multilevel converter, improved analytic hierarchy process, ac and dc transient, high voltage direct current, voltage sourced converter.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5994866 Metal(loids) Speciation Using HPLC-ICP-MS Technique in Klodnica River, Upper Silesia, Poland
Authors: Magdalena Jabłońska-Czapla
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The work allowed gaining knowledge about redox and speciation changes of As, Cr and Sb ionic forms in Klodnica River water. This kind of studies never has been conducted in this region of Poland. In study optimized and validated previously HPLC-ICP-MS methods for determination of As, Sb and Cr was used. Separation step was done using high-performance liquid chromatograph equipped with ion-exchange column followed by ICP-MS spectrometer detector. Preliminary studies included determination of the total concentration of As, Sb and Cr, pH, Eh, temperature and conductivity of the water samples. The study was conducted monthly from March to August 2014, at six points on the Klodnica River. The results indicate that exceeded at acceptable concentration of total Cr and Sb was observed in Klodnica River and we should qualify Klodnica River waters below the second purity class. In Klodnica River waters dominates oxidized antimony and arsenic forms, as well as the two forms of chromium Cr(VI) and Cr(III). Studies have also shown the methyl derivative of arsenic's presence.
Keywords: Antimony, arsenic, chromium, HPLC-ICP-MS, river water, speciation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21324865 Student and Group Activity Level Assessment in the ELARS Recommender System
Authors: Martina Holenko Dlab, Natasa Hoic-Bozic
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This paper presents an original approach to student and group activity level assessment that relies on certainty factors theory. Activity level is used to represent quantity and continuity of student’s contributions in individual and collaborative e‑learning activities (e‑tivities) and is calculated to assist teachers in assessing quantitative aspects of student's achievements. Calculated activity levels are also used to raise awareness and provide recommendations during the learning process. The proposed approach was implemented within the educational recommender system ELARS and validated using data obtained from e‑tivity realized during a blended learning course. The results showed that the proposed approach can be used to estimate activity level in the context of e-tivities realized using Web 2.0 tools as well as to facilitate the assessment of quantitative aspect of students’ participation in e‑tivities.
Keywords: Assessment, ELARS, e-learning, recommender systems, student model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10614864 Exploitation of Public Technology for Industrial Use
Authors: Seongykyoon Jeong, Sungki Lee, Jaeyun Kim, Seunghun Oh, Kiho Kwak
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The purpose of study is to demonstrate how the characteristics of technology and the process required for development of technology affect technology transfer from public organisations to industry on the technology level. In addition, using the advantage of the analytic level and the novel means of measuring technology convergence, we examine the characteristics of converging technologies as compared to non-converging technologies in technology transfer process. In sum, our study finds that a technology from the public sector is likely to be transferred when its readiness level is closer to generation of profit, when its stage of life cycle is early and when its economic values is high. Our findings also show that converging technologies are less likely to be transferred.
Keywords: Interdisciplinary, Technology transfer, Technology convergence.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16924863 Selective Separation of Lead and Mercury Ions from Synthetic Produced Water via a Hollow Fiber Supported Liquid Membrane
Authors: S. Suren, U. Pancharoen
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A double module hollow fiber supported liquid membrane (HFSLM) was applied to selectively separate lead and mercury ions from dilute synthetic produced water. The experiments were investigated on several variables: types of extractants (D2EHPA, Cyanex 471, Aliquat 336, and TOA), concentration of the selected extractant and operating time. The results clearly showed that the double module HFSLM could selectively separate Pb(II) and Hg(II) in feed solution at a very low concentration to less than the regulatory discharge limit of 0.2 and 0.005 mg/L issued by the Ministry of Industry and the Ministry of Natural Resource Environment, Thailand. The highest extractions of lead and mercury ions from synthetic produced water were 96% and 100% using 0.03 M D2EHPA and 0.06 M Aliquat 336 as the extractant for the first and second modules.Keywords: Hollow fiber, Lead ions, Liquid membrane, Mercury ions, Selective separation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23344862 A Case Study of Collective Action in Fishermen's Wives Group (KUNITA), Malaysia
Authors: Nor Hafizah S., Salfarina A. G., Intan Hashimah H., Juliana A. W.
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Collective action can be an effective means for local development as well as important strategy to enhance livelihoods especially among rural people. This article explores the level of collective action among members of Fishermen-s Wives Group (KUNITA) in Malaysia. KUNITA was established by the Malaysian Fishery Development Authority (LKIM) with an objective to increase the socio-economic status of fishermen-s families. The members who are mostly the wives and daughters of fishermen are strongly encouraged by LKIM to venture into entrepreneurship activities. The objective of this research was to see the level of collective action among members in KUNITA groups in the state of Selangor. The finding shows that high level of collective action among KUNITA members is strongly based on volunteerism. However, the level of cooperation among members in the group is relatively low. The findings present significant challenges for the group in maintaining the sustainability of KUNITA organization.
Keywords: Collective action, entrepreneurship, fishermen' swives group, LKIM.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19244861 Computer Aided Diagnostic System for Detection and Classification of a Brain Tumor through MRI Using Level Set Based Segmentation Technique and ANN Classifier
Authors: Atanu K Samanta, Asim Ali Khan
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Due to the acquisition of huge amounts of brain tumor magnetic resonance images (MRI) in clinics, it is very difficult for radiologists to manually interpret and segment these images within a reasonable span of time. Computer-aided diagnosis (CAD) systems can enhance the diagnostic capabilities of radiologists and reduce the time required for accurate diagnosis. An intelligent computer-aided technique for automatic detection of a brain tumor through MRI is presented in this paper. The technique uses the following computational methods; the Level Set for segmentation of a brain tumor from other brain parts, extraction of features from this segmented tumor portion using gray level co-occurrence Matrix (GLCM), and the Artificial Neural Network (ANN) to classify brain tumor images according to their respective types. The entire work is carried out on 50 images having five types of brain tumor. The overall classification accuracy using this method is found to be 98% which is significantly good.
Keywords: Artificial neural network, ANN, brain tumor, computer-aided diagnostic, CAD system, gray-level co-occurrence matrix, GLCM, level set method, tumor segmentation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13654860 The Effect of Discontinued Water Spray Cooling on the Heat Transfer Coefficient
Authors: J. Hrabovský, M. Chabičovský, J. Horský
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Water spray cooling is a technique typically used in heat treatment and other metallurgical processes where controlled temperature regimes are required. Water spray cooling is used in static (without movement) or dynamic (with movement of the steel plate) regimes. The static regime is notable for the fixed position of the hot steel plate and fixed spray nozzle. This regime is typical for quenching systems focused on heat treatment of the steel plate. The second application of spray cooling is the dynamic regime. The dynamic regime is notable for its static section cooling system and moving steel plate. This regime is used in rolling and finishing mills. The fixed position of cooling sections with nozzles and the movement of the steel plate produce nonhomogeneous water distribution on the steel plate. The length of cooling sections and placement of water nozzles in combination with the nonhomogeneity of water distribution lead to discontinued or interrupted cooling conditions. The impact of static and dynamic regimes on cooling intensity and the heat transfer coefficient during the cooling process of steel plates is an important issue. Heat treatment of steel is accompanied by oxide scale growth. The oxide scale layers can significantly modify the cooling properties and intensity during the cooling. The combination of static and dynamic (section) regimes with the variable thickness of the oxide scale layer on the steel surface impact the final cooling intensity. The study of the influence of the oxide scale layers with different cooling regimes was carried out using experimental measurements and numerical analysis. The experimental measurements compared both types of cooling regimes and the cooling of scale-free surfaces and oxidized surfaces. A numerical analysis was prepared to simulate the cooling process with different conditions of the section and samples with different oxide scale layers.
Keywords: Heat transfer coefficient, numerical analysis, oxide layer, spray cooling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29794859 Durability Study of Pultruded CFRP Plates under Sustained Bending in Distilled Water and Seawater Immersions: Effects on the Visco-Elastic Properties
Authors: Innocent Kafodya, Guijun Xian
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This paper presents effects of distilled water, seawater and sustained bending strains of 30% and 50% ultimate strain at room temperature, on the durability of unidirectional pultruded carbon fiber reinforced polymer (CFRP) plates. In this study, dynamic mechanical analyzer (DMA) was used to investigate the synergic effects of the immersions and bending strains on the viscoelastic properties of (CFRP) such as storage modulus, tan delta and glass transition temperature. The study reveals that the storage modulus and glass transition temperature increase while tan delta peak decreases in the initial stage of both immersions due to the progression of curing. The storage modulus and Tg subsequently decrease and tan delta increases due to the matrix plasticization. The blister induced damages in the unstrained seawater samples enhance water uptake and cause more serious degradation of Tg and storage modulus than in water immersion. Increasing sustained bending decreases Tg and storage modulus in a long run for both immersions due to resin matrix cracking and debonding. The combined effects of immersions and strains are not clearly reflected due to the statistical effects of DMA sample sizes and competing processes of molecular reorientation and postcuring.
Keywords: Pultruded CFRP plate, bending strain, glass transition temperature, storage modulus, tan delta.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18864858 Contribution to the Analytical Study of Barrier Surface Waves: Decomposition of the Solution
Authors: T. Zitoun, M. Bouhadef
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When a partially or completely immersed solid moves in a liquid such as water, it undergoes a force called hydrodynamic drag. Reducing this force has always been the objective of hydrodynamic engineers to make water slide better on submerged bodies. This paper deals with the examination of the different terms composing the analytical solution of the flow over an obstacle embedded at the bottom of a hydraulic channel. We have chosen to use a linear method to study a two-dimensional flow over an obstacle, in order to understand the evolution of the drag. We set the following assumptions: incompressible inviscid fluid, irrotational flow, low obstacle height compared to the water height. Those assumptions allow overcoming the difficulties associated with modelling these waves. We will mathematically formulate the equations that allow the determination of the stream function, and then the free surface equation. A similar method is used to determine the exact analytical solution for an obstacle in the shape of a sinusoidal arch.Keywords: Free-surface wave, inviscid fluid, analytical solution, hydraulic channel.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7984857 Eco-Friendly Cleansers Initiation for Eco-Campsite Development in Khao Yai National Park, Thailand
Authors: T. Utarasakul
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Environmental impact has occurred at Khao Yai National Park, especially the water pollution by tourist activities as a result of 800,000 tourists visiting annually. To develop an eco-campsite, eco-friendly cleansers were implemented in Lam Ta Khlong and Pha Kluay Mai Campsites for tourists and restaurants. The results indicated the positive effects of environmentally friendly cleansers on water quality in Lam Ta Khlong River and can be implemented in other protected areas to decrease chemical contamination in ecosystems.
Keywords: Sustainable Tourism Management, Eco-campsite, Khao Yai National Park.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21304856 Application of Neural Networks to Predict Changing the Diameters of Bubbles in Pool Boiling Distilled Water
Authors: V. Nikkhah Rashidabad, M. Manteghian, M. Masoumi, S. Mousavian, D. Ashouri
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In this research, the capability of neural networks in modeling and learning complicated and nonlinear relations has been used to develop a model for the prediction of changes in the diameter of bubbles in pool boiling distilled water. The input parameters used in the development of this network include element temperature, heat flux, and retention time of bubbles. The test data obtained from the experiment of the pool boiling of distilled water, and the measurement of the bubbles form on the cylindrical element. The model was developed based on training algorithm, which is typologically of back-propagation type. Considering the correlation coefficient obtained from this model is 0.9633. This shows that this model can be trusted for the simulation and modeling of the size of bubble and thermal transfer of boiling.
Keywords: Bubble Diameter, Heat Flux, Neural Network, Training Algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14564855 Specification of Irradiation Conditions in the DONA 5 Rotational Channel of the LVR-15 Reactor
Authors: Zdena Lahodová, Michal Koleška, Ladislav Viererbl
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This article summarizes ways to verify neutron fluence for neutron transmutation doping of silicon with phosphorus on the LVR-15 reactor. Neutron fluence is determined using activation detectors placed along the crystal in a strip or encapsulated in a rod holder. Holders are placed at the centre of a water-filled capsule or in an aluminum or silicon ingot that simulates a real single crystal. If the diameter of the crystal is significantly less than the capsule diameter and water from the primary circuit enters the free space in the capsule, neutron interaction in the water changes neutron fluence, affecting axial irradiation homogeneity. The effect of moving the capsule vertically in the channel relative to maximum neutron fluence in the reactor core was also measured. Even a small shift of the capsule-s centre causes great irradiation inhomogeneity. This effect was measured using activation detectors, and was also confirmed by MCNP calculation.Keywords: Irradiation homogeneity, neutron fluence, neutron transmutation doping, rotational channel.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16454854 Assessment of Hargreaves Equation for Estimating Monthly Reference Evapotranspiration in the South of Iran
Authors: Ali Dehgan Moroozeh, B. Farhadi Bansouleh
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Evapotranspiration is one of the most important components of the hydrological cycle. Evapotranspiration (ETo) is an important variable in water and energy balances on the earth’s surface, and knowledge of the distribution of ET is a key factor in hydrology, climatology, agronomy and ecology studies. Many researchers have a valid relationship, which is a function of climate factors, to estimate the potential evapotranspiration presented to the plant water stress or water loss, prevent. The FAO-Penman method (PM) had been recommended as a standard method. This method requires many data and these data are not available in every area of world. So, other methods should be evaluated for these conditions. When sufficient or reliable data to solve the PM equation are not available then Hargreaves equation can be used. The Hargreaves equation (HG) requires only daily mean, maximum and minimum air temperature extraterrestrial radiation .In this study, Hargreaves method (HG) were evaluated in 12 stations in the North West region of Iran. Results of HG and M.HG methods were compared with results of PM method. Statistical analysis of this comparison showed that calibration process has had significant effect on efficiency of Hargreaves method.Keywords: Evapotranspiration, Hargreaves equation, FAOPenman method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19114853 Greywater Treatment Using Activated Biochar Produced from Agricultural Waste
Authors: Pascal Mwenge, Tumisang Seodigeng
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The increase in urbanisation in South Africa has led to an increase in water demand and a decline in freshwater supply. Despite this, poor water usage is still a major challenge in South Africa, for instance, freshwater is still used for non-drinking applications. The freshwater shortage can be alleviated by using other sources of water for non-portable purposes such as greywater treated with activated biochar produced from agricultural waste. The success of activated biochar produced from agricultural waste to treat greywater can be both economically and environmentally beneficial. Greywater treated with activated biochar produced from agricultural waste is considered a cost-effective wastewater treatment. This work was aimed at determining the ability of activated biochar to remove Total Suspended Solids (TSS), Ammonium (NH4-N), Nitrate (NO3-N), and Chemical Oxygen Demand (COD) from greywater. The experiments were carried out in 800 ml laboratory plastic cylinders used as filter columns. 2.5 cm layer of gravel was used at the bottom and top of the column to sandwich the activated biochar material. Activated biochar (200 g and 400 g) was loaded in a column and used as a filter medium for greywater. Samples were collected after a week and sent for analysis. Four types of greywater were treated: Kitchen, floor cleaning water, shower and laundry water. The findings showed: 95% removal of TSS, 76% of NO3-N and 63% of COD on kitchen greywater and 85% removal of NH4-N on bathroom greywater, as highest removal of efficiency of the studied pollutants. The results showed that activated biochar produced from agricultural waste reduces a certain amount of pollutants from greywater. The results also indicated the ability of activated biochar to treat greywater for onsite non-potable reuse purposes.
Keywords: Activated biochar produced from agriculture waste, ammonium (NH4-N), chemical oxygen demand (COD), greywater, nitrate (NO3-N), total suspended solids (TSS).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14244852 Influence of Organic Supplements on Shoot Multiplication Efficiency of Phaius tankervilleae var. alba
Authors: T. Punjansing, M. Nakkuntod, S. Homchan, P. Inthima, A. Kongbangkerd
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The influence of organic supplements on growth and multiplication efficiency of Phaius tankervilleae var. alba seedlings was investigated. 12 week-old seedlings were cultured on half-strength semi-solid Murashige and Skoog (MS) medium supplemented with 30 g/L sucrose, 8 g/L agar and various concentrations of coconut water (0, 50, 100, 150 and 200 mL/L) combined with potato extract (0, 25 and 50 g/L) and the pH was adjusted to 5.8 prior to autoclaving. The cultures were then kept under constant photoperiod (16 h light: 8 h dark) at 25 ± 2 °C for 12 weeks. The highest number of shoots (3.0 shoots/explant) was obtained when cultured on the medium added with 50 ml/L coconut water and 50 g/L potato extract whereas the highest number of leaves (5.9 leaves/explant) and roots (6.1 roots/explant) could receive on the medium supplemented with 150 ml/L coconut water and 50 g/L potato extract. with 150 ml/L coconut water and 50 g/L potato extract. Additionally, plantlets of P. tankervilleae var. alba were transferred to grow into seven different substrates i.e. soil, sand, coconut husk chip, soil-sand mix (1: 1), soil-coconut husk chip mix (1: 1), sand-coconut husk chip mix (1: 1) and soil-sand-coconut husk chip mix (1: 1: 1) for four weeks. The results found that acclimatized plants showed 100% of survivals when sand, coconut husk chip and sand-coconut husk chip mix are used as substrates. The number of leaves induced by sand-coconut husk chip mix was significantly higher than that planted in other substrates (P > 0.05). Meanwhile, no significant difference in new shoot formation among these substrates was observed (P < 0.05). This precursory developing protocol was likely to be applied for more large scale of plant production as well as conservation of germplasm of this orchid species.
Keywords: Acclimatization, coconut water, orchid, Phaius tankervilleae var. alba., potato extract.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7864851 Processing, Morphological, Thermal and Absorption Behavior of PLA/Thermoplastic Starch/Montmorillonite Nanocomposites
Authors: Esmat Jalalvandi, Rohah Abd. Majid, Taravat Ghanbari
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Thermoplastic starch, polylactic acid glycerol and maleic anhydride (MA) were compounded with natural montmorillonite (MMT) through a twin screw extruder to investigate the effects of different loading of MMT on structure, thermal and absorption behavior of the nanocomposites. X-ray diffraction analysis (XRD) showed that sample with MMT loading 4phr exhibited exfoliated structure while sample that contained MMT 8 phr exhibited intercalated structure. FESEM images showed big lump when MMT loading was at 8 phr. The thermal properties were characterized by using differential scanning calorimeter (DSC). The results showed that MMT increased melting temperature and crystallization temperature of matrix but reduction in glass transition temperature was observed Meanwhile the addition of MMT has improved the water barrier property. The nanosize MMT particle is also able to block a tortuous pathway for water to enter the starch chain, thus reducing the water uptake and improved the physical barrier of nanocomposite.Keywords: Montmorillonite, Nanocomposite, Polylactic acid, Starch.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2521