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Open Access Article
1 - Adsorption Kinetics Study of Removal Rhodamine B and Heavy Metals (Cadmium and Cobalt) from Water Using Rhamnolipid Biosurfactant Produced by Pseudomonas Aeruginosa
Fatemeh Diba Babak Mokhtarani Reza PanahiBackground and Objective: An alternative and environmentally friendly method for purifying the environment from pollution is the use of biosurfactant derived from microorganisms. The advantage of biosurfactant is biodegradability, low toxicity, and effectiveness in incr MoreBackground and Objective: An alternative and environmentally friendly method for purifying the environment from pollution is the use of biosurfactant derived from microorganisms. The advantage of biosurfactant is biodegradability, low toxicity, and effectiveness in increasing biological decomposition. Unlike chemical surfactants, surface active substances produced by microbes are easily decomposed, and for this reason, they are very suitable for environmental applications, especially bioremediation. The aim of this study was bioremediation and investigation of the absorption kinetics of heavy metals and Rhodamine B from water by biosurfactant produced from Pseudomonas aeruginosa bacteria.Material and Methodology: In this study, a biosurfactant-producing bacterium that was isolated and identified as Pseudomonas aeruginosa HAK02 from the Kahrizak waste site in the south of Tehran was used to produce a surface bioactive agent to remove pollutants. Zeta potential test was performed to detect the load of biosurfactant produced and used in bioremediation. The amount of color removal was done by UV device and the removal of heavy metals was done by ICP_AES analysis.Findings: Due to the negative charge of the substance, it was used to remove heavy metals and Rhodamine B cationic dye. Biosurfactant produced with Pseudomonas aeruginosa was able to remove 95% rhodamine B, 43% Cd2+, and 35% Co2+. Examining the kinetic model of absorption showed that better correlation with pseudo-second order kinetic model.Discussion and Conclusion: Bioremediation using surfactants to remove heavy metals and dyeing is a fast and environmentally friendly method. This sample is very suitable for the removal of Rhodamine B and has the moderate ability for heavy metals Cd2+ and Co2+. Manuscript profile -
Open Access Article
2 - Application of Nano-Gamma Alumina Adsorbent for Nickel and Cobalt Removal from Mining Industry Wastewater
Fariba Soleimani Mohammad Hadi Givianrad Amir Hossein HaghighatyBackground and Objective: The development of urbanization and industries has led to an increase in sewage and wastewater production. The defective and non-standard disposal of these wastewaters has resulted in influx of large amounts of heavy metals into the environment MoreBackground and Objective: The development of urbanization and industries has led to an increase in sewage and wastewater production. The defective and non-standard disposal of these wastewaters has resulted in influx of large amounts of heavy metals into the environment which their removal, as bio-irresolvable contaminants, from water and wastewater are considerably important for protecting environment and public health. Method: In this study, gamma Nano-alumina was synthesized and its structural analysis was characterized, which was applied as a high performance adsorbent for heavy metals Nickel and Cobalt. Moreover, by using DX7 software for experiment design, the effects of different conditions such as heavy metals initial concentration, Nano-adsorbent amount and pH were modified. Findings: The results of XRD, FTIR, SEM and EDX analysis, confirmed the existence of gamma Nano-alumina structure, and Nickel and Cobalt contents were determined by UV-Vis spectrophotometry method. Nano gamma alumina, as a powerful adsorbent, could be adsorbed the high levels of Nickel and Cobalt in alkaline pH-rich environments, then in experimental samples, 98.66% of Nickel and 95.1% of Cobalt and in real samples, 100% was eliminated. Discussion and Conclusion: It was found that synthesized gamma Nano-alumina could be considered as a cost-effective and high-performance Nano-absorbent for heavy metals elimination. Consequently, it was verified by Freundlich and Langmuir adsorption isotherms, which the adsorption process of these elements with the Nano-alumina absorbent followed by Freundlich and Langmuir adsorption equation. Manuscript profile -
Open Access Article
3 - Preparation of Modified Nanocellulose with 5-Br-PADAP for Preconcentration and Determination of Trace Amounts of Cobalt Ions in Natural Water Samples
Sekyneh ganji-jouybari Ali Mirabi Ali Shokuhi radBackground and Objective: Separation and determination of trace amounts of cobalt ions in real samples due to their toxicity to humans is very important. In the present study, a nanocellulose was synthesized by the acid hydrolysis and then modified with 2-(5-bromo-2-pyr MoreBackground and Objective: Separation and determination of trace amounts of cobalt ions in real samples due to their toxicity to humans is very important. In the present study, a nanocellulose was synthesized by the acid hydrolysis and then modified with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol (5-Br-PADAP). The size of cellulose nanofibers was determined using transmission electron microscope (TEM). After modification of the nano-sorbent with the 5-Br-PADAP, the thermogravimetric analysis (TGA) of the modified nanocomposite was carried out, and the BET technique was used to determine the surface area of the nano-sorbent before and after modification. In the present work, the aim is to modify the surface of nanocellulose with ligand of 5-Br-PADAP to use them to extraction and pre-concentration of trace amounts of cobalt ions before determination it by flame atomic absorption spectroscopy in real samples.Material and Methodology: Certain volume of cobalt ion into the test tube containing the modified nanosorbent was Poured and buffer solution with pH = 9 was added and place it in a shaker and finally centrifuged for 15 minutes and then discard the top solution and 1 mL HCl was added to recover cobalt ions and placed in a shaker for 10 minutes and then centrifuged, and the absorption of the supernatant was determined by FAAS. The results showed that the modified nanocellulose is very sensitive and selective towards the determination of cobalt ions which could be affected by several parameters such as pH, adsorbent amount, sample volume, extraction time, and type of eluetion.Findings: The calibration curve is linear in the range of 10-500 ng/mL, and the detection limit and the relative standard deviation (RSD) are calculated to be 4.3 ng/mL and 1.8 %, respectively, that result in a high preconcentration and enrichment factor.Discussion and Conclusions: By using the flame atomic absorption spectrometry and applying the standard addition method, the proposed method was used to determination of the trace amounts of cobalt ions in the natural water samples such as seawater, river water, well water, lake water and tap water, with satisfactory results. Manuscript profile -
Open Access Article
4 - Feasibility of zinc recovery from hot-filtrate cake (waste) as practical approach to resolve of environmental problems in zinc industry
Mehdi Hosseini Keivan Shayesteh Vahid Vahid fard Pourya AbbasiBackground and Objective: Cake from hot-filtrate of zinc production industries containing about 16-24% of zinc and harmful metals such as cobalt, which it releases to environment caused to the harmful effects. These pollutions are one of the main concerns of this indust MoreBackground and Objective: Cake from hot-filtrate of zinc production industries containing about 16-24% of zinc and harmful metals such as cobalt, which it releases to environment caused to the harmful effects. These pollutions are one of the main concerns of this industry so the goal of present work is cobalt impurity cementation method and reuse of zinc recovery. Material and Methodology: The work is containing three steps leaching of hot-filtrate cake, optimization of affective parameters on process using Response Surface Methodology (RSM) and removal of cobalt impurity. Using RSM necessary experiments was designed and finally optimum conditions were determined. Finding: Using Design of Expert (DOE) software parameters such as temperature, zinc powder amount, contact time and additive concentration of antimony trioxide were evaluated. Based on the obtained results, the most impressive are belonged to zinc powder amount, temperature, time and additive concentration, respectively. Optimum conditions for cobalt removal containing temperature of 84 C°, concentration of 12.74 g L-1 for zinc powder, contact time of 118 min and concentration of 22.28 mg L-1 were obtained. At these conditions, cobalt impurity amount is reached to the allowed limit for electrolysis process and can be recovery of zinc from obtained solution. Discussion & Conclusion: Using cementation method about 75% of zinc in cake was recovery and cobalt impurity was removed and finally, obtained zinc solution was conducted to the zinc production route. Furthermore, addition of dissolving environmental problems from cake, recovery of zinc and cobalt from the point of economical was important. Manuscript profile -
Open Access Article
5 - Investigation of photocatalytic removal of methyl orange by titanium dioxide nanoparticles modified with silver and cobalt
Nasim Ziaeifar saber KhodaeiBackground and Objective: In order to investigate the photocatalytic activity of modified titanium dioxide nanoparticles in order to remove methyl orange contaminants, parameters such as the amount of contaminant concentration, the amount of photocatalytic, the pH of th MoreBackground and Objective: In order to investigate the photocatalytic activity of modified titanium dioxide nanoparticles in order to remove methyl orange contaminants, parameters such as the amount of contaminant concentration, the amount of photocatalytic, the pH of the solution and the calcination temperature were investigated. Material and Methodology: In this study, Ag-Co / TiO2 nanoparticles were synthesized by sol-gel method and characterized by TEM, SEM, XRD and EDX techniques. The results of XRD diffraction studies showed that the simultaneous deposition of silver and cobalt had no effect on the crystalline pattern of titanium dioxide. The formation of Ag-Co / TiO2 nanoparticles and their approximate size were confirmed using the XRD spectrum and is about 270 nm. TEM images with a particle size of about 300 nm also confirm the XRD results. The morphology and purity of these synthesized nanoparticles were evaluated through SEM and EDX images. The results of EDX analysis showed that Ag-Co / TiO2 nanoparticles prepared by sol-gel method did not have a peak of impurity in the sample. The photocatalytic activity of Ag-Co / TiO2 nanoparticles under visible light irradiation was evaluated in the removal of methyl orange contaminants. Findings: Co doped TiO2 nanoparticles by Ag and Co were shown to have highest activity as compared with the Ag/TiO2 , Co /TiO2 and pure TiO2 nanoparticles. The highest percentage of methyl orange removal by Ag-Co / TiO2 is 99.5% in 75 minutes. Discussion and Conclusion: The optimum contents of silver and Cobalt for the preparation of co-doped Ag,Co/TiO2 nanoparticles were 0.9 and 0.3 at mol%, respectively Manuscript profile -
Open Access Article
6 - Biosorption of Cobalt (II) from Aqueous Solutions by Marine Red Alga Geracilaria sp
Akbar Smaeli Pari Beyrami Abdolhossein Rostaeyan Ashraf BeyramiSome kinds of pollutants such as heavy metals, especially, can be removed from water and waste water by biological materials via biosorption. These heavy metals can be also recovered by adsorbents. The mentioned methods have more important advantages from some aspects s MoreSome kinds of pollutants such as heavy metals, especially, can be removed from water and waste water by biological materials via biosorption. These heavy metals can be also recovered by adsorbents. The mentioned methods have more important advantages from some aspects such as being more economical than others. In this study marine red alga Gerasilaria sp. was used as aquatic seaweed to remove Co2+in the flow operation (packed column) of a glass column with an internal diameter of 2 Cm and the height of 35 Cm as investigated and different stages. The adsorption process was studied under affection of factors such as initial concentrations, pH, retention time (15, 30 and 45min), and adsorbent dosage (2.5 and 3.5 g) in the room temperature. The solution of Co (II) in distilled water was prepared using (Co (NO3)2,6H2O) with initial concentrations 50,100,150 mg/L. The maximum rates of uptake at pH=7 were at different degrees of 92.53%, 83.52% and 71.76% respectively. By prolonging the time of absorption from 15 minutes to 45 minutes, rate of uptake was enhanced and the highest rate was in the first 15 minutes. The final concentration of Co Ions in each sample in atomic absorption spectrometer (GBC-932), appeared that non living Gerasilaria sp. acted based on the Langmuir physics law and the kinetic studies showed that absorption of cobalt by non-living alga samples obeyed the second degree of kinetic absorption model. Manuscript profile -
Open Access Article
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طاهره ناجی شهربانو عریان سارا کرمی12 -
Open Access Article
8 - Effects of Heating Pretreatments and pH on Removal Efficiency of Cadmium, Cobalt and Zinc from Multi-Ionic Solutions using Sepiolite Mineral
Ramin Samiei Fard Ahmad Landi Saeid Hojati Nahid PourrezaBackground and Objective: Due to electrical charge and high specific surface area, clay minerals, such as sepiolite, are widely used for the removal of heavy metals from environment. However, limited information is available to identify their ability for heavy metals re MoreBackground and Objective: Due to electrical charge and high specific surface area, clay minerals, such as sepiolite, are widely used for the removal of heavy metals from environment. However, limited information is available to identify their ability for heavy metals removal from multi-ionic solutions. This study was conducted to determine the ability of Fariman sepiolite for the removal of Cd, Co, and Zn from aqueous solutions, and the effect of different factors, such as contact time and initial solution pH, as well as application of heating pretreatments (150 and 250 Cᵒ) on adsorption process of the mentioned elemnts. . Method: All the experiments were done in 11 contact times from 5 to 2880 minutes, in three replications and at pH values of 4 and 5. After determining the remained amounts of each heavy metal in the centrifuged suspension solutions by atomic absorption machine, the experimental data were fitted by pseudo first order, pseudo second order, and intraparticle diffusion kinetic models. Findings: The results showed that the adsorption potential of the heavy metals depended on contact time, solution pH, and physicochemical characteristics of the elements. Accordingly, by increasing the contact time and pH of solutions, adsorption rate of the heavy metals increased in an order of Co>Zn>Cd. Moreover, the results illustrated that application of heat treated sepiolite particles, compared to natural sepiolite, increases the removal efficiency of the heavy metals from aqueous solutions. Conclusion: Results illustrated that application of heating pretreated sepiolite leads to greater removal of heavy metals in the solutions studied. Besides, greater efficiency in removal of heavy metals would be attained in pH= 5 as compared to pH=4. Manuscript profile -
Open Access Article
9 - A Study of the adsorption of CO on cobalt nanostructures: Cubic and hexagonal crystalline phases
Fatemeh Dolati ali nakhaeipoura vahidreza darugar zohre Dolati vagehe afkhamyIn the present work, the adsorption energies and structures of carbon monoxide (CO) on cubic and hexagonal crystalline phases of cobalt nanoparticles has been evaluated using density functional theory (DFT) calculations. However, the general trend in Fischer- Tropsch sy MoreIn the present work, the adsorption energies and structures of carbon monoxide (CO) on cubic and hexagonal crystalline phases of cobalt nanoparticles has been evaluated using density functional theory (DFT) calculations. However, the general trend in Fischer- Tropsch synthesis (FTS) activities on cobalt-based catalysts is reproduced by comparing adsorption energies. The catalysts with higher fractions of hcp phase exhibited higher conversion in FTS reaction than those cobalt fcc metallic phase. For evaluation of CO adsorption energies on cobalt surfaces, we have calculated the activation energy of adsorption of CO at 1 ML (ML=monolayers) on top of cobalt atoms on cubic and hexagonal crystalline phases of cobalt nanostructures. The results predicted that, the largest adsorption energies are found for the fcc crystalline phases and hcp surface adsorbed CO with lower energies. Since the lower energy of the adsorption of CO on cobalt hcp top sites may explain the higher activity of cobalt catalysts with hexagonal crystalline phases in FTS reaction. Manuscript profile -
Open Access Article
10 - One-step Synthesis of Cobalt Ferrite Nanoparticles by Co-Precipitation
M. Nazari R. Jafarazad S.A. Manafi -
Open Access Article
11 - Synthesis and Characterization of Mesoporous Cobalt Hydroxide and Cobalt Oxide Nanorings
M. Darbandi E. Narimani -
Open Access Article
12 - Investigation of the Effect of CTAB on the Wettability of Nanostructured Cobalt Oxide Coating Prepared by Hydrothermal Method
B. Kabiri R. Norouzbeigi E. Velayi -
Open Access Article
13 - Synthesis of Nanostructured Co3O4 and NiO using Aliphatic Dicarboxylicacids in Neutral Condition
H.R. Rahimipour A. Hosseinian -
Open Access Article
14 - Synthesis and Investigation of Nanostructure and Photocatalytic Behavior of CoFe2O4-TiO2 Core-shell Magnetic Nanocomposites
H. Mozafari H. Hamidinezhad -
Open Access Article
15 - Fabrication and Magnetic Properties of Alloy Nanowires (Co1-xCux/Sn) Using AAO Template: Investigation of Frequency, Electrolyte and Composition Effect on Magnetic Properties
M. Najafi M. Hamehvaisy -
Open Access Article
16 - Synthesis of Cobalt Ferrite Nanoparticles Using Microemulsion Method
H. Ebrahimnia E. Keshavarz-Alamdari M. Kazemzad Y. Ganjkhanlou -
Open Access Article
17 - An overview of the polyol synthesis process of cobalt carbide magnetic nanoparticles
مهدی کبریایی علی قاسمی محمدرضا لقمان شهاب ترکیانThis review explores the synthesis of cobalt carbide nanoparticles through a polyol reduction method, highlighting their acicular morphology, cluster assembly, and magnetic properties. The study reveals room temperature coercivities exceeding 3.4 kOe and maximum energy MoreThis review explores the synthesis of cobalt carbide nanoparticles through a polyol reduction method, highlighting their acicular morphology, cluster assembly, and magnetic properties. The study reveals room temperature coercivities exceeding 3.4 kOe and maximum energy products surpassing 20 kJ m-3. The composition of Co3C and Co2C phases, along with factors such as particle size and morphology, crucially influences permanent magnet characteristics. The acicular shape enhances coercivity and offers potential for particle alignment in nanocomposite cores. However, limitations arise at elevated temperatures due to irreversible dissociation. Further investigation into optimizing particle size, chemistry, and morphology is warranted. Additionally, the polyol process with PVP is shown to induce the formation of Co3C-structured Co carbide particles with enhanced coercivity. The use of hydroxide and chloride anions in the polyol process yields exchange-coupled cobalt–carbide nanocomposites and single-phase Co2C nanoparticles, each exhibiting distinct magnetic properties. Synthesis under a high external magnetic field results in cobalt–cobalt carbide microwires with controlled morphology and composition. The study also demonstrates the successful synthesis of cobalt carbide magnetic nanoparticles via a modified polyol process without rare-earth catalysts, showcasing promising magnetization and coercivity values at room temperature. The influence of reaction parameters, such as temperature, hydroxyl ion concentrations, and duration, on the crystallographic structure and magnetic properties is elucidated. Manuscript profile -
Open Access Article
18 - The Effect of Land Use on the Distribution of Chemical Forms of Copper and Cobalt, and their Biological Risk Assessment in Soils of Zanjan Province
Ali Afshari Parisa AlamdariThis study aimed to determine the chemical forms of cobalt and copper in soil under rain fed and irrigated cultivation and their biological risk assessment in Zanjan province. For this purpose, 120 samples (96 rain fed soil samples and 24 soil samples irrigated) were ta MoreThis study aimed to determine the chemical forms of cobalt and copper in soil under rain fed and irrigated cultivation and their biological risk assessment in Zanjan province. For this purpose, 120 samples (96 rain fed soil samples and 24 soil samples irrigated) were taken and after determination concentration of all the elements, 36 samples with maximum variation were selected for laboratory analysis. The results showed that the concentrations of total and DTPA-extractable cobalt under rain fed and irrigated land uses for Co were 25.6, 0.35 and 24.3 and 0.39 and for Cu were 29.8, 2.1 and 62.3, 5.2 mg/kg respectively. Copper distribution in the rain fed soil included residual fraction (74.2%), oxide fraction (10.5%), organic matter fraction (8.4%), carbonate fraction (4.6%) and soluble+exchangeable fraction (4/2%) and in irrigated soil included residual fraction (70%), organic matter (13.1%), oxide (10.1%), carbonate (4.4%) and soluble+exchangeable (2.3%). Chemical distribution of cobalt in soils showed no significant difference in the proportion of each fraction in order of residual fraction>oxidized>carbonate>soluble+exchangeable>organic fraction achieved. The highest correlation coefficient was found between bound to organic matter fraction of Cu with organic matter (r=0.731). Individual contamination factors (ICF) for copper and cobalt in rain fed and irrigated conditions were 0.35 and 1.11 and 0.50 and 1.28 respectively. Global contamination factor (GCF), under rain fed and irrigated were 1.46 and 1.78 respectively. Risk assessment code (RAC) for copper and cobalt was 6.9 and 27.24% respectively. Manuscript profile -
Open Access Article
19 - Investigation of structural and ultrastructural changes of canola (Brassica napus L.) leaf under cobalt oxide nanoparticles treatment
Malihe Jahani Ramazan Ali Khavari-Nejad Homa Mahmoodzadeh Sara Saadatmand Sedighe JahaniCobalt oxide nanoparticles (Co3O4 NPs) are one of the most widely used magnetic NPs in various industries and their interactions with the environment are predictable. The aim of this study was to investigate the impact of Co3O4 NPs on leaf structure and ultrastructure o MoreCobalt oxide nanoparticles (Co3O4 NPs) are one of the most widely used magnetic NPs in various industries and their interactions with the environment are predictable. The aim of this study was to investigate the impact of Co3O4 NPs on leaf structure and ultrastructure of canola. Seeds were sown in pots under greenhouse conditions and after two weeks, seedlings were treated with Co3O4 NPs (0 and 4000 μg/mL) by leaf spray for five weeks. Then, leaf morphological changes were measured. Also, sampling from control leaf and NPs treatment were performed to investigate structural and ultrastructural changes. Tissue preparation was performed and samples were examined by light and transmission electron microscopy (TEM). Morphological changes including reduction in the length, width and area of leaf of canola treated with Co3O4 NPs were observed. Also, ultrastructural changes of canola leaf mesophilic cells treated with Co3O4 NPs including reduction of chloroplasts number and their swelling, accumulation and deposition of NPs in vacuoles and cell walls, observation of protein bodies, increase in the size of plastoglobules and starch grains in chloroplasts were observed. In addition, the results of cobalt elemental assay by methods of inductive coupled plasma emission spectrometry (ICP-OES) and energy dispersive X-ray spectroscopy (EDX), in line with TEM results, showed the uptake and accumulation of Co3O4 NPs in canola leaves. Ultrastructural damage in TEM results indicated the toxicity of high concentration of Co3O4 NPs at the cellular level. Therefore, potential of hazardous effects of Co3O4 NPs on other crops and environment should be considered. Manuscript profile -
Open Access Article
20 - Determination of Nickel and Cobalt accumulation in edible tissues of Crucian (Rtilus frisii kutum) caught from the International Anzali wetland
A.A Khanipour مینا Seifzadeh Mina AhmadiThe aim of this study was to determine the accumulation of nickel and cobalt in the edible tissues of Crucian (Rtilus frisii kutum) and to compare their concentrations with the FDA/FAO standards. For this purpose, the fish samples were caught from western, central and e MoreThe aim of this study was to determine the accumulation of nickel and cobalt in the edible tissues of Crucian (Rtilus frisii kutum) and to compare their concentrations with the FDA/FAO standards. For this purpose, the fish samples were caught from western, central and eastern stations of Anzali wetland. Using a flame atomic absorption spectrophotometer, Ni and Co contamination were determined. According to the results, the mean value of Ni concentration in the samples caught from the eastern and central stations were 0.93 and 0.80 µg/g, respectively which were not statistically different. Moreover, Ni concentration in the central region was estimated at 1.13 μg/g, which was not significantly different from the FDA standard. In the case of Co, the average concentration in the western parts was below the detection limit; however in the central and eastern parts Co level was 0.13 and 0.07 μg/g dry weight, respectively that was in the approved limit adopted by FDA and FAO. Besides, the difference of Co concentration in the eastern, western as well as central stations was not significantly different. Based on the results, Ni and Co contents in edible tissues of Crucian of the eastern, western and central stations of Anzali wetland were found suitable for human consumption. Manuscript profile -
Open Access Article
21 - تاثیر سطوح مختلف فلزهای سنگین بر جوانهزنی بذر و رشد گیاهچه لولیوم پرنه (Lolium perenne L.)
حسن بیات حسین حمامی محمد امینیفرد -
Open Access Article
22 - تاثیر سطوح مختلف فلزهای سنگین بر جوانهزنی بذر و رشد گیاهچه لولیوم پرنه (Lolium perenne L.)
حسن بیات حسین حمامی محمد امینیفرد -
Open Access Article
23 - The Importance of Arsenic, Vanadium, Cobalt and Strontium in Poultry, A Review
ب. نویدشاد م. محمدرضایی -
Open Access Article
24 - ساخت الکترودهای بر پایه گرافن اکسید احیا شده و بررسی میزان بارگذاری نانوذرات کبالت
سید حمید احمدی کاظم کارگشا پیام همت خواه -
Open Access Article
25 - Synthesis of cobalt ferrite nanoparticles and investigation of magnetic hyperthermia properties at different concentrations
Salah Khanahmadzadeh kamran heydaryanIn this paper, cobalt ferrite nanoparticles were synthesized using a co-precipitation method. The properties and characteristics of the cobalt ferrite nanoparticles were studied using XRD, VSM, and FESEM analyses. The FESEM images showed that the cobalt ferrite nanopart MoreIn this paper, cobalt ferrite nanoparticles were synthesized using a co-precipitation method. The properties and characteristics of the cobalt ferrite nanoparticles were studied using XRD, VSM, and FESEM analyses. The FESEM images showed that the cobalt ferrite nanoparticles had almost spherical morphology, and that the particle size distribution (determined with the help of Digimizer software) was in the range of 25–60 nm. Moreover, the average size of the nanoparticles was calculated to be in the range of 37-47 nm. The VSM results indicated superparamagnetic properties of the cobalt ferrite nanoparticles at room temperature. Besides, the saturation magnetization and coercivity were found to be 30 emu/g and 39 Oe, respectively. The specific loss power (SLP) was investigated by preparing ferrofluid concentrations of 3, 5, and 8 mg/ml under a magnetic field of 400 Oe and at a frequency of 400 kHz. In this case, the rate of the increase in temperature of the cobalt ferrite nanoparticles was measured in a certain period of time, and the related SLP was calculated. The results of the measurements showed that the highest rate of the heat generation occured at the concentration of 8 mg/ml, leading to an SLP value of 162 W/g. Manuscript profile -
Open Access Article
26 - Comparison of Solvent Extraction and Liquid Membrane by Using Cyanex301 for Cobalt (II) Extraction and Recovery
Rezvan TorkamanIn this study, the extraction of cobalt (II) ions from the chloride solution by using Cyanex301 as an extractant and two extraction methods such as solvent extraction and supported liquid membrane was investigated. The effect of different parameters such as pH of feed s MoreIn this study, the extraction of cobalt (II) ions from the chloride solution by using Cyanex301 as an extractant and two extraction methods such as solvent extraction and supported liquid membrane was investigated. The effect of different parameters such as pH of feed solution, concentration of Cyanex301 extractant and stripping acid concentration were studied to determine the optimum conditions. For the liquid membrane process, the aqueous feed pH of 7.3 and 1 mol/L of Cyanex301 in the membrane phase were the best conditions for extraction, whereas the best extraction efficiency by using the solvent extraction method was achieved with 0.1 mol/L of Cyanex301 concentration. The extraction efficiency equal to 99.11% was achieved within 15 min by solvent extraction technique, while the maximum extraction of Cobalt equal to 44.77% was achieved within 180 min by means of liquid membrane. The result shows that the extraction of Cobalt by using the supported liquid membrane were not improved in comparison with using conventional solvent extraction method. Manuscript profile -
Open Access Article
27 - Preparation of heterogeneous magnetic nanocatalysts based on reduced graphene oxide with nickel and cobalt particles and investigation of its activity in Heck and sonogashira cross-coupling reactions and 4-nitrophenol reduction
abdolreza abri forough matloubiToday catalysts are widely used in the production of various materials. Nano-catalysts according to their importance have become one of the most important areas for Nanotechnology research. Development of magnetic catalysts for carbon–carbon and carbon–heter MoreToday catalysts are widely used in the production of various materials. Nano-catalysts according to their importance have become one of the most important areas for Nanotechnology research. Development of magnetic catalysts for carbon–carbon and carbon–heteroatom coupling reactions are one of the most important issues in terms of applications to organic synthesis. At present, many researches are focused on the construction of more active and more stable, heterogeneous Nano-sized metal catalysts, which can be recovered and reused. Nickel and cobalt nanoparticles due to low prices, magnetic properties and high chemical activity attracted particular attention. In this work, nickel and cobalt nanoparticles were synthesized with a green and one-pot method on graphene oxide substrate for reduction reaction of 4-nitrophenol, Heck and Sonogashira cross-coupling reactions. Several characterization techniques such as FTIR, FESEM, XRD, and VSM were employed to characterize the Co and Ni nanoparticle reduced graphene oxide composites witch indicates that nickel and cobalt magnetic particles with a size of about 20-30 nanometers were uniformly anchored on graphene oxide nanosheets. In addition, results showed that incorporation of Co and Ni nanoparticles and GO produce much higher activity in cross-coupling and reduction reactions. The soft-ferromagnetic behavior of the RGO/CoxNi100-x nanocomposite demonstrated the easy separable from the reaction mixture and reusable several times without losing its catalytic activity, Hence, the RGO/CoxNi100-x composites can be a potential promising material to catalyze the cross-coupling reactions Manuscript profile -
Open Access Article
28 - Optimizing the process of chemical coagulation and electrocoagulation in the treatment of Shahid Tandgoyan petrochemical wastewater
hamid reza nooraeinia SOMAYEH ToraniIn this research, using the response surface method, the efficiency of the chemical coagulation and electrocoagulation processes in the treatment of Shahid Tangyuan petrochemical wastewater was modeled and optimized. The composition of Shahid Tangyuan petrochemical wast MoreIn this research, using the response surface method, the efficiency of the chemical coagulation and electrocoagulation processes in the treatment of Shahid Tangyuan petrochemical wastewater was modeled and optimized. The composition of Shahid Tangyuan petrochemical wastewater containing 20-60 ppm of cobalt and manganese was used in this experiment. By employing Design Expert software, an excellent agreement was obtained between the model and experimental observations in the removal efficiency of cobalt and manganese. By using the chemical coagulation method at a temperature of 25 °C, a mixing speed of 120 rpm and time of 90 minutes, pH equal to 6, and initial concentration of 20 ppm for cobalt and manganese, the best removal efficiency of cobalt and manganese was 59.8 and 57.2%, respectively. The optimal parameters in the electrocoagulation process to remove cobalt and manganese were 46 minutes of equilibrium time, pH equal to 6, and voltage of 25.8 volts. The removal efficiency was 98.3% for cobalt and 96.4% for manganese by combined chemical coagulation and electrocoagulation processes. Manuscript profile -
Open Access Article
29 - سنتز اکسیدهای مختلط نانوساختار CoxZn1-xAl2O4 با استفاده از سوخت کیتوزان و احتراق هیبریدی
مارال هاشمپور لیلا ترکیان مریم دقیقی اصلی -
Open Access Article
30 - بررسی کارایی نانوذرات پلاتین بر بستر چندسازه گرافن و کبالت اکسید بهعنوان الکتروکاتالیست مقاوم در برابر نفوذ متانول در پیلهای سوختی متانولی
منیره فرجی پیروز درخشی کامبیز تحویلداری زهره یوسفیان -
Open Access Article
31 - حذف کاتالیستی CH4 و NOx از اگزوز خودروهای گازسوز با نانوذرههای کبالت کرومیت (CoCr2O4)
زهرا کاظمی زاده زهره بهرامی ناهید پارسافر -
Open Access Article
32 - Preparation and characterization of cobalt-manganese-cerium nanocatalyst in order to applying in the Fischer-Tropsch process and study the operating conditions on the activity of the catalyst
Hesam Aldin Hashemzehi Ali Akbar Mirzaei Amin BehzadmehrOne of the most important processes in the petrochemical industry is Fisher-Tropes synthesis. In this process, the synthesis gas, which mainly contains H2 and CO gases, is converted to a mixture of hydrocarbons. The Fischer-Tropsch process is a catalytic process that ca MoreOne of the most important processes in the petrochemical industry is Fisher-Tropes synthesis. In this process, the synthesis gas, which mainly contains H2 and CO gases, is converted to a mixture of hydrocarbons. The Fischer-Tropsch process is a catalytic process that catalyst is an important and determining part of this process. Therefore, in this study, the cobalt-manganese-cerium tri-metal catalyst based on alumina (Al2O3) was prepared by the wet impregnation method. The optimal catalyst was identified using X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermal gravimetry analysis (TGA) techniques. Surface area of the catalyst was measured by BET method. The fabricated catalyst was used to perform the Fisher-Tropes process in a laboratory fixed-bed microreactor and the effect of operating parameters such as temperature, pressure, and feed ratio on the selectivity and activity of the catalyst were investigated. According to the results, a temperature of 300 °C, pressure of 1 atm, and feed molar ratio of H2 / CO = 1.1 were selected as the optimal operating conditions of the catalyst. Manuscript profile -
Open Access Article
33 - جذب رنگ بنفش بلوری از محلولهای آبی با آبژلهای نانوچندسازه مغناطیسی بر پایه صمغ عربی حاوی نانوذرات کبالت
حسین قاسم زاده محمدی فاطمه مهدوی روچی بهمن واشقانی فراهانی -
Open Access Article
34 - Study of heavy metals (Cr,Co,Cd) in macroalgae in intertidal zone of Bushehr
P. Nejatkhah Manavi A. R. Vosoughi E. Shirvani Mahdavi A. GoudarziThis study was done in three mounths of summer season of year 2006 in intertidal zone in the Boshehr town in 4 transcet . Gracillaria, Padina, Acantophora, Laurencia, Digenia, Gania Gellidium, Sargassum,Cladophora, Caulerpa, Entromorpha, Halimeda were indicated in inte MoreThis study was done in three mounths of summer season of year 2006 in intertidal zone in the Boshehr town in 4 transcet . Gracillaria, Padina, Acantophora, Laurencia, Digenia, Gania Gellidium, Sargassum,Cladophora, Caulerpa, Entromorpha, Halimeda were indicated in intertidal zone of Boshehr Then, were analized samples with absorb atomic machines and considered word limited for metales such as Cr, Cd and Co Result measurement of heavy metal in macro alge show that ,there is not any Co and Cr in waters intertidal zone in Boshehr, also Co in macroalge. the most of Cd measured 0.88 ppm in Padina of Brown alge in Radar site and in Caulerpa 0.47 ppm of green alge in Plaj station. the most of Cr measured in Padina 0.6 ppm of Brown alge in Student park, and 0.1 ppm in Acantophora, Laurencia, Gellidium, Graciilaria in Student park and Jalali station. Manuscript profile -
Open Access Article
35 - Effect of cobalt as blood factors on Oscar fish (Astronatus ocellatus)
H. Emadi A. Mahani B. MokhayerFive groups of royal oscar (Astronatus ocellatus) with mean weight of 0.8±0.02 grams were fed for 90 days in 15 aquariums (30 30 40 cm). Their diet contained different levels of cobalt chloride with concentrations of 2.5, 3, 3.5 and 4 milligrams per kilogram of f MoreFive groups of royal oscar (Astronatus ocellatus) with mean weight of 0.8±0.02 grams were fed for 90 days in 15 aquariums (30 30 40 cm). Their diet contained different levels of cobalt chloride with concentrations of 2.5, 3, 3.5 and 4 milligrams per kilogram of feed. Three replicates were used for each concentration. During the experiment, blood factors including RBC, WBC, glucose and hemoglobin, in different groups were measured and compared with control diet. Results indicated that addition of cobalt as growth promotant, significantly affected RBC no., amount of glucose and hemoglobin in blood in all groups of species comparing those fed with the control diet, having no extra cobalt chloride (P<0.05). The best growth, RBC (0.82+1.69) 106 /mm3, glucose (5.03±129.66 mg/dl) and hemoglobin (1.66±8.01)g/dl were obtained with food 4 milligrams /kgr of cobalt chloride, and the highest WBC (9.0)103 /mL was obtained in diet with 3.5 milligrams/kgr of cobalt chloride. It is concluded that the species fed with most cobalt perforemed better than other fishes considering blood indices. Manuscript profile -
Open Access Article
36 - An investigation on the behavior of manganese cobaltite spinel oxide as the SOFC interconnect coating materials
Pooria Lesani Alireza Babaei Abolghasem AtaieIn this study, Manganese cobaltite (MnCo2O4) spinel powders were synthesized by co-precipitation method. X ray diffraction (XRD) patterns show that the spinel phase was formed at around 350°C. Formation of spinel phase was further completed by increasing temperature MoreIn this study, Manganese cobaltite (MnCo2O4) spinel powders were synthesized by co-precipitation method. X ray diffraction (XRD) patterns show that the spinel phase was formed at around 350°C. Formation of spinel phase was further completed by increasing temperature up to 1000°C. Additionally, XRD patterns prove that MnCo2O4 spinel material has been stable in this temperature range. Field emission scanning electron microscope observations show that plate like particles with an average diameter of 148 and thickness of 18 nm was converted to equiaxed particles with an average particle size of 1.5 µm by increasing calcination temperature from 350 to 1000°C. Investigation of the coating of uncalcined and calcined powder on AISI 430 ferritic stainless steel shows that a proper dense coating is developed on the stainless steel surface by using uncalcined precursor powders. And also, this coating performs well by prohibiting of outward diffusion of Fe from the substrate. In this way, a low thickness chromia layer (Cr2O3) is formed between the coating and the substrate. EDX analysis shows that a mixed spinel zone is formed in the interface of the coating and the substrate due to diffusion of some elements such as Mn, Cr, and Fe from substrate to the coating, as well as Mn and Co from coating to the substrate. Manuscript profile -
Open Access Article
37 - The effect of parameters of pulse Electrodeposition and post annealing on properties of Cobalt-tungsten alloy coating
سمیه اباذری سیوندی سعید رستگاری شهرام خیراندیشcobalt-tungsten anano structure alloy coating was produced using pulse electrodeposition in 200 Hz pulse frequency from citrate electrolyte at 60 °C. In this study the influence of cobalt ions concentration in solution and duty cycle on crystal structure, grain size Morecobalt-tungsten anano structure alloy coating was produced using pulse electrodeposition in 200 Hz pulse frequency from citrate electrolyte at 60 °C. In this study the influence of cobalt ions concentration in solution and duty cycle on crystal structure, grain size, hardness and corrosion resistance of coating was investigated. Surface morphology and composition of coatings was examined by scanning electron microscopy (SEM) and (EDS) analysis. The crystallite size of the coatings calculated from the x-ray diffraction patterns using the Scherrer equation. Micro hardness of the coatings was assessed using a Vickers micro-indenter. Results showed that electrodeposited coating at 0.2 mol/l cobalt sulphate and 60% duty cycle with 1A/dm2had optimum coating on 758 Hv. Annealing amorphous coating was produced at current density of 4 A/dm2 in high vacuum pressure makes crystalline coating. Increasing temperature at 600°C makes a well-developed polycrystalline structure of Co3W and CowO4 in the coating. Microhardness of coating increased from 436 Hv to 1059 Hv after heat treatment at 600 °C. Heat treatment of coating improved the corrosion resistance of coating. The coating heat treated at 400 ºC had minimum corrosion rate. Manuscript profile -
Open Access Article
38 - Analysis of the effect of molybdenum and cobalt additives on the structural and electrical properties of PZT5 piezoceramic material
mohammad hadi hemati hossein lexian mohammad hossein Ghezel Ayagh,The purpose of this paper is to analyze the effect of molybdenum and cobalt additives on the dielectric, ferroelectric and piezoelectric properties of PZT5piezoceramic material By adding molybdenum and cobalt in the location of zirconate and titanate, in the range of (0 MoreThe purpose of this paper is to analyze the effect of molybdenum and cobalt additives on the dielectric, ferroelectric and piezoelectric properties of PZT5piezoceramic material By adding molybdenum and cobalt in the location of zirconate and titanate, in the range of (0-2) percent.For this purpose, the powders were first prepared with a wet chemical method. then They were calcined for 2 hours at 850 ° C. The structural properties of the compounds were investigated using the X-ray diffraction (XRD) method to confirm the formation of single phase compounds (with perovskite structure) at room temperature. The Microstructural analysis of the surface of the sintered discs by scanning electron microscopy (SEM) shows that there is a significant change in grain size with increasing molybdenum and cobalt. Detailed studies of the dielectric properties of PZT In the samples made and tested show measurable change in the piezoelectric charge coefficient D33(Up to 84 ℅ reduction), electromechanical coupling coefficient Keff(Up to 78 ℅ reduction) , resonant frequency Fr(Up to 25 ℅ increase) and mechanical quality factor Qm (Up to 110 ℅ increase). Manuscript profile -
Open Access Article
39 - The Effect of Cobalt-oxide Nanoparticles Conjugated with Glutamic Acid and Thiosemicarbazone on Apoptosis of Hepatocellular Carcinoma Cancer Cells
Asal Shahrokhshahi Ali Salehzadeh Hamidreza Vaziri Zeinab Moradi ShoeiliCancer is the second most common cause of death after cardiovascular disease. The present study was aimed at assessing the cobalt oxide nanoparticles conjugated with thiosemicarbazone (CO3O4-TSC) against hepatic cancer cells HepG2 in vitro. The CO3O4-TSC nanoparticles w MoreCancer is the second most common cause of death after cardiovascular disease. The present study was aimed at assessing the cobalt oxide nanoparticles conjugated with thiosemicarbazone (CO3O4-TSC) against hepatic cancer cells HepG2 in vitro. The CO3O4-TSC nanoparticles were synthesized by chemical and condensation methods. The effect of different concentrations of nanoparticles on the growth of Hek392 normal and HepG2 cancerous cells was assessed by MTT assay. The effect of CO3O4-TSC nanoparticles on apoptosis was assessed by measuring apoptotic Bax and anti-apoptotic Bcl2 genes using specific primers with the Real-Time PCR method. Mean expression of Bax gene in nanoparticle-treated cancer cells (2.19 ± 0.091) was significantly higher than normal cells (1.0 ± 0.027) and untreated cancer cells (0.84 ± 0.047) (p <0.001). The mean expression of Bcl2 gene was significantly lower in nanoparticle-treated cancer cells (0.65 ± 0.033) than in normal (1.0 ± 0.017) and untreated cancer cells (1.38 ± 0.033) (p <0.001). The expression ratio of Bax/Bcl2 in nanoparticle-treated cancer cells (3.36) was significantly higher than normal (1.0) and untreated cancer cells (0.61) (p <0.001). CO3O4-TSC nanoparticle has a high cytotoxic effect on cancer cells, possibly mediated by the induction of apoptotic Bax expression and decreased expression of anti-apoptotic Bcl2 gene. Manuscript profile -
Open Access Article
40 - The impact of cobalt in the food of some existing amino acids in Astronatus ocellatus
Hossein Emadi Baba Mokhayer Arezo MahaniFive groups of Astronatus ocellatus were fed with the average mean of 0/8 gr in 90 days in aquariums 30×30×60. The amount of amino acids existing in the muscle of the fish for control treatment and treatment 4 ml/gr was compared. The result showed that there MoreFive groups of Astronatus ocellatus were fed with the average mean of 0/8 gr in 90 days in aquariums 30×30×60. The amount of amino acids existing in the muscle of the fish for control treatment and treatment 4 ml/gr was compared. The result showed that there was a meaningful difference between control treatment and treatment 5 (p<0/05). The amount of Lysine, Methionine, Valine, Phenylalanine, proline, glycine, threonine, glutamic acid was respectively 14/95, 3/14, 9/54, 30/84, 7/01, 11/31, 8/74, 30/18.ml/gr of the muscle of the fish with 4 ml Cobalt chloride in 1 kg of food which was more than the other rations such as treatment ration. Manuscript profile
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