Sharif Digital Repository

This study aimed to evaluate and compare the performance of wastewater disinfection systems using ultraviolet radiation (UV) and ozonation to improve the secondary effluent quality of Isfahan North wastewater treatment plant. Therefore, the filtered effluent by a pretreatment unit from micro-screen drum filter type with a pore size of 20 µm entered the disinfection pilots containing medium pressure (MP) UV lamps and ozonation system as tertiary treatment. In this study, the irradiation dose of UV (430–3,680 mW/cm2), and injection dose (10–40 mg/L), and contact time (1–15 min) of ozonation were altered. The results showed that the total suspended solids were reduced by 61.27% at the maximum... 

Camosol was isolated from the aerial parts of Salvia eremophula Boiss and full assignments of 1H and 13C-NMR spectral data are presented  

Phytochemical investigation of the aerial parts of Salvia eremophila led to the isolation of a lupane triterpenoid, 3β, 20-dihydroxylupane-28-oic acid (1), together with eight other compounds, comprising three diterpene, two triterpene, two flavonoids and a steroidal glucoside. Their structures were elucidated by interpretation of their one-dimensional and two-dimensional NMR spectra and completed by the analysis of the HRESIMS data. Compounds 1, 2-4 and 8 were evaluated for their cytotoxicities against five human tumour cell lines. Compounds 1 and 3 hold a good potential for use in future studies due to their anti-cancer properties  

Spark discharge method in inert gas, due to simplicity, no need for complex equipment and raw materials, ability to produce high-purity nanoparticles and mix metallic nanoparticles, is considered a susceptible method for the synthesis of nanoparticles with narrow size distribution. This method is capable to produce nanoparticles of electrical conductor materials and semiconductors. Also, with small changes in spark discharge system, this method can be capable to deposit thin layers of nanoparticles. Now, this method has been used for producing carbon, metal, alloy and metal oxide nanoparticles. Primary objective of this study was to construct a high voltage electrical discharge system. Next... 

This paper develops a new evolutionary algorithm for generating low autocorrelation binary sequences. These sequences are of interest in pulse compression technique. The proposed algorithm is fast enough to yield optimum or near optimum codes. The generated sequences were compared to the best literature and were seen that its results are better than the others. This suggested method could change 11 rows of the previous best known PSLs table, whereas the previous literature could change only one record. These records were combined with the best results reported in the papers to produce a new best minimal-PSL binary sequence table for bit lengths 71 through 100. ©2008 IEEE  

Abstract: Nickel–titanium (NiTi) nanoparticles are ultrafine smart materials manifesting shape memory effect at very small scales. We have produced NiTi nanoparticles surrounded by an amorphous carbon shell using an innovative spark discharge system. The resulting nanoparticles were studied using various characterization methods to systematically study their size, morphology, size distribution, composition, structure, and thermal behavior. Field-emission scanning electron microscopy and dynamic light-scattering results indicated that the average size of the produced nanoparticles was about 13 nm. High-resolution transmission electron microscopy, energy-dispersive spectroscopy (EDS), and... 

Four compounds β-sitosterol, β-sitosterol-3-O-β-D- glucopyranoside, ursolic acid and 4′,5,6-trihydroxy-3′,7- dimethoxyflavone were characterized from the dichloromethane extract of the aerial parts of Satureja khuzistanica (Lamiaceae), a native medicinal plant growing in Iran, on the basis of spectral analysis and comparing with the data in literature. The natural occurrence of these compounds can be conclusive for the chemotaxonomic characterization of the genus Satureja. © 2006 The Author(s)  

The fabrication of Ni/Ti laminated composite via cross accumulative roll bonding (CARB) and subsequent annealing treatment has been studied. The relationships between annealing conditions and microstructure at interfaces of Ni/Ti have been investigated by SEM, XRD, and EDS analyses. The results show that the layers were well-bonded by the CARB process, and by increasing the temperature and time of annealing treatment, the interfacial layers grew as a result of the interdiffusion of Ni and Ti atoms. The main intermetallic phases were NiTi and NiTi2, both of which obeyed linear kinetics of growth. However, the calculated activation energy of NiTi was lower than that of NiTi2, indicating the... 

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Concern has been raised about authorship irregularities on this paper. Changing authors after submission without permission from the editor is against the journal policy as it is stated in the Guide for Authors. https://www.elsevier.com/journals/journal-of-manufacturing-processes/1526-6125/guide-forauthors. During revision, three authors were added and one author was removed. The author responded to some requests for clarification on these points, but those explanations did not... 

In endurance time method, seismic performance of structures under artificial intensifying accelerograms is investigated. In this method, the time duration of excitation (target time) will be assigned on the basis of linear response spectra. Damage spectra, which are the variation of a damage index versus the system period, can be used effectively to modify the target time of the excitations. In this research, various damage indices for a number of steel moment frames are estimated using the endurance time method with two types of target time, and the results are compared with those corresponding to the scaled real earthquakes. It is observed that damage estimation of the frames via the... 

In seismic resistant design of moment frames, the structure behavior under earthquakes has to be examined considering various damage criteria. Damage indices can be estimated by Endurance Time (ET) method with minimum computational effort. The quality of this estimation can be improved in different ways. In this paper, the graphs of a certain damage index versus natural period of the structure, called damage spectra, are produced applying intensifying ET records and scaled Ground Motions (GM). Then, the excitation duration of ET acceleration functions (target time) is modified in order to reach acceptable consistency between ET and GM damage spectra. Moreover, various damage indices of a... 

In endurance time method, seismic performance of structures under artificial intensifying accelerograms is investigated. In this method, the time duration of excitation (target time) will be assigned on the basis of linear response spectra. Damage spectra, which are the variation of a damage index versus the system period, can be used effectively to modify the target time of the excitations. In this research, various damage indices for a number of steel moment frames are estimated using the endurance time method with two types of target time, and the results are compared with those corresponding to the scaled real earthquakes. It is observed that damage estimation of the frames via the... 

In this paper a continuous-time state-space aerodynamic model is developed based on the boundary element method. Boundary integral equations governing the unsteady potential flow around lifting bodies are presented and modified for thin wing configurations. Next, the BEM discretized problem of unsteady flow around flat wing equivalent to the original geometry is recast into the standard form of a continuous-time state-space model considering some auxiliary assumptions. The system inputs are time derivative of the instantaneous effective angle of attack and thickness/camber correction terms while the outputs are unsteady aerodynamic coefficients. To validate the model, its predictions for... 

Hydroxyapatite nanorods aligned with ultrahigh crystallinity and high-yield were successfully synthesized through a hydrothermal approach. In this experiment, a new composition of cetyltrimethylammonium bromide ((CH 3(CH2)15N+(CH3) 3Br-) was designated as CTAP)/Ca(NO3) 2/ (NH4)2HPO4/NaOH and distilled water under hydrothermal condition, to synthesize single crystal HAp nanorods with diameter of 20 ± 10 nm and length of 80 ± 20 nm, was introduced. Crystal phases were determined by X-ray diffraction (XRD). Scanning electron microscope (SEM) was applied to investigate the morphology. The microstructure of the HAp products were further observed by transmission electron microscope (TEM) and high... 

Among the various techniques of electronic warfare in the sea, chaff has particular importance due to its easy application and its impact on the victim radar. Despite the great history of chaff, the significant research has not been published on its recognition. It is difficult to study the behavior of chaff because of the impossibility of chaff tests in an unechoic chamber. Therefore simulation would be a suitable alternative. In this paper, the simulations of symmetric feature of chaff and target are presented and it is used to propose a processing structure, based on various classifiers, for discrimination between chaff and target. Moreover the comparison between discrimination capability... 

In current study, a meta-analysis approach was used to identify and evaluate the impact of various factors on the performance of integrated systems of anaerobic digestion with microbial electrolysis cell. In this study, related articles on the topic were systematically identified and collected according to the considered criteria, and the effect size that refers to the value of the difference between variables mean (total chemical oxygen demand (TCOD) removal rate and CH4 yield) was estimated. According to the meta-analysis, fed-batch operation mode, the range of 20< temperature ≤30 °C, metal cathodes, the range of 500< anode surface area ≤5000 cm2, HRT (hydraulic retention time) >20 days,...