Showing 10 results for Mohammadkhani
Volume 4, Issue 3 (9-2015)
Abstract
Silicon (Si) is considered as one of the beneficial elements for plants that play important roles in plant resistance to stresses. In this experiment, the effects of three levels of silicon (0, 0.85 and 1.7 mM) on the growth and physiological processes of pumpkin were studied in plants inoculated with Sphaerotheca fuliginea (250000 conidia ml−1) and non-inoculated plants under hydroponic condition. Applying silicon increased the Si concentration in plant tissues. Application of Si in plants inoculated with S. fuliginea decreased significantly severity of disease symptom (30%) and also the shoot membrane permeability was decreased. Addition of Si significantly increased the reactive sulfhydryl group content whereas disease decreased sulfhydryl group which was significantly lower in Si-free medium. The infected plants that were treatedwith 1.7 mM Si levels grew and yielded similar to non -infected pumpkins. Using Si nutrition decreased Fe and Mn and increased Zn concentration in the roots and shoots of plants. Alleviation of disease severity in the silicon treatments may be due to enhancing of plant tolerance to disease by decreasing of shoot membrane permeability, increasing the reactive sulfhydryl group content, and also due to effect of silicon on the uptake and distribution of some ions. This study revealed that Silicon at 1.7 mM used in hydroponic system effectively reduced powdery mildew and improved pumpkin growth.
Roya Mohammadkhani, Ahmad Nadimi, Mohammad Khayrandish,
Volume 5, Issue 1 (3-2019)
Abstract
A survey on sawflies (Hymenoptera: Symphyta) fauna of Gorgan County, northern Iran, during 2015-2017, led to the identification of sixteen species. Six species including Arge cingulata (Jakowlew, 1891); Calameuta pallipes (Klug, 1803); Phylloecus xanthostoma (Eversmann, 1847); Allantus cingulatus (Scopoli, 1763); Ametastegia pallipes (Spinola, 1808) and Nematus lucidus (Panzer, 1801) are recorded for Golestan fauna for the first time and C. pallipes is a new record for the Iranian fauna.
Volume 5, Issue 4 (12-2016)
Abstract
The aqueous and hydroalcoholic extracts from aerial parts of Berberis thunbergii L. and Alhagi maurorum Fisch. were tested against the red flour beetle, Tribolium castaneum (Herbst), for antifeedant activity, which was measured by nutritional indices parameters such as relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and feeding deterrence index (FDI). Treatments were evaluated by the method of flour disc bioassay in the dark, at 27 ± 1 °C and 60 ± 5% RH. Aliquots of 10 µl of several concentrations from each extract (0.25-2.0%) and controls (solvents) were spread evenly on the flour discs. After evaporation of the solvent, 10 adult insects were introduced into each treatment. After 72 h, nutritional indices were calculated. Results indicated that nutritional indices varied significantly as extract concentrations increased. The difference between extracts and treatments was significant (P < 0.05). In this study, A. maurorum decreased RGR, RCR and ECI significantly more than those of B. thunbergii extract. In addition, hydroalcoholic extracts decreased RGR, RCR and ECI significantly more than those of aqueous extracts. Both plant extracts increased FDI as the extract concentrations were increased, showing high feeding deterrence activity against T. castaneum. Generally, antifeedant activity of A. maurorum was greater than that of B. thunbergii and hydroalcoholic extract was more effective than aqueous extract.
Volume 6, Issue 4 (12-2017)
Abstract
Antifeedant activity of the aqueous and hydroalcoholic extracts of leaves of Descurainia sophia L. and Thuja orientalis L. were tested against adults of Tribolium castaneum (Herbst).The experiment was designed to measure the nutritional indices such as relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and feeding deterrence index (FDI). Treatments were evaluated by the method of flour disc bioassay under dark condition, at 27 ± 1 °C and 60 ± 5% RH. Ten microliter portions of each extract at concentrations (0.25-2.0%) was spread evenly on the flour discs. Results indicated that nutritional indices were significantly affected as extract concentrations increased. In this study extracts from T. orientalis decreased RGR, RCR and ECI significantly more than that of D. sophia. In addition, hydroalcoholic extracts decreased RGR, RCR and ECI significantly more than those by aqueous extracts. Both of plant extracts increased FDI as the extract concentrations were increased, showing high feeding deterrence activity against T. castaneum. Generally, antifeedant activity of T. orientalis was greater than D. sophia and hydroalcoholic extracts were more effective than aqueous extracts.
Volume 11, Issue 2 (3-2020)
Abstract
surveying the content of Fars local periodical literatures at the late of Qajar and the beginning of Pahlavi shows that women had an effective role in the political and social activities like as the anti-authoritarian and constitutionalist movement and they had could raise their level of political and social awareness. Women in the form of communities and associations and using the magazines which were the most prevailing device at that time, tried to implement the changes in full for the society. Such efforts resulted in political and social awareness of Fars women and the whispering of the issue of women's social rights. Fars province women, through numerous articles of magazines, and for the first time acquainted with the women rights such as the right to education, the right to trade, etc. and gradually they sought to earn the aforementioned rights in the realm of action. The article is concerned on the extension of press and its influence on the process of political-social awareness and women's identity formation to assert their basic rights. The findings of the study show that the Fars press at this era was essentially self-disciplinary with the continuous pursuit of social and political rights for women and greatly assisted women to identify their rights and being socialized. The research method, since the main sources of research in the press, is based on textual analysis, which can be considered as a deeper level of descriptive-analytical method that ultimately leads to appropriate explanations.
Volume 14, Issue 2 (3-2023)
Abstract
Today, some scholars believe in which a matriarchal structure, hereditary succession is traced to a matrilineality line. The residence is matrilocal and all the essentials’ items are in the hands of women. But today we live in societies with the patriarchal and androcentric structure. Some feminist scholars believe that if a matriarchy society existed in prehistory, it may be possible to hope for the end of today's patriarchal structure. Various materials and deposits such as skeletal data and grave goods can be used to search for women, their way of life and their status in the past. With the help of research on women’s burial and how it is done in a burial site and with the help of the findings of the graves; hypotheses can be made as to the existence or absence of a matriarchal structure in that society. In this article, with the help of library research, we give a brief history of the emergence of the hypothesis of matriarchal societies and some of its features. Then, with a descriptive-analytical method and using field research conducted, we express the interpretations obtained from the findings in some burial sites in Southwest Asia. The findings indicate that there should not consider just one form of structure for all prehistoric societies in this region, and on the other hand, with all the research done in this field, there is still no firm and conclusive findings about the existence of matriarchal societies in the prehistoric area of Southwest Asia.
Volume 16, Issue 7 (9-2016)
Abstract
One of the mainchallenges existing in the field of missile aerodynamics is how to reduce the aerodynamic drag of aerospace vehicles through different mechanisms. Thus far, many investigations have been performed to determine the performance and influence of various parameters on the effectiveness of these mechanisms. The challenge particularly is more pronounced in missiles with a blunt nose. The aim of this study is to reduce the aerodynamic drag of such missiles using hybrid employment of mounted spike at the stagnation point of the nose in addition to jet injection at different positions on the spike. To this aim, spike and jet injection configurations are extracted from the literature. Jet injection is considered in the sonic regime and perpendicular to the surface of spike. All analyses are performed using Fluent software along with Navier-Stokes equations for compressible and three-dimensional flow in both steady and unsteady states considering free stream at a Mach number of 1.89 and different angles of attach. Since the numerical simulation of these models requires high processing speed and memory, parallel processing system is employed. Additionally, structure grid and κ-ω -SST turbulence models are utilized. Results indicated that a significant drop in the drag is achieved using the hybrid utilization of jet injection and spike.
Volume 17, Issue 1 (3-2017)
Abstract
Control systems under normal conditions can provide a desirable performance. But when faults occur in the system, maintaining the appropriate operating condition is a difficult and often necessary matter. In fact, lack of timely fault detection in sensitive systems will lead to damage significant amounts of resources and information. As a result, a growing tendency in the field of fault detection in both scientific and industrial communities has been created. However, if the system under consideration is nonlinear, fault detection cannot be possible with linear methods. In this case the main difficulty is in accurately modeling of process which effects on the accuracy of fault detection and troubleshooting. Fuzzy systems theory, is an effective tool to deal with the complicated and uncertain situations. This paper has considered the problem of fault detection based on the modeling for nonlinear systems using interval type-2 fuzzy system. Our proposed method for fault detection is to create a confidence bound using the estimation of upper and lower bounds for the system output which can be done using a type-2 fuzzy system. Here, a residual signal is produced which determines the presence or absence of fault in the system. In this method in case of deviating the output graph of the control system from the estimated upper and lower bounds, the occurrence of fault can be detected. Finally, in order to show the capabilities of proposed method, the method is applied on three-tank and electro-hydraulic nonlinear systems and the results are very satisfying.
Volume 19, Issue 6 (11-2017)
Abstract
Chelidonium majus is a perennial plant of the Papaveraceae family. This plant has been known as a rich source of isoquinoline alkaloids, chelidonine, and berberine, which are pharmaceutically important for their anti-cancerous activities. In the current study, four extraction techniques were compared in terms of their yield potential for chelidonine and berberine. Afterwards, High Performance Liquid Chromatography (HPLC) with a photodiode array type of UV/VIS detector was used for the detection of chelidonine and berberine from leaves and roots of five ecotypes of C. majus during various ontogenetical stages. Based on our results, ultrasonic procedures and refluxing were the best techniques for extraction of these alkaloids. HPLC results inferred that chelidonine and berberine content of ecotypes belonging to the Northern provinces of Iran, i.e. Mazandaran (IBRCP1006619) and Gorgan (IBRCP1006625), were higher than the other ecotypes. Generally, the roots of the C. majus were the most suitable organ for extraction of chelidonine at the generative stage, while at the vegetative stage, leaves are the most suitable organ for extraction of berberine.
Volume 20, Issue 2 (February 2020)
Abstract
In the present study, a new combined cycle (including a two-step flash evaporation, the Kalina cycle, and a proton-exchange membrane) for simultaneous power and hydrogen generation from Sabalan geothermal wells has been proposed and analyzed from the viewpoints of energy and exergy. The effects of important parameters including separators pressure of flash evaporation, the minimum temperature difference in the pinch point, Kalian higher pressure, superheated geothermal fluid, the ratio of consumed power for hydrogen production and dead state temperature on the amount of produced hydrogen, the net generating power, thermal and exergy efficiencies of the proposed combined cycle have been studied. The results show that for the investigated case in the proposed combined cycle, the amount of the produced hydrogen, net generating power and energy, and exergy efficiency were 1536kg/hr, 12.83MV, 11.39% and 43.64%, respectively. Increasing the pressure of the separators was not effective in increasing hydrogen production, while with increasing the first separator pressure, as well as, the second separator pressure to the optimum pressure, the thermal and exergy efficiency increase. With increasing the temperature of the proton membrane electrolyzer, the produced hydrogen discharge increases and while maintaining cycle net output power, thermal and exergy efficiencies increase. Also, at the optimum point for high-pressure Kalina, the maximum amount of hydrogen production is obtained. The highest amount of exergy degradation was obtained for the protonated membrane electrolyzer, evaporator and condenser 2, respectively.