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81.
A nonequilibrium stage model of reactive absorption processes has been developed, considering the interactions between reaction and diffusion in the film region. Dynamic and steady-state film models have been incorporated into the process model for low and highly soluble gases respectively. The model was validated against experimental data. The data were obtained from a pilot-plant absorption column in which simultaneous reactive absorption of ammonia and carbon dioxide in aqueous partially carbonated ammonia solution occurred. A comparison between simulation results and the experimental data showed that the model could reasonably predict the process. The model predictions were also compared with those of a process model including enhancement factor. The results indicate that using a film model leads to a more accurate process model than applying enhancement factor. 相似文献
82.
83.
Abolfazl Mohammadi Mehrdad Manteghian Amir H. Mohammadi Arash Kamran-Pirzaman 《Chemical Engineering Research and Design》2014
Hydrate dissociation conditions of hydrogen sulfide in the presence of aqueous solution of thermodynamic inhibitor (methanol, ethanol, ethylene glycol, NaCl, KCl and CaCl2) is modeled in this communication. A thermodynamic model is developed to correlate the hydrate dissociation conditions for the systems of H2S + water + salt (single and mixed salts of NaCl, KCl and CaCl2), H2S + water + alcohol (methanol or ethanol), H2S + water + ethylene glycol and H2S + water + mixed salt, and methanol/ethylene glycol. Extended-UNIQUAC (e-UNIQUAC) approach is used for modeling of the activity coefficient of water in aqueous phase. The structural parameters of e-UNIQUAC model are extracted from literature but interaction parameters of this model are obtained by fitting the model with experimental data. The results of the present model are in satisfactory agreement with experimental data. 相似文献
84.
Zeinab Salehnia Daryoush ShahbaziGahrouei Abolfazl Akbarzadeh Behzad Baradaran Safar Farajnia Mehran Naghibi 《IET nanobiotechnology / IET》2019,13(4):400
The aim of this study is to synthesise superparamagnetic iron oxide nanoparticles conjugated with anti‐epidermal growth factor receptor monoclonal antibody (ANTI‐EGFR‐SPION) and investigate its physicochemical characterisation and biocompatibility as a targeted magnetic resonance imaging (MRI) contrast agent for the EGFR‐specific detection in EGFR expressing tumour cells. These particles employed biocompatible polymers, poly(D,L‐lactide‐co‐glycolide) (PLGA) and polyethylene glycol aldehyde (PEG‐aldehyde), to increase the half‐life of particles in circulation and reduce their side effects. The Fe3 O4 ‐loaded PLGA‐PEG‐aldehyde nanoparticles were prepared by a modified water‐in‐oil‐in‐water double emulsion method. The EGFR antibody was conjugated to the surface of SPIONs using the aldehyde‐amine reaction. Synthesised conjugates (nanoprobes) were characterised using Fourier transform infrared spectrophotometry, dynamic light scattering, transmission electron microscopy images, and vibrating‐sample magnetometery, and the results showed that the conjugation was successful. The mean diameter of nanoprobes was about 25 nm. These nanoprobes exhibited excellent water‐solubility, stability, and biocompatibility. Meanwhile, MR susceptibility test proved that synthesised nanoprobes can be managed for negative contrast enhancement. The results of this study suggested the potential use of these nanoprobes for non‐invasive molecular MRI in EGFR detection in the future.Inspec keywords: solubility, nanomedicine, cancer, spectrophotometry, emulsions, biomedical MRI, nanomagnetics, nanofabrication, tumours, nanoparticles, magnetic particles, molecular biophysics, light scattering, proteins, cellular biophysics, Fourier transform spectra, superparamagnetism, polymers, transmission electron microscopy, iron compoundsOther keywords: physicochemical characterisation, superparamagnetic iron oxide nanoparticles, novel targeting cancer detection, anti‐epidermal growth factor receptor monoclonal antibody, ANTI‐EGFR‐SPION, biocompatibility, targeted magnetic resonance imaging contrast agent, EGFR‐specific detection, EGFR expressing tumour cells, biocompatible polymers, PLGA‐PEG‐aldehyde nanoparticles, modified water‐in‐oil‐in‐water double emulsion method, EGFR antibody, aldehyde‐amine reaction, synthesised conjugates were characterised using Fourier, transmission electron microscopy images, synthesised nanoprobes, EGFR detection, size 25.0 nm, Fe3 O4 相似文献
85.
Abolfazl Yousef-Zamanian 《Journal of Modern Optics》2017,64(3):300-308
A comprehensive theoretical study is presented on the polarization state of THz wave radiation from a two-colour laser-induced plasma, and its dependency on optical pulse polarizations and phase difference. We extend the so-called photocurrent model to calculate three-dimensional distribution of photocurrent from which the polarization state of the THz radiation is calculated. It is shown that the calculation results from the photocurrent model, is in agreement with the previously reported experiments. Moreover, we show the possibility of creating any desired polarization state (i.e. elliptical, circular or linear) for the THz radiation through such generation mechanism by adjusting proper parameters. 相似文献
86.
F. Vincent D. Raucoules Corresponding author T. Degroeve G. Edwards M. Abolfazl Mostafavi 《International journal of remote sensing》2013,34(18):3555-3571
In this paper, we present a study consisting of the application of radar interferometry for river/sea ice monitoring in inhabited regions and on commercial waterways. The sites studied are located in Canadian regions where ice jams constitute a common winter hazard that can cause extensive socio-economic damage and impose severe restrictions on ship traffic. ERS and Radarsat images were jointly used with traditional in situ observations to detect ice break-up in order to prevent ice jams and related problems. A coherence study served to define the synthetic aperture radar interferometry (InSAR) limits for river/sea ice dynamics monitoring. Other factors that also help to define the limits of InSAR technology for this application include the frequency of image acquisition, the minimum dimension of detected ice floes and the determination of appropriate ice types. Significant phase shifts were found for small ice floes of several hundred metres with ERS-tandem images. The analysis of the interferograms showed that it is possible to detect deformations in the ice shelf and to discriminate quantitatively the horizontal and vertical components of ice movement when the interferograms are combined with traditional observations such as meteorological data, water level, water flow and ice charts. The deformation estimated on a piece of fast river ice can be interpreted as the first sign of the ice break-up. On an estuary river that is a busy seaway, a qualitative interpretation of the interferograms served to highlight the interaction of river and tidal flows affecting the ice cover. We showed, in particular, the potential of radar interferometry and its integration with other techniques to help the authorities to prevent problems related to ice jams. 相似文献
87.
Tunable micro-electro-mechanical systems (MEMS) capacitors as the fundamental parts are embedded in MEMS AC voltage
reference sources (VRS). Being concerned with the accuracy of the output voltage in the reference sources, it gets important
to address uncertainties in the physical parameters of the MEMS capacitor. The uncertainties have the great inevitable potentiality
of bringing about output voltage perturbation. The output deterioration is more remarkable when the uncertainties
are accompanied by disturbance and noise. Manufacturers have been making great attempts to make the MEMS adjustable
capacitor with desired rigorous physical characteristics. They have also tried to mitigate physical parameter veracity. However,
ambiguity in the values of the parameters inescapably occurs in fabrication procedures since the micro-machining process
might itself suffer from uncertainties. Employing a proportional integral (PI) adaptive sliding mode controller (ASMC),
both terms of matched and unmatched uncertainties as well as the disturbance, are addressed in this work for the MEMS
AC VRS so that a strict voltage is stabilized while the system is simultaneously subjected into uncertainties and exogenous
disturbance. Cross-talk, some inertial forces, and electrostatic coercions may appear as matched and unmatched disturbances.
Alteration in stiffness and damping coefficients might also take place as matched uncertainties due to variations in the fabrication
process or even working environment. The simulation results in the paper are persuasive and the controller design
has shown a satisfactory tracking performance. 相似文献
88.
In order to analyze the stability of the underground rock structures, knowing the sensitivity of geomechanical parameters is important. To investigate the priority of these geomechanical properties in the stability of cavern, a sensitivity analysis has been performed on a single cavern in various rock mass qualities according to RMR using Phase 2. The stability of cavern has been studied by investigating the side wall deformation. Results showed that most sensitive properties are coefficient of lateral stress and modulus of deformation. Also parameters of Hoek–Brown criterion and σc have no sensitivity when cavern is in a perfect elastic state. But in an elasto-plastic state, parameters of Hoek–Brown criterion and σc affect the deformability; such effect becomes more remarkable with increasing plastic area. Other parameters have different sensitivities concerning rock mass quality (RMR). Results have been used to propose the best set of parameters for study on prediction of sidewall displacement. 相似文献
89.
We investigate the entanglement properties of the Kondo spin chain when it is prepared in its ground state as well as its
dynamics following a single bond quench. We show that a true measure of entanglement such as negativity enables to characterize
the unique features of the gapless Kondo regime. We determine the spatial extent of the Kondo screening cloud and propose
an ansatz for the ground state in the Kondo regime accessible to this spin chain; we also demonstrate that the impurity spin
is indeed maximally entangled with the Kondo cloud. We exploit these features of the entanglement in the gapless Kondo regime
to show that a single local quench at one end of a Kondo spin chain may always induce a fast and long lived oscillatory dynamics,
which establishes a high quality entanglement between the individual spins at the opposite ends of the chain. This entanglement
is a footprint of the presence of the Kondo cloud and may be engineered so as to attain—even for very large chains—a constant
high value independent of the length; in addition, it is thermally robust. Moreover, we show that high entanglement between
very distant boundary spins is generated by suddenly connecting two long Kondo spin chains. We show that this procedure provides
an efficient way to route entanglement between multiple distant sites. To better evidence the remarkable peculiarities of
the Kondo regime, we carry a parallel analysis of the entanglement properties of the Kondo spin chain model in the gapped
dimerised regime where these remarkable features are absent. 相似文献
90.
Abolfazl Hasani Baferani Abdolreza Ohadi Ali A. Katbab 《Polymer Engineering and Science》2021,61(12):3037-3049
This study investigated the carbon nanotube's aspect ratio's influence on the nanocomposite foams' cellular structure and mechanical, acoustic absorption characteristics. The free-rising foaming process has been used for producing different flexible polyurethane (PU) foams embedded with other multi-walled carbon nanotubes (MWCNT's). Dynamic mechanical and thermal analysis, flow resistivity, and compressive mechanical measurements were achieved on the prepared samples. The acoustic absorption coefficient in a wide range of frequencies was estimated for the prepared PU/CNT foamed nanocomposite samples. Results indicated that by increasing the aspect ratio of MWCNT, the absorption coefficient's peak shifts toward the lower frequencies and improved sound absorption characteristics of PU foam in the low-frequency region. Moreover, the Young modulus of nanocomposite samples increases by increasing the aspect ratio of MWCNT's, whereas the stored strain energy or area under the stress–strain curve increases. Based on the obtained results, it is observed that the acoustic absorption coefficient of produced nanocomposite foams at the frequency of 800 Hz has been reported to have a 70% improvement in 2 cm samples and a 40% improvement in 3 cm samples compared to obtained results from pure PU foam. 相似文献