A simple and highly accurate semi-analytical method, called the differential transformation method(DTM), was used for solving the nonlinear temperature distribution equation in solid and porous longitudinal fin with t...A simple and highly accurate semi-analytical method, called the differential transformation method(DTM), was used for solving the nonlinear temperature distribution equation in solid and porous longitudinal fin with temperature dependent internal heat generation. The problem was solved for two main cases. In the first case, heat generation was assumed variable by fin temperature for a solid fin and in second heat generation varied with temperature for a porous fin. Results are presented for the temperature distribution for a range of values of parameters appearing in the mathematical formulation(e.g. N, εG, and G). Results reveal that DTM is very effective and convenient. Also, it is found that this method can achieve more suitable results in comparison to numerical methods.展开更多
Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher pr...Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher properties compared to SSW in both elastic and inelastic zones.It is also concluded that the addition of CFRP(carbon fiber reinforced polymers) enhances the seismic parameters of LSSW(stiffness,energy absorption,shear capacity,over strength values).Also,stress values applied to boundary frames are lower due to post buckling forces.The effect of fiber angle was also studied and presented as a mathematical equation.展开更多
Background and aim:The liver is susceptible to ischemia-reperfusion injury(IRI)during hepatic surgery,when the vessels are compressed to control bleeding,or liver transplantation,when there is an obligate period of is...Background and aim:The liver is susceptible to ischemia-reperfusion injury(IRI)during hepatic surgery,when the vessels are compressed to control bleeding,or liver transplantation,when there is an obligate period of ischemia.The hallmark of IRI comprises mitochondrial dysfunction,which generates reactive oxygen species,and cell death through necrosis or apoptosis.Cyclosporine(CsA),which is a well-known immunosuppressive agent that inhibits calcineurin,has the additional effect of inhibiting the mito-chondrial permeability transition pore(mPTP),thereby,preventing mitochondrial swelling and injury.NIM-811,which is the nonimmunosuppressive analog of CsA,has a similar effect on the mPTP.In this study,we tested the effect of both agents on mitigating warm hepatic IRI in a murine model.Materials and methods:Before ischemic insult,the mice were administered with intraperitoneal normal saline(control);CsA at 2.5,10,or 25 mg/kg;or NIM-811 at 10 mg/kg.Thereafter,the mice were subjected to partial warm hepatic ischemia by selective pedicle clamping for 60 min,followed by 6 h of recovery after reperfusion.Serum alanine transaminase(ALT)was measured,and the liver tissue was examined histologically for the presence of apoptosis and the levels of inflammatory cytokines.Results:Compared with the control mice,the mice treated with 10 and 25 mg/kg of CsA and NIM-811 had significantly lower ALT levels(P<0.001,0.007,and 0.031,respectively).Moreover,the liver tissue showed reduced histological injury scores after treatment with CsA at 2.5,10,and 25 mg/kg and NIM-811(P=0.041,<0.001,0.003,and 0.043,respectively)and significant decrease in apoptosis after treatment with CsA at all doses(P=0.012,0.007,and<0.001,respectively).Levels of the pro-inflammatory cyto-kines,particularly interleukin(IL)-1β,IL-2,IL-4,IL-10,and keratinocyte chemoattractant/human growth-regulated oncogene significantly decreased in the mice treated with the highest dose of CsA(25 mg/kg)than those in the control mice.Conclusions:Premedication with CsA or NIM-811 miti展开更多
Recent studies have shown that architectural interior forms could impact the affective state of inhabitants.However,the direct relation of specific forms with specific affective states is difficult to determine.In add...Recent studies have shown that architectural interior forms could impact the affective state of inhabitants.However,the direct relation of specific forms with specific affective states is difficult to determine.In addition,no systematic categorization of architectural forms and their relation to emotional states exists.The investigation of the impact of architectural features on inhabitants'emotions is further complicated by the use of two-dimensional images of forms in laboratory investigations,which cannot perceive real-world architecture.Furthermore,the interior form consists of a combination of different forms rather than only pure forms,which was considered in previous studies.This study aimed to rill these gaps by evaluating interior forms on the basis of clustering different images of built living rooms throughout history as well as their impact on emotions.This study used pleasure,arousal,and dominance ratings with an emphasis on individual differences in personality.Virtual sample rooms were created based on formal clusters of architectural forms.Results showed a relationship between forms and emotional states for different personality traits.This work provided a novel approach on the influence of architecture on emotion by considering systematic form categorization and combinations,personality differences,and a virtual reality setup.展开更多
Magnetic core-shell nanoparticles have been widely studied because of their excellent and convenient magnetic and electrical properties.In this present work core-shell magneticnanoparticles (MNPs) were synthesized by ...Magnetic core-shell nanoparticles have been widely studied because of their excellent and convenient magnetic and electrical properties.In this present work core-shell magneticnanoparticles (MNPs) were synthesized by simple chemical precipitation method. Firstly Mg(x)Fe(1–x)O (magnesiwuestite) nano powder samples were synthesised by low temperature chemical combustion method. Secondly the as synthesised Mg(x)Fe(1–x)O nanoparticles are used to synthesis magnetic core-shell Nano particles byusing 2-propanol, poly ethylene glycol (PEG), ammonia solution 30 wt%, tetraethyl orthosilicate (TEOS). Separation of the core-shell magnetic nanoparticles from the aqueous suspension using a centrifuge. The synthesised MNPs and core shell MNP were characterized by X-ray diffraction (XRD), Thermal gravimetric-differential thermal analyzer (TG-DTA), Transmission electron microscopy (TEM), scanning electron microscopy (SEM), (EDAX) for structural, thermal and morphological respectively. It is observed that the particle size of spherical sampleis 32.5 nm.展开更多
The effects of manganese oxide or ceria promoters on the performance of Na2WO4/SiO2 catalysts for oxidative coupling of methane （OCM） are reported. The OCM reaction was performed in a continuous-flow microreactor at...The effects of manganese oxide or ceria promoters on the performance of Na2WO4/SiO2 catalysts for oxidative coupling of methane （OCM） are reported. The OCM reaction was performed in a continuous-flow microreactor at 800℃, atmospheric pressure and under GHSV = 13200 ml·gCat^-1·h^-1.Catalysts were characterized by in situ conductivity measurement, FT-IR spectroscopy, XRD, SEM and temperature programmed reduction analysis. Manganese oxide promoted Na2WO4/SiO2 is considered as one of the active and selective catalysts for OCM reaction. Ceria with high oxygen storage capacity is selected as a proper oxygen activator, providing a higher concentration of the oxy-anion species which is suitable for OCM reaction and compared with manganese oxide. Electrical conductivity of the catalysts was measured in OCM reaction under oxidizing atmosphere, i.e. in the absence of methane. It was found that the trimetallic catalysts, i.e. the catalysts having sodium, tungsten and Mn or Ce species, exhibited similar crystalline structures and morphologies, which lead to suitable bulk properties for the formation of an active and selective catalyst. However, tungsten had significant effect on the texture and redox properties of the catalysts. It was also shown that the crystalline structure of the bimetallic （Na＋Mn or Ce）/SiO2 samples was quite different. This reveals that the metal oxides have significant effect on the extent of crystallization, taking place in the course of interaction of sodium with silica support. Similar conductivities and catalytic performances of （Na2WO4＋Mn or Ce）/SiO2 catalysts propose that the ability of Na2WO4/SiO2 for utilizing oxy-anions formed in presence of different metal oxides is limited.展开更多
In this paper, a non-Newtonian third-grade blood in coronary and femoral arteries is simulated analytically and numerically. The blood is considered as the third- grade non-Newtonian fluid under the periodic body acce...In this paper, a non-Newtonian third-grade blood in coronary and femoral arteries is simulated analytically and numerically. The blood is considered as the third- grade non-Newtonian fluid under the periodic body acceleration motion and the pulsatile pressure gradient. The hybrid multi-step differential transformation method （Hybrid-Ms- DTM） and the Crank-Nicholson method （CNM） are used to solve the partial differential equation （PDE）, and a good agreement between them is observed in the results. The effects of the some physical parameters such as the amplitude, the lead angle, and the body acceleration frequency on the velocity and shear stress profiles are considered. The results show that increasing the amplitude, Ag, and reducing the lead angle of body acceleration, 9, make higher velocity profiles on the center line of both arteries. Also, the maximum wall shear stress increases when Ag increases.展开更多
Application of CO_(2)gas in foam enhanced oil recovery(EOR)processes has emerged as a win-win strategy for achieving higher oil recovery factor and reducing greenhouse gas emission,which can significantly help the pro...Application of CO_(2)gas in foam enhanced oil recovery(EOR)processes has emerged as a win-win strategy for achieving higher oil recovery factor and reducing greenhouse gas emission,which can significantly help the protection of the ozone layer from depletion.However,lower stability of CO_(2)-foam,as compared to the N_(2)-and CH_(4)^(-)foams,has tempted us to examine combinations of CO_(2)with these gases to not only improve the stability of the produced foam but also have CO_(2)as the gaseous phase of the foam.In this study,we investigated the effect of different gases and the mixture thereof on the performance of foams in EOR while the aqueous phase of foams is a constant mixture of Cocamidopropyl betaine surfactant(0.03 wt%)and silica nanoparticle(0.1 wt%).To this end,seven different gases,including N_(2),CO_(2),CH4,80%N_(2)^(+)20%CO_(2),80%CH_(4)^(+)20%CO_(2),50%CH_(4)^(+)50%CO_(2),50%N_(2)^(+)50%CO_(2)were used as the gases phase for foam generation and the performance of the produced foams were examined through the following experiments:bulk foam stability tests,apparent foam viscosity measurements and core flooding tests.The results of foam stability tests showed that half-life time for the CO_(2)-,CH_(4)^(-)and N_(2)-foams are 13.5,17.0 and 44.0 min,respectively.Also,as revealed from apparent viscosity measurements,the N_(2)-and 80%N_(2)^(+)20%CO_(2)foams have higher apparent foam viscosity values followed by 50%N_(2)^(+)50%CO_(2)foam.Furthermore,we showed that a combination of 80%N_(2)^(+)20%CO_(2)as the gaseous phase for foam generation could not only improve CO_(2)-foam stability,as compared to other foams,but also can substantially increase ultimate oil recovery(56.6%OOIP),even more than that for N_(2) foam(48.6%OOIP),obtained from core flooding experiments.展开更多
A city is a vital organism that lives and grows （ike other organisms. Therefore, implementing development plans that would provide a sense of unity and integration in relation to the city as a who（e is necessary. Tr...A city is a vital organism that lives and grows （ike other organisms. Therefore, implementing development plans that would provide a sense of unity and integration in relation to the city as a who（e is necessary. Traditional Iranian architecture is full of samples evolved during the course of Iranian history that can serve as architectural paragons of the city. In Iran＇s traditional cities, a sense of unity exists in various urban areas. The traditional city of Isfahan is one of the most valuable samples and was selected as the case study in this research. According（y, the most important questions of this research are as follows： （1） What is the role of bazaars in creating a sense of unity in the traditional cities of Iran？ （2） How do bazaars play out their ro（e in the integration of these cities？ This research focuses on the concept of a ＂traditional city＂ to determine the role of bazaars in such cities. The results show that bazaars are crucial in giving a sense of integrity to the concept of a traditional Iranian city. Bazaars provide cohesion among the different parts of cities, such as residential areas, as well as socio-political and trade centers. This condition means that traditional bazaars play two important roles in traditional cities： （1） they interconnect the different parts of thecity＇s physical structure; and （2） the crucial role of bazaars in a city＇s socia（ and cultural structure brings about unity among the citizens in the city. Bazaars as a unifying etement connect the main urban functions and guarantee the city＇s economic and social rife.展开更多
Novel dopamine-derivative compound,3,5-diamino-N-（3,4-dihydroxyphenethyl）benzamide（3,5-DAB）was prepared in two steps.In the first step dopamine hydrochloride was reacted with 3,5-dinitrobenzoyl chloride in the pre...Novel dopamine-derivative compound,3,5-diamino-N-（3,4-dihydroxyphenethyl）benzamide（3,5-DAB）was prepared in two steps.In the first step dopamine hydrochloride was reacted with 3,5-dinitrobenzoyl chloride in the presence of propylene oxide.In the second step reduction of nitro groups resulted in preparation of 3,5-DAB in quantitative yield.This material was characterized using conventional spectroscopic methods such as FT-IR and ~1H NMR.In addition,the redox response of a modified carbon nanotubes paste electrode of 3,5-DAB was investigated in aqueous solution at a neutral pH.The result showed that the electrode process has a quasi-reversible response,withΔE_p,greater than the（59/n） mV expected for a reversible system.Finally,the diffusion coefficient for redox process in paraffin oil matrix obtained using chronoamperometry methods.展开更多
Tin dioxide (SnO2 ) nanoparticles efficiently catalyzed unsymmetrical four-component Hantzsch condensations of various aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate to form polyhydroquinoline derivativ...Tin dioxide (SnO2 ) nanoparticles efficiently catalyzed unsymmetrical four-component Hantzsch condensations of various aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate to form polyhydroquinoline derivatives in excellent yields. This novel method offers several advantages over the traditional method of synthesizing these compounds, including safety, mild conditions, short reaction times, high yields, and an easy workup.展开更多
The detailed kinetics of Fischer-Tropsch synthesis over an industrial Fe/Cu/La/Si catalyst was studied in a continuous spinning basket re- actor under the conditions relevant to industrial operations. Reaction rate eq...The detailed kinetics of Fischer-Tropsch synthesis over an industrial Fe/Cu/La/Si catalyst was studied in a continuous spinning basket re- actor under the conditions relevant to industrial operations. Reaction rate equations were derived on the basis of Langmuir-Hinshelwood- Hougen-Watson type models for Fischer-Tropsch synthesis based on possible reactions sets originated from the carbide, enolic and combined enol/carbide mechanisms. Kinetic model candidates were evaluated by the global optimization of kinetic parameters, which were realized by first minimization of multi-response objective functions with conventional Levenberg-Marquardt method. It was found that an enolic mech- anism based model could produce a good fit of the experimental data. The activation energy for paraffin formation is 95 kJ.mo1-1 which is smaller than that for olefin formation （121 kJ.mol-1）.展开更多
Unsteady turbulent magnetohydrodynamic nanofluid hydrothermal treatment is studied. The zero- equation turbulence model is used to simulate turbulent flow. The modeling results obtained by applying the hybrid differen...Unsteady turbulent magnetohydrodynamic nanofluid hydrothermal treatment is studied. The zero- equation turbulence model is used to simulate turbulent flow. The modeling results obtained by applying the hybrid differential transformation method-finite difference method to solve this problem confirm its viability. An analytical procedure is used for finding the effects of the problem parameters. Results indicate that the average Nusselt number over the lower plate depends linearly on volume fraction of nanofluid, Hall parameter, turbulent Eckert number, and Reynolds number whereas it is inversely proportional on the Hartmann number and the turbulent parameter.展开更多
A hydrodynamic model is used to investigate the characteristics of positive ions in the sheath region of a low-pressure magnetized electronegative discharge. Positive ions are modeled as a cold fluid, while the electr...A hydrodynamic model is used to investigate the characteristics of positive ions in the sheath region of a low-pressure magnetized electronegative discharge. Positive ions are modeled as a cold fluid, while the electron and negative ion density distributions obey the Boltzmann distribution with two different temperatures. By taking into account the ion-neutral collision effect in the sheath region and assuming that the momentum transfer cross section has a power law dependence on the velocity of positive ions, the sheath formation criterion （modified Bohm＇s criterion） is derived and it is shown that there are specified maximum and minimum limits for the ion Mach number M. Considering these two limits of M, the behaviors of electrostatic potential, charged particle density distributions and positive ion velocities in the sheath region are studied for different values of ion-neutral collision frequency.展开更多
The effect of reduction procedure on catalyst properties, activity and products selectivity of ruthenium-promoted Co/γ-Al2O3 catalyst in Fischer-Tropsch synthesis （FTS） was investigated. Catalyst samples were redu...The effect of reduction procedure on catalyst properties, activity and products selectivity of ruthenium-promoted Co/γ-Al2O3 catalyst in Fischer-Tropsch synthesis （FTS） was investigated. Catalyst samples were reduced with different reduction gas compositions and passivated before being characterized by TPR and XRD techniques. Different activity and product selectivity analyses were also performed. These results showed that the catalyst dispersion, particle size, and the degree of reduction changed with different reduction gas compositions, which were resulted from the water partial pressures in reduction process that give varying degrees of interaction with the support. It has been suggested that the FTS activity of cobalt catalyst was directly dependent on the catalyst reducibility. A reduction gas with a molar ratio of H2Prle = 1 was used to prevent the formation of Co-support compound during catalyst reduction.展开更多
Background and Objective: The effectiveness of ephedrine and/or phenylephrine, in treatment of hypotension secondary to spinal anesthesia for cesarean section and their effects on fetal/neonatal outcome were studied. ...Background and Objective: The effectiveness of ephedrine and/or phenylephrine, in treatment of hypotension secondary to spinal anesthesia for cesarean section and their effects on fetal/neonatal outcome were studied. Methods and Materials: Sixty healthy parturients were randomly assigned to two groups;group E (n = 33) received boluses 5 mg/ml increments ephedrine and group P (n = 27) received a boluses of phnylephrine 100 μg/ml increments for treatment of hypotension after spinal block during cesarean section. Changes in maternal blood pressure and heart rate, and incidence of nausea-vomiting, neonatal Apgar score at 1 and 5 minutes of delivery, and umbilical arterial blood gas values were recorded. Results: There were no differences in treatment of hypotension following sympathectomy after spinal block with two drugs. Neonatal outcome was similar in two groups. There were not significant differences in umbilical arterial values in two groups. Conclusion: Ephedrine and phenylephrine are both effective vasopressores for treatment of hypotension associated to spinal block during cesarean section without adverse effects on infants/neonates.展开更多
AIM： To study the effect of a one-year lamivudine regimen in patients with chronic hepatitis B. METHODS： Medical records of HBeAg negative hepatitis B patients who attended a hepatitis clinic in Tehran between March...AIM： To study the effect of a one-year lamivudine regimen in patients with chronic hepatitis B. METHODS： Medical records of HBeAg negative hepatitis B patients who attended a hepatitis clinic in Tehran between March 2002-March 2004 were evaluated. The patients received 100 mg lamivudine tablets once daily for at least 12 mo. Liver enzymes and complete blood count were checked at baseline and the end of treatment （12th mo） and 6 mo after discontinuation of treatment. RESULTS： Of all patients, 24 were excluded. Of 71 patients left, 58 （81.7%） were men. Mean age of the patients was 38 ± 14 years. Mean level of ALT in serum was 1437 ± 205 nkat/L at baseline with a significant reduction at the end of treatment to a mean level of 723 ± 92 nkat/L （P = 0.002）. In 38 patients （53.5%）, the ALT level was normal after one-year treatment. Five patients （7.3%） relapsed （biochemically） within 6 mo after discontinuing lamivudine therapy （the patients with good end of treatment response）. Mean level of AST in serum was 1060 ± 105 nkat/L at baseline which decreased significantly to 652 ± 75 nkat/L at the end of treatment （P = 0.002）. CONCLUSION： Over half （53.5%） of chronic hepatitis B patients with HBeAg negative have normal liver enzyme level at 12-mo lamivudine therapy.展开更多
The quantum theory of dark soliton propagation in fibers is studied based on the linearization approximation. Then the uncertainties in photon number, phase, position （time） and momentum of quantized dark solitons a...The quantum theory of dark soliton propagation in fibers is studied based on the linearization approximation. Then the uncertainties in photon number, phase, position （time） and momentum of quantized dark solitons are calculated. Finally, the squeezing of the dark soliton is investigated by using homodyne detection and compared with bright soliton case.展开更多
Reinforced concrete(RC) load bearing wall is widely used in high-rise and mid-rise buildings. Due to the number of walls in plan and reduction in lateral force portion, this system is not only stronger against earthqu...Reinforced concrete(RC) load bearing wall is widely used in high-rise and mid-rise buildings. Due to the number of walls in plan and reduction in lateral force portion, this system is not only stronger against earthquakes, but also more economical. The effect of progressive collapse caused by removal of load bearing elements, in various positions in plan and stories of the RC load bearing wall system was evaluated by nonlinear dynamic and static analyses. For this purpose, three-dimensional model of 10-story structure was selected. The analysis results indicated stability, strength and stiffness of the RC load-bearing wall system against progressive collapse. It was observed that the most critical condition for removal of load bearing walls was the instantaneous removal of the surrounding walls located at the corners of the building where the sections of the load bearing elements were changed. In this case, the maximum vertical displacement was limited to 6.3 mm and the structure failed after applying the load of 10 times the axial load bored by removed elements. Comparison between the results of the nonlinear dynamic and static analyses demonstrated that the "load factor" parameter was a reasonable criterion to evaluate the progressive collapse potential of the structure.展开更多
文摘A simple and highly accurate semi-analytical method, called the differential transformation method(DTM), was used for solving the nonlinear temperature distribution equation in solid and porous longitudinal fin with temperature dependent internal heat generation. The problem was solved for two main cases. In the first case, heat generation was assumed variable by fin temperature for a solid fin and in second heat generation varied with temperature for a porous fin. Results are presented for the temperature distribution for a range of values of parameters appearing in the mathematical formulation(e.g. N, εG, and G). Results reveal that DTM is very effective and convenient. Also, it is found that this method can achieve more suitable results in comparison to numerical methods.
文摘Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher properties compared to SSW in both elastic and inelastic zones.It is also concluded that the addition of CFRP(carbon fiber reinforced polymers) enhances the seismic parameters of LSSW(stiffness,energy absorption,shear capacity,over strength values).Also,stress values applied to boundary frames are lower due to post buckling forces.The effect of fiber angle was also studied and presented as a mathematical equation.
文摘Background and aim:The liver is susceptible to ischemia-reperfusion injury(IRI)during hepatic surgery,when the vessels are compressed to control bleeding,or liver transplantation,when there is an obligate period of ischemia.The hallmark of IRI comprises mitochondrial dysfunction,which generates reactive oxygen species,and cell death through necrosis or apoptosis.Cyclosporine(CsA),which is a well-known immunosuppressive agent that inhibits calcineurin,has the additional effect of inhibiting the mito-chondrial permeability transition pore(mPTP),thereby,preventing mitochondrial swelling and injury.NIM-811,which is the nonimmunosuppressive analog of CsA,has a similar effect on the mPTP.In this study,we tested the effect of both agents on mitigating warm hepatic IRI in a murine model.Materials and methods:Before ischemic insult,the mice were administered with intraperitoneal normal saline(control);CsA at 2.5,10,or 25 mg/kg;or NIM-811 at 10 mg/kg.Thereafter,the mice were subjected to partial warm hepatic ischemia by selective pedicle clamping for 60 min,followed by 6 h of recovery after reperfusion.Serum alanine transaminase(ALT)was measured,and the liver tissue was examined histologically for the presence of apoptosis and the levels of inflammatory cytokines.Results:Compared with the control mice,the mice treated with 10 and 25 mg/kg of CsA and NIM-811 had significantly lower ALT levels(P<0.001,0.007,and 0.031,respectively).Moreover,the liver tissue showed reduced histological injury scores after treatment with CsA at 2.5,10,and 25 mg/kg and NIM-811(P=0.041,<0.001,0.003,and 0.043,respectively)and significant decrease in apoptosis after treatment with CsA at all doses(P=0.012,0.007,and<0.001,respectively).Levels of the pro-inflammatory cyto-kines,particularly interleukin(IL)-1β,IL-2,IL-4,IL-10,and keratinocyte chemoattractant/human growth-regulated oncogene significantly decreased in the mice treated with the highest dose of CsA(25 mg/kg)than those in the control mice.Conclusions:Premedication with CsA or NIM-811 miti
基金We would like to thank Ms.Elham Rahimi for her kind assistance in VR preparation of this project.This work was supported by the Cognitive Science and Technology Council(COGC),Tehran,Iran to MB[number 1586].All 3D modeling and VR creation were done at Technische Universitat Berlin.This manuscript is independent of Autodesk,Inc.and is not sponsored by Autodesk,Inc.
文摘Recent studies have shown that architectural interior forms could impact the affective state of inhabitants.However,the direct relation of specific forms with specific affective states is difficult to determine.In addition,no systematic categorization of architectural forms and their relation to emotional states exists.The investigation of the impact of architectural features on inhabitants'emotions is further complicated by the use of two-dimensional images of forms in laboratory investigations,which cannot perceive real-world architecture.Furthermore,the interior form consists of a combination of different forms rather than only pure forms,which was considered in previous studies.This study aimed to rill these gaps by evaluating interior forms on the basis of clustering different images of built living rooms throughout history as well as their impact on emotions.This study used pleasure,arousal,and dominance ratings with an emphasis on individual differences in personality.Virtual sample rooms were created based on formal clusters of architectural forms.Results showed a relationship between forms and emotional states for different personality traits.This work provided a novel approach on the influence of architecture on emotion by considering systematic form categorization and combinations,personality differences,and a virtual reality setup.
文摘Magnetic core-shell nanoparticles have been widely studied because of their excellent and convenient magnetic and electrical properties.In this present work core-shell magneticnanoparticles (MNPs) were synthesized by simple chemical precipitation method. Firstly Mg(x)Fe(1–x)O (magnesiwuestite) nano powder samples were synthesised by low temperature chemical combustion method. Secondly the as synthesised Mg(x)Fe(1–x)O nanoparticles are used to synthesis magnetic core-shell Nano particles byusing 2-propanol, poly ethylene glycol (PEG), ammonia solution 30 wt%, tetraethyl orthosilicate (TEOS). Separation of the core-shell magnetic nanoparticles from the aqueous suspension using a centrifuge. The synthesised MNPs and core shell MNP were characterized by X-ray diffraction (XRD), Thermal gravimetric-differential thermal analyzer (TG-DTA), Transmission electron microscopy (TEM), scanning electron microscopy (SEM), (EDAX) for structural, thermal and morphological respectively. It is observed that the particle size of spherical sampleis 32.5 nm.
文摘The effects of manganese oxide or ceria promoters on the performance of Na2WO4/SiO2 catalysts for oxidative coupling of methane （OCM） are reported. The OCM reaction was performed in a continuous-flow microreactor at 800℃, atmospheric pressure and under GHSV = 13200 ml·gCat^-1·h^-1.Catalysts were characterized by in situ conductivity measurement, FT-IR spectroscopy, XRD, SEM and temperature programmed reduction analysis. Manganese oxide promoted Na2WO4/SiO2 is considered as one of the active and selective catalysts for OCM reaction. Ceria with high oxygen storage capacity is selected as a proper oxygen activator, providing a higher concentration of the oxy-anion species which is suitable for OCM reaction and compared with manganese oxide. Electrical conductivity of the catalysts was measured in OCM reaction under oxidizing atmosphere, i.e. in the absence of methane. It was found that the trimetallic catalysts, i.e. the catalysts having sodium, tungsten and Mn or Ce species, exhibited similar crystalline structures and morphologies, which lead to suitable bulk properties for the formation of an active and selective catalyst. However, tungsten had significant effect on the texture and redox properties of the catalysts. It was also shown that the crystalline structure of the bimetallic （Na＋Mn or Ce）/SiO2 samples was quite different. This reveals that the metal oxides have significant effect on the extent of crystallization, taking place in the course of interaction of sodium with silica support. Similar conductivities and catalytic performances of （Na2WO4＋Mn or Ce）/SiO2 catalysts propose that the ability of Na2WO4/SiO2 for utilizing oxy-anions formed in presence of different metal oxides is limited.
文摘In this paper, a non-Newtonian third-grade blood in coronary and femoral arteries is simulated analytically and numerically. The blood is considered as the third- grade non-Newtonian fluid under the periodic body acceleration motion and the pulsatile pressure gradient. The hybrid multi-step differential transformation method （Hybrid-Ms- DTM） and the Crank-Nicholson method （CNM） are used to solve the partial differential equation （PDE）, and a good agreement between them is observed in the results. The effects of the some physical parameters such as the amplitude, the lead angle, and the body acceleration frequency on the velocity and shear stress profiles are considered. The results show that increasing the amplitude, Ag, and reducing the lead angle of body acceleration, 9, make higher velocity profiles on the center line of both arteries. Also, the maximum wall shear stress increases when Ag increases.
文摘Application of CO_(2)gas in foam enhanced oil recovery(EOR)processes has emerged as a win-win strategy for achieving higher oil recovery factor and reducing greenhouse gas emission,which can significantly help the protection of the ozone layer from depletion.However,lower stability of CO_(2)-foam,as compared to the N_(2)-and CH_(4)^(-)foams,has tempted us to examine combinations of CO_(2)with these gases to not only improve the stability of the produced foam but also have CO_(2)as the gaseous phase of the foam.In this study,we investigated the effect of different gases and the mixture thereof on the performance of foams in EOR while the aqueous phase of foams is a constant mixture of Cocamidopropyl betaine surfactant(0.03 wt%)and silica nanoparticle(0.1 wt%).To this end,seven different gases,including N_(2),CO_(2),CH4,80%N_(2)^(+)20%CO_(2),80%CH_(4)^(+)20%CO_(2),50%CH_(4)^(+)50%CO_(2),50%N_(2)^(+)50%CO_(2)were used as the gases phase for foam generation and the performance of the produced foams were examined through the following experiments:bulk foam stability tests,apparent foam viscosity measurements and core flooding tests.The results of foam stability tests showed that half-life time for the CO_(2)-,CH_(4)^(-)and N_(2)-foams are 13.5,17.0 and 44.0 min,respectively.Also,as revealed from apparent viscosity measurements,the N_(2)-and 80%N_(2)^(+)20%CO_(2)foams have higher apparent foam viscosity values followed by 50%N_(2)^(+)50%CO_(2)foam.Furthermore,we showed that a combination of 80%N_(2)^(+)20%CO_(2)as the gaseous phase for foam generation could not only improve CO_(2)-foam stability,as compared to other foams,but also can substantially increase ultimate oil recovery(56.6%OOIP),even more than that for N_(2) foam(48.6%OOIP),obtained from core flooding experiments.
文摘A city is a vital organism that lives and grows （ike other organisms. Therefore, implementing development plans that would provide a sense of unity and integration in relation to the city as a who（e is necessary. Traditional Iranian architecture is full of samples evolved during the course of Iranian history that can serve as architectural paragons of the city. In Iran＇s traditional cities, a sense of unity exists in various urban areas. The traditional city of Isfahan is one of the most valuable samples and was selected as the case study in this research. According（y, the most important questions of this research are as follows： （1） What is the role of bazaars in creating a sense of unity in the traditional cities of Iran？ （2） How do bazaars play out their ro（e in the integration of these cities？ This research focuses on the concept of a ＂traditional city＂ to determine the role of bazaars in such cities. The results show that bazaars are crucial in giving a sense of integrity to the concept of a traditional Iranian city. Bazaars provide cohesion among the different parts of cities, such as residential areas, as well as socio-political and trade centers. This condition means that traditional bazaars play two important roles in traditional cities： （1） they interconnect the different parts of thecity＇s physical structure; and （2） the crucial role of bazaars in a city＇s socia（ and cultural structure brings about unity among the citizens in the city. Bazaars as a unifying etement connect the main urban functions and guarantee the city＇s economic and social rife.
文摘Novel dopamine-derivative compound,3,5-diamino-N-（3,4-dihydroxyphenethyl）benzamide（3,5-DAB）was prepared in two steps.In the first step dopamine hydrochloride was reacted with 3,5-dinitrobenzoyl chloride in the presence of propylene oxide.In the second step reduction of nitro groups resulted in preparation of 3,5-DAB in quantitative yield.This material was characterized using conventional spectroscopic methods such as FT-IR and ~1H NMR.In addition,the redox response of a modified carbon nanotubes paste electrode of 3,5-DAB was investigated in aqueous solution at a neutral pH.The result showed that the electrode process has a quasi-reversible response,withΔE_p,greater than the（59/n） mV expected for a reversible system.Finally,the diffusion coefficient for redox process in paraffin oil matrix obtained using chronoamperometry methods.
基金the research facilities provided by the Ayatollah Amoli Branch of the Islamic Azad University
文摘Tin dioxide (SnO2 ) nanoparticles efficiently catalyzed unsymmetrical four-component Hantzsch condensations of various aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate to form polyhydroquinoline derivatives in excellent yields. This novel method offers several advantages over the traditional method of synthesizing these compounds, including safety, mild conditions, short reaction times, high yields, and an easy workup.
文摘The detailed kinetics of Fischer-Tropsch synthesis over an industrial Fe/Cu/La/Si catalyst was studied in a continuous spinning basket re- actor under the conditions relevant to industrial operations. Reaction rate equations were derived on the basis of Langmuir-Hinshelwood- Hougen-Watson type models for Fischer-Tropsch synthesis based on possible reactions sets originated from the carbide, enolic and combined enol/carbide mechanisms. Kinetic model candidates were evaluated by the global optimization of kinetic parameters, which were realized by first minimization of multi-response objective functions with conventional Levenberg-Marquardt method. It was found that an enolic mech- anism based model could produce a good fit of the experimental data. The activation energy for paraffin formation is 95 kJ.mo1-1 which is smaller than that for olefin formation （121 kJ.mol-1）.
文摘Unsteady turbulent magnetohydrodynamic nanofluid hydrothermal treatment is studied. The zero- equation turbulence model is used to simulate turbulent flow. The modeling results obtained by applying the hybrid differential transformation method-finite difference method to solve this problem confirm its viability. An analytical procedure is used for finding the effects of the problem parameters. Results indicate that the average Nusselt number over the lower plate depends linearly on volume fraction of nanofluid, Hall parameter, turbulent Eckert number, and Reynolds number whereas it is inversely proportional on the Hartmann number and the turbulent parameter.
文摘A hydrodynamic model is used to investigate the characteristics of positive ions in the sheath region of a low-pressure magnetized electronegative discharge. Positive ions are modeled as a cold fluid, while the electron and negative ion density distributions obey the Boltzmann distribution with two different temperatures. By taking into account the ion-neutral collision effect in the sheath region and assuming that the momentum transfer cross section has a power law dependence on the velocity of positive ions, the sheath formation criterion （modified Bohm＇s criterion） is derived and it is shown that there are specified maximum and minimum limits for the ion Mach number M. Considering these two limits of M, the behaviors of electrostatic potential, charged particle density distributions and positive ion velocities in the sheath region are studied for different values of ion-neutral collision frequency.
文摘The effect of reduction procedure on catalyst properties, activity and products selectivity of ruthenium-promoted Co/γ-Al2O3 catalyst in Fischer-Tropsch synthesis （FTS） was investigated. Catalyst samples were reduced with different reduction gas compositions and passivated before being characterized by TPR and XRD techniques. Different activity and product selectivity analyses were also performed. These results showed that the catalyst dispersion, particle size, and the degree of reduction changed with different reduction gas compositions, which were resulted from the water partial pressures in reduction process that give varying degrees of interaction with the support. It has been suggested that the FTS activity of cobalt catalyst was directly dependent on the catalyst reducibility. A reduction gas with a molar ratio of H2Prle = 1 was used to prevent the formation of Co-support compound during catalyst reduction.
文摘Background and Objective: The effectiveness of ephedrine and/or phenylephrine, in treatment of hypotension secondary to spinal anesthesia for cesarean section and their effects on fetal/neonatal outcome were studied. Methods and Materials: Sixty healthy parturients were randomly assigned to two groups;group E (n = 33) received boluses 5 mg/ml increments ephedrine and group P (n = 27) received a boluses of phnylephrine 100 μg/ml increments for treatment of hypotension after spinal block during cesarean section. Changes in maternal blood pressure and heart rate, and incidence of nausea-vomiting, neonatal Apgar score at 1 and 5 minutes of delivery, and umbilical arterial blood gas values were recorded. Results: There were no differences in treatment of hypotension following sympathectomy after spinal block with two drugs. Neonatal outcome was similar in two groups. There were not significant differences in umbilical arterial values in two groups. Conclusion: Ephedrine and phenylephrine are both effective vasopressores for treatment of hypotension associated to spinal block during cesarean section without adverse effects on infants/neonates.
文摘AIM： To study the effect of a one-year lamivudine regimen in patients with chronic hepatitis B. METHODS： Medical records of HBeAg negative hepatitis B patients who attended a hepatitis clinic in Tehran between March 2002-March 2004 were evaluated. The patients received 100 mg lamivudine tablets once daily for at least 12 mo. Liver enzymes and complete blood count were checked at baseline and the end of treatment （12th mo） and 6 mo after discontinuation of treatment. RESULTS： Of all patients, 24 were excluded. Of 71 patients left, 58 （81.7%） were men. Mean age of the patients was 38 ± 14 years. Mean level of ALT in serum was 1437 ± 205 nkat/L at baseline with a significant reduction at the end of treatment to a mean level of 723 ± 92 nkat/L （P = 0.002）. In 38 patients （53.5%）, the ALT level was normal after one-year treatment. Five patients （7.3%） relapsed （biochemically） within 6 mo after discontinuing lamivudine therapy （the patients with good end of treatment response）. Mean level of AST in serum was 1060 ± 105 nkat/L at baseline which decreased significantly to 652 ± 75 nkat/L at the end of treatment （P = 0.002）. CONCLUSION： Over half （53.5%） of chronic hepatitis B patients with HBeAg negative have normal liver enzyme level at 12-mo lamivudine therapy.
文摘The quantum theory of dark soliton propagation in fibers is studied based on the linearization approximation. Then the uncertainties in photon number, phase, position （time） and momentum of quantized dark solitons are calculated. Finally, the squeezing of the dark soliton is investigated by using homodyne detection and compared with bright soliton case.
文摘Reinforced concrete(RC) load bearing wall is widely used in high-rise and mid-rise buildings. Due to the number of walls in plan and reduction in lateral force portion, this system is not only stronger against earthquakes, but also more economical. The effect of progressive collapse caused by removal of load bearing elements, in various positions in plan and stories of the RC load bearing wall system was evaluated by nonlinear dynamic and static analyses. For this purpose, three-dimensional model of 10-story structure was selected. The analysis results indicated stability, strength and stiffness of the RC load-bearing wall system against progressive collapse. It was observed that the most critical condition for removal of load bearing walls was the instantaneous removal of the surrounding walls located at the corners of the building where the sections of the load bearing elements were changed. In this case, the maximum vertical displacement was limited to 6.3 mm and the structure failed after applying the load of 10 times the axial load bored by removed elements. Comparison between the results of the nonlinear dynamic and static analyses demonstrated that the "load factor" parameter was a reasonable criterion to evaluate the progressive collapse potential of the structure.
