Search results for: mobile application

Authors: Mohsen Akhlaghi, Tahereh Ebrahimi

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Considering the increasing demand for water and limited resources, there is a possibility of a water crisis in the not-so-distant future. Therefore, to prevent this crisis, other options for drinking water supply should be examined. In this regard, the application of multi-criteria decision-making methods in various aspects of water resource management and planning has always been of great interest to researchers. In this report, six options for supplying drinking water to Tehran City were considered. Then, experts' opinions were collected through matrices and questionnaires, and using the TOPSIS method, which is one of the types of multi-criteria decision-making methods, they were calculated and analyzed. In the TOPSIS method, the options were ranked by calculating their proximity to the ideal (Ci). The closer the numerical value of Ci is to one, the more desirable the option is. Based on this, the option with the optimization pattern of water consumption, with Ci = 0.9787, is the best option among the proposed options for supplying drinking water to Tehran City. The other options, in order of priority, are rainwater harvesting, wastewater reuse, increasing current water supply sources, desalination and its transfer, and transferring water from freshwater sources between basins. In conclusion, the findings of this study highlight the importance of exploring alternative drinking water supply options and utilizing multi-criteria decision-making approaches to address the potential water crisis.

Keywords: multi-criteria decision, sustainable development, topsis, water supply

Procedia PDF Downloads 47

Authors: Sumeyra Sevim, Gulsum Gizem Topal, Mercan Merve Tengilimoglu-Metin, Mevlude Kizil

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Aflatoxin M1 (AFM1) is a major toxic and carcinogenic molecule in milk and milk products. Therefore, it poses a risk for public health. Probiotics can be biological agent to remove AFM1. The aim of this study is to evaluate the effect of probiotic bacteria on AFM1 detoxification in phosphate buffer saline. The PBS samples artificially contaminated with AFM1 at concentration 100 pg/ml were prepared with probiotics bacteria that including monoculture (L. plantarum, B. bifidum ATCC, B. animalis ATCC 27672) and binary culture (L. bulgaricus + S. thermophiles, B. bifidum ATCC + B. animalis ATCC 27672, L. plantarum+B. bifidum ATCC, L. plantarum+ B. animalis ATCC 27672). The samples were incubated at 37°C for 4 hours and stored for 1, 5 and 10 days. The toxin was measured by the ELISA. The highest levels of AFM1 binding ability (63.6%) in PBS were detected yoghurt starter bacteria, while L. plantarum had the lowest levels of AFM1 binding ability (35.5%) in PBS. In addition, it was found that there was significant effect of storage on AFM1 binding ability in all groups except the one including B. animalis (p < 0.05). Consequently, results demonstrate that AFM1 detoxification by probiotic bacteria has a potential application to reduce toxin concentrations in yoghurt. Moreover, probiotic strains can react with itself as synergic or antagonist.

Keywords: aflatoxin M1, ELISA, probiotics, storage

Procedia PDF Downloads 309

Authors: Xinyuan Y. Song, Kai Kang

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Joint models for analyzing longitudinal and survival data are widely used to investigate the relationship between a failure time process and time-variant predictors. A common assumption in conventional joint models in the survival analysis literature is that all predictors are observable. However, this assumption may not always be supported because unobservable traits, namely, latent variables, which are indirectly observable and should be measured through multiple observed variables, are commonly encountered in the medical, behavioral, and financial research settings. In this study, a joint modeling approach to deal with this feature is proposed. The proposed model comprises three parts. The first part is a dynamic factor analysis model for characterizing latent variables through multiple observed indicators over time. The second part is a random coefficient trajectory model for describing the individual trajectories of latent variables. The third part is a proportional hazard model for examining the effects of time-invariant predictors and the longitudinal trajectories of time-variant latent risk factors on hazards of interest. A Bayesian approach coupled with a Markov chain Monte Carlo algorithm to perform statistical inference. An application of the proposed joint model to a study on the Alzheimer's disease neuroimaging Initiative is presented.

Keywords: Bayesian analysis, joint model, longitudinal data, time-to-event data

Procedia PDF Downloads 124

Authors: Mahnaz Hosseinzadeh, Shaghayegh Rezaee Amiri

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This paper presents a methodology for serial production planning problem in wire and cable manufacturing process that addresses the problem of input-output imbalance in different consecutive stations, hoping to minimize the halt of machines in each stage. To this end, a linear Goal Programming (GP) model is developed, in which four main categories of constraints as per the number of runs per machine, machines’ sequences, acceptable inventories of machines at the end of each period, and the necessity of fulfillment of the customers’ orders are considered. The model is formulated based upon on the real data obtained from IKO TAK Company, an important supplier of wire and cable for oil and gas and automotive industries in Iran. By solving the model in GAMS software the optimal number of runs, end-of-period inventories, and the possible minimum idle time for each machine are calculated. The application of the numerical results in the target company has shown the efficiency of the proposed model and the solution in decreasing the lead time of the end product delivery to the customers by 20%. Accordingly, the developed model could be easily applied in wire and cable companies for the aim of optimal production planning to reduce the halt of machines in manufacturing stages.

Keywords: goal programming approach, GP, production planning, serial manufacturing process, wire and cable industry

Procedia PDF Downloads 141

Authors: Tshilenge Kabongo, John Kabuba

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The distillery wastewater has become major issues in sanitation sectors. One of the solutions to overcome this sewage is to install the Wastewater Treatment Plant. Economic analysis is fundamentally required for its viability. Integrated anaerobic digestion and advanced oxidation (AD-AOP) in the treatment of distillery wastewater (DWW), anaerobic digestion achieved sufficient biochemical oxygen demand (BOD) and chemical oxygen demand (COD) removals of 95% and 75%, respectively, and methane production of 0.292 L/g COD removed at an organic loading rate of 15 kg COD/m3/d. However, a considerable amount of biorecalcitrant compounds still existed in the anaerobically treated effluent, contributing to a residual COD of 4.5 g/L and an intense dark brown color. To remove the biorecalcitrant color and COD, ozonation, which is an AOP, was introduced as a post-treatment method to AD. Ozonation is a highly competitive treatment technique that can be easily applied to remove the biorecalcitrant compounds, including color, and turbidity. In the ozonation process carried out for an hour, more than 80% of the color was removed at an ozone dose of 45 mg O3/L/min (corresponding to 1.8 g O3/g COD). Thus, integrating AD with the AOP can be effective for organic load and color reductions during the treatment of DWW. The deliverable established the best configuration of the AD-AOP system, where DWW is first subjected to AD followed by AOP post-treatment. However, for establishing the feasibility of the industrial application of the integrated system, it is necessary to carry out the economic analysis. This may help the starting point of the wastewater treatment plant construction and its operation and maintenance costs.

Keywords: distillery wastewater, economic analysis, integrated anaerobic digestion, ozonolysis, treatment

Procedia PDF Downloads 112

Authors: Zoran Herceg, Višnja Stulić, Tomislava Vukušić, Anet Režek Jambrak

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High voltage electrical discharge is a new technology used for inactivation of pathogen microorganisms. Pathogen yeasts can cause diseases in humans if they are ingested. Nowadays new technologies have become the focus of researching all over the world. Rhodotorula is known as yeast that can cause diseases in humans. The aim of this study was to examine whether the high voltage electrical discharge treatment generated in gas phase has an influence on yeast reduction and recovery of Rhodotorula spp 74 in pure culture. Rhodotorula spp. 74 was treated in 200 mL of model solution. Treatment time (5 and 10 min), frequency (60 and 90 Hz) and injected gas (air or argon 99,99%) were changed. Titanium high voltage needle was used as high voltage electrode (positive polarity) through which air or argon was injected at the gas flow of 0.6 L/min. Experimental design and statistical analyses were obtained by Statgraphics Centurion software (StatPoint Technologies, Inc., VA, USA). The best inactivation rate 1.7 log10 reduction was observed after the 10 min of treatment, frequency of 90 Hz and injected air. Also with a longer treatment time inactivation rate was higher. After the 24 h recovery of treated samples was observed. Therefore the further optimization of method is needed to understand the mechanism of yeasts inactivation and cells recovery after the treatment. Acknowledgements: The authors would like to acknowledge the support by Croatian Science Foundation and research project ‘Application of electrical discharge plasma for preservation of liquid foods’.

Keywords: rhodotorula spp. 74, electrical discharge plasma, inactivation, stress response

Procedia PDF Downloads 217

Authors: M. J. Suriani, F. Mansor, W. Siti Maizurah, I. Nurizwani

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Silicon Carbide (SiC) is one of the Silicon-based materials, which get interested by the researcher. SiC is an emerging semiconductor material, which has received a great deal of attention due to their application in high frequency and high power systems. Although its superior characteristic for a semiconductor material, its outstanding mechanical properties, chemical inertness and thermal stability has gained important aspect for a surface coating for deployment in extreme environments. Very high frequency (VHF)-PECVD technique utilized to deposit nano ns-SiC film in which variation in chamber pressure, substrate temperature, RF power and precursor gases flow rate will be investigated in order to get a good quality of thin film coating. Characterization of the coating performed in order to study the surface morphology, structural information. This performance of coating evaluated through corrosion test to determine the effectiveness of the coating for corrosion prevention. Ns-SiC film expected to possess better corrosion resistance and optical properties, as well as preserving the metal from the marine environment. Through this research project, corrosion protection performance by applying coating will be explored to obtain a great corrosion prevention method to the shipping and oil and gas industry in Malaysia. Besides, the cost of repair and maintenance spending by the government of Malaysia can be reduced through practicing this method.

Keywords: composite materials, marine corrosion, nano-composite, nano structure–coating

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Authors: Sarthak S. Salunke

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Development, as a notion, is seen in perspective of western philosophical conceptions, and the western developed nations have become a yardstick for setting up development goals for developing and underdeveloped nations around the world. This blanket term of development becomes superficial and materialistic in context of the vast geopolitical, territorial, cultural and behavioral diversities existing in countries of the Africa and the Asia, and tends to undermine the atomistic aspect of development. Indian political theories, which are often seen as religious philosophies, have inherent structure of development of human being as an individual and as a part of the society, and, in result, development of the State. These theories, primarily individualistic in nature, have a combination of altruism and rationalism which guides human beings towards constructing a collectively developed and morally sustainable society. This research focuses on the application of this Indian thought in combination of classical liberal thought to tackle the issues of development in diverse societies. The proposed restructured model of development is based on molecular individualism, instead of atomic individual approach of liberalists, which lets development modelers to target meaningful clusters for designating goals for development based on the particular needs based on geopolitical, cultural and ethical requirements, and making it meaningful in conjunction with global development to establish a harmony between western and eastern worlds.

Keywords: Indian political thought, development, liberalism, molecular individualism

Procedia PDF Downloads 170

Authors: Brian Romansky

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There are many practical, commercially available robots and semi-autonomous systems that are currently available for use in a wide variety of construction tasks. Adoption of these technologies has the potential to reduce the time and cost to deliver a project, reduce variability and risk in delivery time, increase quality, and improve safety on the job site. These benefits come with a cost for equipment rental or contract fees, access to specialists to configure the system, and time needed for set-up and support of the machines while in use. Calculation of the net ROI (Return on Investment) requires detailed information about the geometry of the site, the volume of work to be done, the overall project schedule, as well as data on the capabilities and past performance of available robotic systems. Assembling the required data and comparing the ROI for several options is complex and tedious. Many project managers will only consider the use of a robot in targeted applications where the benefits are obvious, resulting in low levels of adoption of automation in the construction industry. This work demonstrates how data already resident in many BIM (Building Information Model) projects can be used to automate ROI estimation for a sample set of commercially available construction robots. Calculations account for set-up and operating time along with scheduling support tasks required while the automated technology is in use. Configuration parameters allow for prioritization of time, cost, or safety as the primary benefit of the technology. A path toward integration and use of automatic ROI calculation with a database of available robots in a BIM platform is described.

Keywords: automation, BIM, robot, ROI.

Procedia PDF Downloads 70

Authors: Xinyi Zhao, Furong Tian

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Mycotoxins are secondary metabolic products of fungi. These are poisonous, carcinogens and mutagens in nature and pose a serious health threat to both humans and animals, causing severe illnesses and even deaths. The rapid, simple and cheap detection methods of mycotoxins are of immense importance and in great demand in the food and beverage industry as well as in agriculture and environmental monitoring. Lateral flow immunochromatographic strips (ICSTs) have been widely used in food safety, environment monitoring. Forty-six papers were identified and reviewed on Google Scholar and Scopus for their limit of detection and nanomaterial on Lateral flow immunochromatographic strips on different types of mycotoxins. The papers were dated 2001-2021. Twenty five papers were compared to identify the lowest limit of detection of among different mycotoxins (Aflatoxin B1: 10, Zearalenone:5, Fumonisin B1: 5, Trichothecene-A: 5). Most of these highly sensitive strips are competitive. Sandwich structure are usually used in large scale detection. In conclusion, the mycotoxin receives that most researches is aflatoxin B1 and its limit of detection is the lowest. Gold-nanopaticle based immunochromatographic test strips has the lowest limit of detection. Five papers involve smartphone detection and they all detect aflatoxin B1 with gold nanoparticles. In these papers, quantitative concentration results can be obtained when the user uploads the photograph of test lines using the smartphone application.

Keywords: aflatoxin B1, limit of detection, gold nanoparticle, lateral flow immunochromatographic strips, mycotoxins

Procedia PDF Downloads 180

Authors: Hendrik Bernard Van Der Walt, Frik Van Niekerk

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Fuel models render a reduction in BOL when thorium is added to a reactor core. Thorium emulates the role of a fertile poison, and is beneficial for reducing beginning of cycle (BOC) excess reactivity. In spite of the build-up of 233U over the duration of a fuel cycle, the effects of fuel reloading have a significant impact on fuel viability, especially in the case of heterogeneous thorium-based fuels. The most common practice of compensating for the reduction of BOC reactivity is the addition of fissile isotopes (uranium fuel with increased enrichment or plutonium). This study introduces a heterogeneous thorium-based fuel with minimal fissile isotope additions. A pseudo reloading scheme was developed for numerical simulations of an infinite reactor based on the North-Anna 1 reactor operating in Virginia, USA. Use of this reloading pattern allows new thorium-based fuel to be loaded into the reactor model as part of a phasing in strategy at the end of any conventional reactor cycle. Results demonstrate the effects of thorium-based fuel on fuel cycle characteristics such as fuel cycle length, neutron economy and material matrix. Application of the above mentioned approach delivered promising results and presents a heterogeneous thorium-based fuel which could replace conventional fuel of typical, currently operating (or future) reactors without the need for expensive reactor redesign or fuel recycling strategies.

Keywords: nuclear fuel, nuclear characteristics, nuclear fuel cycle, thorium-based fuel, heterogeneous design, fuel reloading

Procedia PDF Downloads 117

Authors: F. Jiménez, R. Jódar, M. Martín, G. Sánchez, G. Sciavicco

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Abstract—Attribute or feature selection is one of the basic strategies to improve the performances of data classification tasks, and, at the same time, to reduce the complexity of classifiers, and it is a particularly fundamental one when the number of attributes is relatively high. Its application to unsupervised classification is restricted to a limited number of experiments in the literature. Evolutionary computation has already proven itself to be a very effective choice to consistently reduce the number of attributes towards a better classification rate and a simpler semantic interpretation of the inferred classifiers. We present a feature selection wrapper model composed by a multi-objective evolutionary algorithm, the clustering method Expectation-Maximization (EM), and the classifier C4.5 for the unsupervised classification of data extracted from a psychological test named BASC-II (Behavior Assessment System for Children - II ed.) with two objectives: Maximizing the likelihood of the clustering model and maximizing the accuracy of the obtained classifier. We present a methodology to integrate feature selection for unsupervised classification, model evaluation, decision making (to choose the most satisfactory model according to a a posteriori process in a multi-objective context), and testing. We compare the performance of the classifier obtained by the multi-objective evolutionary algorithms ENORA and NSGA-II, and the best solution is then validated by the psychologists that collected the data.

Keywords: evolutionary computation, feature selection, classification, clustering

Procedia PDF Downloads 347

Authors: Abdelhak Djoudi, Hachemi Chekireb, El Madjid Berkouk

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The doubly fed induction generator (DFIG) received recently an important consideration in medium and high power wind energy conversion systems integration, due to its advantages compared to other generators types. The stator power sliding mode control (SPSMC) proves a great efficiency judge against other control laws and schemes. In the SPSMC laws elaborated by several authors, only the slide surface tracking conditions are elaborated using Lyapunov functions, and the boundedness of the DFIG states is never treated. Some works have validated theirs approaches by experiments results in the case of specified machines, but these verifications stay insufficient to generalize to other machines range. Adding to this argument, the DFIG states boundedness demonstration is widely suggested in goal to ensure that in the application of the SPSMC, the states evaluates within theirs tolerable bounds. Our objective in the present paper is to highlight the efficiency of the SPSMC by stability analysis. The boundedness of the DFIG states such as the stator current and rotor flux is discussed. Moreover, the states trajectories are finding using analytical proves taking into consideration the SPSMC gains.

Keywords: Doubly Fed Induction Generator (DFIG), Stator Powers Sliding Mode Control (SPSMC), lyapunov function, stability, states boundedness, trajectories mathematical proves

Procedia PDF Downloads 382

Authors: Rui Chen, Shu-min Zhou, Xiong-jie Zhang, Ren-bo Wang, Fan Huang, Bin Tang

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During the temperature changes in reactor core, the nuclide cross section in reactor can vary with temperature, which eventually causes the changes of reactivity. To simulate the interaction between incident neutron and various materials at different temperatures on the nose, it is necessary to generate all the relevant reaction temperature-dependent cross section. Traditionally, the real time cross section generation method is used to avoid storing huge data but contains severe problems of low efficiency and adaptability for narrow energy region. Focused on the research on multi-temperature cross sections generation in real time during in neutron transport, this paper investigated the on-the-fly cross section generation method for resolved resonance region, thermal region and unresolved resonance region, and proposed the real time multi-temperature cross sections generation method based on double-exponential formula for resolved resonance region, as well as the Neville interpolation for thermal and unresolved resonance region. To prove the correctness and validity of multi-temperature cross sections generation based on wide energy region of incident neutron, the proposed method was applied in critical safety benchmark tests, which showed the capability for application in reactor multi-physical coupling simulation.

Keywords: cross section, neutron transport, numerical simulation, on-the-fly

Procedia PDF Downloads 179

Authors: Mei-Jen Lin, Yuan-Yuan Yu

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Low heat stability of goat milk limited the application of ultra-high temperature (UHT) sterilization on producing sterilized goat milk in order to keep excess goat milk in summer for producing goat dairy products in winter in Taiwan. Therefore, this study aimed to add stabilizers in goat milk to increase the heat stability for producing UHT sterilized goat milk preserved for making goat dairy products in winter. The amounts of 0.05-0.11% blend of sodium phosphates (Na) and blend of sodium/potassium phosphates (Sp) were added in raw goat milk at different seasons a night before autoclaved sterilization at 135°C 4 sec. The coagulation, ion calcium concentration and ethanol stability of sterilized goat milk were analyzed. Results showed that there were seasonal differences on choosing the optimal stabilizers and the addition levels. Addition of 0.05% and 0.22% of both Na and Sp salts in Spring goat milk, 0.10-0.11% of both Na and Sp salts in Summer goat milk, and 0.05%Na Sp group in Autumn goat milk were coagulated after autoclaved, respectively. There was no coagulation found with the addition of 0.08-0.09% both Na and Sp salts in goat milk; furthermore, the ionic calcium concentration were lower than 2.00 mM and ethanol stability higher than 70% in both 0.08-0.09% Na and Sp salts added goat milk. Therefore, the optimal addition level of blend of sodium phosphates and blend of sodium/potassium phosphates were 0.08-0.09% for producing sterilized goat milk at different seasons in Taiwan.

Keywords: coagulation, goat milk, phosphates, stability

Procedia PDF Downloads 348

Authors: M. I. Benamrani, H. Benamrani

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In the research to replace silicon and other thin-film semiconductor technologies and to develop long-term technology that is environmentally friendly, low-cost, and abundant, there is growing interest today given to organic materials. Our objective is to prepare polymeric layers containing metal particles deposited on a surface of semiconductor material which can have better electrical properties and which could be applied in the fields of nanotechnology as an alternative to the existing processes involved in the design of electronic circuits. This work consists in the development of composite materials by complexation and electroreduction of copper in a film of poly (pyrrole benzoic acid). The deposition of the polymer film on a monocrystalline silicon substrate is made by electrochemical oxidation in an organic medium. The incorporation of copper particles into the polymer is achieved by dipping the electrode in a solution of copper sulphate to complex the cupric ions, followed by electroreduction in an aqueous solution to precipitate the copper. In order to prepare the monocrystalline silicon substrate as an electrode for electrodeposition, an in-depth study on its surface state was carried out using photoacoustic spectroscopy. An analysis of the optical properties using this technique on the effect of pickling using a chemical solution was carried out. Transmission-photoacoustic and impedance spectroscopic techniques give results in agreement with those of photoacoustic spectroscopy.

Keywords: photoacoustic, spectroscopy, copper sulphate, chemical solution

Procedia PDF Downloads 69

Authors: Mamidi Ramakrishna Rao

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Doubly-fed induction generators (DFIG) due to their advantages like speed variation and four-quadrant operation, find its application in wind turbines. DFIG besides supplying power to the grid has to support reactive power (kvar) under grid voltage variations, should contribute minimum fault current during faults, have high efficiency, minimum weight, adequate rotor protection during crow-bar-operation from +20% to -20% of rated speed.  To achieve the optimum performance, a good electromagnetic design of DFIG is required. In this paper, a simple and heuristic global optimization – Differential Evolution has been used. Variables considered are lamination details such as slot dimensions, stack diameters, air gap length, and generator stator and rotor stack length. Two operating conditions have been considered - voltage and speed variations. Constraints included were reactive power supplied to the grid and limiting fault current and torque. The optimization has been executed separately for three objective functions - maximum efficiency, weight reduction, and grid fault stator currents. Subsequent calculations led to the conclusion that designs determined through differential evolution help in determining an optimum electrical design for each objective function.

Keywords: design optimization, performance, DFIG, differential evolution

Procedia PDF Downloads 132

Authors: Maslan Lamria, Ralph E. H. Sims, Tatang H. Soerawidjaja

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In increasing its self-sufficiency on transportation fuel, Indonesia is currently developing commercial production and use of drop-in biofuel (DBF) from vegetable oil. To maximize the level of success, it is necessary to get insights on how the implementation would develop as well as any important factors. This study assessed the dynamics of transition from existing fossil fuel system to a renewable fuel system, which involves the transition from existing biodiesel to projected DBF. A systems dynamics approach was applied and a model developed to simulate the dynamics of liquid biofuel transition. The use of palm oil feedstock was taken as a case study to assess the projected DBF implementation by 2045. The set of model indicators include liquid fuel self-sufficiency, liquid biofuel share, foreign exchange savings and green-house gas emissions reduction. The model outputs showed that supports on DBF investment and use play an important role in the transition progress. Given assumptions which include application of a maximum level of supports over time, liquid fuel self-sufficiency would be still unfulfilled in which palm biofuel contribution is 0.2. Thus, other types of feedstock such as algae and oil feedstock from marginal lands need to be developed synergically. Regarding support on DBF use, this study recommended that removal of fossil subsidy would be necessary prior to applying a carbon tax policy effectively.

Keywords: biofuel, drop-in biofuel, energy transition, liquid fuel

Procedia PDF Downloads 119

Authors: Vitalii Yu. Kapitan, Aleksandr V. Perzhu, Konstantin V. Nefedev

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The necessity of studying magnetic multilayer structures is explained by the prospects of their practical application as a technological base for creating new storages medium. Magnetic multilayer films have many unique features that contribute to increasing the density of information recording and the speed of storage devices. Multilayer structures are structures of alternating magnetic and nonmagnetic layers. In frame of the classical Heisenberg model, lattice spin systems with direct short- and long-range exchange interactions were investigated by Monte Carlo methods. The thermodynamic characteristics of multilayer structures, such as the temperature behavior of magnetization, energy, and heat capacity, were investigated. The processes of magnetization reversal of multilayer structures in external magnetic fields were investigated. The developed software is based on the new, promising programming language Rust. Rust is a new experimental programming language developed by Mozilla. The language is positioned as an alternative to C and C++. For the Monte Carlo simulation, the Metropolis algorithm and its parallel implementation using MPI and the Wang-Landau algorithm were used. We are planning to study of magnetic multilayer films with asymmetric Dzyaloshinskii–Moriya (DM) interaction, interfacing effects and skyrmions textures. This work was supported by the state task of the Ministry of Education and Science of the Russia # 3.7383.2017/8.9

Keywords: The Monte Carlo methods, Heisenberg model, multilayer structures, magnetic skyrmion

Procedia PDF Downloads 151

Authors: Apurwa Rastogi, Anant Parghi

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Shape memory alloys (SMAs) are memory metals with a high calibre to outperform as a civil construction material. They showcase novel functionality of undergoing large deformations and self-healing capability (pseudoelasticity) that leads to its emerging applications in a variety of areas. In the existing literature, most of the studies focused on the behaviour of SMA when used in critical regions of the smart buildings/bridges designed to withstand severe earthquakes without collapse and also its various applications in retrofitting works. However, despite having high ductility, their uses as construction joints and shear connectors in composite bridges are still unexplored in the research domain. This article presents to gain a broad outlook on whether SMAs can be partially used as shear connectors in composite bridges. In this regard, existing papers on the characteristics of shear connectors in the composite bridges will be discussed thoroughly and matched with the fundamental characteristics and properties of SMA. Since due to the high strength, stiffness, and ductility phenomena of SMAs, it is expected to be a good material for the shear connectors in composite bridges, and the collected evidence encourages the prior scrutiny of its partial use in the composite constructions. Based on the comprehensive review, important and necessary conclusions will be affirmed, and further emergence of research direction on the use of SMA will be discussed. This opens the window of new possibilities of using smart materials to enhance the performance of bridges even more in the near future.

Keywords: composite bridges, ductility, pseudoelasticity, shape memory alloy, shear connectors

Procedia PDF Downloads 175

Authors: Santos Cabrera, Halbert Yesid, Moncada Nino, Alvaro Fernando, Rincon Cuta, Yeisson Alexis

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The present work evaluates the feasibility of implementing a health and use monitoring system (HUMS), based on vibration analysis as a condition-based maintenance program for the UH60L 'Blackhawk' helicopters. The mixed approach used consists of contributions from national and international experts, the analysis of data extracted from the software (Meridium), the correlation of variables derived from the diagnosis of availability, the development, and application of the HUMS system, the evaluation of the latter through of the use of instruments designed for the collection of information using the DELPHI method and data capture with the device installed in the helicopter studied. The results obtained in the investigation reflect the context of maintenance in aerial operations, a reduction of operation and maintenance costs of over 2%, better use of human resources, improvement in availability (5%), and fulfillment of the aircraft’s security standards, enabling the implementation of the monitoring system (HUMS) in the condition-based maintenance program. New elements are added to the study of maintenance based on condition -specifically, in the determination of viability based on qualitative and quantitative data according to the methodology. The use of condition-based maintenance will allow organizations to adjust and reconfigure their strategic, logistical, and maintenance capabilities, aligning them with their strategic objectives of responding quickly and adequately to changes in the environment and operational requirements.

Keywords: air transportation sustainability, HUMS, maintenance based condition, maintenance blackhawk capability

Procedia PDF Downloads 136

Authors: Silvina Caíno-Lores, Jesús Carretero

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Large scale computing infrastructures have been widely developed with the core objective of providing a suitable platform for high-performance and high-throughput computing. These systems are designed to support resource-intensive and complex applications, which can be found in many scientific and industrial areas. Currently, large scale data-intensive applications are hindered by the high latencies that result from the access to vastly distributed data. Recent works have suggested that improving data locality is key to move towards exascale infrastructures efficiently, as solutions to this problem aim to reduce the bandwidth consumed in data transfers, and the overheads that arise from them. There are several techniques that attempt to move computations closer to the data. In this survey we analyse the different mechanisms that have been proposed to provide data locality for large scale high-performance and high-throughput systems. This survey intends to assist scientific computing community in understanding the various technical aspects and strategies that have been reported in recent literature regarding data locality. As a result, we present an overview of locality-oriented techniques, which are grouped in four main categories: application development, task scheduling, in-memory computing and storage platforms. Finally, the authors include a discussion on future research lines and synergies among the former techniques.

Keywords: data locality, data-centric computing, large scale infrastructures, cloud computing

Procedia PDF Downloads 241

Authors: M. M. Hassani, S. Ammann, F. K. Wittel, P. Niemz, H. J. Herrmann

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Application of engineered wood, especially in the form of glued-laminated timbers has increased significantly. Recent progress in plywood made of high strength and high stiffness hardwoods, like European beech, gives designers in general more freedom by increased dimensional stability and load-bearing capacity. However, the strong hygric dependence of basically all mechanical properties renders many innovative ideas futile. The tendency of hardwood for higher moisture sorption and swelling coefficients lead to significant residual stresses in glued-laminated configurations, cross-laminated patterns in particular. These stress fields cause initiation and evolution of cracks in the bond-lines resulting in: interfacial de-bonding, loss of structural integrity, and reduction of load-carrying capacity. Subsequently, delamination of glued-laminated timbers made of hardwood elements can be considered as the dominant failure mechanism in such composite elements. In addition, long-term creep and mechano-sorption under changing environmental conditions lead to loss of stiffness and can amplify delamination growth over the lifetime of a structure even after decades. In this study we investigate the delamination process of adhesively bonded hardwood (European beech) elements subjected to changing climatic conditions. To gain further insight into the long-term performance of adhesively bonded elements during the design phase of new products, the development and verification of an authentic moisture-dependent constitutive model for various species is of great significance. Since up to now, a comprehensive moisture-dependent rheological model comprising all possibly emerging deformation mechanisms was missing, a 3D orthotropic elasto-plastic, visco-elastic, mechano-sorptive material model for wood, with all material constants being defined as a function of moisture content, was developed. Apart from the solid wood adherends, adhesive layer also plays a crucial role in the generation and distribution of the interfacial stresses. Adhesive substance can be treated as a continuum layer constructed from finite elements, represented as a homogeneous and isotropic material. To obtain a realistic assessment on the mechanical performance of the adhesive layer and a detailed look at the interfacial stress distributions, a generic constitutive model including all potentially activated deformation modes, namely elastic, plastic, and visco-elastic creep was developed. We focused our studies on the three most common adhesive systems for structural timber engineering: one-component polyurethane adhesive (PUR), melamine-urea-formaldehyde (MUF), and phenol-resorcinol-formaldehyde (PRF). The corresponding numerical integration approaches, with additive decomposition of the total strain are implemented within the ABAQUS FEM environment by means of user subroutine UMAT. To predict the true stress state, we perform a history dependent sequential moisture-stress analysis using the developed material models for both wood substrate and adhesive layer. Prediction of the delamination process is founded on the fracture mechanical properties of the adhesive bond-line, measured under different levels of moisture content and application of the cohesive interface elements. Finally, we compare the numerical predictions with the experimental observations of de-bonding in glued-laminated samples under changing environmental conditions.

Keywords: engineered wood, adhesive, material model, FEM analysis, fracture mechanics, delamination

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Authors: Ammar Maziz, Prateek Gupta, Thiago Vasconcellos Birro, Benoit Gely

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Hydrogen as a sustainable fuel has the highest energy density per mass as compared to conventional non-renewable sources. As the world looks to move towards sustainability, especially in the sectors of aviation and automotive, it becomes important to address the issue of storage of hydrogen as compressed gas in high-pressure tanks. To improve the design for the efficient storage and transportation of Hydrogen, this paper presents the design and stress analysis of Dome Composite Overwrapped Pressure Vessels (COPVs) using the geodesic trajectory approach. The geodesic trajectory approach is used to optimize the dome design, resulting in a lightweight and efficient structure. Python scripting is employed to implement the mathematical modeling of the COPV, and after validating the model by comparison to the published paper, stress analysis is conducted using Abaqus commercial code. The results demonstrate the effectiveness of the geodesic trajectory approach in achieving a lightweight and structurally sound dome design, as well as the accuracy and reliability of the stress analysis using Abaqus commercial code. This study provides insights into the design and analysis of COPVs for aerospace applications, with the potential for further optimization and application in other industries.

Keywords: composite overwrapped pressure vessels, carbon fiber, geodesic trajectory approach, dome design, stress analysis, plugin python

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Authors: Shubhangi R. Deshmukh, Anupam B. Soni

Abstract:

Clean water and electricity are vital services needed in all communities. Bio-degradation of wastewater contaminants and desalination technologies are the best possible alternatives for the global shortage of fresh water supply. Osmotic microbial fuel cell (OMFC) is a versatile technology that uses microorganism (used for biodegradation of organic waste) and membrane technology (used for water purification) for wastewater treatment and energy generation simultaneously. This technology is the combination of microbial fuel cell (MFC) and forward osmosis (FO) processes. OMFC can give more electricity and clean water than the MFC which has a regular proton exchange membrane. FO gives many improvements such as high contamination removal, lower operating energy, raising high proton flux than other pressure-driven membrane technology. Lower concentration polarization lowers the membrane fouling by giving osmotic water recovery without extra cost. In this review paper, we have discussed the principle, mechanism, limitation, and application of OMFC technology reported to date. Also, we have interpreted the experimental data from various literature on the water recovery and electricity generation assessed by a different component of OMFC. The area of producing electricity using OMFC has further scope for research and seems like a promising route to wastewater treatment.

Keywords: forward osmosis, microbial fuel cell, osmotic microbial fuel cell, wastewater treatment

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Authors: Kolawole Taiwo Olabode

Abstract:

This is a comparative study of ICTs adoption and use in selected manufacturing industries in for development. This study was carried out 2004 and was repeated 2013 (nine years after) using the same selected manufacturing industries to assess the level, improvement and extent ICT facilities used in these companies. The theory of modernization was explored to explain some developmental issues in this study. The same semi-structured questionnaire and IDI were used to elicit data on the subject matter. About 24.9% of the total workers (1,247) were sampled for this study using quota sampling technique. SPSS was used to analysis the quantitative data. The qualitative data was used to buttress the quantitative data. Findings indicated that Seven-Up Bottling Company and Frigoglass Glass Industry still remained Intensive ICT Users while only Niger Match Nigeria Limited still remained Non-Intensive ICT User while unfortunately, Askar Paint Nigeria Limited has gone liquidated. It is also important to discover that only the Intensive ICT users improved on relevant ICT facilities. The existing problems of ICT adoption and used in these companies remained the same in Niger Match Limited. The study concluded that for a society to be developed, management and government at all levels must do all things necessary to ensure that all existing organisations must be ICT compliance for workers and organisational performance and to enhance nation’s development in order to compete with other companies for global standard or recognition.

Keywords: ICT, intensive ICT-users, entrepreneurial, manufacturing industries, industries and development

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Authors: Gianni Jacucci

Abstract:

Alfred Schutz (1932), at the very turning towards phenomenology, of the attention for the social sciences, stated that successful communication of meanings requires the sharing of “sedimenta-tions “ of previous meanings. Börje Langefors (1966), at the very beginning of the social studies of information systems, stated that a common professional basis is required for a correct sharing of meanings, e. g., “standardised accounting data among accountants”. Harold Garfinkel (1967) at the very beginning of ethnomethodology, stated that the accounting of social events must be carried out in the same language used by the actors of those events in managing their practice. Community of practice: we advocate professional descriptions of community of practice members to scientifically determine the level of child psycho social emotional development. Our approach consists of an application to Human Sciences of Husserl’s Phenomenological Philosophy using a method reminder of Giorgi’s DPM in Psychology. Husserl’s requirement of "Epoché," which in-volves eliminating prejudices from the minds of observers, is met through "concept cleaning," achieved by consistently sharing disciplinary concepts within their community of practice. Mean-while, the absence of subjective bias is ensured by the meticulous attention to detail in their pro-fessional expertise.

Keywords: scientific rigour, descriptive phenomenological method, sedimentation of meanings, community of practice

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Authors: Mostafa A. Amer, I. A. El-Samra, I. I. Abou-ElSeoud, S. M. El-Abd, N. K. Shawertamimi

Abstract:

Tomato Fusarium wilt disease caused by Fusarium oxysporum f. sp. Lycopercisi (FOL) is considered one of the most destructive diseases in Egypt. Effect of some biotic inducers such as Bacillus megaterium var. phosphaticum, Glomus intraradices and Glomus macrocarpum at seven different mixed treatments, was tested for their ability to induce resistance in tomato plants against the disease. According to pathogenicity tests, all the tested isolates of FOL showed wilt symptoms on both of the tested cultivars; however, they considerably varied in percentages of disease incidence (DI) and disease severity (DS). Castle Rock was more susceptible than Peto 86, which was relatively resistant. Pretreatment of both cultivars, under greenhouse conditions, with the tested biotic inducers alone or in combination with each other's, significantly increased the induction of chitinase, β-1,3-glucanase, peroxidase, and polyphenoloxidase and reduced disease incidence and severity, compared with untreated noninoculated (C1) and untreated inoculated (C2) controls. Application of a combination of BMP, with GI and GM was the most effective in increasing the induction rated of the tested enzymes, compared with the other treatments. Induction of enzymes in most of the tested bioinducers treatments gradually increased, attaining maximum values after 48 or/and 72 hrs after challenging with FOL, then gradually declined. GI was the least effective bioinducer.

Keywords: F. oxysporum f. sp. lycopersici, defense enzymes, induced systemic resistance, ISR, B. megaterium var. phosphaticum, G. macrocarpum, G. intraradices

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Authors: Mike R. Bambach

Abstract:

Increasing awareness of environmental concerns is leading a drive towards more sustainable structural products for the built environment. Natural fibres such as flax, jute and hemp have recently been considered for fibre-resin composites, with a major motivation for their implementation being their notable sustainability attributes. While recent decades have seen substantial interest in the use of such natural fibres in composite materials, much of this research has focused on the materials aspects, including fibre processing techniques, composite fabrication methodologies, matrix materials and their effects on the mechanical properties. The present study experimentally investigates the compression strength of structural channel sections of flax, jute and hemp, with a particular focus on their suitability for residential stud wall applications. The section geometry is optimised for maximum strength via the introduction of complex stiffeners in the webs and flanges. Experimental results on both natural fibre composite channel sections and typical steel and timber residential wall studs are compared. The geometrically optimised natural fibre composite channels are shown to have compression capacities suitable for residential wall stud applications, identifying them as a potentially viable alternative to traditional building materials in such application, and potentially other light structural applications.

Keywords: channel sections, natural fibre composites, residential stud walls, structural composites

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Authors: Reza Keihani, Ali Bahadori-Jahromi, Timothy James Clacy

Abstract:

Plastic as an environmental burden is a well-rehearsed topic in the research area. This is due to its global demand and destructive impacts on the environment, which has been a significant concern to the governments. Typically, the use of plastic in the construction industry is seen across low-density, non-structural applications due to its diverse range of benefits including high strength-to-weight ratios, manipulability and durability. It can be said that with the level of plastic consumption experienced in the construction industry, an ongoing responsibility is shown for this sector to continually innovate alternatives for application of recycled plastic waste such as using plastic made replacement from polyethylene, polystyrene, polyvinyl and polypropylene in the concrete mix design. In this study, the impact of partially replaced fine aggregate with polypropylene in the concrete mix design was investigated to evaluate the concrete’s compressive strength by conducting an experimental work which comprises of six concrete mix batches with polypropylene replacements ranging from 0.5 to 3.0%. The results demonstrated a typical decline in the compressive strength with the addition of plastic aggregate, despite this reduction generally mitigated as the level of plastic in the concrete mix increased. Furthermore, two of the six plastic-containing concrete mixes tested in the current study exceeded the ST5 standardised prescribed concrete mix compressive strength requirement at 28-days containing 1.50% and 2.50% plastic aggregates, which demonstrated the potential for use of recycled polypropylene in structural applications, as a partial by mass, fine aggregate replacement in the concrete mix.

Keywords: compressive strength, concrete, polypropylene, sustainability

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