Objective:To entrap carvacrol(CAR)in bovine serum albumin nanoparticles(BSANPs)to form CAR-loaded BSANPs(CAR@BSANPs)and to explore the anti-cancer effects in breast adenocarcinoma cells(MCF-7 cells)treated with CAR an...Objective:To entrap carvacrol(CAR)in bovine serum albumin nanoparticles(BSANPs)to form CAR-loaded BSANPs(CAR@BSANPs)and to explore the anti-cancer effects in breast adenocarcinoma cells(MCF-7 cells)treated with CAR and CAR@BSANPs.Methods:A desolvation method was used to synthesize BSANPs and CAR@BSANPs.The BSANPs and CAR@BSANPs were characterized by several physicochemical methods,including visual observation,high-resolution field emission scanning electron microscopy,Fourier transform infrared spectroscopy,and high-performance liquid chromatography.MCF-7 cells were used and analyzed after 24 h of exposure to CAR and CAR@BSANPs at half-maximal inhibitory concentration.The anti-proliferative,apoptotic,reactive oxygen species(ROS),and nitric oxide(NO)scavenging activity as well as gene expression analysis were investigated by the cell viability assay,phase-contrast microscopy,2',7'-dichlorofluorescein-diacetate assay,Griess-Illosvoy colorimetric assay,and quantitative real-time polymerase chain reaction,respectively.Results:CAR and CAR@BSANPs showed anti-proliferative,apoptotic,ROS generation,and NO scavenging effects on MCF-7 cells.Expression profile of B-cell lymphoma 2-like 11(BCL2L11),vascular endothelial growth factor A(VEGFA),hypoxia inducible factor factor-1α(HIF1A),BCL2L11/apoptosis regulator(BAX),and BCL2L11/Bcl2 homologous antagonist/killer 1(BAK1)ratios revealed downregulated genes;and BAX,BAK1,and CASP8 were upregulated by CAR and CAR@BSANPs treatment.In vitro anticancer assays of the CAR and CAR@BSANPs showed that CAR@BSANPs demonstrated higher therapeutic efficacy in the MCF-7 cells than CAR.Conclusions:CAR and CAR@BSANPs affect gene expression and may subsequently reduce the growth and proliferation of the MCF-7 cells.Molecular targeting of regulatory genes of the MCF-7 cells with CAR and CAR@BSANPs may be an effective therapeutic strategy against breast cancer.展开更多
Objective:To evaluate the effect of rosmarinic acid on tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.Methods:Rats were randomly divided into six groups:the control gr...Objective:To evaluate the effect of rosmarinic acid on tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.Methods:Rats were randomly divided into six groups:the control group,the asthmatic group,and the asthmatic groups treated with dexamethasone(1 mg/kg;oral gavage)or three doses of rosmarinic acid(0.5,1,and 2 mg/kg;oral gavage).For induction of asthma,rats received intraperitoneal injections and inhalation of ovalbumin.After 21 days,bronchoalveolar lavage fluid and lung samples were collected for histopathological analyses.Moreover,total and differential white blood cell counts were determined.Results:The rosmarinic acid-treated group had significantly lower tracheal smooth muscle responses to methacholine than the asthmatic group.In addition,rosmarinic acid reduced white blood cell count and the percentages of eosinophils,monocytes,and neutrophils while increasing the percentage of lymphocytes.Ovalbumin-induced lung pathological changes were significantly improved by treatment with rosmarinic acid.Conclusions:Rosmarinic acid improves tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.展开更多
Noise is one of the environmental factors with mental and physical effects.The workload is also the multiple mental and physical demands of the task.Therefore,his study investigated the relationship between noise expo...Noise is one of the environmental factors with mental and physical effects.The workload is also the multiple mental and physical demands of the task.Therefore,his study investigated the relationship between noise exposure and mood states at different levels of workload.The study recruited 50 workers from the manufacturing sector(blue-collar workers)as the exposed group and 50 workers from the office sector(white-collar workers)as the control group.Their occupational noise exposure was measured by dosimetry.The Stress-Arousal Checklist(SACL)and the NASA Task Load Index(NASA-TLX)were used to measure mood and workload,respectively.The equivalent noise exposure level of the exposed group at high and very high workload levels was 85 and 87 dBA,respectively.The mean mood score of the exposed group was 76 at very high workload.The correlation coefficient between noise exposure level and mood state based on workload levels ranged from 0.3 at medium workload to 0.57 at very high workload.Noise exposure at high workload levels can increase its adverse effects,so controlling and optimizing the multiple demands of the task in the workplace can be used as a privative measure to reduce the adverse effects of noise.展开更多
The ameliorative effect of fulvic acid(0, 300, and 600 mg L-1) on photosystem II and antioxidant enzyme activity of the rapeseed(Brassica napus L.) plant under water stress(60, 100, and 140 mm evaporation from class A...The ameliorative effect of fulvic acid(0, 300, and 600 mg L-1) on photosystem II and antioxidant enzyme activity of the rapeseed(Brassica napus L.) plant under water stress(60, 100, and 140 mm evaporation from class A pan) was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid(FA) improved the maximum quantum efficiency of PSII(Fv/Fm)and performance index(PI) of plants under both well-watered and limited-water conditions. The time span from Foto Fmand the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species(ROS) is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.展开更多
The impacts of climate change on agriculture are still shadowed with uncertainty. However, climate change is expected to adversely affect Iran＇s agricultural practices through changes in precipitation, temperature an...The impacts of climate change on agriculture are still shadowed with uncertainty. However, climate change is expected to adversely affect Iran＇s agricultural practices through changes in precipitation, temperature and carbon dioxide fertilization. Therefore, adaptation of this sector to the increasing weather events is imperative. This study is aimed to document the likely impacts of climate change on Iran＇s agriculture and the current adaptation efforts made by government and farmers. The review of literature shows that changes in rainfall and water endowments will have significant impacts on crop yield, crops＇ water requirements and income and welfare of farm families. The extent of the changes in yield depends on the crop type, assumptions related to the CO2 fertilization effect, climate scenarios and adaptation abilities. On adaptation, the government＇s efforts have been distinguished in the improving agricultural productivity and irrigation development based on current technology, developing new technologies and policy reforms. Farmers＇ adaptive responses have also been identified. Some conclusions and recommendations are offered to increase the adaptive capacity of farmers and reduce negative impacts of climate change.展开更多
In this article,the effect of using water/zinc oxide nanofluid as a working fluid on the performance of solar collector is investigated experimentally.The volumetric concentration of nanoparticles is 0.4%,and the part...In this article,the effect of using water/zinc oxide nanofluid as a working fluid on the performance of solar collector is investigated experimentally.The volumetric concentration of nanoparticles is 0.4%,and the particle size is 40 nm,and the mass flow rate of the fluid varies from 1 to 3 kg/min.For this experiment,a device has been prepared with appropriate measuring instruments whose energy source is solar radiation.The solar energy absorbed by the flat plate collector is absorbed by the nanofluid of water/zinc oxide.The nanofluid is pumped to the consumer,a heat exchanger,where it heats the water.The temperature,radiation level,flow rate,and pressure in different parts of the device were measured.The pressure drop and the heat transferred are the most important results of this experimental work.The ASHRAE standard is used to calculate efficiency.The results showed that the use of water/zinc oxide nanofluid increases the collector performance compared to water.For 1 kg/min of mass flow rate,the nanofluids have a 16% increase in efficiency compared to water.From the results,it can be concluded that the choice of optimum mass flow rate in both water and nanofluid cases increases efficiency.展开更多
In this paper,we analytically study vibration of functionally graded piezoelectric(FGP)nanoplates based on the nonlocal strain gradient theory.The top and bottom surfaces of the nanoplate are made of PZT-5H and PZT-4,...In this paper,we analytically study vibration of functionally graded piezoelectric(FGP)nanoplates based on the nonlocal strain gradient theory.The top and bottom surfaces of the nanoplate are made of PZT-5H and PZT-4,respectively.We employ Hamilton’s principle and derive the governing differential equations.Then,we use Navier’s solution to obtain the natural frequencies of the FGP nanoplate.In the first step,we compare our results with the obtained results for the piezoelectric nanoplates in the previous studies.In the second step,we neglect the piezoelectric effect and compare our results with those obtained for the functionally graded(FG)nanoplates.Finally,the effects of the FG power index,the nonlocal parameter,the aspect ratio,and the lengthto-thickness ratio,and the nanoplate shape on natural frequencies are investigated.展开更多
This article is about the absorbed-dose-dependent threshold voltage shift of the MOSFET transistors.Performance of the MOSFETs has been tested in different gate voltages.Sensitivity of the transistors for 662 ke V gam...This article is about the absorbed-dose-dependent threshold voltage shift of the MOSFET transistors.Performance of the MOSFETs has been tested in different gate voltages.Sensitivity of the transistors for 662 ke V gamma ray is studied in 1–5 Gy dose range.It was found that for transistors irradiated in biased mode,significant changes in the threshold voltage occurred,and the sensitivity to gamma rays increased with the bias voltage.展开更多
In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammoniu...In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–vip inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.展开更多
Kerman area is located in southern parts of central Iranian volcanic belt. The area under study is located in the southern part of this complex copper mineralization in the area, which is mainly porphyry type and is a...Kerman area is located in southern parts of central Iranian volcanic belt. The area under study is located in the southern part of this complex copper mineralization in the area, which is mainly porphyry type and is associated with extensive hydrothermal alteration. This area has a great potential as far as tertiary porphyry copper deposits are concerned. To the exploration of porphyry copper deposits in study area, we have analyzed the lineaments. The lineaments interpreted out from ETM + (band8) data is recognized as another method for locating porphyry type copper mineralization. There is a close correlation between photo lineament factor values and the known copper mineralization in the area. The relationship between 16 porphyry copper deposits with faults and fractures in the area is studied. Photo lineament factor assessments by using satellite photos indicate a strong relationship between a number of lineation intersection in each cell refer to an amount of average lineation in whole map (c/C ratio). In the study area, ratio of c/C even has more relationship refers to PF factor that has previously described in the papers.展开更多
An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trich...An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trichloro-1,3,5-triazine（TCT） under solvent-free condition at 130℃.展开更多
The fluorination reaction involving a β-ketosulfones by Selectfluor^TM was efficiently promoted by the ionic liquid, [Hbim]BF4 （IL） as a reaction medium with methanol as co-solvent at room temperature under ultraso...The fluorination reaction involving a β-ketosulfones by Selectfluor^TM was efficiently promoted by the ionic liquid, [Hbim]BF4 （IL） as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation.展开更多
The Soursat metamorphic complex （SMC） in northwestern Iran is part of the Sanandaj- Sirjan metamorphic belt. The complex is composed of different metamorphic and plutonic rocks, but is dominated by metapelites compo...The Soursat metamorphic complex （SMC） in northwestern Iran is part of the Sanandaj- Sirjan metamorphic belt. The complex is composed of different metamorphic and plutonic rocks, but is dominated by metapelites composed of garnet, staurolite, kyanite, fibrolite, cordierite, and andalusite. Porphyroblasts in schists have the same fabric, and three stages of schistosity are present. The internal schistosity （Sn） inclusion trails are also offset by conjugate sets of extensional schistosity （Sn＋l） and a second （Sn＋2） that crenulates （Sn＋l）. Polyphase metamorphisms are present in the complex. Garnet, staurolite, kyanite, and fibrolite assemblage preserves conditions during the M1 metamorphic event. This assemblage yields a P-t estimate of 645±11℃ and 6.5±0.5 kbar. Other samples of the central part of SMC contain cordierite and andalusite （M2） overgrowth that yields a P- t estimate of 532±33℃ and 2.1±1.1 kbar.展开更多
A Ni/Al layered double hydroxide(LDH) nanoparticle modified carbon ceramic electrode(Ni/Al LDH/NMCC) was fabricated and used for the electrocatalytic oxidation of methanol and ethanol in alkaline media.Cyclic voltamme...A Ni/Al layered double hydroxide(LDH) nanoparticle modified carbon ceramic electrode(Ni/Al LDH/NMCC) was fabricated and used for the electrocatalytic oxidation of methanol and ethanol in alkaline media.Cyclic voltammetric(CV) studies showed that it gave a significantly higher activity for methanol and ethanol oxidation and can be used as an electrocatalytic anode for fuel cells.The kinetic parameters of the electron transfer coefficient(α) and number of electrons involved in the rate determining step(nα) for the oxidation of methanol and ethanol were determined using CV.The anodic currents showed a linear dependence on the concentration of methanol and ethanol.展开更多
This paper deals with the free vibration analysis of circular alumina （Al2O3） nanobeams in the presence of surface and thermal effects resting on a Pasternak foun- dation. The system of motion equations is derived u...This paper deals with the free vibration analysis of circular alumina （Al2O3） nanobeams in the presence of surface and thermal effects resting on a Pasternak foun- dation. The system of motion equations is derived using Hamilton＇s principle under the assumptions of the classical Timoshenko beam theory. The effects of the transverse shear deformation and rotary inertia are also considered within the framework of the mentioned theory. The separation of variables approach is employed to discretize the governing equa- tions which are then solved by an analytical method to obtain the natural frequencies of the alumina nanobeams. The results show that the surface effects lead to an increase in the natural frequency of nanobeams as compared with the classical Timoshenko beam model. In addition, for nanobeams with large diameters, the surface effects may increase the natural frequencies by increasing the thermal effects. Moreover, with regard to the Pasternak elastic foundation, the natural frequencies are increased slightly. The results of the present model are compared with the literature, showing that the present model can capture correctly the surface effects in thermal vibration of nanobeams.展开更多
We investigated the influence of different levels of osmotic stress on growth and development in selected wild almond species （eight Prunus spp.） grown in vitro. The study, while endorsing the efficacy of in vitro s...We investigated the influence of different levels of osmotic stress on growth and development in selected wild almond species （eight Prunus spp.） grown in vitro. The study, while endorsing the efficacy of in vitro screening of auxiliary buds of wild almond for osmotic stress tolerance, showed species variability in its response to osmotic stress. Osmotic stress reduced growth and development of all the species. How-ever, the putative tolerant Prunus spp. showed better performance than the putative susceptible genotypes. On average there was an 80% de-crease in shoot dry weight at -1.2 MPa. Reduction in shoot weight was more common in osmotic stress-susceptible species in the section labeled‘Euamygdalus’. The tolerant Prunus species produced smaller changes in biochemical responses than the sensitive cultivars for malondialdehyde content, catalase activity, relative permeability of protoplast membranes, and net photosynthetic rate. The tolerant species maintained cell integrity better than drought sensitive species. Wild almond species in the section labeled ‘Spartioides’ （Prunus arabica （Olivier） Neikle, Prunus glauca＆amp;nbsp;（Browicz） A.E. Murray, Prunus scoparia Spach） and ‘Lycioides’ （Pru-nus lycioides Spach, Prunus reuteri Bossi. et Bushe） were best adapted to osmotic stress. Increase in chlorophyll concentration and leaf thickness under high osmotic stress can be considered as preliminary selection parameters for osmotic stress tolerance in Prunus spp. The study con-firmed the efficacy of the in vitro method for screening of large number of genotypes for osmotic stress tolerance in wild almond species.展开更多
Sulfonic acid functionalized pyridinium chloride [pyridine-SO3 H]Cl has been synthesized as a novel Brnsted acidic ionic liquid and characterized on the basis of its FT-IR,1H and 13C NMR,MS,ther-mogravimetry,and deriv...Sulfonic acid functionalized pyridinium chloride [pyridine-SO3 H]Cl has been synthesized as a novel Brnsted acidic ionic liquid and characterized on the basis of its FT-IR,1H and 13C NMR,MS,ther-mogravimetry,and derivative thermogravimetry data.The material has also been used as a highly efficient,homogeneous,and reusable catalyst for the preparation of hexahydroquinolines according to the one-pot multi-component condensation of arylaldehydes,dimedone(5,5-dimethylcyclohexane-1,3-dione),β-ketoesters,and ammonium acetate under solvent-free conditions.展开更多
Background:Given the importance of customers as the most valuable assets of organizations,customer retention seems to be an essential,basic requirement for any organization.Banks are no exception to this rule.The comp...Background:Given the importance of customers as the most valuable assets of organizations,customer retention seems to be an essential,basic requirement for any organization.Banks are no exception to this rule.The competitive atmosphere within which electronic banking services are provided by different banks increases the necessity of customer retention.Methods:Being based on existing information technologies which allow one to collect data from organizations’databases,data mining introduces a powerful tool for the extraction of knowledge from huge amounts of data.In this research,the decision tree technique was applied to build a model incorporating this knowledge.Results:The results represent the characteristics of churned customers.Conclusions:Bank managers can identify churners in future using the results of decision tree.They should be provide some strategies for customers whose features are getting more likely to churner’s features.展开更多
To enable the lithostratigraphic and biostratigraphie study of the Gurpi Formation, within the ＇Dezak＇ or Globigerina Marl, a stratigraphic section at Booraki, located to the NNW of Shiraz, SW Iran, through the late...To enable the lithostratigraphic and biostratigraphie study of the Gurpi Formation, within the ＇Dezak＇ or Globigerina Marl, a stratigraphic section at Booraki, located to the NNW of Shiraz, SW Iran, through the late Cretaceous was examined. The formation consists of shale and greenish-gray marls interbedded with cream limestone, brown sandstones and siltstones with an exposed thickness of 160 m in the studied section. Samples were taken at regular intervals in all yielding 14 genera and 16 different species of benthic and planktic foraminifera that allowed determination of the age of the beds as Maastrichtian. To examine the paleoecology of the formation, some important ecological factors including water level, salinity, and oxygen regime change during the depositional courses of the formation were analyzed. The density of foraminiferans decreases from the base to top of the Gurpi Formation whereas the ratio of planktic to benthic Foraminifera （i.e., P/B） and proportion of shallow-water fauna increase. These foraminiferal changes indicate an increase and decrease in depth, temperature, salinity and oxygen, respectively, at the base and top of the Formation.展开更多
文摘Objective:To entrap carvacrol(CAR)in bovine serum albumin nanoparticles(BSANPs)to form CAR-loaded BSANPs(CAR@BSANPs)and to explore the anti-cancer effects in breast adenocarcinoma cells(MCF-7 cells)treated with CAR and CAR@BSANPs.Methods:A desolvation method was used to synthesize BSANPs and CAR@BSANPs.The BSANPs and CAR@BSANPs were characterized by several physicochemical methods,including visual observation,high-resolution field emission scanning electron microscopy,Fourier transform infrared spectroscopy,and high-performance liquid chromatography.MCF-7 cells were used and analyzed after 24 h of exposure to CAR and CAR@BSANPs at half-maximal inhibitory concentration.The anti-proliferative,apoptotic,reactive oxygen species(ROS),and nitric oxide(NO)scavenging activity as well as gene expression analysis were investigated by the cell viability assay,phase-contrast microscopy,2',7'-dichlorofluorescein-diacetate assay,Griess-Illosvoy colorimetric assay,and quantitative real-time polymerase chain reaction,respectively.Results:CAR and CAR@BSANPs showed anti-proliferative,apoptotic,ROS generation,and NO scavenging effects on MCF-7 cells.Expression profile of B-cell lymphoma 2-like 11(BCL2L11),vascular endothelial growth factor A(VEGFA),hypoxia inducible factor factor-1α(HIF1A),BCL2L11/apoptosis regulator(BAX),and BCL2L11/Bcl2 homologous antagonist/killer 1(BAK1)ratios revealed downregulated genes;and BAX,BAK1,and CASP8 were upregulated by CAR and CAR@BSANPs treatment.In vitro anticancer assays of the CAR and CAR@BSANPs showed that CAR@BSANPs demonstrated higher therapeutic efficacy in the MCF-7 cells than CAR.Conclusions:CAR and CAR@BSANPs affect gene expression and may subsequently reduce the growth and proliferation of the MCF-7 cells.Molecular targeting of regulatory genes of the MCF-7 cells with CAR and CAR@BSANPs may be an effective therapeutic strategy against breast cancer.
文摘Objective:To evaluate the effect of rosmarinic acid on tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.Methods:Rats were randomly divided into six groups:the control group,the asthmatic group,and the asthmatic groups treated with dexamethasone(1 mg/kg;oral gavage)or three doses of rosmarinic acid(0.5,1,and 2 mg/kg;oral gavage).For induction of asthma,rats received intraperitoneal injections and inhalation of ovalbumin.After 21 days,bronchoalveolar lavage fluid and lung samples were collected for histopathological analyses.Moreover,total and differential white blood cell counts were determined.Results:The rosmarinic acid-treated group had significantly lower tracheal smooth muscle responses to methacholine than the asthmatic group.In addition,rosmarinic acid reduced white blood cell count and the percentages of eosinophils,monocytes,and neutrophils while increasing the percentage of lymphocytes.Ovalbumin-induced lung pathological changes were significantly improved by treatment with rosmarinic acid.Conclusions:Rosmarinic acid improves tracheal smooth muscle responsiveness and lung pathological changes in ovalbumin-sensitized rats.
文摘Noise is one of the environmental factors with mental and physical effects.The workload is also the multiple mental and physical demands of the task.Therefore,his study investigated the relationship between noise exposure and mood states at different levels of workload.The study recruited 50 workers from the manufacturing sector(blue-collar workers)as the exposed group and 50 workers from the office sector(white-collar workers)as the control group.Their occupational noise exposure was measured by dosimetry.The Stress-Arousal Checklist(SACL)and the NASA Task Load Index(NASA-TLX)were used to measure mood and workload,respectively.The equivalent noise exposure level of the exposed group at high and very high workload levels was 85 and 87 dBA,respectively.The mean mood score of the exposed group was 76 at very high workload.The correlation coefficient between noise exposure level and mood state based on workload levels ranged from 0.3 at medium workload to 0.57 at very high workload.Noise exposure at high workload levels can increase its adverse effects,so controlling and optimizing the multiple demands of the task in the workplace can be used as a privative measure to reduce the adverse effects of noise.
文摘The ameliorative effect of fulvic acid(0, 300, and 600 mg L-1) on photosystem II and antioxidant enzyme activity of the rapeseed(Brassica napus L.) plant under water stress(60, 100, and 140 mm evaporation from class A pan) was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid(FA) improved the maximum quantum efficiency of PSII(Fv/Fm)and performance index(PI) of plants under both well-watered and limited-water conditions. The time span from Foto Fmand the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species(ROS) is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.
文摘The impacts of climate change on agriculture are still shadowed with uncertainty. However, climate change is expected to adversely affect Iran＇s agricultural practices through changes in precipitation, temperature and carbon dioxide fertilization. Therefore, adaptation of this sector to the increasing weather events is imperative. This study is aimed to document the likely impacts of climate change on Iran＇s agriculture and the current adaptation efforts made by government and farmers. The review of literature shows that changes in rainfall and water endowments will have significant impacts on crop yield, crops＇ water requirements and income and welfare of farm families. The extent of the changes in yield depends on the crop type, assumptions related to the CO2 fertilization effect, climate scenarios and adaptation abilities. On adaptation, the government＇s efforts have been distinguished in the improving agricultural productivity and irrigation development based on current technology, developing new technologies and policy reforms. Farmers＇ adaptive responses have also been identified. Some conclusions and recommendations are offered to increase the adaptive capacity of farmers and reduce negative impacts of climate change.
文摘In this article,the effect of using water/zinc oxide nanofluid as a working fluid on the performance of solar collector is investigated experimentally.The volumetric concentration of nanoparticles is 0.4%,and the particle size is 40 nm,and the mass flow rate of the fluid varies from 1 to 3 kg/min.For this experiment,a device has been prepared with appropriate measuring instruments whose energy source is solar radiation.The solar energy absorbed by the flat plate collector is absorbed by the nanofluid of water/zinc oxide.The nanofluid is pumped to the consumer,a heat exchanger,where it heats the water.The temperature,radiation level,flow rate,and pressure in different parts of the device were measured.The pressure drop and the heat transferred are the most important results of this experimental work.The ASHRAE standard is used to calculate efficiency.The results showed that the use of water/zinc oxide nanofluid increases the collector performance compared to water.For 1 kg/min of mass flow rate,the nanofluids have a 16% increase in efficiency compared to water.From the results,it can be concluded that the choice of optimum mass flow rate in both water and nanofluid cases increases efficiency.
文摘In this paper,we analytically study vibration of functionally graded piezoelectric(FGP)nanoplates based on the nonlocal strain gradient theory.The top and bottom surfaces of the nanoplate are made of PZT-5H and PZT-4,respectively.We employ Hamilton’s principle and derive the governing differential equations.Then,we use Navier’s solution to obtain the natural frequencies of the FGP nanoplate.In the first step,we compare our results with the obtained results for the piezoelectric nanoplates in the previous studies.In the second step,we neglect the piezoelectric effect and compare our results with those obtained for the functionally graded(FG)nanoplates.Finally,the effects of the FG power index,the nonlocal parameter,the aspect ratio,and the lengthto-thickness ratio,and the nanoplate shape on natural frequencies are investigated.
文摘This article is about the absorbed-dose-dependent threshold voltage shift of the MOSFET transistors.Performance of the MOSFETs has been tested in different gate voltages.Sensitivity of the transistors for 662 ke V gamma ray is studied in 1–5 Gy dose range.It was found that for transistors irradiated in biased mode,significant changes in the threshold voltage occurred,and the sensitivity to gamma rays increased with the bias voltage.
文摘In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–vip inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.
文摘Kerman area is located in southern parts of central Iranian volcanic belt. The area under study is located in the southern part of this complex copper mineralization in the area, which is mainly porphyry type and is associated with extensive hydrothermal alteration. This area has a great potential as far as tertiary porphyry copper deposits are concerned. To the exploration of porphyry copper deposits in study area, we have analyzed the lineaments. The lineaments interpreted out from ETM + (band8) data is recognized as another method for locating porphyry type copper mineralization. There is a close correlation between photo lineament factor values and the known copper mineralization in the area. The relationship between 16 porphyry copper deposits with faults and fractures in the area is studied. Photo lineament factor assessments by using satellite photos indicate a strong relationship between a number of lineation intersection in each cell refer to an amount of average lineation in whole map (c/C ratio). In the study area, ratio of c/C even has more relationship refers to PF factor that has previously described in the papers.
文摘An efficient one-pot synthesis of 2,4,6-triarylpyridines has been described.This involves the three-component reaction of aldehydes,ketones and ammonium acetate in the presence of a catalytic amount of wet 2,4,6-trichloro-1,3,5-triazine（TCT） under solvent-free condition at 130℃.
文摘The fluorination reaction involving a β-ketosulfones by Selectfluor^TM was efficiently promoted by the ionic liquid, [Hbim]BF4 （IL） as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation.
基金supported by the Research Vice Chancellor of Tarbiat Moallem University(Tehran,I.R of Iran)
文摘The Soursat metamorphic complex （SMC） in northwestern Iran is part of the Sanandaj- Sirjan metamorphic belt. The complex is composed of different metamorphic and plutonic rocks, but is dominated by metapelites composed of garnet, staurolite, kyanite, fibrolite, cordierite, and andalusite. Porphyroblasts in schists have the same fabric, and three stages of schistosity are present. The internal schistosity （Sn） inclusion trails are also offset by conjugate sets of extensional schistosity （Sn＋l） and a second （Sn＋2） that crenulates （Sn＋l）. Polyphase metamorphisms are present in the complex. Garnet, staurolite, kyanite, and fibrolite assemblage preserves conditions during the M1 metamorphic event. This assemblage yields a P-t estimate of 645±11℃ and 6.5±0.5 kbar. Other samples of the central part of SMC contain cordierite and andalusite （M2） overgrowth that yields a P- t estimate of 532±33℃ and 2.1±1.1 kbar.
文摘A Ni/Al layered double hydroxide(LDH) nanoparticle modified carbon ceramic electrode(Ni/Al LDH/NMCC) was fabricated and used for the electrocatalytic oxidation of methanol and ethanol in alkaline media.Cyclic voltammetric(CV) studies showed that it gave a significantly higher activity for methanol and ethanol oxidation and can be used as an electrocatalytic anode for fuel cells.The kinetic parameters of the electron transfer coefficient(α) and number of electrons involved in the rate determining step(nα) for the oxidation of methanol and ethanol were determined using CV.The anodic currents showed a linear dependence on the concentration of methanol and ethanol.
文摘This paper deals with the free vibration analysis of circular alumina （Al2O3） nanobeams in the presence of surface and thermal effects resting on a Pasternak foun- dation. The system of motion equations is derived using Hamilton＇s principle under the assumptions of the classical Timoshenko beam theory. The effects of the transverse shear deformation and rotary inertia are also considered within the framework of the mentioned theory. The separation of variables approach is employed to discretize the governing equa- tions which are then solved by an analytical method to obtain the natural frequencies of the alumina nanobeams. The results show that the surface effects lead to an increase in the natural frequency of nanobeams as compared with the classical Timoshenko beam model. In addition, for nanobeams with large diameters, the surface effects may increase the natural frequencies by increasing the thermal effects. Moreover, with regard to the Pasternak elastic foundation, the natural frequencies are increased slightly. The results of the present model are compared with the literature, showing that the present model can capture correctly the surface effects in thermal vibration of nanobeams.
文摘We investigated the influence of different levels of osmotic stress on growth and development in selected wild almond species （eight Prunus spp.） grown in vitro. The study, while endorsing the efficacy of in vitro screening of auxiliary buds of wild almond for osmotic stress tolerance, showed species variability in its response to osmotic stress. Osmotic stress reduced growth and development of all the species. How-ever, the putative tolerant Prunus spp. showed better performance than the putative susceptible genotypes. On average there was an 80% de-crease in shoot dry weight at -1.2 MPa. Reduction in shoot weight was more common in osmotic stress-susceptible species in the section labeled‘Euamygdalus’. The tolerant Prunus species produced smaller changes in biochemical responses than the sensitive cultivars for malondialdehyde content, catalase activity, relative permeability of protoplast membranes, and net photosynthetic rate. The tolerant species maintained cell integrity better than drought sensitive species. Wild almond species in the section labeled ‘Spartioides’ （Prunus arabica （Olivier） Neikle, Prunus glauca＆amp;nbsp;（Browicz） A.E. Murray, Prunus scoparia Spach） and ‘Lycioides’ （Pru-nus lycioides Spach, Prunus reuteri Bossi. et Bushe） were best adapted to osmotic stress. Increase in chlorophyll concentration and leaf thickness under high osmotic stress can be considered as preliminary selection parameters for osmotic stress tolerance in Prunus spp. The study con-firmed the efficacy of the in vitro method for screening of large number of genotypes for osmotic stress tolerance in wild almond species.
基金partial support for this work from the Research Affairs Office of Sayyed Jamaleddin Asadabadi University,Bu-Ali Sina University(Grant no. 32-1716 entitled development of chemical methods,reagents and molecules)the Center of Excellence in Development of Chemical Method(CEDCM),Hamedan,I.R. Iran
文摘Sulfonic acid functionalized pyridinium chloride [pyridine-SO3 H]Cl has been synthesized as a novel Brnsted acidic ionic liquid and characterized on the basis of its FT-IR,1H and 13C NMR,MS,ther-mogravimetry,and derivative thermogravimetry data.The material has also been used as a highly efficient,homogeneous,and reusable catalyst for the preparation of hexahydroquinolines according to the one-pot multi-component condensation of arylaldehydes,dimedone(5,5-dimethylcyclohexane-1,3-dione),β-ketoesters,and ammonium acetate under solvent-free conditions.
文摘Background:Given the importance of customers as the most valuable assets of organizations,customer retention seems to be an essential,basic requirement for any organization.Banks are no exception to this rule.The competitive atmosphere within which electronic banking services are provided by different banks increases the necessity of customer retention.Methods:Being based on existing information technologies which allow one to collect data from organizations’databases,data mining introduces a powerful tool for the extraction of knowledge from huge amounts of data.In this research,the decision tree technique was applied to build a model incorporating this knowledge.Results:The results represent the characteristics of churned customers.Conclusions:Bank managers can identify churners in future using the results of decision tree.They should be provide some strategies for customers whose features are getting more likely to churner’s features.
文摘To enable the lithostratigraphic and biostratigraphie study of the Gurpi Formation, within the ＇Dezak＇ or Globigerina Marl, a stratigraphic section at Booraki, located to the NNW of Shiraz, SW Iran, through the late Cretaceous was examined. The formation consists of shale and greenish-gray marls interbedded with cream limestone, brown sandstones and siltstones with an exposed thickness of 160 m in the studied section. Samples were taken at regular intervals in all yielding 14 genera and 16 different species of benthic and planktic foraminifera that allowed determination of the age of the beds as Maastrichtian. To examine the paleoecology of the formation, some important ecological factors including water level, salinity, and oxygen regime change during the depositional courses of the formation were analyzed. The density of foraminiferans decreases from the base to top of the Gurpi Formation whereas the ratio of planktic to benthic Foraminifera （i.e., P/B） and proportion of shallow-water fauna increase. These foraminiferal changes indicate an increase and decrease in depth, temperature, salinity and oxygen, respectively, at the base and top of the Formation.
