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Open Access Article
1 - Investigation of carbon monoxide gas adsorption on the Al2O3/Pd(NO3)2/zeolite composite film
Nastaran Mozaffari Alireza Haji Seyed Mirzahosseini Amir Hossein Sari Leila Fekri Aval -
Open Access Article
2 - Adsorption of Methylene Blue Dye from Aqueous Solution by Using Gamma Alumina Nanoparticles
gholamali haghdoost -
Open Access Article
3 - Elimination of Congored from Aqueous Solution by the using of gamma alumina nanoparticles
gholamali haghdoost -
Open Access Article
4 - CATALYTIC REFORMING OF n-HEPTANE ON PLATINUMNIOBIUM SUPPORTED ON GAMMA-ALUMINA
Mehdi Vadi Gholamreza Farmani Hamidreza Seyedjafari M. Sohrabi -
Open Access Article
5 - Catalytic Reforming of n-Heptane on Platimum - Rhenium Supported on Gamma-Alumina
M. Vadi M. Bazargani N. Astaneh M. Alipour -
Open Access Article
6 - CATALYTIC REFORMING OF n-HEPTANE ON PLATINUM-TUNGSTEN SUPPORTED ON GAMMA-ALUMINA
M. Vadi A. Safavi A. Jamshidi -
Open Access Article
7 - Determination of Activity and Selectivity of n-Heptane by Reforming Catalytic Pt-V Supported on gamma-Alumina
Mahdi Vadi Najimeh Astaneh -
Open Access Article
8 - Investigation of Activity and Selectivity of n-Heptane by Reforming Pt-Ta Catalyst Supported on y-Alumina
M. Vadi -
Open Access Article
9 - Morphology investigation of alumina nano-powders prepared by a sol-gel combustion method
S. A. Khorrami R. Lotfi M. A. Baghchesara S. Moradi -
Open Access Article
10 - Synthesis of Nanozeolite NaX and Optimization of the Method
S. Jalilehvand B. Amirpour R. Fazaeli M. H. Givianrad A. Mashinchian moradi -
Open Access Article
11 - Flame atomic absorption spectrometric determination of Cd(II), Zn(II) and Ag(I) in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their 2,3 Di Hydro 2,3 para tolyl Qinazoline (1 H)- 4 one (DPTQO)
Farveh Raoufi Saidah Bagheri Ebrahim Niknam Khodabakhsh Niknam Hamid Reza Farmani -
Open Access Article
12 - The effect of core@shell nanoparticle concentration on the barrier properties of carboxymethyl cellulose-based films
S. Tavakolian H. Ahari M. H. Givianrad H. Hosseini -
Open Access Article
13 - 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
14 - Recycling the Spent Catalysts of Claus Unit in Natural Gas Refineries and Their Application for Synthesis of Composite Adsorbents Coated by Polypyrrole for the removal of lead ions
Nima Fallah Tayebeh Johari mohammad Toosi mohammad hasan PeyroviBackground and Objective: Catalytic processes in oil and gas industries are very important for refining, purification and production of useful compounds. Regeneration of spent catalysts is interested due to their environmental problems as solid wastes in the refineries. MoreBackground and Objective: Catalytic processes in oil and gas industries are very important for refining, purification and production of useful compounds. Regeneration of spent catalysts is interested due to their environmental problems as solid wastes in the refineries. Activated alumina is a very useful catalyst in gas refinery for conversion of hydrogen sulfide to the elemental sulfur in Claus unit.In this paper regeneration of spent catalyst of Claus process in Sulfur Recovery Unit (SRU) and application of it for synthesis of polypyrrole/Al2O3 composite as an adsorbent of lead ion was investigated. Method: Catalyst regeneration was performed via washing by water or caustic washing and then thermal process. Characterization and analysis of catalysts were performed by XRF, XRD, FTIR, and BET measurements. Polypyrrole /Al2O3 composite was synthesized by in situ polymerization and used for removal of lead ions in batch experiments and different values of pH, lead concentration and temperature. Findings: Results showed that regeneration process caused to removal of impurities and sulfur without any change in the catalyst structure. Specific area of catalyst increased from 84 m2/g in spent catalyst to 186 m2/g in regenerated sample while the sulfur content decreased from 2.53% to 0.005-0.007%. Discussion and Conclusion: The results indicated that the composite showed high ability for lead removal. Adsorption behavior was determined as Langmuir isotherm and pseudo-second order kinetic. Manuscript profile -
Open Access Article
15 - Separation of alumina from the paint sludge of automotive industry by leaching method
Mostafa Khezri Fateme AbdollahPaint sludge of automotive industries, due to having heavy metals, unbaked polymers, organic andinorganic pollutants, has been classified as a hazardous waste. For this reason, its proper disposal isfaced with many problems. Various methods yet have been developed by th MorePaint sludge of automotive industries, due to having heavy metals, unbaked polymers, organic andinorganic pollutants, has been classified as a hazardous waste. For this reason, its proper disposal isfaced with many problems. Various methods yet have been developed by the great automobilecompanies of the world to reduce the environmental impacts of paint sludge. One of the effective aneconomical methods for reduction of pollution is separation of heavy metals from paint sludge. Thepresent study was carried out to investigate the pollution of paint sludge from automotive industry, toreduce its pollution to environmental standard levels, and to recover alumina from the paint sludgethrough leaching method. After XRD and XRF tests on paint sludge, it was found that the amount ofalumina is relatively high. Separation of alumina was considered because of its economic value andvarious applications in different industries. After utilizing the common separation methods, it wasrevealed that by optimizing the parameters such as temperature, sludge particle size, and sulfuric acidconcentration through the leaching method, about 70% of alumina can be recovered Manuscript profile -
Open Access Article
16 - The Impact of Jajarm Alumina Plant on Topsoil Contamination with Lead
Mehdi Elahi Soheila Rezaitabar Abdolali Vahdani Mohamad sharif FazeliBackground and Objective: Presence of heavy metals in different parts of the environment (such as, soil) has adverse effects on organisms’ health. The main sources releasing these pollutants to the environment are industries and mines. Therefore, in this study, th MoreBackground and Objective: Presence of heavy metals in different parts of the environment (such as, soil) has adverse effects on organisms’ health. The main sources releasing these pollutants to the environment are industries and mines. Therefore, in this study, the effect of Jajarm Alumina plant (located in North Khorasan province) on contamination of topsoil with Lead (Pb) around the factory, has been proceed. Method: Sampling of topsoil (depth < 10 cm) was carried out in 2008, considering the dominant wind direction (Northwest-Southeast) and distance from factory. 38 sites in 10 km of radius around the factory and also one evidence site 20 km away from the factory were studied. After preparing samples, Pb concentration was measured by atomic absorption spectrometry (Philips, PU 9400). Results: Comparison of mean concentration of Pb in main geological directions of the factory, showed a significant difference between them (p < 0.05). Despite the direction of dominant wind, maximum and minimum mean concentrations of Pb were observed in the north (27.34 mg/kg) and south (9.40 mg/kg) respectively. Also, investigation of relationship between Pb concentrations with distance from the factory (in main geological directions) showed a positive significant correlation in the east of the factory. Conclusion: Overall, results showed that Jajarm Alumina plant has not a significant effect on topsoil contamination with Pb Manuscript profile -
Open Access Article
17 - Effect of Solvents on the Synthesis of SrAl2O4 Nanoparticles by Reverse Micelle Process
Azita Moheb Saeid Abedini Khorramie Shahram Moradi Dehagi -
Open Access Article
18 - Effect of Formaldehyde on Pulsed Electro-Plated Nickel-Alumina Nanocomposite Coatings
S Mirzamohammadi M Velashjerdi A Anbarzadeh -
Open Access Article
19 - Influence of Al2O3 Additive on Mechanical Properties of Wollastonite Glass-Ceramics
Monavvar Rahimi Babak Sadeghi Maryam Kargar Razi -
Open Access Article
20 - Representative Sampling for Elaboration of the Alumina Manufacturing Process (Theory and Practice )
George KomlÛssySampling of any geological formation needs comprehensive knowledge of the rock genesis, through the dia- and epigenetic processes (secondary alterations) up to the physical properties and the chemical and mineralogical composition of the rock. Well established theoretic MoreSampling of any geological formation needs comprehensive knowledge of the rock genesis, through the dia- and epigenetic processes (secondary alterations) up to the physical properties and the chemical and mineralogical composition of the rock. Well established theoretical knowledge should be complemented by practical experience. Besides the geological exploration of a raw material, its representative sampling is the most responsible task of the expert. Elaboration of the technology of the mineral processing i.e. the operating cost of the plant highly depends on reliable sampling which is essential for an optimal utilisation of the deposit. Nowadays, when green-field plants below 1 Mt/a capacity are rarely set up, proper sampling is even more important than before. Several million USD/annum can be saved in operating cost with a well-established sampling procedure which, according to the experience of the author, is often neglected by the investors or project management. In this paper the author clarifies the terminology of the characteristic and representative samples and introduces several typical cases both for karst and laterite bauxites.Distinction is made between technologically homogenous and heterogeneous type deposits. Examples are taken from Iranian, Indian, Vietnamese, West African, and South American deposits. Proposals are given for sampling procedures in different stages of the exploration, when the first samples are to be taken for technological tests. The question is investigated whether the bauxite is necessary for an already operating plant (when the bauxite should be fitted to the plant) or when a green- field refinery technology is to be fitted to the deposit(s). In conclusion, it is established that no reasonable economy may exist for mining and alumina processing separately. The economy of the mine and the plant is to be regarded as a single economic unit. For achieving this purpose reliable representative samples are necessary. Manuscript profile -
Open Access Article
21 - P2O5/Al2O3 as an effieientcatalystfor one-potsynthesis of polyhydroquinoline derivativesundersolvent-free conditions
Tayebeh Sanaeishoar Sara Roueen -
Open Access Article
22 - Synthesis of 1,8-dioxo-octahydroxanthenes under solvent-free conditions via Phosphorus pentoxide supported on alumina (P2O5/Al2O3) catalyzed tandem reaction of Aldehyde with dimedone
Tayebeh Sanaeishoar Negar Hormozinezhad -
Open Access Article
23 - Nanoalumina sulfonic acid catalyzed rapid N-formylation under solvent-free conditions
Elham Tahanpesar Vajihe Rohani Nejad -
Open Access Article
24 - P2O5/Al2O3 as an effieient catalyst for one-pot synthesis of polyhydroquinoline derivatives under solvent-free conditions
Tayebeh Sanaeishoar Sara Roueen -
Open Access Article
25 - The study of sedimentological and mineralogical loess sediments as raw material for produce Brick and other industrial products in Golestan Province
Mansoor khajeh Hossein Tuluian Araz- Mohammad mofidi- khajeh Mansoor RahmatiIn recent years, many industries activities such as refining crude oil, aluminum and zinc production, ship repairand construction, loading and unloading of minerals and chemicals, etc. As a development center in BandarAbbas, southern Iran, which formed the subject exace MoreIn recent years, many industries activities such as refining crude oil, aluminum and zinc production, ship repairand construction, loading and unloading of minerals and chemicals, etc. As a development center in BandarAbbas, southern Iran, which formed the subject exacerbate pollution load destruction of sensitive ecosystemscoastal waters region. Therefore, measures to identify and measure heavy metals and trace elements with regardto harmful effects on marine ecosystems including aquatic and consequently affects puts man in sediments ofcoastal waters is an important. Based on this in this study the amount of heavy metals Zn, Cr, Ni and Cd insediments in coastal areas target Bandar Abbas apparatus flame atomic absorption spectroscopy (AAS) wasmeasured. All stages of sample and digestion of sediment according to standard methods (MOOPAM) were.Thus, the average concentration of heavy metals Zn, Cr, Ni and Cd in sediments, respectively 89.1 ± 0.3, 90.4 ±0.3, 27.9 ± 0.3 and 2.1 ± 0.2 (µg g-1) dry weight sediment, respectively. This value with an average concentrationof elements in sediments above and other global internal and external areas were analyzed and compared.Statistical analysis (ANOVA: Single Factor) showed that the average concentration of heavy metals Zn, Cr, Niand Cd in sediment are significant differences between the crossings. Two elements Cd and Zn with a correlationcoefficient of 0.7651 have the highest correlation and then the order of elements Ni and Cr with the coefficientcorrelation 0.7410, Cd and Cr with the coefficient correlation 0.599, Zn and Cr coefficient correlation 0.5603and Ni and Zn with the coefficient correlation 0.1704 are. With coefficient significant and positive correlationbetween Cd and Zn, Cd and Cr, Zn and Cr and finally be determined that the source of pollution in the sedimentsof these elements is the same. The results show there are no statistically significant correlations for Cd, Nicoefficient. Manuscript profile -
Open Access Article
26 - Antibacterial activity of zinc aluminate nanoparticles against foodborne pathogenic bacteria of E. coli and P. aeruginosa
A. Taheri M. Ziaadini M. GahramzeiMaterials in nanoscale dimensions have a high surface-to-volume ratio, and thus have better reactions with other materials. The development of nanotechnology over the past decades has opened up opportunities for discovering the antibacterial effects of metallic nanopart MoreMaterials in nanoscale dimensions have a high surface-to-volume ratio, and thus have better reactions with other materials. The development of nanotechnology over the past decades has opened up opportunities for discovering the antibacterial effects of metallic nanoparticles. In this study, the antibacterial properties of nanoparticles on aluminate (ZnAl2O4) were studied on Escherichia coli and Pseudomonas aeruginosa bacteria. Antibacterial activity was assessed by using the disk diffusion method on agar using nanoparticles on synthesized aluminate. The non-growth halo diameter indicates the sensitivity of bacteria to antimicrobials. The minimum inhibitory concentration of bacterial growth (MIC) and minimum bacterial leaching concentration (MBC) was measured by microdilution in sterile tubes. Statistical analysis was done by T-test. The results of this study showed that Pseudomonas aeruginosa sensitivity (16.06±1.8mm) was higher than E. coli (11.64±2.2mm) (p < 0.05). The minimum inhibitory concentration (MIC) and bactericidal concentration MBC of bacteria Pseudomonas aeruginosa and Escherichia coli bacteria MIC and MBC was lacking. According to the results obtained in this study, we conclude that Pseudomonas aeruginosa was more sensitive to alumina than that of E. coli against nanoparticles. Manuscript profile -
Open Access Article
27 - The removal of Tartrazine dye by modified Alumina with sodium dodecyl sulfate from aqueous solutions: equilibrium and thermodynamic studies
A. Parchebaf Jadid S. Sadeghi Edible colors are materials which in the case of adding to food and drinks cause transferring color to them. Most of these colors are not acceptable in terms of applying in human food and underlies various diseases like gastrointestinal disorders, renal, liver an More Edible colors are materials which in the case of adding to food and drinks cause transferring color to them. Most of these colors are not acceptable in terms of applying in human food and underlies various diseases like gastrointestinal disorders, renal, liver and blood toxicity. The goal of this study was investigating the efficiency of improved alumina by sodium dodecyl sulfate (SDS) in eliminating Tartrazine from aqueous environments. In this research, the impact of effective parameters such as initial concentration of Tartrazine, time, pH, alumina dose and SDS value were studied in order to approach an optimal condition for eliminating the color. Also, absorption behavior was evaluated by Freundlich and Langmuir isotherms. The highest efficiency of Tartrazine elimination in the solution resulted in optimal pH of 2, the amount of adsorbent 1.5 g/L, 16 min duration and value 0.04 SDS g/l which was obtained for dye concentration 5 mg/L about 94.13%. Also, results suggested that Tartrazine absorption follows Langmuir isotherm (R2 = 0.9867). Obtained results from thermodynamic studies such as Gibbs free energy (-5.728 Kj/mol) and enthalpy (-85.86 Kj/mol) and entropy (-271.102 J/mol.K) also suggested that the absorption process was exothermic. The results of this research suggested that improved alumina by sodium dodecyl sulfate had a relative good capability in Tartrazine elimination from aqueous environments. Thus Manuscript profile -
Open Access Article
28 - Comparing the capability of various models for predicting of the Bayer process parameters
Ahad Ghaemi Shahrokh Shahhosseini Mostafa Mahmoudian -
Open Access Article
29 - Polyacrylamide synthesis of nanostructured copper aluminate for photocatalytic application
reza pournajaf Sayed Ali Hassanzadeh-Tabrizi -
Open Access Article
30 - Fabrication of high–strength alumina composite foams through gel–casting process
Sanaz Naghibi Elham Sheikhi -
Open Access Article
31 - Photocatalytic degradation of Malachite Green by Sr3MxAl2O6+δ ﴾M=None, Sm3+, Eu3+, Ho3+ and Yb3+) nanomaterial as an excellent and recyclable photocatalyst
Alireza Hakimyfard shahin khademinia -
Open Access Article
32 - Inclusion Removal Mechanisms of Al-Killed 304 Low Carbon Stainless Steel Melt Using Hercynite Coated Al2O3-C Ceramic Foam Filters
Ali Baghaei Amir Abbas Nourbakhsh Reza Ebrahimi-Kahrizsangi -
Open Access Article
33 - The effect of adding different amount of spinning additives on preparation of nano Alumina fibers using a combined method of sol gel and electrospining
Fateme Mirjalili fyrozeh danafar -
Open Access Article
34 - The effect of MgCl2.6H2O and NaF on properties of Chitosan / HA-Al2O3 Scaffold
Fateme Mirjalili esmail salahi Ali kaffashiyan -
Open Access Article
35 - Optimization of fuel ratio in solution combustion method for fabrication of nickel aluminate spinel used in the esterification reaction
Hamed Nayebzadeh Alireza Heydari Ali Ahmadpour Naser Saghatoleslami Amir-Hossein Azmoon -
Open Access Article
36 - Adsorption Behavior of the Primary, Secondary and Tertiary Alkyl, Allyl and Aryl Alcohols Over Nanoscale (1 0 0) Surface of γ-Alumina
Mehdi Zamani Hossein A. Dabbagh -
Open Access Article
37 - Effect of Alumina Nanoparticles on the Enhancement of Shape Memory, Mechanical and Impact Properties of TPU/ABS blend
Zeinab Sohrabi Abdolhossein Fereidoon Farzaneh Memarian -
Open Access Article
38 - Adsorption and Optimization Removal of Co(tsPc)-4 from aqueous solution using Nanoalumina
Amir Vahid Majid Abdous Aliakbar MiranBeigi Shahnaz Nayeri -
Open Access Article
39 - The effect of MgCl2.6H2O and NaF on properties of Chitosan / HAAl2O3 Scaffold
Fateme Mirjalili Ali Kafashiyan Esmail Salahi -
Open Access Article
40 - The effect of adding different amount of spinning additives on preparation of nano Alumina fibers using a combined method of sol gel and electrospining
F. Mirjalili F. Danafar A. Zarei Mahmodabadi -
Open Access Article
41 - Investigation of the Impact of the Alumina Powder Presence in Dielectric on Electrical Discharge Machining Parameters of A413 Aluminum Workpiece using Taguchi's Experiment Design, Signal-to-noise Analysis, and Total Normalized Quality Loss
Mojtaba Shahbazi Dastjerdi Ali Mokhtarian Mojtaba Rahimi -
Open Access Article
42 - Surface modification of γ-alumina by NaNO2, NaNO3, HNO2, HNO3 and H2SO4: A DFT-D approach
Mehdi Zamani Hossein A. Dabbagh -
Open Access Article
43 - Operating condition effect on achieving higher propene yield in propane oxidative dehydrogenation process
Yousef Zeinaly Seyed Mehdi Alavi -
Open Access Article
44 - Friedel–Crafts synthesis of triarylmethanes over 3-methyl-1-sulfonic acid imidazolium tetrachloroaluminate under solvent-free conditions
Saeid Azimi Mohammad Ali Zolfigol Ahmad Reza Moosavi-Zare -
Open Access Article
45 - Effect of NaNO2, HNO3 and H2SO4 on the structure and reactivity of gamma-alumina
Abdol Hossein Dabbagh Marzie Naderi Mehdi Zamani -
Open Access Article
46 - Sol-gel synthesis of nanoporous γ-alumina using TX-100 or gelatin/TX-100 mixture as effective catalysts for dehydration of alcohols
Soheyl Alidoust Mehdi Zamani Morteza Jabbari -
Open Access Article
47 - Efficient one-pot synthesis of pyrazoles catalyzed by nano-crystalline solid acid catalyst
Abbas Teimouri Alireza Najafi Chermahini Leila Ghorbanian -
Open Access Article
48 - Improving methodology for the preparation of highly substituted imidazoles using nano-MgAl2O4 as catalyst under microwave irradiation
Javad Safari Soheila Gandomi-Ravandi Zahra Akbari -
Open Access Article
49 - The effect of post-synthesis modification of Faujasite zeolites (X, Y) on the catalytic performance of diesel hydrodesulfurization process
Hamid Karami Mohammad Kazemeini Saeed Soltanali Mehdi RashidzadehFaujasite zeolites are considered as the main and important component of catalysts of hydrotreating process; In order to zeolites to be achieved higher acidity and volume of mesopores, post-synthetic modification method (dealumination) with different techniques such as: MoreFaujasite zeolites are considered as the main and important component of catalysts of hydrotreating process; In order to zeolites to be achieved higher acidity and volume of mesopores, post-synthetic modification method (dealumination) with different techniques such as: acid treatment (H4EDTA) and thermal (calcination) was used. The dealumination process, while maintaining the crystal lattice of zeolite, led to exit of structural aluminum of zeolite and increase of acidity. NH3-TPD, BET, FESEM, FT-IR, AAS, XRD analyzes were used to investigate the physicochemical properties of zeolite. Atomic adsorption analysis shows an increase in the ratio of silicon to aluminum in the modified zeolite that in the De-Y and De-X zeolites, the Si/ Al ratio increased from 2.27 and 1.2 to 7.8 and 2.2 from the initial values, respectively. Measurement of surface area of zeolite and pore volume were performed by BET and BJH methods; decrease in surface area and increase in mesopore volume in modified zeolites is evident. During the dealumination process, acidity of De-Y zeolite increased from 0.72 mmol NH3 /g to 1.96 mmol NH3 /g and in De-X zeolite, the acidity increased from 0.95 mmol NH3/ g to 0.32 mmol (Na-X). Modified zeolites were used in the synthesis of HDS catalyst. The results showed that the synthesized catalysts had a better performance in removing sulfur compounds and by increasing acidity, the removal of sulfur compounds increased so that Cat-De-Y catalyst has the highest acidity and sulfur removal rate (Conversion= 89%). Manuscript profile -
Open Access Article
50 - The role of metal and non-metal nano oxides in improving the physical properties of drugsin drug formulation
Somaye Golsanamlou Aliakbar TarlaniIn this review article, the role of porous inorganic oxide compounds as drug carriers in order to improve the physical properties of drugs is discussed. Solubility and permeability of drugs in the digestive system is one of the determining factors of oral bioavailabilit MoreIn this review article, the role of porous inorganic oxide compounds as drug carriers in order to improve the physical properties of drugs is discussed. Solubility and permeability of drugs in the digestive system is one of the determining factors of oral bioavailability of drugs. There have always been drugs whose solubility needed to be optimized to prepare a suitable oral formula. Today, as a result of extensive research and the emergence of new drugs, the number of drugs that have solubility problems has increased, including some cardiac drugs that are in the second class of drugs and have low solubility. The low solubility of these types of drugs has caused therapeutic limitations because to increase the effectiveness of these drugs, a higher dose of them has to be prescribed which causes the drug to accumulate in the blood and deposit in the blood vessel wall. Therefore, drugs need a drug carrier to improve their performance. Drug delivery systems (DDS) including biodegradable polymer nanoparticles, polymer micelles, solid nanoparticles, nanoliposomes, dendrimers, magnetic nanoparticles and quantum dots have been used for this purpose for decades. However, in recent years, the use of metal and non-metal oxides in modern drug delivery systems has attracted the attention of scientists. Compared to other conventional compounds, these inorganic porous compounds have many advantages, including improving solubility and stability, the possibility of controlling the drug dosage, controlling the kinetics of drug release, delivering the drug to the target tissue, reducing side effects, increasing the biocompatibility of the drug, etc. Therefore, the use of new drug delivery systems based on the new generation of metal and non-metal oxides in order to improve the solubility, permeability and biocompatibility of drugs is an important and essential step in the formulation of drugs, which has been discussed in this article. Manuscript profile -
Open Access Article
51 - STUDY OF CO HYDROGENATION TO VALUABLE PRODUCTS USING IRON-BASED CATALYST, WITH AND WITHOUT GAMMA-ALUMINA Support PROMOTER
Neda Choodari Milani Yahya Zamani Sahar Baniyaghoob Ali Nakhaei PourPromoted and unpromoted iron-based catalysts in the Fischer-Tropsch synthesis were prepared by the impregnation method. The composition of the final iron catalysts, regarding to the atomic ratio is as follow 20%Fe/-Al2O3, 20%Fe/5%Cu/3%Zr/-Al2O3. The catalysts were cha MorePromoted and unpromoted iron-based catalysts in the Fischer-Tropsch synthesis were prepared by the impregnation method. The composition of the final iron catalysts, regarding to the atomic ratio is as follow 20%Fe/-Al2O3, 20%Fe/5%Cu/3%Zr/-Al2O3. The catalysts were characterized by X-ray diffraction (XRD), inductively coupled plasma (ICP), field emission scanning electron microscopy (FE-SEM), hydrogen temperature programmed reduction (H2-TPR), and BET techniques. The catalyst activity and product selectivity were studied in a fixed bed reactor under 20 bar of pressure, H2/CO = 1, in the temperature (270, 285, and 300 °C) and GHSV range of (2, 4, and 6 l.h-1.gcat-1). Then, the effect of temperature, GHSV and promoters (Cu and Zr) on the catalyst performance were investigated. Increasing the temperatures and GHSV were change CO conversion and product selectivity. The promoted iron-based catalysts have higher C5+ selectivity than the unpromoted catalyst, while C2-C4 selectivity decreased because of simultaneous use of Cu and Zr for promoting the iron catalyst. The Zr and Cu promoters increased the reduction rate of Fe2O3 by providing H2 dissociation sites. The unpromoted and promoted catalysts were tested, where the promoted catalyst showed desirable performance. Manuscript profile -
Open Access Article
52 - Removal of some textile cationic dyes from industrial wastewater using modified gamma alumina nanoparticles
Masoud Saadati Mortaza Iranifam Seyyed Iman MosaviThe present study deals with the removal of two cationic dyes from aqueos solutions by surfactant-modified gamma alumina nanoparticles. The nanoparticles were synthesized by sol-gel method and after modifying with sodium dodecyl sulfate (SDS), an anionic surfactant, had MoreThe present study deals with the removal of two cationic dyes from aqueos solutions by surfactant-modified gamma alumina nanoparticles. The nanoparticles were synthesized by sol-gel method and after modifying with sodium dodecyl sulfate (SDS), an anionic surfactant, had been successfully performed to remove basic brown 1 (BB1) and basic red 46 (BR46) from textile industrial effluents. The SEM images, FTIR spectra, and XRD patterns showed a successful synthesis of the nanoparticles followed by surface modification. The relationships between different condition factors (contact time, concentration of dyes, amount of adsorbent, and pH) were investigated by response surface methodology (RSM). The optimal conditions were determined to be a contact time of 15 minutes, pH of 6, initial concentrations of 27.5 mg/l and 41.6 mg/l for BB1 and BR46, respectively; and adsorbent doses of 0.030g and 0.035 g for BB1and BR46, respectively. The effect of other parameters including temperature and interfering species on the removal of dyes were also investigated and the dye removal obtained under optimal conditions were 93.12% for BB1 and 97.34% for BR46. The obtained results showed that the removal of dye with modified nanoparticles was better than unmodified nanoparticles. Manuscript profile -
Open Access Article
53 - Characterization and evaluation of effective parameters for Alumina Claus Catalysts in Iranian Refineries
maryam safaei akbar IrandoukhtClaus process is based on hundreds process of sulfur recovery units in the worldwide because of the shortening sweet hydrocarbons reservoirs and increasing the extraction of oil and gas from sour reservoirs. Suitable selection and predicting the performance of pure alum MoreClaus process is based on hundreds process of sulfur recovery units in the worldwide because of the shortening sweet hydrocarbons reservoirs and increasing the extraction of oil and gas from sour reservoirs. Suitable selection and predicting the performance of pure alumina Claus catalysts in view of the diversity of manufacturers and the high consumption is an important issue in the efficiency of Claus process. In this paper, catalysts were taken and their physical, chemical, and microstructural properties were evaluated by X-ray diffraction, scanning electron microscope, nitrogen and mercury adsorption, mechanical resistance etc. According to the results obtained from the study of the properties, the presence of active alumina phases and sodium impurity up to 2500 ppm, the lack of boehmite phase and others impurities like silica and iron oxide, good distribution of pore volumes for increasing active surface area and free access to the reaction zone are important properties. These properties lead to a longer life for the catalyst. The high attrition and mechanical resistance with maintaining proper distribution of pore volume and low density are important characters for the catalyst selection. Nanostructured catalysts have suitable properties. Manuscript profile -
Open Access Article
54 - Synthesis of highly pure poly (vinylacetate) by one- step controlled radical polymerization in the presence of cobalt catalyst using cross linked suspended polyvinyl acetate particles
محمد علی سمسارزاده علیرضا سبزواری سیده محبوبه رضویOne of the main drawbacks in organometallic-mediated radical polymerization techniques is a high amount of catalyst residual in the polymer product, which results in deep colors in polymer mixture .In this research, cross linked suspended polyvinyl acetate )SPVAc( was u MoreOne of the main drawbacks in organometallic-mediated radical polymerization techniques is a high amount of catalyst residual in the polymer product, which results in deep colors in polymer mixture .In this research, cross linked suspended polyvinyl acetate )SPVAc( was used as catalyst adsorbing agent and its release in cobalt-mediated radical polymerization of vinyl acetate. For this purpose, firstly, the adsorption process of cobalt acetylacetonate on these particles and also the thermodynamics of this process were studied. SPVAc particles have the capability of the catalyst adsorption at low temperatures and adsorbed catalyst particles are gradually released by increasing temperature to polymerization reaction temperature. The kinetic studies for vinyl acetate polymerization in the presence of cobalt acetylacetonate adsorbed on the SPVAc particle is compared with cobalt acetylacetonate mediated polymerization of vinyl acetate in the absence of SPVAc particle. The results have proved positive effects of these particles on the rate and kinetic of reaction. Then, radical polymerization of vinyl acetate without the need for purification of polymer was carried out successfully through a single reaction in a column packed with alumina and a layer of adsorbed cobalt acetylacetonate catalyst on the SPVAc particles. In this method, the slow adsorption and desorption of cobalt complex by suspended polyvinyl acetate, were followed by the radical polymerization and the final separation step. Manuscript profile -
Open Access Article
55 - Study of the effect of digestion media on the properties of γ-alumina granules prepared via an oil-drop technique
محمد عبدالهی حسین آتشی فرشاد فرشچی تبریزیHCl is always used as precursor in synthesis of γ-alumina granules via oil-drop. A comparative study was conducted to evaluate the effect of precursor on the catalytic characteristics and performance of γ-alumina prepared via the oil-drop technique. The synt MoreHCl is always used as precursor in synthesis of γ-alumina granules via oil-drop. A comparative study was conducted to evaluate the effect of precursor on the catalytic characteristics and performance of γ-alumina prepared via the oil-drop technique. The synthesized materials were characterized by X-ray diffraction (XRD), BET (Brunauer-Emmett-Teller), BJH (Barret-Joyner-Halenda), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), transmitting electron microscopy (TEM), and ammonia temperature programmed desorption (NH3-TPD( techniques. As a general trend, the γ-alumina catalyst prepared via oil-drop using HNO3 as the precursor has the higher surface area, pore volume, pore size, and distribution which are preferred in catalysis. Based on the results, the γ-alumina samples prepared using HNO3 are superior in activity about two times at 250 °C due to the differences in crystalline size, morphology, textural properties, and acid strength. Moreover, the incorporation of chlorine into γ-alumina structure is responsible for poisoning of catalysts which is evident by the less activity for the reaction Manuscript profile -
Open Access Article
56 - افزایش جذب نانو ذرات آلومینای تقویت شده در پوششهای نانوکامپوزیتی نیکلین آلومینا با استفاده از حلال آلی متانول
صادق میرزامحمدی حمید خورسند محمود محمود علی اف خضرایی -
Open Access Article
57 - بررسی تحلیلی و عددی تأثیر تراکم پرتابه بر توانایی نفوذ آن در زره پوش آلومینا
حسین کیا علی مهدی پور عمرانی -
Open Access Article
58 - Thermal and catalytic degradation study of polyethylene and investigation the catalytic effect of X-Zeolite and Silica-Alumina on degradation kinetic
Mohammad Taghi Taghizadeh Parinaz Seifi-Aghjekohal Ali Bahadori, Banafsheh Zeraatkar -
Open Access Article
59 - Effect of Reinforcer Percentage and Its Distribution on Mechanical Behavior of Alumina Reinforced Epoxy Composite
محمدحسین بینا کوروش شیروانی حمید رضا سلیمی جزیIn this paper, the shear and tensile properties of alumina reinforced epoxy composite have been studied. For this purpose, the composite samples were first produced with different weight percentages of alumina particles (10 to 50 percent). Then, the shear punching test MoreIn this paper, the shear and tensile properties of alumina reinforced epoxy composite have been studied. For this purpose, the composite samples were first produced with different weight percentages of alumina particles (10 to 50 percent). Then, the shear punching test was used for the evaluation of the shear and tensile properties of composite samples; the dispersion and distribution of alumina particles, interface of particles/ matrix, and the fracture surface of the samples were examined by the scanning electron microscope (SEM) equipped with EDS analyzer. The results of the tests showed that by the addition of alumina up to 30 percent resulted in homogenous and uniform distribution as well as more shear strength of composites. But, when the rate of the reinforcer exceeds 30 percent, the rate of the aggregation of the particles increases and consequently the composite strength is reduced. Also, a significant difference was observed between the fracture surface of pure epoxy and that of composites. Unlike pure polymers, the fracture surface of the composites reinforced with alumina (up to 30 percent) was more uneven, denoting an increase in the surface roughness due to the crack path deflection. Fracture in the reinforced composites with a percentage higher than 30 percent has again taken place due to the rate of low wetting of alumina particles with epoxy resin in particle-particle contacts. Manuscript profile -
Open Access Article
60 - Investigation the causes of corrosion and failure of the submerged entry nozzle for continuous casting of steel
رحمت الله عمادی آرش حاجی پور حسین عمادیAt present, Continuous casting is the most important method of producing ingot in the world. The controlling parts of melts are shroud, stopper and submerged entry nozzle (SEN), which are special refractories. Among the special refractory components, SEN is very importa MoreAt present, Continuous casting is the most important method of producing ingot in the world. The controlling parts of melts are shroud, stopper and submerged entry nozzle (SEN), which are special refractories. Among the special refractory components, SEN is very important. The duty of SEN is pouring the liquid steel from tundish to crystallizator. The aim of this study was to investigate the causes of corrosion and failure of the soundless SEN that used in continuous casting of Saba Steel Company. At the beginning, different sections of a sound and soundless SEN were prepared. Bulk density, apparent porosity, XRD, XRF and scanning electron microscopy was performed in this research. The results showed that unsuitable coating applied on the surface of SEN and less graphite content of zirconia graphite body of SEN are the major causes of failure so that the soundless and sound nozzle has 8 and 10 graphite percent, which leading to decreased resistance to thermal shock and corrosion. Manuscript profile -
Open Access Article
61 - The effect of niobium oxide (Nb2O5 ) on the sintering behavior of composite Al2O3-ZrO2
حسین خوارزمی پور khalil ranjbarIn this research, the effect of adding niobium oxide to the microstructure and stability of the zirconia phase in the sintering sample obtained from an alumina-zirconia composite following mechanical milling. To this end, alumina and zirconia powders were used as the ra MoreIn this research, the effect of adding niobium oxide to the microstructure and stability of the zirconia phase in the sintering sample obtained from an alumina-zirconia composite following mechanical milling. To this end, alumina and zirconia powders were used as the raw materials and niobium oxide powder was used as additive. All of the alumina-zirconia composites contained an invariant zirconia content equal to 10 weight percent, and 1 weight percent of niobium oxide was added to composite samples. Composite powders were subjected to axial pressure in tablet casts. Afterwards, samples were exposed to sintering for two hours in a thermal furnace at a temperature of 1300 to 1500 . X-ray diffraction was used to identify phases, and microstructures were examined through the SEM (scanning electron microscope) method. Examination and experiment results indicated that niobium oxide considerably influenced sintering density, and increased density up to 3.75 g/cm3. On the other hand, the size of background particles increased to 2.19 microns after sintering and the tetragonal phases decreased. In this research, the effect of this oxide on the sintering mechanism of the alumina-zirconia composite and stability of the zirconia tetragonal phase were discussed and analyzed. Manuscript profile -
Open Access Article
62 - Precipitation synthesis and luminescence properties of MgAl2O4 nanoparticles doped with samarium
مژده ملک پور جرقویه سید علی حسن زاده تبریزی علی صفارA surfactant assisted Co-Precipitation method was employed for the synthesis of magnesium aluminate spinel with nanocrystalline size and high specific surface area. Calcination operations were performed in 800-1000° C for two hours. Different percentages of samarium MoreA surfactant assisted Co-Precipitation method was employed for the synthesis of magnesium aluminate spinel with nanocrystalline size and high specific surface area. Calcination operations were performed in 800-1000° C for two hours. Different percentages of samarium were doped to magnesium aluminate spinel to examine the properties of magnesium aluminate spinel. The prepared samples were characterized by thermal gravimetric and differential thermal gravimetric analyses (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Transmission electron microscopy (TEM), and photoluminescence spectrum (PL). XRD results showed that nanocrystals of magnesium aluminate spinel were influenced by the type of surfactant in 800° C. The results of luminescence spectrum show that by increasing the amount of samarium after 0.15 of weight percentage, concentration suppression happens and reduces the intensity of luminescence properties. Manuscript profile -
Open Access Article
63 - Influence of the electrode distance and applied electrical potential on deposition of nano alumina in ethanol suspension
Mostafa Milani Syed Mohammad Zahraee Syed Mohammad MirkazemiThe kinetics of electrophoretic deposition is influenced by various factors. Hamakr summarized them on five parameters such as suspension concentration, electric field on the suspension, the surface area of the electrodes, electrophoretic mobility, and the process time. MoreThe kinetics of electrophoretic deposition is influenced by various factors. Hamakr summarized them on five parameters such as suspension concentration, electric field on the suspension, the surface area of the electrodes, electrophoretic mobility, and the process time. The electric field in the suspension can be changed using the electric potential applied between the electrodes and electrode distance change. Since the suspensions is a non-ohmic resistance, these two parameters will not be the same. The change of electric field using each of these two parameters causes kinetic equations change. In long distances electrodes and poor electrical potential, kinetic equations are based on electrical resistance more accurately. In the strong fields and low electrode distance kinetic equations based on equivalent conductivity are more accurate. The results of this study showed that, in the electric field 70V/cm Ferrari et al. equation and in the electric field 25V/cm Sarkar and Nicholson equation have accuracy of less than 0.01 and less than 0.1, respectively. Manuscript profile -
Open Access Article
64 - Synthesis of Lanthanum Hexaaluminate (LaMgAl11O19) Powder in order to plasma spary coating on the nickel superalloy as Thermal Barrier coating
mohammad mehdi khorramirad محمد رضا رحیمی پور سید محمد مهدی هادوی کوروش شیروانی جوزانیLanthanum hexaaluminate (LaMgAl11O19) as a new thermal barrier coating due to the properties and superior features is selected as a preferred composition instead of yttria -stabilized zirconia (YSZ) Composition. In this paper, synthesis of this composition by solid stat MoreLanthanum hexaaluminate (LaMgAl11O19) as a new thermal barrier coating due to the properties and superior features is selected as a preferred composition instead of yttria -stabilized zirconia (YSZ) Composition. In this paper, synthesis of this composition by solid state reaction method was investigated then it was prepared to coat by atmospheric plasma spraying (APS) method. Scanning electron microscope with X-ray microanalysis (SEM-EDS), differential thermal analysis (TGA/DTA), X-ray diffraction (XRD) were used to characterize of the synthesized powder, granules and free standing as-sprayed LaMgAl11O19 coating. In this research first, α-Al2O3 powder was used as a raw material. The results showed that this material was not suitable for the synthesis of this compound. Therefore γ-Al2O3 powder was used. As a result of that, a single phase compound with plate-like morphology was formed and the synthesis temperature was 1330 Cº. Also α-Al2O3, LaAlO3 and MgAl2O3 compounds were formed at 850-1100 ºC that the final phase transformation was occurred due to reaction between these three compounds. From the phase analysis results, it can be concluded that the main role of γ -Al2O3 phase in structure is to reduce the synthesis temprature of MgAl2O4 spinel phase to a temperature of less than 1100 ºC. Also chemical analysis results of granules and APS coating with optimal parameters indicated the existence of single phase structure and the second phase was not found. Manuscript profile -
Open Access Article
65 - Investigation of Microstructure of Alumina Single-Splate Made By Solution Precursor High-Velocity Flame Spraying
Saeid Taghi-ramezani Zia ValefiSolution precursor thermal Spraying (SPTS) processes are suitable methods for producing nano-structured coatings. Due to the uncompleted reactions such as solvent evaporation and pyrolysis of the precursor, achieving coatings with controlled properties at a satisfactory MoreSolution precursor thermal Spraying (SPTS) processes are suitable methods for producing nano-structured coatings. Due to the uncompleted reactions such as solvent evaporation and pyrolysis of the precursor, achieving coatings with controlled properties at a satisfactory precipitation rate remains an important challenge in these processes that needs to precise control of spray parameters. In this study, in order to investigate the effect of Solution precursor high velocity flame spraying parameters such as fuel and oxygen content, spraying distance and solution injection rate, single-scan spraying test was performed on glass substrates. The morphology of the formed splats and their structural characteristics were investigated using Scanning Electron Microscope (SEM). Structural comparison in the single-scan spraying test performed in two ratios of fuel to oxygen, showed that in the flame parameter with oxygen pressure of 6 bar and fuel 3 bar at the injection rate of Solution precursor 20 cm3/min and spray distance of 5 cm was selected as the optimal parameter. In this parameter, due to the low injection rate of the solution and higher heat transfer per drop of the solution precursor and completion of processes that resulting in melting and crystallization, the number of splats increased. Also, evaluation of single-scan spraying in the flame with oxygen pressure of 8 bar and fuel bar of 4 bar and spray distance of 5 cm showed that the injection rate of 40 cm3/min solution precursor would be more appropriate due to increasing the number of fine splats and improving coating efficiency. Manuscript profile -
Open Access Article
66 - Investigating of High Temperature Oxidation and Thermal Shock Properties of YSZ/Al2O3 Composite Thermal Barrier Coatings with Alumina Made by Solution Precursor Thermal Spray
Saeid Taghi-ramezani Zia Valefi Naser EhsaniIn this research, a double layer thermal barrier coating was applied and then an alumina diffusion barrier layer was deposited on the YSZ by two solution precersore plasma and solution precersore flame spraying. High temperature oxidation and thermal shock resistance te MoreIn this research, a double layer thermal barrier coating was applied and then an alumina diffusion barrier layer was deposited on the YSZ by two solution precersore plasma and solution precersore flame spraying. High temperature oxidation and thermal shock resistance tests were done at 1100˚C. Microstructure of coatings were studied by optical Microscopy and Field Emission Scanning Electron Microscopy. Comparison of the microstructures of coatings showed that applying of Alumina with the solution precursor flame spray process upgrades the thermal properties. High temperature oxidation and thermal shock resistance of YSZ/Al2O3 coatings with Alumina applied by the solution precersoure thermal spray with the same compound were studied. Findings showed that applying alumina with the solution precursor flame spray process leads to increase the amount of the deposited splats and proper contact between them, causes to decrease the diffusion of O2 and as a result TGO thickness decreases and also thermal shock resistance increases. Manuscript profile -
Open Access Article
67 - Comparison of Oxidation and Thermal Shock Properties of YSZ/Nanoal2o3 Composite Thermal Barrier Coatings Made By Plasma Spraying of Un-Pyrolyzed Precursor and Aglomerated Nanocrystalline Alumina Powder
Saeid Taghi-ramezani Zia Valefi Naser Ehsani masud mirjaniIn this research, firstly amorphous Alumina powder was produced by co-precipitation method. Then YSZ/Al2O3 coatings were applied by plasma spraying process in two types of pyrolyzed and crystalline nano-alumina. High temperature oxidation and thermal shock resistance te MoreIn this research, firstly amorphous Alumina powder was produced by co-precipitation method. Then YSZ/Al2O3 coatings were applied by plasma spraying process in two types of pyrolyzed and crystalline nano-alumina. High temperature oxidation and thermal shock resistance test were done at 1100˚C. Microstructure and phase analysis of coatings were studied by optical and electron microscopes and XRD method. Comparison of the microstructure of coatings showed that the use of crystalline nano-alumina powder in the YSZ/Alumina layer composite upgrades the thermal properties. High temperature oxidation and thermal shock resistance of plasma sprayed YSZ/Al2O3 with un-pyrolysed nano-alumina and coatings with same composition with crystalline nano-alumina to created by plasma spraying were studied. Findings showed that the use of un-pyrolyzed nano-alumina powder in YSZ/Al2O3 layer composite resulted in increased porosity and shrinkage cavities in the coating, which increased the diffusion of O2 that causes the TGO growth rate. Also, high density and proper contact between the splats made of crystalline nano-alumina powder results in higher resistance of thermal cycles. Manuscript profile -
Open Access Article
68 - The Investigation of the Corrosion Resistance of Al/Alumina Composites Fabricated Via ARB Process
Ali Jahangiri Sadri Mohammad Heydari Vini Saeed DaneshmandMetal matrix composites, high mechanical performance, usability at high temperatures, good wear resistance and low creep rate. This type of composite manufacturing method is very important. Among manufacturing processes, ARB process as a method of applying severe plasti MoreMetal matrix composites, high mechanical performance, usability at high temperatures, good wear resistance and low creep rate. This type of composite manufacturing method is very important. Among manufacturing processes, ARB process as a method of applying severe plastic deformation is used on the sheets. In this study 5Wt. % Al/alumina composites fabricated by accumulative roll bonding process up to eight steps using Al1060. Microstructure, mechanical properties and corrosion behavior of the composite were studied by scanning electron microscopy (SEM), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), measurement in 3.5wt% NaCl solution. Corrosion behavior of the composite revealed a considerable improvement in the main electrochemical parameters, as a result of enhancing influence of cold rolling. Also, the electrochemical experiments showed that corrosion resistance of samples increasing with increasing the number of ARB cycles. After 8- cycle ARB have a low corrosion density in comparison with high corrosion density of annealed specimens. Manuscript profile -
Open Access Article
69 - Investigation of the Wear Corrosion and Hot Corrosion Properties of Alumina Coating Applied on Steel Substrate via High Velocity Oxy-Fuel Method
seyed Ali Khosravifard Amirhosein Yaghtin Amin Akhbarizadeh Alireza AraghiIn the present work, Alumina coating with an approximate thickness of 240 µm was applied via high velocity oxy-fuel (HVOF) method on a 4340 hot-work tool steel substrate. The morphology of the coating and the influences of the corrosive medium which contained hydr MoreIn the present work, Alumina coating with an approximate thickness of 240 µm was applied via high velocity oxy-fuel (HVOF) method on a 4340 hot-work tool steel substrate. The morphology of the coating and the influences of the corrosive medium which contained hydro-chloric acid (5-15 vol.%) were studied using scanning electron microscope (SEM). Afterwards, the wear behavior of the coatings in dry and acidic wet environments were studied using a pin-on-disk wear apparatus and the wear mechanism was analyzed through SEM studies. The results of the wear tests showed that the wear rate in the 5% acidic medium was approximately the same as that of the dry test. Furthermore, the results showed that increasing the concentration of acid in the wear medium (up to 15%), leads to a continuous increase of the wear rate which was ascribed to increased corrosion rate. The dominant wear mechanism in all the tested situations was determined as sticking wear. As the wear rate increased, the wear surfaces showed increased roughness. Finally, hot corrosion experiments were carried on the coated specimens at the temperature of 880 ˚C. At this condition, the coating lasted for about 460 hours. Manuscript profile -
Open Access Article
70 - The effect of pressure on the Mg alloy-Alumina composite properties fabricated by infiltration casting
Bahman Eghtedari Mahmoud Meratian Ali Maleki Mohamad KhodaeiOne of the advanced routes for manufacturing the magnesium-matrix composites is infiltration casting into ceramic foams. In this research, magnesium-matrix composite AZ91-Al2O3 production has been investigated. Therefore, AZ91 alloy molten is prepared by usage of torch MoreOne of the advanced routes for manufacturing the magnesium-matrix composites is infiltration casting into ceramic foams. In this research, magnesium-matrix composite AZ91-Al2O3 production has been investigated. Therefore, AZ91 alloy molten is prepared by usage of torch furnace under protection of MAGREX flux, then, poured in preheated mold at 250°C with preheated alumina foam at 800 °C. For investigating the effect of pressure, pressures at 50, 75 and 100 MPa in 1 minute applied until solidification was completed. For comparison, similar experiments were done without applying pressure. The results showed that solidification under pressure reduced porosity noticeably in comparison with gravity casting to 60%. By addition the ceramic reinforcement to the base alloy, mechanical strength reduced due to formation of MgAl2O4 spinel phase at interface and formation of residual compression stresses because of thermal mismatch between matrix and reinforcement. The mechanical strength and ductility of the samples are increased by rising of applied pressure to (0-100 MPa) due to decrease grain size and better strength interface of alumina and alloy. Additionally, wear rate due of composite decreased in comparison to base alloy declined markedly (about 53%). This may be due to higher intrinsic alumina strength. Also, by applying pressure on molten metal during solidification, wear rate is noticeably lesser than similar gravity sample due to decreasing the grain size and markedly declining the porosity. The dominant mechanism for base alloy is adhesive wear and for composite is abrasive wear and delamination. Manuscript profile -
Open Access Article
71 - Design, Synthesis, Characterization and Bioactivity Evaluation of Chitosan-Grafted Alumina Nanoparticles
Elham Rostami Elham HovaziNowadays, the nanotechnology development has expanded to various medical fields, drug delivery, etc. novel drug delivery systems have made diseases cure such as cancer easier. Alumina nanoparticles have a vast use in this area due to their thermal properties. Among nume MoreNowadays, the nanotechnology development has expanded to various medical fields, drug delivery, etc. novel drug delivery systems have made diseases cure such as cancer easier. Alumina nanoparticles have a vast use in this area due to their thermal properties. Among numerous applications uses of these nanoparticles, one of the hazards to discuss is their toxicity. Besides, surface modification of these nanoparticles with chitosan as a biopolymer lead to the bioavailability improvement. In this research, alumina NPs were covered with chitosan biopolymer. Analysis of the size of particles indicated about 70 nm. FT-IR analysis on alumina and alumina/chitosan NPs showed surface modification of alumina NPs greatly. Besides, TEM images of the nanoparticles approved suitable size for drug delivery purposes. HeLa cells were treated with Alumina and Alumina/CS for 24 h, and IC50 concentration was determined. Toxic effects of these components on the cells were evaluated by MTT assay and acridine orange/ethidium bromide (AO/EB) staining. The results of the bioassay of nanoparticles well showed their successful coating by chitosan polymer. Moreover, the results detected that Alumina samples had toxic effects on the cells in a dose dependent manner and their IC50 concentration was about 25 mM. While coated samples had significantly lower toxicity and it had no significant toxicity on HeLa cells in concentrations below 5 mM. Manuscript profile -
Open Access Article
72 - The effect of the anodization voltage changes on the electric resistance of porous anodic alumina barrier layer and its thickness used in strain sensing devices
Abolfazl Salehi Amnieh Khuzani -
Open Access Article
73 - Removal of Heavy Metals (Lead and Nickel) from Water Sources by Adsorption of Activated Alumina
Fereshteh Ghomi Avili