Search results for: particle removal efficiency

Authors: Nastaran Hazrati, Ali Akbar Miran Beigi, Majid Abdouss, Amir Vahid

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Hydrogen sulfide is the most toxic gas of crude oil. Adsorption is an energy-efficient process used to remove undesirable compounds such as H2S in gas or liquid streams by passing the stream through a media bed composed of an adsorbent. In this study, H2S of Iran crude oil was separated via cold stripping then zinc incorporated MCM-41 was synthesized via an in-situ method. ZnO functionalized mesoporous silica samples were characterized by XRD, N2 adsorption and TEM. The obtained results of adsorption of H2S showed superior ability of all the materials and with an increase in ZnO amount adsorption was increased.

Keywords: MCM-41, ZnO, H2S removal, adsorption

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Authors: Nastaran Soltani

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Heavy metals such as Mercury are toxic elements that enter the environment through different ways and endanger the environment, plants, animals, and humans’ health. Microbial activities reduce the amount of heavy metals. Therefore, an effective mechanism to eliminate heavy metals in the nature and factory slops, is using bacteria living in polluted areas. Karun River in Khuzestan Province in Iran has been always polluted by heavy metals as it is located among different industries in the region. This study was performed based on the data from sampling water and sediments of four stations across the river during the four seasons of a year. The isolation of resistant bacteria was performed through enrichment and direct cultivation in a solid medium containing mercury. Various bacteria such as Pseudomonas sp., Serratia Marcescens, and E.coli were identified as mercury-resistant bacteria. The power of these bacteria to remove mercury varied from 28% to 86%, with strongest power belonging to Pseudomonas sp. isolated in spring making a good candidate to be used for mercury biological removal from factory slops.

Keywords: bacteria, Karun River, mercury, biological removal, mercury-resistant

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Authors: Norhayati Mohd Rasip, Abd. Samad Hasan Basari , Nuzulha Khilwani Ibrahim, Burairah Hussin

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The allocation of working schedule especially for shift environment is hard to fulfill its fairness among them. In the case of nurse scheduling, to set up the working time table for them is time consuming and complicated, which consider many factors including rules, regulation and human factor. The scenario is more complicated since most nurses are women which have personnel constraints and maternity leave factors. The undesirable schedule can affect the nurse productivity, social life and the absenteeism can significantly as well affect patient's life. This paper aimed to enhance the scheduling process by utilizing the particle swarm optimization in order to solve nurse scheduling problem. The result shows that the generated multiple initial schedule is fulfilled the requirements and produces the lowest cost of constraint violation.

Keywords: nurse scheduling, particle swarm optimisation, nurse rostering, hard and soft constraint

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Authors: Ehsan Abdolzadeh, Sanaz Nouri, Siamak Khalaj

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Today WSNs have many applications in different fields like the environment, military operations, discoveries, monitoring operations, and so on. Coverage size and energy consumption are the important challenges that these networks need to face. This paper tries to solve the problem of coverage with a requirement of k-coverage and minimum energy consumption. In order to minimize energy consumption, visual sensor networks have been used that observe and process just those targets that are located in their view direction. As a result, sensor rotations have decreased, and subsequently, energy consumption has been minimized. To solve the problem of coverage particle swarm optimization, coverage optimization has been able to ensure coverage requirement together with minimizing sensor rotations while meeting the problem requirement of k≤14. So energy consumption has decreased, and this could extend the sensors’ lifetime subsequently.

Keywords: K coverage, particle union optimization algorithm, wireless sensor networks, visual sensor networks

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Authors: Liu De-jun, Fu Jing, Zhang Rong, Luo Tian, Ma Ning

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Cs-137, the radioactive fission products of uranium, can be easily dissolved in water during the accident of nuclear power plant, such as Chernobyl, Three Mile Island, Fukushima accidents. The concentration of Cs in the groundwater around the nuclear power plant exceeded the standard value almost 10,000 times after the Fukushima accident. The adsorption capacity of Titanate nano-materials for radioactive cation (Cs+) is very strong. Moreover, the radioactive ion can be tightly contained in the nanotubes or nanofibers without reversible adsorption, and it can safely be fixed. In addition, the nano-material has good chemical stability, thermal stability and mechanical stability to minimize the environmental impact of nuclear waste and waste volume. The preparation of titanate nanotubes or nanofibers was studied by hydrothermal methods, and chemical kinetics of removal of Cs by nano-materials was obtained. The adsorption time with maximum adsorption capacity and the effects of pH, coexisting ion concentration and the optimum adsorption conditions on the removal of Cs by titanate nano-materials were also obtained. The adsorption boundary curves, adsorption isotherm and the maximum adsorption capacity of Cs-137 as tracer on the nano-materials were studied in the research. The experimental results showed that the removal rate of Cs-137 in 0.01 tons of waste water with only 1 gram nano-materials could reach above 98%, according to the optimum adsorption conditions.

Keywords: preparation, titanate, cs-137, removal, nuclear

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Authors: Onur Yel

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This study represents the removal of harmful dye substances from wastewaters by using waste and cheap adsorbents. Rapid population growth and industrialization occasion anthropogenic pollution which gives irreversible damage to the environment. One of the ways in which water pollution occurs is caused by the release of the dyestuffs in the textile industry. The release of dyestuffs to the environment directly damages the living creatures that have acquired water habitat. Especially, wastewater cannot be used for nutritional purposes. In addition, some adsorbents have mutagenic and/or carcinogenic effects. By blocking photosynthesis, it hinders the inhibition of photosynthetic bacteria in the water, which damages the ecological balance and also causes the formation of malodorous compounds. Moreover, the lack of oxygen can pose a serious danger to the lives of other living organisms that need oxygen. In recent years, some physical and chemical methods are preferred for the removal of dyestuffs. However, the utilization of these methods is expensive. For this reason, the availability of new and cheap adsorbents becomes the more significant issue. In this study, an investigation of various variables on the removal of Methylene Blue and Acid Red-88 dyestuffs from wastewaters by the usage of pulverized cypress cones has been carried out. Thus, various masses of absorbent (0.1-0.25-0.5-1-2-4-5 grams) are used in 50, 100, 150, 200, 300 ppm concentrations of Methylene Blue and Acid Red-88 dyestuffs’ solutions, and with a variety of the interaction time (0.25-0.5-1-2-4-5 hours). The mixtures were centrifuged and the absorbance of the filtrates was measured on a UV spectrophotometer to determine their remaining concentrations. In the study, the highest removal ratio of Acid Red-88 dyestuff was found to be 81% at 200 ppm of dyestuff with 2 grams of adsorbent at 300 minutes. For Methylene Blue experiments, the removal percentage was found as 98% where 2 grams of adsorbent is used in 200 ppm dyestuff solution at 120 minutes of interaction.

Keywords: acid red-88, biosorption, methylene blue, cypress cones, water pollution

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Authors: Sania Ashraf

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The paper focuses on the prevalence of informational efficiency and integration of GCC Shariah Equity market for the period of 01st January 2010 to 31st June 2015 with daily equity returns of Kuwait, Oman, Qatar, Bahrain, Saudi Arabia and United Arab Emirates. The study employs traditional as well as the modern approach of tracing out the efficiency and integration in the return series. From the results of efficiency it was observed that the market lacked efficiency in terms of its past information. The results of integration test clearly indicates that there was a long memory in the returns of GCC Shariah during the study period. Hence it was concluded and proved that the returns of all GCC Equity Shariah were not informationally efficient but fractionally integrated during the study period.

Keywords: efficiency, Fama, GCC shariah, hurst exponent, integration, serial correlation

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Authors: Riham Hazzaa , Mohamed Hussien Abd El Megid

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Dyes are toxic and cause severe problems to aquatic environment. The use of agricultural solid wastes is considered as low-cost and eco-friendly adsorbents for removing dyes from waste water. Date palm fibre, an abundant agricultural by-product in Egypt was used to prepare activated carbon by physical activation method. This study investigates the use of date palm fiber (DPF) and activated carbon (DPFAC) for the removal of a basic dye, methylene blue (MB) from simulated waste water. The effects of temperature, pH of solution, initial dye (concentration, adsorbent dosage and contact time were studied. The experimental equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Dubinin, Radushkevich and Harkins–Jura isotherms. Adsorption kinetics data were modeled using the pseudo-first and pseudo-second order and Elvoich equations. The mechanism of the adsorption process was determined from the intraparticle diffusion model. The results revealed that as the initial dye concentration , amount of adsorbent and temperature increased, the percentage of dye removal increased. The optimum pH required for maximum removal was found to be 6. The adsorption of methylene blue dye was better described by the pseudo-second-order equation. Results indicated that DPFAC and DPF could be an alternative for more costly adsorbents used for dye removal.

Keywords: adsorption, basic dye, palm fiber, activated carbon

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Authors: Nima Khosravi

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This paper describes an integrated optimization technique with concurrent use of sequential quadratic programming, genetic algorithm, and simulated annealing particle swarm optimization for the design and optimization of a beam column. In this research, the comparison between 4 different types of optimization methods. The comparison is done and it is found out that all the methods meet the required constraints and the lowest value of the objective function is achieved by SQP, which was also the fastest optimizer to produce the results. SQP is a gradient based optimizer hence its results are usually the same after every run. The only thing which affects the results is the initial conditions given. The initial conditions given in the various test run were very large as compared. Hence, the value converged at a different point. Rest of the methods is a heuristic method which provides different values for different runs even if every parameter is kept constant.

Keywords: beam column, genetic algorithm, particle swarm optimization, sequential quadratic programming, simulated annealing

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Authors: Phanindra Prasad Thummala, Umran Tezcan Un

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In this study, hydrodynamics analysis of two batch type electrocoagulation stirred tank reactors, used for the electrocoagulation treatment of Cr(VI) wastewater, was carried using computational fluid dynamics (CFD). The aim of the study was to evaluate the impact of mixing characteristics on overall performance of electrocoagulation reactor. The CFD simulations were performed using ANSYS FLUENT 14.4 software. The mixing performance of each reactor was evaluated by numerically modelling tracer dispersion in each reactor configuration. The uniformity in tracer dispersion was assumed when 90% of the ratio of the maximum to minimum concentration of the tracer was realized. In parallel, experimental evaluation of both the electrocoagulation reactors for removal of Cr(VI) from wastewater was also carried out. The results of CFD and experimental analysis clearly show that the reactor which can give higher uniformity in lesser time, will perform better as an electrocoagulation reactor for removal of Cr(VI) from wastewater.

Keywords: CFD, stirred tank reactors, electrocoagulation, Cr(VI) wastewater

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Authors: Zahra Akbari, Farzin Zokaee, Talat Ghomashchi

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Whey is a by-product of the dairy industry whose major components are lactose (44–52 g/L), proteins (6–8 g/L) and mineral salts (4–9 g/L). Approximately 50% of 121 million tons of whey produced in the world in 1993 were disposed into rivers, lakes or other water bodies, treated in wastewater treatment plants or loaded onto land. This represents a significant loss of resources and causes serious pollution problems since whey is a heavy organic pollutant with high COD and BOD values, 40–60 g/L and 50–80 g/L, respectively. The removal of cheese whey proteins and minerals represent an important task both in environmental and in food sciences. The most important treatments which are considered in this study, have been done by using lime, Al2O3, FeCl3 and AlCl3 along with heating and also acidic-alkaline method. Results show that the best way for removal of protein is accomplished with adding HCl to decrease pH from 6 to 4, boiling for 20 min, and filtering protein aggregates. Also partial demineralization in whey solution for reducing ash is accomplished by adding NaOH to increase pH to 7.2 and heating solution for 20 min.

Keywords: whey treatment, dairy industry, precipitation, protein, mineral

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Authors: Himanshu Shekhar Maharana, S. K .Dash

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Economic Load Dispatch (ELD) proves to be a vital optimization process in electric power system for allocating generation amongst various units to compute the cost of generation, the cost of emission involving global warming gases like sulphur dioxide, nitrous oxide and carbon monoxide etc. In this dissertation, we emphasize ramp rate constriction factor based particle swarm optimization (RRCPSO) for analyzing various performance objectives, namely cost of generation, cost of emission, and a dual objective function involving both these objectives through the experimental simulated results. A 6-unit 30 bus IEEE test case system has been utilized for simulating the results involving improved weight factor advanced ramp rate limit constraints for optimizing total cost of generation and emission. This method increases the tendency of particles to venture into the solution space to ameliorate their convergence rates. Earlier works through dispersed PSO (DPSO) and constriction factor based PSO (CPSO) give rise to comparatively higher computational time and less good optimal solution at par with current dissertation. This paper deals with ramp rate and constriction factor based well defined ramp rate PSO to compute various objectives namely cost, emission and total objective etc. and compares the result with DPSO and weight improved PSO (WIPSO) techniques illustrating lesser computational time and better optimal solution. 

Keywords: economic load dispatch (ELD), constriction factor based particle swarm optimization (CPSO), dispersed particle swarm optimization (DPSO), weight improved particle swarm optimization (WIPSO), ramp rate and constriction factor based particle swarm optimization (RRCPSO)

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Authors: Victor R. Thulari, John Akach, Haleden Chiririwa, Aoyi Ochieng

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Solar-light activated titanium dioxide photocatalysts were prepared by hydrolysis of titanium (IV) isopropoxide with thiourea, followed by calcinations at 450 °C. The experiments demonstrated that methyl orange in aqueous solutions were successfully degraded under solar light using doped TiO₂. The photocatalytic oxidation of a mono azo methyl-orange dye has been investigated in multi ion doped TiO₂ and solar light. Solutions were irradiated by solar-light until high removal was achieved. It was found that there was no degradation of methyl orange in the dark and in the absence of TiO₂. Varieties of laboratory prepared TiO₂ catalysts both un-doped and doped using titanium (IV) isopropoxide and thiourea as a dopant were tested in order to compare their photoreactivity. As a result, it was found that the efficiency of the process strongly depends on the working conditions. The highest degradation rate of methyl orange was obtained at optimum dosage using commercially produced TiO₂. Our work focused on laboratory synthesized catalyst and the maximum methyl orange removal was achieved at 81% with catalyst loading of 0.04 g/L, initial pH of 3 and methyl orange concentration of 0.005 g/L using multi-ion doped catalyst. The kinetics of photocatalytic methyl orange dye stuff degradation was found to follow a pseudo-first-order rate law. The presence of the multi-ion dopant (thiourea) enhanced the photoefficiency of the titanium dioxide catalyst.

Keywords: degradation, kinetics, methyl orange, photocatalysis

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Authors: Onur Karaman, Ceren Karaman

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In this study, the adsorption of Methylene Blue (MB), a cationic dye, onto Orange Peel Derived Activated Carbon (OPAC) and chitosan(OPAC/Chitosan composite) composite (a low-cost absorbent) was carried out using a batch system. The composite was characterised using IR spectra, XRD, FESEM and Pore size studies. The effects of initial pH, adsorbent dose rate and initial dye concentration on the initial adsorption rate, capacity and dye removal efficiency were investigated. The Langmuir and Freundlich adsorption models were used to define the adsorption equilibrium of dye-adsorbent system mathematically and it was decided that the Langmuir model was more suitable to describe the adsorption equilibrium for the system. In addition, first order, second order and saturation type kinetic models were applied to kinetic data of adsorption and kinetic constants were calculated. It was concluded that the second order and the saturation type kinetic models defined the adsorption data more accurately. Finally, the evaluated thermodynamic parameters of adsorption show a spontaneous and exothermic behavior. Overall, this study indicates OPAC/Chitosan composite as an effective and low-cost adsorbent for the removal of MB dye from aqueous solutions.

Keywords: activated carbon, adsorption, chitosan, methylene blue, orange peel

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Authors: Yaniv Knop, Alva Peled

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Over the past few years there has been a growing interest in the development of Portland Composite Cement, by partial replacement of the clinker with mineral additives. The motivations to reduce the clinker content are threefold: (1) Ecological - due to lower emission of CO2 to the atmosphere; (2) Economical - due to cost reduction; and (3) Scientific\Technology – improvement of performances. Among the mineral additives being used and investigated, limestone is one of the most attractive, as it is considered natural, available, and with low cost. The goal of the research is to develop green cement, by partial replacement of the clinker with limestone powder while improving the performances of the cement paste. This work studied blended cements with three limestone powder particle diameters: smaller than, larger than, and similarly sized to the clinker particle. Blended cement with limestone consisting of one particle size distribution and limestone consisting of a combination of several particle sizes were studied and compared in terms of hydration rate, hydration degree, and water demand to achieve normal consistency. The performances of these systems were also compared with that of the original cement (without added limestone). It was found that the ability to replace an active material with an inert additive, while achieving improved performances, can be obtained by increasing the packing density of the cement-based particles. This may be achieved by replacing the clinker with limestone powders having a combination of several different particle size distributions. Mathematical and physical models were developed to simulate the setting history from initial to final setting time and to predict the packing density of blended cement with limestone having different sizes and various contents. Besides the effect of limestone, as inert additive, on the packing density of the blended cement, the influence of the limestone particle size on three different chemical reactions were studied; hydration of the cement, carbonation of the calcium hydroxide and the reactivity of the limestone with the hydration reaction products. The main results and developments will be presented.

Keywords: packing density, hydration degree, limestone, blended cement

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Authors: Ildiko Fekete-Kertesz, Jade Chaker, Sylvain Berthelot, Viktoria Feigl, Monika Molnar, Lidia Favier

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There has been growing concern about emerging micropollutants in recent years, because of the possible environmental and health risk posed by these substances, which are released into the environment as a consequence of anthropogenic activities. Among them pharmaceuticals are currently not considered under water quality regulations; however, their potential effect on the environment have become more frequent in recent years. Due to the fact that these compounds can be detected in natural water matrices, it can be concluded, that the currently applied water treatment processes are not efficient enough for their effective elimination. To date, advanced oxidation processes (AOPs) are considered as highly competitive water treatment technologies for the removal of those organic micropollutants not treatable by conventional techniques due to their high chemical stability and/or low biodegradability. AOPs such as (photo)chemical oxidation and heterogeneous photocatalysis have proven their potential in degrading harmful organic compounds from aqueous matrices. However, some of these technologies generate reaction by-products, which can even be more toxic to aquatic organisms than the parent compounds. Thus, target compound removal does not necessarily result in the removal of toxicity. Therefore, to evaluate process efficiency the determination of the toxicity and ecotoxicity of the reaction intermediates is crucial to estimate the environmental risk of such techniques. In this context, the present study investigates the effectiveness of TiO2 assisted photodegradation for the removal of emerging water contaminants. Two drugs named losartan (used in high blood pressure medication) and levetiracetam (used to treat epilepsy) were considered in this work. The photocatalytic reactions were carried out with a commercial catalyst usually employed in photocatalysis. Moreover, the toxicity of the by-products generated during the process was assessed with various ecotoxicological methods applying aquatic test organisms from different trophic levels. A series of experiments were performed to evaluate the toxicity of untreated and treated solutions applying the Aliivibrio fischeri bioluminescence inhibition test, the Tetrahymena pyriformis proliferation inhibition test, the Daphnia magna lethality and immobilization tests and the Lemna minor growth inhibition test. The applied ecotoxicological methodology indicated sensitively the toxic effects of the treated and untreated water samples, hence the applied test battery is suitable for the ecotoxicological characterization of TiO2 based photocatalytic water treatment technologies and the indication of the formation of toxic by-products from the parent chemical compounds. Obtained results clearly showed that the TiO2 assisted photodegradation was more efficient in the elimination of losartan than levetiracetam. It was also observed that the treated levetiracetam solutions had more severe effect on the applied test organisms. A possible explanation would be the production of levetiracetam by-products, which are more toxic than the parent compound. The increased toxicity and the risk of formation of toxic metabolites represent one possible limitation to the implementation of photocatalytic treatment using TiO2 for the removal of losartan and levetiracetam. Our results proved that, the battery of ecotoxicity tests used in this work can be a promising investigation tool for the environmental risk assessment of photocatalytic processes.

Keywords: aquatic micropollutants, ecotoxicology, nano titanium dioxide, photocatalysis, water treatment

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Authors: Maja Benkovic, Dubravka Novotni, Bojana Voucko, Duska Curic, Damir Jezek, Nikolina Cukelj

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Cryo-grinding is an ultra-fine grinding method used in the pharmaceutical industry, production of herbs and spices and in the production and handling of cereals, due to its ability to produce powders with small particle sizes which maintain their favorable bioactive profile. The aim of this study was to determine the particle size distributions of the proso millet (Panicum miliaceum) bran fraction grinded at cryogenic temperature (using liquid nitrogen (LN₂) cooling, T = - 196 °C), in comparison to non-cooled grinding. Proso millet bran is primarily used as an animal feed, but has a potential in food applications, either as a substrate for extraction of bioactive compounds or raw material in the bakery industry. For both applications finer particle sizes of the bran could be beneficial. Thus, millet bran was ground for 2, 4, 8 and 12 minutes using the ball mill (CryoMill, Retsch GmbH, Haan, Germany) at three grinding modes: (I) without cooling, (II) at cryo-temperature, and (III) at cryo-temperature with included 1 minute of intermediate cryo-cooling step after every 2 minutes of grinding, which is usually applied when samples require longer grinding times. The sample was placed in a 50 mL stainless steel jar containing one grinding ball (Ø 25 mm). The oscillation frequency in all three modes was 30 Hz. Particle size distributions of the bran were determined by a laser diffraction particle sizing method (Mastersizer 2000) using the Scirocco 2000 dry dispersion unit (Malvern Instruments, Malvern, UK). Three main effects of the grinding set-up were visible from the results. Firstly, grinding time at all three modes had a significant effect on all particle size parameters: d(0.1), d(0.5), d(0.9), D[3,2], D[4,3], span and specific surface area. Longer grinding times resulted in lower values of the above-listed parameters, e.g. the averaged d(0.5) of the sample (229.57±1.46 µm) dropped to 51.29±1.28 µm after 2 minutes grinding without LN₂, and additionally to 43.00±1.33 µm after 4 minutes of grinding without LN₂. The only exception was the sample ground for 12 minutes without cooling, where an increase in particle diameters occurred (d(0.5)=62.85±2.20 µm), probably due to particles adhering to one another and forming larger particle clusters. Secondly, samples with LN₂ cooling exhibited lower diameters in comparison to non-cooled. For example, after 8 minutes of non-cooled grinding d(0.5)=46.97±1.05 µm was achieved, while the LN₂ cooling enabled collection of particles with average sizes of d(0.5)=18.57±0.18 µm. Thirdly, the application of intermediate cryo-cooling step resulted in similar particle diameters (d(0.5)=15.83±0.36 µm, 12 min of grinding) as cryo-milling without this step (d(0.5)=16.33±2.09 µm, 12 min of grinding). This indicates that intermediate cooling is not necessary for the current application, which consequently reduces the consumption of LN₂. These results point out the potential beneficial effects of millet bran grinding at cryo-temperatures. Further research will show if the lower particle size achieved in comparison to non-cooled grinding could result in increased bioavailability of bioactive compounds, as well as protein digestibility and solubility of dietary fibers of the proso millet bran fraction.

Keywords: ball mill, cryo-milling, particle size distribution, proso millet (Panicum miliaceum) bran

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Authors: Abhijeet Kumar, Palaniswamy N. K.

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Heavy metal contamination in water sources endangers both the environment and human health. Various water filtration techniques have been employed till now for purification and removal of hazardous metals from water. Among all the existing methods, nanofibres have emerged as a viable alternative for effective heavy metal removal in recent years because of their unique qualities, such as large surface area, interconnected porous structure, and customizable surface chemistry. Among the numerous manufacturing techniques, solution blow spinning has gained popularity as a versatile process for producing nanofibers with customized properties. This paper seeks to offer a complete overview of the use of nanofibers for heavy metal filtration, particularly those produced using solution blow spinning. The review discusses current advances in nanofiber materials, production processes, and heavy metal removal performance. Furthermore, the field's difficulties and future opportunities are examined in order to direct future research and development activities.

Keywords: heavy metals, nanofiber composite, filter membranes, adsorption, impaction

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Authors: M. Jerold, V. Sivasubramanian

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In this study, nano zero valent iron Sargassum swartzii (nZVI-SS) biocomposite a marine algal based biosorbent was used for the removal of simulated crystal violet (CV) in batch and continuous fixed bed operation. The Box-Behnen design (BBD) experimental results revealed the biosoprtion was maximum at pH 7.5, biosorbent dosage 0.1 g/L and initial CV concentration of 100 mg/L. The effect of various column parameters like bed depth (3, 6 and 9 cm), flow rate (5, 10 and 15 mL/min) and influent CV concentration (5, 10 and 15 mg/L) were investigated. The exhaustion time increased with increase of bed depth, influent CV concentration and decrease of flow rate. Adam-Bohart, Thomas and Yoon-Nelson models were used to predict the breakthrough curve and to evaluate the model parameters. Out of these models, Thomas and Yoon-Nelson models well described the experimental data. Therefore, the result implies that nZVI-SS biocomposite is a cheap and most promising biosorbent for the removal of CV from wastewater.

Keywords: algae, biosorption, zero-valent, dye, wastewater

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Authors: R. Z. Wang, B. C. Lin, C. H. Huang

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This study proposes a new method to simulate the crack propagation under mode-I loading using Vector Form Intrinsic Finite Element (VFIFE) method. A new idea which is expected to combine both VFIFE and J-integral is proposed to calculate the stress density factor as the crack critical in elastic crack. The procedure of implement the cohesive crack propagation in VFIFE based on the fictitious crack model is also proposed. In VFIFIE, the structure deformation is described by numbers of particles instead of elements. The strain energy density and the derivatives of the displacement vector of every particle is introduced to calculate the J-integral as the integral path is discrete by particles. The particle on the crack tip separated into two particles once the stress on the crack tip satisfied with the crack critical and then the crack tip propagates to the next particle. The internal force and the cohesive force is applied to the particles.

Keywords: VFIFE, crack propagation, fictitious crack model, crack critical

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Authors: Pritam Kumar Ghosh

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The phenomenon of inter-country parental child removal and the protection of children against removal from lawful custody by their own parents has been a major issue over the last five decades. This occurs when parents take away their children during pending divorce and custody proceedings or in violation of pre-existing foreign or Indian custody orders through which they may have obtained visitation rights only after divorce but not permanent custody. Even though considerable efforts have been made by the Indian judiciary to resolve the issue, a lot is still left to be desired. A study of the spate of judicial decisions on the issue since 1970 reveals that judges have attempted to resolve the issue mainly through the application of the existing personal law regime and the principle of the best interest of the child. This has made the position of law extremely confusing. The existing precedential jurisprudence contains a wide variety of custody orders in the name of enforcement of the paramount consideration of the best interest and welfare of children. The problem is aggravated by the fact that India has decided not to accede to the Hague Abduction Convention of 1980, which is the main international instrument combating the issue. In this context, the paper discusses the reasons behind the rising instances of inter-country parental child removals. It then goes on to analyze the existing jurisprudence of international child custody disputes in India, which have come before courts post-removal of children from lawful custody. The paper concludes by suggesting essential reforms in the existing Indian legal framework governing the issue. In the process, the paper proposes new legislation for India governing inter-country parental child removals and subsequent custody disputes. The possible structure and content of this new law shall also be outlined as a part of the paper.

Keywords: custody, dispute, child removal, Hague convention

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Authors: Khomkrit Mongkhuntod, Chatchawal Chaichana, Atipoang Nuntaphan

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Feed Water Heater is the important equipment for thermal power plant. The heating temperature from feed heating process is an impact to power plant efficiency or heat rate. Normally, the degradation of feed water heater that operated for a long time is effect to decrease plant efficiency or increase plant heat rate. For Mae Moh power plant, each unit operated more than 20 years. The degradation of the main equipment is effect of planting efficiency or heat rate. From the efficiency and heat rate analysis, Mae Moh power plant operated in high heat rate more than the commissioning period. Some of the equipment were replaced for improving plant efficiency and plant heat rates such as HP turbine and LP turbine that the result is increased plant efficiency by 5% and decrease plant heat rate by 1%. For the target of power generation plan that Mae Moh power plant must be operated more than 10 years. These work is focus on thermal efficiency analysis of feed water heater to compare with the commissioning data for find the way to improve the feed water heater efficiency that may effect to increase plant efficiency or decrease plant heat rate by use heat balance model simulation and economic value add (EVA) method to study the investment for replacing the new feed water heater and analyze how this project can stay above the break-even point to make the project decision.

Keywords: feed water heater, power plant efficiency, plant heat rate, thermal efficiency analysis

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Authors: Zhankun Wang, Timothy Makubuya

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The efficiency of public sports service of prefecture-level cities in Zhejiang from 2008 to 2012 was evaluated by applying the DEA method, then its influencing factors were also analyzed through Tobit model. Upon analysis, the results revealed the following; (i) the change in average efficiency of public sports service in Zhejiang present a smooth uptrend and at a relatively high level from 2008 to 2012 (ii) generally, the productivity of public sports service in Zhejiang improved from 2008 to 2012, the productivity efficiency varied greatly in different years, and the regional difference of production efficiency increased. (iii) The correlations for urbanization rate, aging rate, per capita GDP and the population density were significantly positive with the public sports service efficiency in Zhejiang, of which the most significant was the aging rate. However, the population density and per capita GDP had less impact on the efficiency of public sports service in Zhejiang. In addition, whether the efficiency of public sports services in different areas in Zhejiang reciprocates to overall benefits in public wellbeing in both rural and urban settings is still arguable.

Keywords: DEA model, public sports service, efficiency, Tobit model, Malmquist productivity index, Zhejiang

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Authors: L. Khalfa, M. Bagane, M. L. Cervera, S. Najjar

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The aim of this work is to present a low cost adsorbent for removing toxic heavy metals from aqueous solutions. Therefore, we are interested to investigate the efficiency of natural clay minerals collected from south Tunisia and their modified form using sulfuric acid in the removal of toxic metal ions: Zn(II) and Pb(II) from synthetic waste water solutions. The obtained results indicate that metal uptake is pH-dependent and maximum removal was detected to occur at pH 6. Adsorption equilibrium is very rapid and it was achieved after 90 min for both metal ions studied. The kinetics results show that the pseudo-second-order model describes the adsorption and the intraparticle diffusion models are the limiting step. The treatment of natural clay with sulfuric acid creates more active sites and increases the surface area, so it showed an increase of the adsorbed quantities of lead and zinc in single and binary systems. The competitive adsorption study showed that the uptake of lead was inhibited in the presence of 10 mg/L of zinc. An antagonistic binary adsorption mechanism was observed. These results revealed that clay is an effective natural material for removing lead and zinc in single and binary systems from aqueous solution.

Keywords: heavy metal, activated clay, kinetic study, competitive adsorption, modeling

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Authors: Sirus Mohammadi, Rohala Moghimi

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The main advantages of microgrids are high energy efficiency through the application of Combined Heat and Power (CHP), high quality and reliability of the delivered electric energy and environmental and economic advantages. This study presents an energy management system (EMS) to optimize the operation of the microgrid (MG). In this paper an Adaptive Modified Firefly Algorithm (AMFA) is presented for optimal operation of a typical MG with renewable energy sources (RESs) accompanied by a back-up Micro-Turbine/Fuel Cell/Battery hybrid power source to level the power mismatch or to store the energy surplus when it’s needed. The problem is formulated as a nonlinear constraint problem to minimize the total operating cost. The management of Energy storage system (ESS), economic load dispatch and operation optimization of distributed generation (DG) are simplified into a single-object optimization problem in the EMS. The proposed algorithm is tested on a typical grid-connected MG including WT/PV/Micro Turbine/Fuel Cell and Energy Storage Devices (ESDs) then its superior performance is compared with those from other evolutionary algorithms such as Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Fuzzy Self Adaptive PSO (FSAPSO), Chaotic Particle PSO (CPSO), Adaptive Modified PSO (AMPSO), and Firefly Algorithm (FA).

Keywords: microgrid, operation management, optimization, firefly algorithm (AMFA)

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Authors: Mefteh Bouhalleb

Abstract:

With the recent progress in nanotechnology, nanofluids have excellent potentiality in many modern engineering processes, particularly for solar systems such as concentrated solar power plants (CSP). In this context, a numerical simulation is performed to investigate laminar natural convection nanofluids in an inclined rectangular enclosure. Mass conservation, momentum, and energy equations are numerically solved by the finite volume element method using the SIMPLER algorithm for pressure-velocity coupling. In this work, we tested the acting factors on the system response time, such as the particle volume fraction of nanoparticles, particle material, particle size, an inclination angle of enclosure and Rayleigh number. The results show that the diameter of solid particles and Rayleigh number plays an important role in the system response time. The orientation angle of the cavity affects the system response time. A phenomenon of hysteresis appears when the system does not return to its initial state.

Keywords: nanofluid, nanoparticles, heat transfer, time response

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Authors: Inba Blesso P., Senthil Kumar P.

Abstract:

The main consideration of any tire manufacturing process is wear resistance. One of the factors that cause tire wear is improper removal of vent and flash from the tire surface. The contact point between tyre surface and vent is highly supposed to wear. When the vehicle running at higher speed with heavy load, the tire vent and flash is wearing initially and it makes few of the tire surface material to wear along with it. Hence, provision must be given to efficient removal vent and flash thereby tire wear. Human efforts in trimming of tire vent results in time consuming and inaccurate output. Hence, this lead to the reduction in production rate and profit. Thus, the development of automated system can helps to attain minimum time consumption and provide a possible way to get the profitable production. Semi-automated system that employs Pneumatic actuators and sequencing circuits are focused in this study. By implementing this, one can achieve the accurate results with reduction in time and profitable output.

Keywords: tire manufacturing, pneumatic system, vent and flash removal, engineering and technology

Procedia PDF Downloads 381

Authors: Md. Z. Alam, Amal A. Elgharbawy, Muhammad Moniruzzaman, Nassereldeen A. Kabbashi, Parveen Jamal

Abstract:

The enzymatic hydrolysis of lignocellulosic biomass is one of the obstacles in the process of sugar production, due to the presence of lignin that protects the cellulose molecules against cellulases. Although the pretreatment of lignocellulose in ionic liquid (IL) system has been receiving a lot of interest; however, it requires IL removal with an anti-solvent in order to proceed with the enzymatic hydrolysis. At this point, introducing a compatible cellulase enzyme seems more efficient in this process. A cellulase enzyme that was produced by Trichoderma reesei on palm kernel cake (PKC) exhibited a promising stability in several ILs. The enzyme called PKC-Cel was tested for its optimum pH and temperature as well as its molecular weight. One among evaluated ILs, 1,3-diethylimidazolium dimethyl phosphate [DEMIM] DMP was applied in this study. Evaluation of six factors was executed in Stat-Ease Design Expert V.9, definitive screening design, which are IL/ buffer ratio, temperature, hydrolysis retention time, biomass loading, cellulase loading and empty fruit bunches (EFB) particle size. According to the obtained data, IL-enzyme system shows the highest sugar concentration at 70 °C, 27 hours, 10% IL-buffer, 35% biomass loading, 60 Units/g cellulase and 200 μm particle size. As concluded from the obtained data, not only the PKC-Cel was stable in the presence of the IL, also it was actually stable at a higher temperature than its optimum one. The reducing sugar obtained was 53.468±4.58 g/L which was equivalent to 0.3055 g reducing sugar/g EFB. This approach opens an insight for more studies in order to understand the actual effect of ILs on cellulases and their interactions in the aqueous system. It could also benefit in an efficient production of bioethanol from lignocellulosic biomass.

Keywords: cellulase, hydrolysis, lignocellulose, pretreatment

Procedia PDF Downloads 365

Authors: M. Berrehail, F. Benamira

Abstract:

We study the quantum motion of a particle in the presence of a time- dependent linear potential using an operator invariant that is quadratic in p and linear in q within the framework of the Lewis-Riesenfeld invariant, The special invariant operator proposed in this work is demonstrated to be an Hermitian operator which has an Airy wave packet as its Eigenfunction

Keywords: airy wave packet, ivariant, time-dependent linear potential, unitary transformation

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Authors: Bahram Fathi, Seyedhossein Sajadifar, Naser Khiabani

Abstract:

Data envelopment analysis (DEA) has recently gained popularity in energy efficiency analysis. A common feature of the previously proposed DEA models for measuring energy efficiency performance is that they treat energy consumption as an input within a production framework without considering undesirable outputs. However, energy use results in the generation of undesirable outputs as byproducts of producing desirable outputs. Within a joint production framework of both desirable and undesirable outputs, this paper presents several DEA-type linear programming models for measuring energy efficiency performance. In addition to considering undesirable outputs, our models treat different energy sources as different inputs so that changes in energy mix could be accounted for in evaluating energy efficiency. The proposed models are applied to measure the energy efficiency performances of 12 OPEC countries and the results obtained are presented.

Keywords: energy efficiency, undesirable outputs, data envelopment analysis

Procedia PDF Downloads 736