C. Xin-Hui Su; T. Tow Teng; N. Morad; M. Rafatullah
Abstract
A novel inorganic-organic hybrid polymer of magnesium chloride-polyethylene oxide (MgCl2-PEO) was prepared, characterised and applied in the coagulation-flocculation of a reactive dye, Cibacron Blue F3GA (RCB). The hybrid polymers were prepared in various ratios and their conductivity and viscosities ...
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A novel inorganic-organic hybrid polymer of magnesium chloride-polyethylene oxide (MgCl2-PEO) was prepared, characterised and applied in the coagulation-flocculation of a reactive dye, Cibacron Blue F3GA (RCB). The hybrid polymers were prepared in various ratios and their conductivity and viscosities were measured. For the application in the coagulation-flocculation of RCB, the hybrid polymer of 90% MgCl2:10% PEO ratio was selected as it showed the highest conductivity and lowest viscosity. The factors that affect coagulation-flocculation of RCB, namely initial dye concentration, initial pH, agitation speed, agitation time and hybrid polymer dosage, were studied using fractional factorial design and response surface methodology (RSM). The process was also optimised, with respect to colour removal and chemical oxygen demand (COD) reduction efficiency. The five factors studied showed significant effects toward the colour removal and COD reduction of RCB. The process was optimum at initial dye concentration of 173 mg/L, pH 11.13, agitation speed of 150 rpm, agitation time of 6 minutes and hybrid polymer dosage of 1020 mg/L. Under these optimum conditions, maximum colour removal of 99.76% and COD reduction of 92.09%, were achieved.
S. Jain; U. Chandrawat
Abstract
Nickel titanium oxide (NiTiO3) nanoparticles were synthesized at low temperature in non aqueous medium by modified Pechini method using ethylene glycol and citric acid as polymeric precursors. The structural and morphological characteristics of the products were studied by X-ray diffraction, fourier ...
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Nickel titanium oxide (NiTiO3) nanoparticles were synthesized at low temperature in non aqueous medium by modified Pechini method using ethylene glycol and citric acid as polymeric precursors. The structural and morphological characteristics of the products were studied by X-ray diffraction, fourier transform infrared spectroscopy (FT-IR), UV-Visible diffuse reflectance spectroscopy (UV-DRS), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDAX). XRD patterns of powder revealed crystalline rhombohedral NiTiO3 obtained at 700 o C and this crystalinity increased with temperature. SEM images estimated that the grain sizes of NiTiO3 to be in the range 10–250 nm. DRS spectra reveal two peaks, one at around 440-450 nm and another one at around 740-750 nm. The band gap energy was calculated using Tauc plot and it was found to be 1.67 eV. In this study, photocatalytic properties of NiTiO3 on sulfamethoxazole drug degradation was investigated which has not been reported elsewhere and results shows that it is a prominent material for photodegradation of drug in the range of visible light.
T. Mumladze; M. Tatariants; A. Rimšaitė; S. Yousef; G. Denafas
Abstract
Multilayer Packaging wastes are one of the major problem in the world. About 6 billion tons of packages are generated per year in the world (in EU is about 82 million tons per year). Multilayer packaging foils are approximately 17% of all produced packaging films. Most produced multilayer film is based ...
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Multilayer Packaging wastes are one of the major problem in the world. About 6 billion tons of packages are generated per year in the world (in EU is about 82 million tons per year). Multilayer packaging foils are approximately 17% of all produced packaging films. Most produced multilayer film is based on different polymers, such as: polyethylene terephthalate (PET), polypropylene (PP), and polyethylene (PE) as main components, and an aluminum layer. However, because of their poor recyclability, most multi layers are usually incinerated or landfill, this is counteracting the efforts towards a circular economy. There are different recycling methods for this type of waste, but the main problem is that there is less company which recycling multilayer packaging foils. Also, it is very important that, mostly they recovering only one or two components and others are burned or landfilled. The aim of this research was to find the most suitable solvent for recycling multilayer packaging foils and recover two common components: polymer and Al foil. For the first experiment, there was chosen multilayer packaging foil’s different samples, such as: packaging for chocolate, chips, medicines and coffee. There was used several chemicals: acetic acid, acetone, dimethyl formamide, ethanol, ethyl acetate and toluene. These solvents are on the list of green chemicals and they were selected, due to their less impact on environment and human health. The recycling process and result was different for each samples and solvents, because of their individual characteristics.
Energy
M. Bagheri; I. Mirzaee; M. Khalilian; V. Mousapour
Abstract
The present study simulates Invelox in a three-dimensional and stable way. The flow regime is turbulent flow and an unorganized grid with 350000 cells was utilized. This work has studied the modeling of invelox with conventional dimensions and four different sizes in the form of four modes for use in ...
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The present study simulates Invelox in a three-dimensional and stable way. The flow regime is turbulent flow and an unorganized grid with 350000 cells was utilized. This work has studied the modeling of invelox with conventional dimensions and four different sizes in the form of four modes for use in a residential building. The numerical data with an error of less than 6% are in good agreement with the available experimental and analytical data. The results show that considering the average velocity of mode 2 with a velocity of 6.54 m/s and a 5% difference from the other two modes, it can be operated in a residential building. It is worth noting that in this investigation, in addition, the effect of dust on the turbine performance was evaluated. The results represent that the oscillation frequency of the blades increases with the increase of the rotational speed. In the case of not considering dust particles on blades, this amount increases by 25%, while considering dust particles with an amount of 0.1%, it increases up to 300%, and this can cause irreparable damage to the turbine as well as the power generation system.
G. Anju; B. Subha; M. Muthukumar; T. Sangeetha
Abstract
A treatment method based on the degradation of sago processing wastewater using ozonation process was conducted in this research study. The optimization of the process variables was designed with the aid of software called Design Expert and the technique was called response surface methodology (RSM) ...
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A treatment method based on the degradation of sago processing wastewater using ozonation process was conducted in this research study. The optimization of the process variables was designed with the aid of software called Design Expert and the technique was called response surface methodology (RSM) in Central composite design. The effect of ozonation variables like pH, treatment time and ozone concentration on the reduction of chemical oxygen demand (COD) of sago waste water was investigated. Interestingly, two different types of results like maximum removal of COD and optimum removal of COD were observed. Maximum COD removal of 62.45% was at pH 9.8, ozonation time 95.7 min, ozone dose 42% and optimum COD removal 0f 56.7% was at pH 9.8, ozonation time 35.7 min, and ozone dose 42%. Bacterial count was found to be nil after ozonation and microscopic observation of biomass proved that the sludge content had effectively reduced after ozonation treatment. It was determined that the ozonation of sago wastewater was a promising effort in wastewater treatment.
A. A. Abbood Al-Khazzar
Abstract
In this study, PVsyst simulation software is used to analyze a PV grid tied system in a typical primary school in Iraq. The proposed system is 5kW which is affordable and applicable from the cost and required area points respectively. The monthly averaged electrical load for a typical school is approximately ...
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In this study, PVsyst simulation software is used to analyze a PV grid tied system in a typical primary school in Iraq. The proposed system is 5kW which is affordable and applicable from the cost and required area points respectively. The monthly averaged electrical load for a typical school is approximately calculated. The system simulation has been done for thirteen Iraqi provinces while it is described and its performance is analyzed in details for Baghdad city as an example. The performance ratio for the system in Baghdad is 0.825 and about 9.82MWhr is generated by the system per year, 62.7% is consumed by the load and the remaining is injected to the national grid. The results showed that the initial capital cost is 5,442$ which is returned after five and a half years. The cost of 1 kWhr if the system operates for 10 years is 0.058$. This study clearly demonstrates that photovoltaic power system can effectively assist the peak load on the grid. In addition, these systems are very economical/no maintenance project and can be hooked to any the peak time load.
A. Ebrahimi; G. D. Najafpour
Abstract
Microorganisms play an important role in biological treatment processes. Biodegradable organic matter in wastewater would be removed completely by proper microbial consortia. The mixed culture is either generally present in the wastewater, or is introduced to the target wastewater by mixing it with domestic ...
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Microorganisms play an important role in biological treatment processes. Biodegradable organic matter in wastewater would be removed completely by proper microbial consortia. The mixed culture is either generally present in the wastewater, or is introduced to the target wastewater by mixing it with domestic wastewater or sewage sludge. However, pure cultures bioprocess may be used in certain cases for the removal of specific contaminants. In favorable environmental condition, microorganisms are capable of presenting high efficiency in destruction of pollutants. If environmental conditions such as nutrition, pH, temperature, dissolved oxygen, hydraulic and sludge retention time are suitable and consistent with the nature of process, microorganisms grow and remove organic pollutants through biochemical activities. The aim of this article was to investigate the performance and mechanism of various systems of suspended and attached growth; while the detail of process in different fabricated systems was evaluated. The advantages and disadvantages of NRBC, UASFF, UAPB and normal activated sludge process were discussed. Growth kinetics and COD removal of effluents were also investigated. The result indicated the combination of fluidized and fixed film has created active biogranules which were quite faster and more efficient in treatment of industrial wastewater.
A. B. Bayu; T. A. Amibo; D. A. Akuma
Abstract
The study was done to explore the production of charcoal briquettes that could meet the need for energy in the community of Jimma city. The primary objective of this work is to produce charcoal from the most promising wastes. Under these objectives the main activities which performed were sorting waste, ...
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The study was done to explore the production of charcoal briquettes that could meet the need for energy in the community of Jimma city. The primary objective of this work is to produce charcoal from the most promising wastes. Under these objectives the main activities which performed were sorting waste, characterization of wastes that can easily degradable, designing carbonizer equipment, manual press molding machine, and characterizing charcoal briquettes. Degradable municipal waste was collected from Jimma city. The charcoal production process includes a collection of degradable municipal waste, drying, carbonization, crushing and sieving, binder preparation, binder – charcoal mixing, briquette charcoal (compaction and drying), and packing. The test result of degradable municipal solid waste for its density, % of moisture, % of volatile matter, % of ash, % of fixed carbon, and caloric value of was determined as 157.3kg/m3, 18.15%, 66.95%, 4.07%, 10.83%, and 18.5MJ/kg, respectively. In the same way the test result for charcoal briquette for its density, porosity weight index, shatter resistance ,moisture content, volatile matter, ash content, fixed carbon content, and caloric value was obtained as 50.06kg/m3, 29.05%, 92.3 %, 9.87%, 29.4%, 3.21%, 57.52% and 27.0MJ/kg, respectively. These results show in the range compared with others reported in literature. Therefore, there is the possibility to convert Jimma City degradable solid wastes into charcoal briquette using starch as a binder. We can increase the quality of charcoal briquette rather than polluting the environment.
M. Karimizadeh; K. Payandeh
Abstract
This study was conducted in 2017 with the aim of determining the distribution of heavy metals lead, nickel, cadmium, vanadium and the parameters of acidity, electrical conductivity and organic matter in the surface soils of the city of Khorramabad. Sampling was performed monthly from 12 stations and ...
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This study was conducted in 2017 with the aim of determining the distribution of heavy metals lead, nickel, cadmium, vanadium and the parameters of acidity, electrical conductivity and organic matter in the surface soils of the city of Khorramabad. Sampling was performed monthly from 12 stations and was repeated 3 times in the autumn. The highest amount of cadmium was observed in the soil samples of industrial areas of the city in the two sampling periods of October and December to be 7 ppm. A comparison of the mean measured values of heavy elements showed that the highest average amounts of heavy elements are in industrial areas and the lowest in residential areas. The lowest amount was measured in 8th and 11th stations at 2 ppm. The highest amount of lead in the 6th station, a bustling area, was measured to be 22 ppm. The average nickel in industrial areas was higher than other areas. In industrial area, during the sampling period of October, its amount was determined to be 58 mg/kg. The highest amount of vanadium was recorded in staion9 at 52 mg/kg. Lead has a significant correlation with nickel, cadmium and soil acidity. This correlation is 0.01% for acidity and cadmium variables and 0.03% for nickel. Nickel has a significant correlation with cadmium and vanadium at the level of 0.01%. The results indicate that the surface soil of the city of Khorramabad is not contaminated with the studied metals. In general, the results showed that both human and natural factors are always involved in the distribution and concentration of heavy metals.
Environment
H. Tamadon Ghareghie; M. Yazdi; D. Yousefi Kebria; H. Aminirad
Abstract
Soil contamination is considered a controversial issue in most countries. Nowadays, it is important to clearly understand how pollutants influence the soil from different sources. Today, hydrocarbons are one of the most important sources of soil contaminants, which is considered as a fundamental issue ...
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Soil contamination is considered a controversial issue in most countries. Nowadays, it is important to clearly understand how pollutants influence the soil from different sources. Today, hydrocarbons are one of the most important sources of soil contaminants, which is considered as a fundamental issue at the global level. The current study aims to analyze and model the effect of simultaneous parameters (time and concentration) of phenols and naphthalene with different percentages (10, 15, 20 and 25%) together with the amount of bentonite in fine-grained sandy soil. The designed experiments made use of response surface methodology (RSM) and Design-Expert software to carry out a computer-based simulation. According to the proposed model, the amount of bentonite is most affected by the permeability of the soil. The obtained results also showed that the permeability significantly decreases in the light of increasing the percentage of phenol and naphthalene coupled with the amount of bentonite and the age of contamination. On average, an 80% reduction of permeability was observed in contaminated soil, which was found in the soil contaminated with naphthalene. According to the results of the synergistic effects of time, the considerable impacts of both the percentage of hydrocarbon pollutants and the amount of bentonite on the reduction of permeability are quite evident.
M. Anbia; Z. Khodashenas; L. Kamel
Abstract
The development of an efficient adsorbent for phosphate removal from wastewater to prevent the eutrophication of surface waters is very important. In this study, porous silicon powder prepared with acidic etching solution (HF: HNO3: H2O). Then, Zirconium-modified porous silicon has been synthesized by ...
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The development of an efficient adsorbent for phosphate removal from wastewater to prevent the eutrophication of surface waters is very important. In this study, porous silicon powder prepared with acidic etching solution (HF: HNO3: H2O). Then, Zirconium-modified porous silicon has been synthesized by a simple and low-cost hydrothermal process. The morphology and structure of the samples were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD). This material has been used as an adsorbent for phosphate ion (PO43-) removal from synthetic aqueous solutions. The effect of operating conditions such as contact time, initial anion concentration, pH, the presence of competitive ions on the adsorption performances and the regeneration of the adsorbent have been investigated. Maximum adsorption amount of 47.7 mg P/g has been obtained at ambient temperature. The maximum removal of phosphate was reached at pH= 4 for Zirconium-modified porous silicon. The adsorption was almost unaffected by the presence of competitive ions. Regeneration tests have shown that the adsorbent retains its capacity after 3 adsorption-desorption cycles.
P. Shwethambika; J. Ishwara Bhat
Abstract
Theobroma cocoa dry bean extract (CDBE) was prepared by Soxhlet extraction method and was characterized for its chemical constituents using Fourier Transform-Infrared Spectroscopy (FT-IR), Gas chromatography-Mass spectroscopy (GC-MS) and also by Thermogravimetric Analysis-Differential Scanning Calorimetry ...
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Theobroma cocoa dry bean extract (CDBE) was prepared by Soxhlet extraction method and was characterized for its chemical constituents using Fourier Transform-Infrared Spectroscopy (FT-IR), Gas chromatography-Mass spectroscopy (GC-MS) and also by Thermogravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC) techniques. FT-IR analysis gave information about the mostly like to be present functional groups in the extract. GC-MS analysis of the extract revealed the presence of important 07 chemical constituents with cis-13-octadecanoic acid as the major component. TGA-DSC study gave the idea about different stages of thermal decomposition of the chemical constituents present in the extract. CDBE was then tested for its ability to inhibit the corrosion rate of mild steel in 1.0M HCl solution medium by means of weight loss, Potentiodynamic polarization, and Electrochemical impedance spectroscopy (EIS) techniques. The weight loss experiments revealed the anticorrosive property of it on mild steel, which was found to increase with increase in the concentration of the inhibitor CDBE and decrease with an increase in temperature of corrosive medium. EIS results showed the adsorption of organic constituents present in the extract at the metal-solution interface. Potentiodynamic polarization studies revealed that CDBE functioned as a mixed type inhibitor. The surface morphological studies of mild steel surface were carried out by Scanning electron microscopy (SEM). The inhibition efficiency values obtained by electrochemical measurements were consistent with those from weight loss measurements and hence it can be proposed that CDBE as a potent inhibitor towards corrosion of mild steel under acidic conditions.
M. A. Sayid Mia; M. Nur-E-Alam; S. Huque; M. M. Rahman; H. Ratnaweera
Abstract
Annually about 85,000 tons of raw hides and skins are estimated to be processed for leather production in Bangladesh. Tannery generates huge amount of solid and liquid wastes. Anaerobic digestion (AD) is a potential treatment to stabilize waste and produce biogas for renewable energy. The aim of this ...
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Annually about 85,000 tons of raw hides and skins are estimated to be processed for leather production in Bangladesh. Tannery generates huge amount of solid and liquid wastes. Anaerobic digestion (AD) is a potential treatment to stabilize waste and produce biogas for renewable energy. The aim of this study was to investigate the potential of AD of tannery solid waste (TSW) generated from the pre-tanning operation and to compare the effect of cow dung as the substrate to TSW. For the reaction with TSW by mixing with different substrates, biogas production was observed starting on 4th day with a steady increase. The cumulative gas production from each of the test reactors operating at the various organic loading of tannery solid waste, domestic sewage, and cow dung were different. This study shows an optimal AD process of TSW by mixing with different substrates for the obtained optimum C/N ratio and also for the high volatile solids (VS). The COD removal rates for the series of 5 reactors (R1, R2, R3, R4 and R5) were 48.75, 50.84, 46.07, 45.94 and 47.78% respectively. Maximum COD removal was achieved from reactor R2 where maximum gas was also produced.
Energy
J. Ahmadi; S. M. Maddahi; R. Mirzaei
Abstract
All important decisions that affect the thermal performance of the building are made in the early stages of design. Accordingly, in this research, the initial stage of architectural design which is related to space plan was targeted. The aim of this research is the perfect approach to evaluate, and optimize ...
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All important decisions that affect the thermal performance of the building are made in the early stages of design. Accordingly, in this research, the initial stage of architectural design which is related to space plan was targeted. The aim of this research is the perfect approach to evaluate, and optimize the energy a set of alternative spatial layout solutions through the functional computational design model. The method of this research includes the production of coherent design solutions and the evaluation and optimization of the energy performance of the selected solutions. In the first part, space allocation at a level produces the plan through an evolutionary technique. In the next step, certain plans were evaluated for energy performance, performance rank, and optimization. The energy simulation tool is Honeybee and Ladybug plugins,. The optimization tool is Pareto Evolutionary Algorithm in the Octopus plugin. The reproduction rate, the mutation rate and the possibility of mutation were 0.9, 0.8 and 0.2, respectively. The results showed that each algorithm is a suitable tool for design solutions, thermal performance of floor plans, helping architects’ perspective in the decision-making process, and speeding up the design process. Finally, based on the optimization, the final result of the research algorithm is 70 elite answers in the Pareto front. Only during the Pareto front optimal responses, energy consumption can be reduced by more than 30%; in daylight time and more than 39% improvement was achieved.
J. M. Patra; S. S. Panda; N. K. Dhal
Abstract
Citrus fruits world production is estimated to be over 88 million tons per year, and oranges alone account for about 55% of such amount. Orange peel waste (OPW) is the solid residue of membranes, cores, juice sacs, etc which represents over 50% of the processed fruits. Its disposal is of great concern ...
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Citrus fruits world production is estimated to be over 88 million tons per year, and oranges alone account for about 55% of such amount. Orange peel waste (OPW) is the solid residue of membranes, cores, juice sacs, etc which represents over 50% of the processed fruits. Its disposal is of great concern from the environmental point of view. Due to the large availability and composition rich in the present investigation was focused on the production of ethanol from OPW which will be an economic, environmental friendly and efficient approach. Strains of Aspergillus niger and Saccharamyces cerevisiae was used for hydrolysis and fermentation of pretreated orange waste, respectively. Spectrometry scanning electron microscopy (SEM) and Fourier transformation infrared (FTIR) were used to characterize the sample. Sugar percentage was found to be 3.64 in pretreated sample after 24 hours, which is responsible for the yield of ethanol (6.17 v/v). The results indicated that orange peel can be used as a good low cost alternative feedstock for ethanol production.
M. El-khomri; N. El-messaoudi; S. Bentahar; A. Dbik; A. Lacherai
Abstract
In this work, Crystal Violet (CV), cationic dye, is removed from aqueous solution, using wood of Argan shell(ARS) and Almond shell (ALS), as low-cost and eco-friendly biosorbants. The parameters influencing the adsorption of CVon each of our adsorbents, contact time (5–180 min), adsorbent dose ...
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In this work, Crystal Violet (CV), cationic dye, is removed from aqueous solution, using wood of Argan shell(ARS) and Almond shell (ALS), as low-cost and eco-friendly biosorbants. The parameters influencing the adsorption of CVon each of our adsorbents, contact time (5–180 min), adsorbent dose (0.2–2 g), pH of the solution (3–11), temperature (20–50°C) and the initial dye concentration (50–500 mg.L-1), were studied.The modeling of experimental results obtained, shows that the CV adsorption on both biomaterials follows a pseudo-second-order kinetic and in perfect agreement with Langmuir isotherm. Also CV is better adsorbed on ALS that ARS, with maximum biosorption amounts 51.99 mg.g-1 and 37.32mg.g-1, respectively, at 40 ° C. Thermodynamic calculations have shown that the sorption is spontaneous, endothermic and random at the solid / solution interface. Adsorption capacities of dyes by ARS and ALS are better or comparable to those of several other biomaterials already studied.ALS and ARS biomaterials studied can be considered as alternative biosorbants low-cost and eco-friendly..
Z. Ghorbani Kharaji; M. H. Fazaelipoor
Abstract
In this research five different solutions were used to wash an oil contaminated soil with the initial TPH (Total Petroleum Hydrocarbon) content of 46 g kg-1 (grams of TPH per kg of dry soil). The solutions were a basal mineral medium (solution I), the basal mineral medium inoculated with petroleum degrading ...
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In this research five different solutions were used to wash an oil contaminated soil with the initial TPH (Total Petroleum Hydrocarbon) content of 46 g kg-1 (grams of TPH per kg of dry soil). The solutions were a basal mineral medium (solution I), the basal mineral medium inoculated with petroleum degrading microorganisms (solution II), the basal mineral medium inoculated with a culture of petroleum degrading microorganisms and supplemented with a commercial washing powder (solution III), the basal mineral medium inoculated with the microorganisms and supplemented with Tween 80 (solution IV), and the basal mineral medium inoculated with the microorganisms and supplemented with sucrose (Solution V). Washing was performed by saturation of the soil with the solutions in columns and intermittent mixing. Solutions IV and V performed better than the others, giving more than 90% TPH removal in two months. In a separate experiment TPH removal was monitored as a function of time during washing. Solution V reduced the TPH content of the soil more rapidly than the others, with more than 70% TPH removal in 28 days. Addition of sand particles to the soil for the purpose of better mixing resulted in marginal positive effects.
A. Jodaei; Z. Moravej
Abstract
In this paper, a novel approach is introduced for Fault Detection and Fault Location in power systems that incorporate Large-Scale Photovoltaic Power Plants (LSPPPs). Given that short-circuit (SC) characteristics in photovoltaic systems differ significantly from those observed in traditional Synchronous ...
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In this paper, a novel approach is introduced for Fault Detection and Fault Location in power systems that incorporate Large-Scale Photovoltaic Power Plants (LSPPPs). Given that short-circuit (SC) characteristics in photovoltaic systems differ significantly from those observed in traditional Synchronous Generators (SGs). The increasing integration of LSPPPs into the power grid is anticipated to have an impact on the performance of conventional protection relay systems; initially designed for SG-dominated setups. Therefore, the proposed method revolves around analyzing the influence of LSPPPs on the alteration of observed transmission line impedance to identify and locate faults accurately. Furthermore, the methodology takes into consideration factors such as fault location, fault resistance, fault type, changing the LSPPP generation, and noise conditions. when calculating the phase angle of the fault loop current. The effectiveness of this approach was assessed through testing and evaluation on 2-bus and IEEE 39-bus test systems connected to an LSPPP, simulated using PSCAD/EMTDC and MATLAB/SIMULINK.
M. F. Mohd Yusof; P. N. K Abd Hamid; R. Hashim; A. A. Tajuddin; S. Bauk; N. Mohd Isa
Abstract
Phantom materials are important tools for quality control and dosimetry works in medical physics. The tannin-bonded Rhizophora spp. particleboards in were fabricated as phantom and the dosimetric properties at high energy photons and electrons were evaluated. The particleboards were fabricated at dimensions ...
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Phantom materials are important tools for quality control and dosimetry works in medical physics. The tannin-bonded Rhizophora spp. particleboards in were fabricated as phantom and the dosimetric properties at high energy photons and electrons were evaluated. The particleboards were fabricated at dimensions of 30 x 30 x 1 cm3 and target density of 1.0 g/cm3 based on the commonly used solid water phantoms in radiotherapy. The effective atomic number of the particleboard was determined based on the elemental compositions measured using energy dispersive x-ray analysis (EDXA). The mass attenuation coefficients at high energy photon were measured at 16.59-25.26 keV photons and 60Co and 137Cs gamma energies. The percentage depth dose and beam parameters of the particleboards were measured at 6 MV photons and 6 MeV electrons using Gafchromic EBT2 film and treatment planning system (TPS) software. The results showed that the effective atomic number and electron density of the particleboards were close to the value of water. The mass attenuation coefficient at high energy photons were close to the XCOM value of water. The percentage depth dose at high energy photons and electrons showed an agreement to the value in water and solid water phantom within 10% at all measured depths. The overall results indicated the suitability of tannin-bonded Rhizophora spp. as phantom material for high energy photons and electrons.
G. Ramezani; S. E. Moradi; M. Emadi
Abstract
Graphene oxide based nano-composites have attracted huge attention for wastewater treatment specially removal of heavy metals. This paper reports adsorption of onto modified magnetic graphene oxide with chitosan and cysteine (GO/ /Chi/Cys). To study the adsorbent morphology, Field Emission Scanning ...
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Graphene oxide based nano-composites have attracted huge attention for wastewater treatment specially removal of heavy metals. This paper reports adsorption of onto modified magnetic graphene oxide with chitosan and cysteine (GO/ /Chi/Cys). To study the adsorbent morphology, Field Emission Scanning Electron Microscope (FE-SEM) and Fourier Transform Infrared Spectrometer (FTIR) were used in different stages of surface modification. In order to reveal the nature of sorption process, linear forms of different adsorption isotherms such as Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich were studied. Experimental data were fitted well by Langmuir model with a maximum monolayer coverage capacity ( ) of 86.21 . Prediction of from Langmuir model was in good agreement with maximum empirical adsorption capacity ( =85.4 ). Various types of kinetic models such as pseudo-first-order, pseudo-second-order, Elovich, and intra particle diffusion were investigated to determine characteristic parameters in the adsorption process. The kinetic studies showed that pseudo-second-order model represents the adsorption process better than others due to its high correlation coefficient ( =0.9996). Therefore, the adsorption process is chemisorption.
P. Chaithra; K. Hemashree; J. Ishwara Bhat
Abstract
Activated carbon (AC) was synthesized from raw cocoa pod (RCP) by three activation methods; physical (CPC), chemical (Z CPC, zinc chloride) and microwave activation (MW-CPC). The synthesized AC was characterized using powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), ...
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Activated carbon (AC) was synthesized from raw cocoa pod (RCP) by three activation methods; physical (CPC), chemical (Z CPC, zinc chloride) and microwave activation (MW-CPC). The synthesized AC was characterized using powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopic technique (FT-IR), thermal analysis and differential thermal analysis (TGA-DTA), atomic absorption spectroscopic technique (AAS) and flame photometer instrument. The characterization data reveals that microwave activated carbon having good adsorbent character than physical and chemical activated carbon. Adsorption of malachite green on CPC, Z CPC and MW-CPC were studied at various experimental condition. Freundlich adsorption isotherm model holds good for the adsorption process. The mechanism of adsorption followed the second order kinetics. Thermodynamics of adsorption were studied. The amount of dye adsorbed onto activated carbons varies in the order MW-CPC (29.3632mg/g) > CPC (29.3537mg/g) > Z CPC (27.9905mg/g).
B. Raei; F. Shahraki; M. Khorrami; A. Ghadi
Volume 1, Issue 1 , January 2010
R. Adjia; W.M.L Fezeu; J.B. Tchatchueng; S. Sorho; M.B. Ngassoum
Volume 1, Issue 2 , April 2010
Ali Aberoum
Volume 1, Issue 3 , July 2010
S.H. Sengar; A.K. Kurchania
Volume 1, Issue 4 , October 2010