http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Farshid Ahmadi (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Farshid Ghanbari,Mahsa Moradi,Mohammad Manshouri,Kambiz Ahmadi Angali 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2
Dyes have always been considered in the context of recalcitrant organic pollutants in water. The present research has focused on the decolorization of Direct Blue 71 (DB71) using photocatalysis process of nano-ZrO2/UV/ Persulfate. Response surface method with central composite design was applied to determine the effects of four main factors (time, ZrO2 dosage, persulfate dosage and pH) on decolorization of DB71. The results indicated that the obtained quadratic model had a high R-squared coefficient based on the analysis of variance (ANOVA). Time had the highest effect (45.5%) on decolorization of DB71. The optimum condition predicted for complete decolorization was pH=7, 0.4 g ZrO2, 0.75 mM persulfate and 40 min reaction time. Verification experiments confirmed that there was good agreement between the experimental and predicted responses. The studied photocatalytic process could oxidize and destruct the structure of the DB71, and average oxidation state (AOS) significantly increased from −1.5 to +1.33, indicating the presence of more oxidized by-products and, consequently, improvement of biodegradability. The quenching tests showed that sulfate radical was the major agent in DB71 decolorization. It can be concluded that nano-ZrO2/ UV/Persulfate is a very effective process for decolorization of colored wastewater.
-
Mehdi Ahmadi,Farshid Ghanbari,Alberto Alvarez,Susana Silva Martinez 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.8
The performance of UVA-LEDs assisted peroxymonosulfate (PMS)/Fe2+ system was evaluated on carmoisine (E122) decolorization. Complete color removal was obtained under the conditions of pH=3.0, PMS=1.5mM, Fe2+=1mM and 25 min reaction time. UVA-LEDs were preferable compared to conventional UVA lamp in terms of decolorization. The functions of Co2+, Cu2+, Mn2+ and Fe2+ were compared and their results showed that Co2+ and Fe2+ had the highest efficiencies. Moreover, the presence of chloride ion showed a double role in different concentrations in which promotional effect was observed in 100mM Cl−<, while inhibitory effect occurred in 1-10mM Cl−. However, the high concentration of chloride had no influence on mineralization of E122. The scavenging results demonstrated that the UV irradiation increased the contribution of HO•. In addition, in the presence of chloride ion, HOCl along with sulfate and hydroxyl radicals were the major oxidative agents.
-
Mehdi Abbasi,Farshid Ahmadi,Mahmoud Farzin 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.4
The only problem of pure titanium for dental implant applications is its low strength and failure under different loadings. Various studies have shown that the utilization of severe plastic deformation processes such as Equal Channel AngularPressing (ECAP), through reducing the grain size of titanium, can improve not only its mechanical properties but also itscorrosion resistance and biocompatibility. In this study, a reduced-scale ECAP process on pure titanium was performed toinvestigate the effects of scale reduction. An ECAP die was made with an internal diameter of d = 3 mm, and the tests wereperformed at 250 °C for several number of passes. It was found out that after 10 passes of reduced-scale ECAP, the grainsize of CP Ti had strongly been reduced from 25 to 122 nm. This sharp reduction in grain size resulted in an increase inmicro-hardness from 205.5 to 321.3 Hv. Moreover, Nano-hardness test results showed that after 10 passes, the hardness oftitanium increased from 2461 to 3812 MPa, and simultaneously elastic modulus decreased from 108.1 to 94.8 GPa. Suchreduction of elastic modulus of titanium for dental implant applications decreased stress-shielding and jaw bone damages. According to the results of this research, after RS-ECAP process the strength of titanium is greatly increased and its elasticmodulus is reduced, which are desirable features for dental implant applications. Since dental implants are small in size, thereduced ECAP process (d = 3–5 mm) can produce titanium implants with improved properties.
-
Ghaedi, Mehrorang,Ahmadi, Farshid,Karimi, Hajir,Gharaghani, Shiva Korean Chemical Society 2006 대한화학회지 Vol.50 No.1
원자흡수분광법을 사용하여 실제 시료 중의 구리를 예비 농축하고 정량하는데 활성탄 변형법을 사용하였다. 구리 이온을 4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline(ADMPP) 또는 4-(4-methoxybenzylidenimin)thiophenole (MBITP)과 착물을 형성시켜 활성탄에 정량적으로 흡착시키고, 고체상에 흡착된 구리를 소량의 질산을 사용하여 정량적으로 용리시켰다. 최대 회수율을 얻는데 있어서 중요한 pH, 운반체의 양, 흐름속도, 활성탄의 양, 용리제의 종류 및 농도와 같은 파라미터의 영향을 조사하였다. 최적 조건에서 ADMPP와 MBITP를 사용하는 이 방법은 0.05-1.5g mL1 and 0.05-1.2g mL1의 구리 농도 범위에서 각각 상관계수 0.9997 및 0.9994의 선형성을 보이며 검출한계는 1.4 ng mL1 였다. 예비 농축의 농축인자는 310에 이르며 돌파부피는 두 리간드에서 모두 1550 mL였다. 이 방법은 방해 이온에 대한 공차한계와 선택성이 좋아서 수돗물, 샘물, 강물 및 폐수와 같은 실제 시료 중의 구리 함량을 정량하는 데 성공적으로 사용되었다. carbon modified methods were used for the preconcentration and determination of copper in some real samples using the flame atomic absorption spectrometry. The copper ions was adsorbed quantitatively on the activated carbon due to their complexation with 4- amino-2, 3-dimethyl-1-phenyl-3-pyrazoline (ADMPP) or 4-(4- methoxybenzylidenimin) thiophenole (MBITP). The adsorbed copper on solid phase was eluted quantitatively using small amount of nitric acid. The influence of important parameters including pH, amount of carrier, flow rate, amount of activated carbon and type and concentration of eluting agent for obtaining maximum recovery were investigated. The methods based on ADMPP and MBITP at optimum conditions is linear over concentration range of 0.05-1.5 g mL-1 and 0.05-1.2 g mL-1 of copper with correlation coefficient of 0.9997 and 0.9994 and both detection limit of 1.4 ng mL-1, respectively. The preconcentration leads to enrichment factor of 310 and break through volume of 1550 mL for both ligands. The method has a good tolerance limit of interfering ion and a selectivity that has been successfully applied for the determination of copper content in real sample such as tap, spring, river and waste water.
-
Rouzhan Feizi,Mehdi Ahmadi,Sahand Jorfi,Farshid Ghanbari 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.6
Sunset yellow (SY) dye removal from aqueous solution was assessed by ultrasound/peroxymonosulfate/ CuFe2O4 nanoparticles. CuFe2O4 nanoparticles were synthesized and their properties were well determined by several advanced techniques. The effects of pH, catalyst dosage, peroxymonosulfate (PMS) concentration, and ultrasound (US) intensity were investigated on the decolorization. The best results (95.8% removal) were observed at pH=7, CuFe2O4= 25mg/L, PMS=1.5mM, US=200 W and 30 min. Nitrite and bicarbonate ions demonstrated high inhibition effect on the decolorization. PMS depicted high activity in the presence of CuFe2O4 compared to S2O8 2 and H2O2. Around 40% reduction in the decolorization was observed in reusability experiments. Sulfate and hydroxyl radicals were the major species of SY degradation based on quenching experiments. A mineralization of 50% was obtained only in 30min reaction time. This process can be effective for the destruction of organic dyes in colored wastewater.
DBpia
ScienceON연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
