Amin Jajarmi  Mojtaba Hajipour 《Asian journal of control》2017,19(2):554-563

In this paper, an efficient finite difference method is presented for the solution of time‐delay optimal control problems with time‐varying delay in the state. By using the Pontryagin's maximum principle, the original time‐delay optimal control problem is first transformed into a system of coupled two‐point boundary value problems involving both delay and advance terms. Then the derived system is converted into a system of linear algebraic equations by using a second‐order finite difference formula and a Hermite interpolation polynomial for the first‐order derivatives and delay terms, respectively. The convergence analysis of the proposed approach is provided. The new scheme is also successful for the optimal control of time‐delay systems affected by external persistent disturbances. Numerical examples are included to demonstrate the validity and applicability of the new technique. Some comparative results are included to illustrate the effectiveness of the proposed method.  相似文献   

    

Mojtaba Aghajani Delavar  Junye Wang 《American Institute of Chemical Engineers》2020,66(6):e16919

In this article, we developed a pore-scale model of integrated lattice Boltzmann method and cellular automata to investigate competitive growth of aerobic nitrite and ammonium oxidizers in a bioreactor. The results showed that inlet nutrient concentrations have significant effects on maximum biofilm concentration, ratio of microorganisms' concentrations, growth pattern, and time. The local availability of oxygen could control the competition, resulting in different growth patterns. The coexistence of ammonium and nitrite in same inlet zone increased not only the biofilm concentration (7%) but also the ratio of microorganisms' concentrations (36%). Although this coexistence decreased the total biofilm concentration in some cases, it increased the growth rate about 25%. Changes of the maximum biomass concentration could change biofilm concentration of about 40% and microorganisms' concentrations ratio of about 30%. This framework provides a powerful tool to improve our understanding of dynamic interdependency of many complex microbial consortia systems with environments.  相似文献   

    

Mingfei Xiao  Aditya Sadhanala  Mojtaba Abdi-Jalebi  Tudor H. Thomas  Xinglong Ren  Tao Zhang  Hu Chen  Remington L. Carey  Qijing Wang  Satyaprasad P. Senanayak  Cameron Jellett  Ada Onwubiko  Maximilian Moser  Hailiang Liao  Wan Yue  Iain McCulloch  Mark Nikolka  Henning Sirringhaus 《Advanced functional materials》2021,31(7):2007359

The measurement of the mechanical properties of conjugated polymers can reveal highly relevant information linking optoelectronic properties to underlying microstructures and the knowledge of the glass transition temperature (T_g) is paramount for informing the choice of processing conditions and for interpreting the thermal stability of devices. In this work, we use dynamical mechanical analysis to determine the T_g of a range of state-of-the-art conjugated polymers with different degrees of crystallinity that are widely studied for applications in organic field-effect transistors. We compare our measured values for T_g to the theoretical value predicted by a recent work based on the concept of effective mobility ζ. The comparison shows that for conjugated polymers with a modest length of the monomer units, the T_g values agree well with theoretically predictions. However, for the near-amorphous, indacenodithiophene–benzothiadiazole family of polymers with more extended backbone units, values for T_g appear to be significantly higher, predicted by theory. However, values for T_g are correlated with the sub-bandgap optical absorption suggesting the possible role of the interchain short contacts within materials’ amorphous domains.  相似文献   

    

Mohammad Moghaddam  Leila Mehdizadeh  Hossein Mirzaei Najafgholi  Abdollah Ghasemi Pirbalouti 《International Journal of Food Properties》2018,21(1):158-170

The aim of this study was to determine the chemical composition and the in vitro antimicrobial effects of seed essential oil of Ferulago angulata. The oil analyses by GC and GC/MS resulted in the identification of 39 compounds representing 91.07% of the oil. The major constituents were (Z)-β-ocimene (19.93%), α-pinene (15.50%), p-cymene (7.67%), sabinene (7.49%), β-phellandrene (5.5%), and α-phellandrene (4.95%). The oil was also screened for its antimicrobial properties against six bacteria (Erwinia amylovora, Xanthomonas oryzae, Pseudomonas syringae, Pectobacterium carotovorum, Ralstonia solanacearum, Bacillus thuringiensis) and six fungi (Alternaria alternata, Culvularia fallax, Macrophomina phaseolina, Fusarium oxysporum, Cytospora sacchari, Colletotrichum tricbellum). According to the results of antibacterial activity, B. thuringiensis (with 8 µL mL^?1 minimal inhibitory concentration (MIC) and 15 µL mL^?1 minimum bactericidal concentration (MBC)) was the most sensitive bacterium; P. carotovorum and R. solanacearum (with 20 µL mL^?1 MIC and 30< MBC) were the most resistant bacteria. Additionally, a broad differentiation against all of the tested fungi showed that the most susceptible and resistant fungi after 6 days at the highest concentration (800 µL L^?1) were F. oxysporum (100.0 ± 0.00%) and C. tricbellum (52.50 ± 1.67%) of growth inhibition, respectively.  相似文献   

    

Ershad Sheibani  Arasb Dabbagh Moghaddam  Anousheh Sharifan  Zahra Afshari 《Journal of the science of food and agriculture》2018,98(4):1444-1452

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Mojtaba Mirdrikvand  Jan Ilsemann  Jorg Thöming  Wolfgang Dreher 《化学工程与技术》2018,41(9):1871-1880

Gas diffusivity measurements in opaque porous media were performed using nuclear magnetic resonance. An optimized pulsed‐field gradient stimulated echo method with free volume selection was used to investigate the propagator of thermally polarized methane gas within commercial monolithic catalyst supports. Since signal losses due to T₂ relaxation were minimized by using a short echo time, diffusion processes could be characterized by the measured propagator functions and effective diffusion coefficients were determined for a broad range of observation times and in different spatial directions. The study of this noninvasive characterization of gas diffusion found a clear effect of the monolith type and its pore size and coating on the effective gas diffusion coefficient and the apparent tortuosity for a given observation time.  相似文献   

    

Elham Khanniri  Mojtaba Yousefi  Nasim Khorshidian  Sara Sohrabvandi  Amir M Mortazavian 《International Journal of Dairy Technology》2019,72(1):8-14

The effects of locust bean, carboxymethyl cellulose, a mixture of locust bean and carboxymethyl cellulose and Persian gum on different properties of nonfat doogh were studied over a period of 28 days. The results showed that samples containing a mixture of locust bean and carboxymethyl cellulose had the highest stability. Furthermore, the rheological behaviour of the doogh changed from Newtonian to pseudoplastic. Better sensory acceptability was shown for the treatments containing a mixture of locust bean gum and carboxymethyl cellulose. In general, it was shown that a mixture of locust bean and carboxymethyl cellulose could be of practical use in the industrial production of nonfat doogh.  相似文献   

    

Ali Saberi Moghaddam  Mohammad Reza Rezaei  Saeed Tavangar 《Propellants, Explosives, Pyrotechnics》2019,44(9):1154-1159

Gel propulsion systems are of increasing interest due to their valuable energetic and safety considerations. In this paper, performance parameters of gelled UDMH/IRFNA bi‐propellant were compared with performance parameters of its liquid bi‐propellant. Fire tests were carried out with combustion chamber pressures of about 1 to 3 MPa and L* values of 89, 127 and 162 cm. The results showed that the suitable L* to obtain best performance for liquid UDMH/IRFNA combination at the mentioned conditions was 127 cm and for gelled UDMH/IRFNA bi‐propellant was 162 cm, although the increase in performance with an increase of L* from 127 to 162 cm for the gel was very low.  相似文献   

    

Bahador Hajimohammadi  Mojtaba Raeisi  Ebrahim Eftekhar  Razieh Mohebat  Azadeh Saffari 《Journal of Food Safety》2019,39(1)

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Zahra Andaji‐Garmaroudi  Mojtaba Abdi‐Jalebi  Dengyang Guo  Stuart Macpherson  Aditya Sadhanala  Elizabeth M. Tennyson  Edoardo Ruggeri  Miguel Anaya  Krzysztof Galkowski  Ravichandran Shivanna  Kilian Lohmann  Kyle Frohna  Sebastian Mackowski  Tom J. Savenije  Richard H. Friend  Samuel D. Stranks 《Advanced materials (Deerfield Beach, Fla.)》2019,31(42)

Mixed‐halide lead perovskites have attracted significant attention in the field of photovoltaics and other optoelectronic applications due to their promising bandgap tunability and device performance. Here, the changes in photoluminescence and photoconductance of solution‐processed triple‐cation mixed‐halide (Cs_0.06MA_0.15FA_0.79)Pb(Br_0.4I_0.6)₃ perovskite films (MA: methylammonium, FA: formamidinium) are studied under solar‐equivalent illumination. It is found that the illumination leads to localized surface sites of iodide‐rich perovskite intermixed with passivating PbI₂ material. Time‐ and spectrally resolved photoluminescence measurements reveal that photoexcited charges efficiently transfer to the passivated iodide‐rich perovskite surface layer, leading to high local carrier densities on these sites. The carriers on this surface layer therefore recombine with a high radiative efficiency, with the photoluminescence quantum efficiency of the film under solar excitation densities increasing from 3% to over 45%. At higher excitation densities, nonradiative Auger recombination starts to dominate due to the extremely high concentration of charges on the surface layer. This work reveals new insight into phase segregation of mixed‐halide mixed‐cation perovskites, as well as routes to highly luminescent films by controlling charge density and transfer in novel device structures.  相似文献