Search results for: chemical systems engineering

Authors: M. A. Badr, A. N. Mohib, M. M. Ibrahim

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The objective of this research is to study the technical and economic performance of wind/diesel/battery (W/D/B) system supplying a remote small gathering of six families using HOMER software package. The electrical energy is to cater for the basic needs for which the daily load pattern is estimated. Net Present Cost (NPC) and Cost of Energy (COE) are used as economic criteria, while the measure of performance is % of power shortage. Technical and economic parameters are defined to estimate the feasibility of the system under study. Optimum system configurations are estimated for two sites. Using HOMER software, the simulation results showed that W/D/B systems are economical for the assumed community sites as the price of generated electricity is about 0.308 $/kWh, without taking external benefits into considerations. W/D/B systems are more economical than W/B or diesel alone systems, as the COE is 0.86 $/kWh for W/B and 0.357 $/kWh for diesel alone.

Keywords: optimum energy systems, remote electrification, renewable energy, wind turbine systems

Procedia PDF Downloads 388

Authors: Małgorzata Golonka, Jadwiga Laska

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Self-healing polymers are one of the most investigated groups of smart materials. As materials engineering has recently focused on the design, production and research of modern materials and future technologies, researchers are looking for innovations in structural, construction and coating materials. Based on available scientific articles, it can be concluded that most of the research focuses on the self-healing of cement, concrete, asphalt and anticorrosion resin coatings. In our study, a method of obtaining and testing the properties of several types of microcapsules for use in self-healing polymer materials was developed. A method to obtain microcapsules exhibiting various mechanical properties, especially compressive strength was developed. The effect was achieved by using various polymer materials to build the shell: urea-formaldehyde resin (UFR), melamine-formaldehyde resin (MFR), melamine-urea-formaldehyde resin (MUFR). Dicyclopentadiene (DCPD) was used as the core material due to the possibility of its polymerization according to the ring-opening olefin metathesis (ROMP) mechanism in the presence of a solid Grubbs catalyst showing relatively high chemical and thermal stability. The ROMP of dicyclopentadiene leads to a polymer with high impact strength, high thermal resistance, good adhesion to other materials and good chemical and environmental resistance, so it is potentially a very promising candidate for the self-healing of materials. The capsules were obtained by condensation polymerization of formaldehyde with urea, melamine or copolymerization with urea and melamine in situ in water dispersion, with different molar ratios of formaldehyde, urea and melamine. The fineness of the organic phase dispersed in water, and consequently the size of the microcapsules, was regulated by the stirring speed. In all cases, to establish such synthesis conditions as to obtain capsules with appropriate mechanical strength. The microcapsules were characterized by determining the diameters and their distribution and measuring the shell thickness using digital optical microscopy and scanning electron microscopy, as well as confirming the presence of the active substance in the core by FTIR and SEM. Compression tests were performed to determine mechanical strength of the microcapsules. The highest repeatability of microcapsule properties was obtained for UFR resin, while the MFR resin had the best mechanical properties. The encapsulation efficiency of MFR was much lower compared to UFR, though. Therefore, capsules with a MUFR shell may be the optimal solution. The chemical reaction between the active substance present in the capsule core and the catalyst placed outside the capsules was confirmed by FTIR spectroscopy. The obtained autonomous repair systems (microcapsules + catalyst) were introduced into polyethylene in the extrusion process and tested for the self-repair of the material.

Keywords: autonomic self-healing system, dicyclopentadiene, melamine-urea-formaldehyde resin, microcapsules, thermoplastic materials

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Authors: Fabienne Baraud, Lydia Leleyter, Sandra Poree, Melanie Lemoine

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SEDIBRIC (valorization de SEDIments en BRIQues et tuiles) is a French project that aims to replace a part of natural clays with dredged sediments in the preparation of fired bricks in order to propose an alternative solution for the management of harbor dredged sediments. The feasibility of such re-use is explored from a technical, economic, and environmental point of view. The present study focuses on the potential environmental impact of various chemical elements (Al, Ca, Cd, Co, Cr, Cu, Fe, Ni, Mg, Mn, Pb, Ti, and Zn) that are initially present in the dredged sediments. The total content (after acid digestion) and the environmental availability (estimated by single extractions with various extractants) of these elements are determined in the raw sediments and in the obtained fired bricks. The possible influence of some steps of the manufacturing process (sediment pre-treatment, firing) is also explored. The first results show that the pre-treatment step, which uses tap water to desalinate the raw sediment, does not influence the environmental availability of the studied elements. However, the firing process, performed at 900°C, can affect the amount of some elements detected in the bricks, as well as their environmental availability. We note that for Cr, or Ni, the HCl or EDTA availability was increased in the brick (compared to the availability in the raw sediment). For Cd, Cu, Pb, and Zn, the HCl and EDTA availability was reduced in the bricks, meaning that these elements were stabilized within the bricks.

Keywords: bricks, chemical extraction, metals, sediment

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Authors: Sinem O. Aktan, Musa Y. Akkurt

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Experimental pressure calibration methods can be classified into three areas: (1) measurements in liquid or gas systems, (2) measurements in static-solid media systems, and (3) measurements in dynamic shock systems. Fluid (liquid and gas) systems high accuracies can be obtainable and commonly used for the calibration method of a pressure sensor. Pressure calibrations can be performed for metrological traceability in two ways, which are on-site (field) and in the laboratory. Laboratory and on-site calibration procedures and the requirements of the DKD-R-6-1 and Euramet cg-17 guidelines will also be addressed. In this study, calibration methods of direct and indirect reading pressure sensor and measurement uncertainty contributions will be explained.

Keywords: pressure metrology, pressure calibration, dead-weight tester, pressure uncertainty

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Authors: Pei Li, Chunyi Zhi

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Conversion-type lithium-ion batteries show great potential as high-energy-density, low-cost and sustainable alternatives to current transition-metal-based intercalation cells. Li-Cl₂/Li⁻I₂ conversion batteries, based on anionic redox reactions of Cl⁻/Cl⁰ or I⁻/I⁰, are highly attractive due to their superior voltage and capacity. However, a redox-active and reversible chlorine cathode has not been developed in organic electrolytes. And thermodynamic instability and shuttling issues of iodine cathodes have plagued the active iodine loading, capacity retention and cyclability. By reversible chemical bonds, we develop reversible chlorine redox reactions in organic electrolytes with interhalogen bonds between I and Cl for Li-I₂ batteries and develop a highly thermally stable I/I₃--bonded organic salts with iodine content up to 80% as cathode materials for the rechargeable Li-I₂ batteries. The demonstration of reversible chemical bonds enabled rechargeable Li-halogen batteries opens a new avenue to develop halogen compound cathodes.

Keywords: conversion-type, chlorine, halogen cathode, high energy density, iodine, interhalogen bond, lithium-ion batteries

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Authors: Yehya Abdellatif, Ahmed Alsalaymeh, Iyad Muslih, Ali Alshduifat

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Photovoltaic (PV) power generation systems, mainly small scale, are rapidly being deployed in Jordan. The impact of these systems on the grid has not been studied or analyzed. These systems can cause many technical problems such as reverse power flows and voltage rises in distribution feeders, and real and reactive power transients that affect the operation of the transmission system. To fully understand and address these problems, extensive research, simulation, and case studies are required. To this end, this paper studies the cloud shadow effect on the power generation of a ground mounted PV system installed at the test field of the Renewable Energy Center at the Applied Science University.

Keywords: photovoltaic, cloud effect, MPPT, power transients

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Authors: Saleem Z. Ramadan

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In this paper, a model is proposed to determine the life distribution parameters of the useful life region for the PV system utilizing a combination of non-parametric and linear regression analysis for the failure data of these systems. Results showed that this method is dependable for analyzing failure time data for such reliable systems when the data is scarce.

Keywords: masking, bathtub model, reliability, non-parametric analysis, useful life

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Authors: Sergo Tsiramua, Sulkhan Sulkhanishvili, Elisabed Asabashvili, Lazare Kvirtia

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The paper presents logical-probabilistic methods, models and algorithms for reliability assessment of complex systems, based on which a web application for structural analysis and reliability assessment of systems was created. The reliability assessment process included the following stages, which were reflected in the application: 1) Construction of a graphical scheme of the structural reliability of the system; 2) Transformation of the graphic scheme into a logical representation and modeling of the shortest ways of successful functioning of the system; 3) Description of system operability condition with logical function in the form of disjunctive normal form (DNF); 4) Transformation of DNF into orthogonal disjunction normal form (ODNF) using the orthogonalization algorithm; 5) Replacing logical elements with probabilistic elements in ODNF, obtaining a reliability estimation polynomial and quantifying reliability; 6) Calculation of weights of elements. Using the logical-probabilistic methods, models and algorithms discussed in the paper, a special software was created, by means of which a quantitative assessment of the reliability of systems of a complex structure is produced. As a result, structural analysis of systems, research and designing of optimal structure systems are carried out.

Keywords: Complex systems, logical-probabilistic methods, orthogonalization algorithm, reliability, weight of element

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Authors: S. Lemoussu, J. C. Chaudemar, R. A. Vingerhoeds

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The aeronautics sector is currently living an unprecedented growth largely due to innovative projects. In several cases, such innovative developments are being carried out by Small and Medium sized-Enterprises (SMEs). For instance, in Europe, a handful of SMEs are leading projects like airships, large civil drones, or flying cars. These SMEs have all limited resources, must make strategic decisions, take considerable financial risks and in the same time must take into account the constraints of safety, cost, time and performance as any commercial organization in this industry. Moreover, today, no international regulations fully exist for the development and certification of this kind of projects. The absence of such a precise and sufficiently detailed regulatory framework requires a very close contact with regulatory instances. But, SMEs do not always have sufficient resources and internal knowledge to handle this complexity and to discuss these issues. This poses additional challenges for those SMEs that have system integration responsibilities and that must provide all the necessary means of compliance to demonstrate their ability to design, produce, and operate airships with the expected level of safety and reliability. The final objective of our research is thus to provide a methodological framework supporting SMEs in their development taking into account recent innovation and institutional rules of the sector. We aim to provide a contribution to the problematic by developing a specific Model-Based Systems Engineering (MBSE) approach. Airspace regulation, aeronautics standards and international norms on systems engineering are taken on board to be formalized in a set of models. This paper presents the on-going research project combining Systems Engineering and Project Management process modeling and taking into account the metamodeling problematic.

Keywords: aeronautics, certification, process modeling, project management, SME, systems engineering

Procedia PDF Downloads 151

Authors: Tuji Jemal Ahmed

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Fresh produce is an essential component of a healthy diet. However, it can also be a potential source of pathogenic microorganisms that can cause foodborne illnesses. Traditional disinfection methods, such as washing with water and chlorine, have limitations and may not effectively remove or inactivate all microorganisms. This has led to the development of alternative/new methods of fresh produce disinfection, including physical and chemical methods. In this paper, we explore the physical and chemical new methods of fresh produce disinfection, their advantages and disadvantages, and their suitability for different types of produce. Physical methods of disinfection, such as ultraviolet (UV) radiation and high-pressure processing (HPP), are crucial in ensuring the microbiological safety of fresh produce. UV radiation uses short-wavelength UV-C light to damage the DNA and RNA of microorganisms, and HPP applies high levels of pressure to fresh produce to reduce the microbial load. These physical methods are highly effective in killing a wide range of microorganisms, including bacteria, viruses, and fungi. However, they may not penetrate deep enough into the product to kill all microorganisms and can alter the sensory characteristics of the product. Chemical methods of disinfection, such as acidic electrolyzed water (AEW), ozone, and peroxyacetic acid (PAA), are also important in ensuring the microbiological safety of fresh produce. AEW uses a low concentration of hypochlorous acid and a high concentration of hydrogen ions to inactivate microorganisms, ozone uses ozone gas to damage the cell membranes and DNA of microorganisms, and PAA uses a combination of hydrogen peroxide and acetic acid to inactivate microorganisms. These chemical methods are highly effective in killing a wide range of microorganisms, but they may cause discoloration or changes in the texture and flavor of some products and may require specialized equipment and trained personnel to produce and apply. In conclusion, the selection of the most suitable method of fresh produce disinfection should take into consideration the type of product, the level of microbial contamination, the effectiveness of the method in reducing the microbial load, and any potential negative impacts on the sensory characteristics, nutritional composition, and safety of the produce.

Keywords: fresh produce, pathogenic microorganisms, foodborne illnesses, disinfection methods

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Authors: F. Laatar, S. Ktifa, H. Ezzaouia

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Plasma Enhanced Chemical Vapor Deposition (PECVD) method is used to deposit hydrogenated nanocrystalline silicon films (nc-Si: H) on Porous Anodic Alumina Films (PAF) on glass substrate at different deposition duration. Influence of the deposition time on the physical properties of nc-Si: H grown on PAF was investigated through an extensive correlation between micro-structural and optical properties of these films. In this paper, we present an extensive study of the morphological, structural and optical properties of these films by Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD) techniques and a UV-Vis-NIR spectrometer. It was found that the changes in DT can modify the films thickness, the surface roughness and eventually improve the optical properties of the composite. Optical properties (optical thicknesses, refractive indexes (n), absorption coefficients (α), extinction coefficients (k), and the values of the optical transitions EG) of this kind of samples were obtained using the data of the transmittance T and reflectance R spectra’s recorded by the UV–Vis–NIR spectrometer. We used Cauchy and Wemple–DiDomenico models for the analysis of the dispersion of the refractive index and the determination of the optical properties of these films.

Keywords: hydragenated nanocrystalline silicon, plasma processing chemical vapor deposition, X-ray diffraction, optical properties

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Authors: P. Zakikhani, R. Zahari, M. T. H. Sultan, D. L. Majid

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Natural plant fibres reinforced polymeric composite materials have been used in many fields of our lives to save the environment. Especially, bamboo fibres due to its environmental sustainability, mechanical properties, and recyclability have been utilized as reinforced polymer matrix composite in construction industries. In this review study bamboo structure and three different methods such as mechanical, chemical and combination of mechanical and chemical to extract fibres from bamboo are summarized. Each extraction method has been done base on the application of bamboo. In addition Bamboo fibre is compared with glass fibre from various aspects and in some parts it has advantages over the glass fibre.

Keywords: bamboo fibres, natural fibres, bio composite, mechanical extraction, glass fibres

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Authors: A. A. Abaker Omer, H. B. Mohamed Balh, W. Liu, A. Abas, J. Yu, S. Li, W. Ma, W. El Kolaly, Y. Y. Ahmed Abuker

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We have discovered an important technical solution that could make new approaches in the processing of wet silicon etching, especially in the production of photovoltaic cells. During its inferior light-trapping and structural properties, the inverted pyramid structure outperforms the conventional pyramid textures and black silicone. The traditional pyramid textures and black silicon can only be accomplished with more advanced lithography, laser processing, etc. Importantly, our data demonstrate the feasibility of an inverted pyramidal structure of silicon via one-step Cu-catalyzed chemical etching (CCCE) in Cu (NO₃)₂/HF/H₂O₂/H₂O solutions. The effects of etching time and reaction temperature on surface geometry and light trapping were systematically investigated. The conclusion shows that the inverted pyramid structure has ultra-low reflectivity of ~4.2% in the wavelength of 300~1000 nm; introduce of Cu particles can significantly accelerate the dissolution of the silicon wafer. The etching and the inverted pyramid structure formation mechanism are discussed. Inverted pyramid structure with outstanding anti-reflectivity includes useful applications throughout the manufacture of semi-conductive industry-compatible solar cells, and can have significant impacts on industry colleagues and populations.

Keywords: Cu-catalyzed chemical etching, inverted pyramid nanostructured, reflection, solar cells

Procedia PDF Downloads 140

Authors: G. Singh, H.Schuster, U. Füssel

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The stability of electric arc and durability of electrode tip used in Tungsten Inert Gas (TIG) welding demand a metallurgical study about the chemical transport mechanism of emitter oxide particles in tungsten electrode during its real welding conditions. The tungsten electrodes doped with emitter oxides of rare earth oxides such as La₂O₃, Th₂O₃, Y₂O₃, CeO₂ and ZrO₂ feature a comparatively lower work function than tungsten and thus have superior emission characteristics due to lesser surface temperature of the cathode. The local change in concentration of these emitter particles in tungsten electrode due to high temperature diffusion (chemical transport) can change its functional properties like electrode temperature, work function, electron emission, and stability of the electrode tip shape. The resulting increment in tip surface temperature results in the electrode material loss. It was also observed that the tungsten recrystallizes to large grains at high temperature. When the shape of grain boundaries are granular in shape, the intergranular diffusion of oxide emitter particles takes more time to reach the electrode surface. In the experimental work, the microstructure of the used electrode's tip surface will be studied by scanning electron microscope and reflective X-ray technique in order to gauge the extent of the diffusion and chemical reaction of emitter particles. Besides, a simulated model is proposed to explain the effect of oxide particles diffusion on the electrode’s microstructure, electron emission characteristics, and electrode tip erosion. This model suggests metallurgical modifications in tungsten electrode to enhance its erosion resistance.

Keywords: rare-earth emitter particles, temperature-dependent diffusion, TIG welding, Tungsten electrode

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Authors: Zineb Ouahdi

Abstract:

Spirocyclic compound derivatives, with their unique heterocyclic motifs, serve as a continual source of inspiration in the pursuit of developing potential therapeutic agents. These compounds are diverse in their chemical structures; some have fully saturated skeletons, while others are partially unsaturated. Nevertheless, these compounds share a characteristic feature with natural products - the presence of at least one heteroatom in one of their rings. The inclusion of a C = O dipolarophile in pyridazinones imparts an exciting aspect for 1,3-dipolar cycloaddition reactions, the focal point of our study. Our research has involved a detailed theoretical investigation of the reaction between ethyl (Z)-2-bromo-2-(2-(p-tolyl)hydrazono)acetate and 6-methyl-4,5-dihydropyridazine-3(2H)-one. This has been accomplished using the DFT/B3LYP/6-31g(d,p) method, intending to illuminate the chemical pathway of this reaction. The chemical reactivity theories we used for this purpose included FMO, TS, and local and global indices derived from conceptual DFT. The theoretical framework outlined in this study allowed us to propose a reaction mechanism for cycloaddition reactions. It also enabled the identification of the potential activities of the analyzed compounds (P1, P2, P3, P4, P5, and P6) against the major protease of the coronavirus disease (COVID-19). This was achieved using various computational tools, including AutoDock Tools, Autodock Vina, Autodock 4, and PYRX.

Keywords: MEDT, pyridazin, cycloaddition, FMO, DFT, docking

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Authors: D. Pinto, L. Castro, M. L. Cruzat, S. Barros, J. Gironás, C. Oberli, M. Torres, C. Escauriaza, A. Cipriano

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Flash floods, together with landslides, are a common natural threat for people living in mountainous regions and foothills. One way to deal with this constant menace is the use of Early Warning Systems, which have become a very important mitigation strategy for natural disasters. In this work, we present our proposal for a pilot Flash Flood Early Warning System for Santiago, Chile, the first stage of a more ambitious project that in a future stage shall also include early warning of landslides. To give a context for our approach, we first analyze three existing Flash Flood Early Warning Systems, focusing on their general architectures. We then present our proposed system, with main focus on the decision support system, a system that integrates empirical models and fuzzy expert systems to achieve reliable risk estimations.

Keywords: decision support systems, early warning systems, flash flood, natural hazard

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Authors: Ruedee Niyomrath

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This research aimed at surveying the local red clay raw material sources in Samut Songkram province, Thailand to test the physical and chemical properties of the local red clay, including to find the approach to develop the local red clay properties for ceramic production. The findings of this research would be brought to apply in the ceramic production industry of the country all at the upstream level which was the community in the raw material source, at the mid water level which was the ceramic producer and at the downstream level which was the distributor and the consumer as well as the community producer who would apply them to their identity and need of the community business.

Keywords: chemical properties of red clay, physical properties of red clay, ceramic production, red clay product

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Authors: Jeremy Moloney

Abstract:

A major oil and gas operator in western Canada producing approximately 50,000 BOE per day of sour fluids was experiencing increased water production along with decreased oil production over several years. The higher water volumes being produced meant an increase in the operator’s incumbent corrosion inhibitor (CI) chemical requirements but with reduced oil production revenues. Thus, a cost-effective corrosion inhibitor solution was sought to deliver enhanced corrosion mitigation of the carbon steel pipeline infrastructure but at reduced chemical injection dose rates. This paper presents the laboratory work conducted on the development of a corrosion inhibitor under the operator’s simulated sour operating conditions and then subsequent field testing of the product. The new CI not only provided extremely good levels of general and localized corrosion inhibition and outperformed the incumbent CI under the laboratory test conditions but did so at vastly lower concentrations. In turn, the novel CI product facilitated field chemical injection rates to be optimized and reduced by 40% compared with the incumbent whilst maintaining superior corrosion protection resulting in significant cost savings and associated sustainability benefits for the operator.

Keywords: carbon steel, sour gas, hydrogen sulphide, localized corrosion, pitting, corrosion inhibitor

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Authors: Ian Marc G. Cabugsa, Kim Ryan Won, Kareem Mamac, Manuel Dee, Merlita Garcia

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An optimized cacao fermentation technique was developed for the cacao farmers of Davao City Philippines. Cacao samples with weights ranging from 150-250 kilograms were collected from various cacao farms in Davao City and Zamboanga City Philippines. Different fermentation techniques were used starting with design of the sweat box, prefermentation conditionings, number of days for fermentation and number of turns. As the beans are being fermented, its temperature was regularly monitored using a digital thermometer. The resultant cacao beans were assessed using physical and chemical means. For the physical assessment, the bean cut test, bean count tests, and sensory test were used. Quantification of theobromine, caffeine, and antioxidants in the form of equivalent quercetin was used for chemical assessment. Both the theobromine and caffeine were analyzed using HPLC method while the antioxidant was analyzed spectrometrically. To come up with the best fermentation procedure, the different assessment were given priority coefficients wherein the physical tests – taste test, cut, and bean count tests were given priority over the results of the chemical test. The result of the study was an optimized fermentation protocol that is readily adaptable and transferable to any cacao cooperatives or groups in Mindanao or even Philippines as a whole.

Keywords: cacao, fermentation, HPLC, optimization, Philippines

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Authors: M. Lamamra, H. Laouer, A. Adjaoud, Sahli Farida

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Essential oils can have significant antimicrobial activities and can successfully replace antibiotics that show their ineffectiveness against resistant germs. The chemical composition of the essential oil obtained by hydrodistillation from the aerial part of Daucus aristidis (Apiaceae) at the pre-flowering stage was investigated for the first time, by GC and GC-MS and evaluated for in vitro antimicrobial activity by the disk diffusion method. The Main components of D. aristidis oil were α-pinene (20.13%), cedrol (20.11%), and E- asarone (18.53%). The oil exhibited an antibacterial activity against almost strains tested except for Klebsiella pneumoniae ATCC 700603 K6 and Enterococcus faecalis ATCC 49452, the oil of D. aristidis had no activity against all fungi tested.

Keywords: α-pinene, antimicrobial activity, Daucus aridtidis, essential oil

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Authors: Komal Saini, S. K. Sahoo, B. S. Bajwa

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The Laser Fluorimetery Technique has been used for the microanalysis of uranium content in water samples collected from different sources like the hand pumps, tube wells in the drinking water samples of SW & NE Punjab, India. The geographic location of the study region in NE Punjab is between latitude 31.21º- 32.05º N and longitude 75.60º-76.14º E and for SW Punjab is between latitude 29.66º-30.48º N and longitude 74.69º-75.54º E. The purpose of this study was mainly to investigate the uranium concentration levels of ground water being used for drinking purposes and to determine its health effects, if any, to the local population of these regions. In the present study 131 samples of drinking water collected from different villages of SW and 95 samples from NE, Punjab state, India have been analyzed for chemical and radiological toxicity. In the present investigation, uranium content in water samples of SW Punjab ranges from 0.13 to 908 μgL−1 with an average of 82.1 μgL−1 whereas in samples collected from NE- Punjab, it ranges from 0 to 28.2 μgL−1 with an average of 4.84 μgL−1. Thus, revealing that in the SW- Punjab 54 % of drinking water samples have uranium concentration higher than international recommended limit of 30 µgl-1 (WHO, 2011) while 35 % of samples exceeds the threshold of 60 µgl-1 recommended by our national regulatory authority of Atomic Energy Regulatory Board (AERB), Department of Atomic Energy, India, 2004. On the other hand in the NE-Punjab region, none of the observed water sample has uranium content above the national/international recommendations. The observed radiological risk in terms of excess cancer risk ranges from 3.64x10-7 to 2.54x10-3 for SW-Punjab, whereas for NE region it ranges from 0 to 7.89x10-5. The chemical toxic effect in terms of Life-time average Daily Dose (LDD) and Hazard Quotient (HQ) have also been calculated. The LDD for SW-Punjab varies from 0.0098 to 68.46 with an average of 6.18 µg/ kg/day whereas for NE region it varies from 0 to 2.13 with average 0.365 µg/ kg/day, thus indicating presence of chemical toxicity in SW Punjab as 35% of the observed samples in the SW Punjab are above the recommendation limit of 4.53 µg/ kg/day given by AERB for 60 µgl-1 of uranium. Maximum & Minimum values for hazard quotient for SW Punjab is 0.002 & 15.11 with average 1.36 which is considerably high as compared to safe limit i.e. 1. But for NE Punjab HQ varies from 0 to 0.47. The possible sources of high uranium observed in the SW- Punjab will also be discussed.

Keywords: uranium, groundwater, radiological and chemical toxicity, Punjab, India

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Authors: Parastou Kharazmi, Folke Björk

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Some of the main causes for degradation of polymeric materials are thermal aging, hydrolysis, oxidation or chemical degradation by acids, alkalis or water. The first part of this paper provides a brief summary of advances in technology, methods and specification of composite materials for relining as a rehabilitation technique for sewage systems. The second part summarizes an investigation on frequently used composite materials for relining in Sweden, the rubber filled epoxy composite and reinforced polyester composite when they were immersed in deionized water or in dry conditions, and elevated temperatures up to 80°C in the laboratory. The tests were conducted by visual inspection, microscopy, Dynamic Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC) as well as mechanical testing, three point bending and tensile testing.

Keywords: composite, epoxy, polyester, relining, sewage

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Authors: Ramazan Kadiev, Arkadi Ponossov

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Semidiscrete systems contain both continuous and discrete components. This means that the dynamics is mostly continuous, but at certain instants, it is exposed to abrupt influences. Such systems naturally appear in applications, for example, in biological and ecological models as well as in the control theory. Therefore, the study of semidiscrete systems has recently attracted the attention of many specialists. Stochastic effects are an important part of any realistic approach to modeling. For example, stochasticity arises in the population dynamics, demographic and ecological due to a change in time of factors external to the system affecting the survival of the population. In control theory, random coefficients can simulate inaccuracies in measurements. It will be shown in the presentation how to incorporate such effects into semidiscrete systems. Stability analysis is an essential part of modeling real-world problems. In the presentation, it will be explained how sufficient conditions for the moment stability of solutions in terms of the coefficients for linear semidiscrete stochastic equations can be derived using non-Lyapunov technique.

Keywords: abrupt changes, exponential stability, regularization, stochastic noises

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Authors: Divya Mohanan, Deepa G. Nair

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The most accepted international definition of sustainable development quoted from the Brundtland Report published in 1987 states that development that meets the needs of the present without compromising the ability of future generations to meet their own needs. This definition serves as a foundation for many fields including the building sector to consider sustainability and focuses on the three pillars of sustainability social, economic, and environment. The building industry due to its multi-faceted nature requires building codes, standards, and certification systems to effectively address the sustainability assessment. In the last decade, many buildings rating systems evolved that address sustainability in one way and many more are on the drawing boards yet to come. This paper attempts to offer a comprehensive literature review of seven popular building rating systems (LEED (US), BREEAM (UK), CASBEE (Japan), GRIHA, LEED, IGBC), scrutinizing their macro-areas, segments of sustainability and thus highlight the need for a framework which addresses the assessment of the building in terms of sustainability as a whole.

Keywords: building rating systems, sustainability, LEED, BREEAM, CASBEE, GRIHA, IGBC

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Authors: Riddhi Jangid, Gajendra Pratap Singh

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Petri nets, a mathematical tool, is used for modeling in different areas of computer sciences, biological networks, chemical systems and many other disciplines. A Petri net model of a given system is created by the graphical representation that describes the properties and behavior of the system. While looking for the behavior of any system, 1-safe Petri nets are of particular interest to many in the application part. Boolean Petri nets correspond to those class in 1- safe Petri nets that generate all the binary n-vectors in their reachability analysis. We study the class by changing different parameters like the token counts in the places and how the structure of the tree changes in the reachability analysis. We discuss here an extended class of Boolean Petri nets that generates n-ary trees in their reachability-based analysis.

Keywords: marking vector, n-vector, petri nets, reachability

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Authors: Hyunsang Kim, Younghun Kim, Younghee Kim, Sangku Lee

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We investigated ecotoxicity and performed an experiment for removing ZnO nanoparticles in water. Short-term exposure of hatching test using fertilized eggs (O. latipes) showed deformity in 5 ppm of ZnO nanoparticles solution, and in 10ppm ZnO nanoparticles solution delayed hatching was observed. Herein, chemical precipitation method was suggested for removing ZnO nanoparticles in water. The precipitated ZnO nanoparticles showed the form of ZnS after addition of Na2S, and the form of Zn3(PO4)2 for Na2HPO4. The removal efficiency of ZnO nanoparticles in water was closed to 100% for two case. In ecotoxicity evaluation of as-precipitated ZnS and Zn3(PO4)2, they did not cause any acute toxicity for D. magna. It is noted that this precipitation treatment of ZnO is effective to reduce the potential cytotoxicity.

Keywords: ZnO nanopraticles, ZnS, Zn3(PO4)2, ecotoxicity evaluation, chemical precipitation

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Authors: Abiola Ayopo Abiodun, Zalihe Nalbantoglu

Abstract:

The electrokinetic application (EKA), a relatively modern chemical treatment has a potential for in-situ ground improvement in an open field or under existing structures. It utilizes a low electrical gradient to transport electrolytic chemical ions between bespoke electrodes inserted in the fine-grained, low permeable soft soils. The paper investigates the efficacy of the EKA as a mitigation technique for the soft clay beds. The laboratory model of the EKA comprises of rectangular plexiglass test tank, electrolytes compartments, geosynthetic electrodes and direct electric current supply. Within this setup, the EK effects resulted from the exchange of ions between anolyte (anodic) and catholyte (cathodic) ends through the tested soil were examined by basic experimental laboratory testing methods. As such, the treated soft soil properties were investigated as a function of the anode-to-cathode distances and curing periods. The test results showed that there have been some changes in the physical and engineering properties of the treated soft soils. The significant changes in the physicochemical and electrical properties suggested that their corresponding changes can be utilized as a monitoring technique to evaluate the improvement in the engineering properties EK treated soft clay soils.

Keywords: electrokinetic, electrolytes, exchange ions, geosynthetic electrodes, soft soils

Procedia PDF Downloads 293

Authors: A. Esra Pişkin, L. Yusuf Yivlik

Abstract:

Polyurethane consumption in the world increases every year. Polyetherpolyol, which is the main raw material of polyurethane, is produced from petroleum, and bioresources are needed in polyol production due to the damage it causes to the environment and the consumption of too much energy during the production phase. In this present work, bio polyol was synthesized with castor oil and soybean oil, and its use in rigid polyurethane systems was investigated. Transesterification and ring opening methods were applied for polyol synthesis, and the obtained bio polyols were compared with polyols derived petroleum. The goal of the present study was to synthesize biopolyols and to investigate the mechanical, thermal, and chemical properties of the synthesized polyurethane in terms of bio polyols.

Keywords: polyurethane, polyol, biopolyol, vegetable oil, foam, rigid polyurethane foam, ring opening, transesterification

Procedia PDF Downloads 445

Authors: Ahmed N. Shmroukh, I. M. S. Taha, A. M. Abdel-Ghany, M. Attalla

Abstract:

Fog systems application for cooling and humidification is still limited, although these systems require less initial cost compared with that of other cooling systems such as pad-and-fan systems. The undesirable relative humidity and air temperature inside the space which have been cooled or humidified are the main reasons for its limited use, which results from the poor control of fog systems. Any accurate control system essentially needs air dry bulb temperature as an input parameter. Therefore, the air dry-bulb temperature in the space needs to be measured accurately. The Scope of the present work is the separation of the fog droplets from the air in a fogged space to measure the air dry bulb temperature accurately. The separation is to be done in a small device inside which the sensor of the temperature measuring instrument is positioned. Vortex separator will be designed and used. Another reference device will be used for measuring the air temperature without separation. A comparative study will be performed to reach at the best device which leads to the most accurate measurement of air dry bulb temperature. The results showed that the proposed devices improved the measured air dry bulb temperature toward the correct direction over that of the free junction. Vortex device was the best. It respectively increased the temperature measured by the free junction in the range from around 2 to around 6°C for different fog on-off duration.

Keywords: fog systems, measuring air dry bulb temperature, temperature measurement, vortex separator

Procedia PDF Downloads 278

Authors: Saeed Chehri, Sirvan Moradi, Amin Rostami

Abstract:

Cooperative catalyst systems have been developed as highly promising sustainable alternatives to traditional catalysts. In these catalysts, two or more catalytic centers cooperate to reduce the energy of chemical transformations. In nature, such systems are abundantly seen in metalloenzymes that use metal and an organic cofactor. We have designed a reusable cooperative catalyst oxidation system consisting of palladium nanoparticles and polyoxometalate. This biomimetic cooperative catalytic system was synthesized by the stepwise immobilization of palladium nanoparticlesandpolyoxometalateinto the same cavity of siliceous mesocellularfoams (Pd-POM@MCF)and wascharacterizedby SEM, EDX, FT-IR, TGAand ICP techniques. POM-Pd@MCF/HQexhibits high activity toward aerobic oxidation of alcohols to the corresponding carbonyl compoundsin water solvent at room temperature. The major novelties and advantages of this oxidation method are as follows: (i) this is the first report of the co-immobilization of polyoxometalateand palladium for use as a robust and highlyefficient heterogeneouscooperative oxidative nanocatalyst system for aerobic oxidation of alcohols, (ii) oxidation of alcoholswere performed using an ideal oxidant with good to high yields in a green solvent at ambient temperature and (iii) the immobilization of the oxygen-activating catalyst(polyoxometalate) and oxidizing catalyst (Pd) onto MCF provide practical cooperative catalyst the system that can be reused several times without a significant loss of activity (vi) the methodsconform to several of the guiding principles of green chemistry.

Keywords: palladium nanoparticles, polyoxometalate, reusable cooperative catalytic system, biomimetic oxidation reaction

Procedia PDF Downloads 99