Search published articles
Showing 153 results for Field
Volume 0, Issue 0 (1-2024)
Abstract
This study aimed to increase the vase life of cut rose flowers by improving the regulation of Programmed Cell Death (PCD). Experiments were carried out on cut rose (Rosa hybrida cv. Dolce vita+) flowers under either physical treatment of Static Magnetic Field (SMF; 15 and 25 mT) for 3 hours, or chemical treatments of silver nano particle (Nano-Ag; 5 and 10 ppm), 6-Benzyladenine (BA; 25 and 50 mg L-1), 1% sucrose, and combinations of 5 and 10 ppm nano-Ag with 3 and 6% sucrose. Results showed that a 15 mT-SMF significantly increased vase life up to 25 days, compared to the controls and to all chemical treatments. Among the chemicals, 5 ppm Nano-Ag and 1% (w/v) sucrose increased vase life to 23 and 18 days, respectively. The smallest decline in fresh weight was observed in the 15 mT-SMF physical treatment. Markedly, the 15 mT-SMF treatment led to the least reduction in Chlorophyll (Chl) content. On the 17th day of the applied different treatments, both Water Uptake (WU) and Relative Fresh Weight (RFW) showed an inverse significant relationship with PCD in cut rose flowers, verifying there markable delayed PCD which is favored the market. As a whole, the most effective induced treatments (15 mT-SMF, 5 ppm Nano-Ag, and 1% Sucrose) are suggested to be promising for enhancing postharvest quality and prolonged vase life of cut rose flowers.
Volume 0, Issue 0 (1-2024)
Abstract
Land use severely affects the carbon and nitrogen stock and the soil's physical, mechanical, hydraulic and chemical characteristics of the soil. This study aims to investigate the effect of land use type on some soil characteristics, including carbon stock (CS), nitrogen stock (NS), S-index, structural stability index (SSI), soil pore size distribution, soil shear strength (τ), internal friction angle (φ˚), shear cohesion (C), soil water characteristic curve (SWCC), relative field capacity (RFC), available water (AW), aeration porosity (AP) and effective porosity (Pe) in Shandiz city, Khorasan Razavi province (northeast Iran) was studied. For this purpose, 60 soil samples were taken from the surface layer (0-20 cm) in pasture and agricultural land uses. The results showed that S-Index, SSI, RFC, AW, Pe, Cs, and Ns in pasture land use were significantly higher than agricultural land use. The values of τ, C, and φ˚ in the pasture land use were significantly (p<0.01) less than the pasture land use. The relationship between soil organic carbon stock index and bulk density (r=-0.69), coarse fragments (r=-0.73), cohesion (r=-0.70), and internal friction angle (r=-0.52) were significant and negative. The amounts of carbon and nitrogen stock indices in pasture land use were 61.6 and 33.1 % greater than agricultural land use, respectively. Therefore, it can be concluded that as a result of land use change, the carbon and nitrogen stock, S-index, relative field capacity, structural stability index, available water, aeration porosity, effective porosity, and consequently, the soil quality decrease, and soil degradation increase in agricultural land use.
Volume 0, Issue 0 (8-2024)
Abstract
Concrete slabs subjected to near-field explosion loading often fail in a brittle manner. Common failure types include spalling and scabbing. Brittle failure leads to an inflexible and brittle structural response, producing small and large fragments that can be extremely dangerous due to their high velocities. Therefore, designing concrete slabs for explosive loading requires methods that either prevent or mitigate brittle failures or transform them into ductile failures. This study validates numerical models using LS-DYNA finite element software and compares them with reputable research. Simulations of concrete slabs were conducted using conventional methods, reinforced concrete slabs with steel plates, reinforced concrete slabs with wire mesh, and ultra-high-performance concrete (UHPC) slabs. The analysis of five slab types under similar explosion loading reveals that UHPC slabs exhibit less deflection and damage compared to other types, while conventional concrete slabs experience greater deflection and damage. The optimal reduction in damage for reinforced concrete slabs occurs when a steel plate measuring 2 by 4.2 meters and 0.5 centimeters thick is applied to the backside. Additionally, using wire mesh dimensions 25% larger than the initial slab damage yields the best performance. A comparative analysis of explosion-induced damage across different slab types indicates that reinforced concrete slabs with a 0.5-centimeter thick steel plate exhibit the largest damage area (8m2); whereas UHPC slabs show no damage, resulting in the smallest damage area. Further investigations into the dynamic response of these slabs demonstrate that advanced materials and reinforcement techniques significantly enhance their resilience against explosive forces. This study emphasizes the importance of innovative design strategies in civil engineering, highlighting that the adoption of UHPC slab minimizes structural damage and improves safety in high-risk environments. These findings underscore the necessity of incorporating modern materials and methodologies in protective structure design, ensuring better performance and longevity under extreme loading conditions. A comparative analysis of various methods for strengthening concrete slabs using identical materials shows that UHPC slabs outperform others in reducing deflection and failure. This illustrates their exceptional ability to withstand explosive dynamic loads. However, the primary limitation of UHPC slabs is their high cost and complexity of implementation. Reinforcement with steel sheets has proven more effective than wire mesh in minimizing deflection. In models reinforced with 0.5 cm steel sheets, deflection was reduced by 50% compared to conventional concrete slabs. The slabs reinforced with wire mesh demonstrated a significant decrease in failure rates compared to conventional slabs, with reductions ranging from 75% to 80% across various reinforcement methods using the same materials. Conversely, some models reinforced with steel sheets exhibited increased failure rates. The findings indicate that, in most cases, slabs with greater flexibility, such as those reinforced with wire mesh, sustained less damage. This can be attributed to the enhanced flexibility and ductility of wire mesh-reinforced slabs compared to those reinforced with steel sheets.
Concrete slabs subjected to near-field explosion loading often fail in a brittle manner. Common failure types include spalling and scabbing. Brittle failure leads to an inflexible and brittle structural response, producing small and large fragments that can be extremely dangerous due to their high velocities. Therefore, designing concrete slabs for explosive loading requires methods that either prevent or mitigate brittle failures or transform them into ductile failures. This study validates numerical models using LS-DYNA finite element software and compares them with reputable research. Simulations of concrete slabs were conducted using conventional methods, reinforced concrete slabs with steel plates, reinforced concrete slabs with wire mesh, and ultra-high-performance concrete (UHPC) slabs. The analysis of five slab types under similar explosion loading reveals that UHPC slabs exhibit less deflection and damage compared to other types, while conventional concrete slabs experience greater deflection and damage. The optimal reduction in damage for reinforced concrete slabs occurs when a steel plate measuring 2 by 4.2 meters and 0.5 centimeters thick is applied to the backside. Additionally, using wire mesh dimensions 25% larger than the initial slab damage yields the best performance. A comparative analysis of explosion-induced damage across different slab types indicates that reinforced concrete slabs with a 0.5-centimeter thick steel plate exhibit the largest damage area (8m2); whereas UHPC slabs show no damage, resulting in the smallest damage area. Further investigations into the dynamic response of these slabs demonstrate that advanced materials and reinforcement techniques significantly enhance their resilience against explosive forces. This study emphasizes the importance of innovative design strategies in civil engineering, highlighting that the adoption of UHPC slab minimizes structural damage and improves safety in high-risk environments. These findings underscore the necessity of incorporating modern materials and methodologies in protective structure design, ensuring better performance and longevity under extreme loading conditions. A comparative analysis of various methods for strengthening concrete slabs using identical materials shows that UHPC slabs outperform others in reducing deflection and failure. This illustrates their exceptional ability to withstand explosive dynamic loads. However, the primary limitation of UHPC slabs is their high cost and complexity of implementation. Reinforcement with steel sheets has proven more effective than wire mesh in minimizing deflection. In models reinforced with 0.5 cm steel sheets, deflection was reduced by 50% compared to conventional concrete slabs. The slabs reinforced with wire mesh demonstrated a significant decrease in failure rates compared to conventional slabs, with reductions ranging from 75% to 80% across various reinforcement methods using the same materials. Conversely, some models reinforced with steel sheets exhibited increased failure rates. The findings indicate that, in most cases, slabs with greater flexibility, such as those reinforced with wire mesh, sustained less damage. This can be attributed to the enhanced flexibility and ductility of wire mesh-reinforced slabs compared to those reinforced with steel sheets.
Volume 1, Issue 1 (6-2020)
Abstract
Since the national symbol is the most important urban element in terms of nationality, analyzing the influence of time on this symbol seems necessary. Less attention has been paid to the concept of time in the initial comments regarding urban issues. However, it was considered a serious matter after passing of time and observing its influence on urban and identity issues. The current study mainly aims to study the influence of time in the formation of the complex of national monuments, the direct and indirect influence of the time dimension on qualitative indicators of space and its influence on the appearance and semantic dimension of the national symbol and its immediate field. Thus, after reviewing the theoretical basics, many case studies of the world have been reviewed due to the lack of sufficient information and specialist investigations. Only nine case studies have been randomly selected and addressed in the present study. These studies are in line with theoretical basics and the thinkers’ ideas and they led to the final output. The descriptive-analytical method was used to gather the information and the outputs were analyzed by the survey method and Delphi tool for validation. The results show that the influence of time on the appearance dimension generally includes structural and apparent changes, erosion, deterioration, and ruin and the influence of time on the semantic dimension mostly includes semantic, identity, and revolutionary changes. In the qualitative indicators of the national symbol and its immediate field, the time dimension indirectly influences on some of indicators such as diversity, readability, permeability, visual richness, and vitality. In some indicators such as permeability and visual richness, the influence of time is associated with the appearance and in some indicators such as diversity, readability, and vitality, it is associated with appearance and semantic dimension. It is also influential in the quality of sustainability and efficiency in time dimension. Since there are two types of the national monuments in general, the influence of time dimension on them is different. Time triggers memory, meaning, layer structure and accessibility in the monuments built in the passing of time but it triggers patterns of receiving feature and lessons about designing such as observing flexibility and designing a timed and dramatic place in space.
Volume 1, Issue 1 (3-2024)
Abstract
Most of the common oil and gas fields are located in the Persian Gulf, which is one of the shallowest seas in the world. The region of West Asia and the Persian Gulf is experiencing countless geopolitical tensions. Historically, these common oil fields are a source of conflict and tension that has led to wars. Iran and Iraq have 15 common oil fields. The present study, entitled Analysis of the geopolitical consequences of the shared oil resources between Iran and Iraq, seeks to answer the question of what role the shared oil resources of Iran and Iraq play in the relations between the two countries. Also, descriptive-analytical method and Dimetal technique have been used to investigate the title of the research. The findings of the research show that variables such as regional competition, unilateral development of common oil fields, close economic cooperation, regional differences, Iran's economic growth and the reduction of the effect of sanctions, different business partners, differences in attracting foreign investment, Iran's inability to invest, geopolitical convergence in the Strait of Hormuz, joint ventures, instability in economic diplomacy, etc. in the region indicate high interaction and strong systemic connection with other variables. Based on the analysis, it seems that it is necessary for Iran to develop relations with Iraq with a detailed analysis of the current situation and according to Kargosha's predictions about the future, while trying to maintain its share and wealth in common reservoirs and foreign investment in the oil industry in order to transform potential threats into new opportunities and provide maximum benefits by creating cooperation.
Volume 2, Issue 1 (12-2019)
Abstract
Fundamentalism is one of the most important security issues in today’s world, in a way, territoriality has drawn a large part of the world’s security literature. Over the past decade, the North African region became locality of internal crisis, regional ideological and rivalries, and intra-regional powers intervention and expansion of extremist ideas that has cost and effects on both internal, regional and international levels. In the meantime, the north of the African continent, and specially Tunisia country, has created opportunities for the growth and development of ISIL’s fundamentalist organization. The present study is a descriptive-analytical research and its data and information gathering by the library method. Hypothesis of this study based on unified Field Theory of Stephen B. Jones and belive that Territoriality of Fundamentalist Organizations in Tunisaia affected by internal factors (social crisis) and external factors (intervention powers). The result of the study showed that the fragility of the government, the geographical structure, and geopolitical integration in Tunisia, along with the political and international limitations caused territoriality of fundamentalist organization and acted as an obstacle for emerging and developing of a new political entity in this country.
Volume 2, Issue 2 (4-2000)
Abstract
The purpose of the study was to identify and prioritize the educational needs and support needed by agricultural extension agents in Isfahan, Islamic Republic of Iran. The target population for the study consisted of S3 agricultural extension agents in Isfahan province. Census population were used therefore, sampling procedures were not utilized and genera I izability of the results was limited to study population. Results indicate the five most highly ranked items on educational needs of extension agents were: extension philosophy, instructional technology, innovation and adoption process, adult education, and extension methods. Respondents indicated that the major support needed were availability of subject matter specialists to help them with their technical and communication methods.
Volume 3, Issue 3 (12-2021)
Abstract
Provinces of Iran bordering with Iraq were battle fields during Iran-Iraq war and today are among tourist attracting places in Iran. The factors provoking tourists to see these regions are important to characterize because the needs of the tourists should be identified and supplied. This paper tries to characterize factors driving and provoking the tourists who visit battle fields in Kermanshah. The research method adopted here is field finding and the data gathering procedure is based on library and field findings (N= 384) methods. The T-test and Friedman Test are used to analyze the data. The research sample includes the tourists who visited battle fields in Kermanshah in 2018. Random sampling is used to reach the required sample. The research results show that driving factors are more effective than attracting factors in journey to visit the battle fields in Kermanshah. Political-national identity, perseverance, curiosity and self-flourishing factors are among the most important driving factors with 3.32, 2.85, 2.37 and 1.45 mean rank, respectively. And location holiness, leisure and necessity are among the most important attracting factors with 2.59, 1.72 and 1.69 mean rank, respectively.
Volume 3, Issue 5 (12-2014)
Abstract
In this study, the spatial distribution of overwintered adults of Sunn pest, Eurygaster integriceps Puton, was investigated by using dispersion parameters and indices, mathematical distribution, and regression techniques in rainfed wheat fields by sample size of 1 m2 in 2009 and 2010. The dispersion parameters including: mean-variance test and clumping parameter () showed that the overwintered adults of Sunn pest population followed the negative binomial distribution pattern. Furthermore, the dispersion indices including: variance to mean ratio, Lloyd's index of mean crowding and Morisita index also confirmed the aggregated distribution pattern of overwintered adults of Sunn pest. Also, mathematical distribution and Taylor's power law () and Iwao's patchiness regression () showed the contagious distribution of overwintered adults of E. integriceps. These results can be useful in patch spraying for control of overwintered adults of E. integriceps in early season in wheat fields.
Volume 4, Issue 4 (2-2019)
Abstract
Aim: Musculoskeletal pain refers to pain in the muscles, bones, ligaments, tendons, and nerves. The purpose of this study was to investigate the relationship between factors affecting musculoskeletal pain and demographic variables of nursing and midwifery students. studying
in Tehran University of Medical Sciences (TUMS)
Method and Instrument: The method of this cross-sectional study was descriptive– correlational through which 120 nursing and midwifery students of Tehran University of medical sciences aged between 18-22 years were studied. The sample was selected by simple random sampling and standard Nordic pain questionnaire was used to measure the prevalence of pain. To test the hypotheses, in addition to descriptive statistics such as mean and standard deviation, chi-square test was used. Data were analyzed by SPSS-25 software. Findings: Totally, 120 nursing and midwifery students including 55.8% of nursing students (N=67) and 44.2% midwifery students (N=53) were studied. The results showed that nursing students more than midwifery students were suffering from at least one more musculoskeletal pain. This study showed that there is statistically significant difference
between nursing and midwifery students in terms of foot pain (P <0.01) that means the rate of foot pain in nursing students was higher than midwifery students.
Conclusion: Findings from this study showed that there was a relationship between demographic variables, field of study and musculoskeletal pain. Therefore, nursing students might suffer from more musculoskeletal pain.
in Tehran University of Medical Sciences (TUMS)
Method and Instrument: The method of this cross-sectional study was descriptive– correlational through which 120 nursing and midwifery students of Tehran University of medical sciences aged between 18-22 years were studied. The sample was selected by simple random sampling and standard Nordic pain questionnaire was used to measure the prevalence of pain. To test the hypotheses, in addition to descriptive statistics such as mean and standard deviation, chi-square test was used. Data were analyzed by SPSS-25 software. Findings: Totally, 120 nursing and midwifery students including 55.8% of nursing students (N=67) and 44.2% midwifery students (N=53) were studied. The results showed that nursing students more than midwifery students were suffering from at least one more musculoskeletal pain. This study showed that there is statistically significant difference
between nursing and midwifery students in terms of foot pain (P <0.01) that means the rate of foot pain in nursing students was higher than midwifery students.
Conclusion: Findings from this study showed that there was a relationship between demographic variables, field of study and musculoskeletal pain. Therefore, nursing students might suffer from more musculoskeletal pain.
Volume 4, Issue 5 (12-2015)
Abstract
A survey was performed to investigate the fauna of Ichneumonidae in Fars province during 2012 to 2013. Totally, 14 species belonging to 13 genera and six subfamilies were collected and identified including: Exetastes adpressorius (Thunberg, 1822) (Banchinae); Diadegma semiclausum (Hellén, 1949) (Campopleginae); Cryptus inculcator (Linnaeus, 1758); Dichrogaster saharator (Aubert, 1964) (Cryptinae); Diplazon laetatorius (Fabricius, 1781); Enizemum ornatum (Gravenhorst, 1829); Homotropus nigritarsus (Gravenhorst, 1829); Homotropus signatus (Gravenhorst, 1829) (Diplazontinae); Colpognathus celerator (Gravenhorst, 1807); Diadromus collaris (Gravenhorst, 1829); Ichneumon sarcitorius Linnaeus, 1758; Virgichneumon callicerus (Gravenhorst, 1820) (Ichneumoninae); Orthocentrus asper (Gravenhorst, 1829); Picrostigeus setiger (Brischke, 1871) (Orthocentrinae), of which Exetastes adpressorius and Picrostigeus setiger are newly recorded for the fauna of Iran. In addition the male of the latter species is recorded for the first time and described. All species except Dichrogaster saharator are new for Fars province.
Volume 5, Issue 0 (0-2005)
Abstract
In this paper, we show how to obtain suitable differential charactristics for block ciphers with neural networks. We represent the operations of a block cipher, regarding their differential characteristics, through a directed weighted graph. In this way, the problem of finding the best differential characteristic for a block cipher reduces to the problem of finding the minimum-weight multi-path way between two known nodes in the proposed graph. We applied Hopfield network to find the minimum-weight multi-path way. In this technique, the probability of convergence to a local minimum increases when the number of rounds of the cipher increases. We also applied Boltzmann machine to avoid local minima. We applied these techniques to find 3-round, 4-round and 5-round differential characteristics of Serpent block cipher, and repeated the optimization procedures for each characteristics 100 times. With Hopfield network, we obtained suitable results 100, 20 and 1 times for 3-round, 4-round and 5-round of the Serpent respectively. With Boltzmann machine, we obtained suitable results 100, 99 and 30 times for 3-round, 4-round and 5-round of the Serpent respectively. These results show that simulated annealing help avoiding the many local minima of energy function. We compare the probabilities of our obtained differential characteristics for Serpent with the probabilities of eight differential characteristics previously reported in other papers. The comparison shows that our proposed technique obtains better results in 6 cases, and the same results in 2 cases. We also found a 7-round differential characteristic with a probability of 2-125 with Boltzmann machine. Neglecting the reported Bommerang differential characteristics of Serpent, our obtained 7-round differential characteristic is the first report on a differential characteristic for more than 6 rounds of this cipher. The results of experiments indicate the efficiency of neural networks to find suitable differential characteristics of block ciphers.
Fatemeh Jamily, Zeinab Nadi,
Volume 5, Issue 1 (9-2013)
Volume 5, Issue 1 (9-2013)
Abstract
Nowadays, ambivalenceinclude differentelemdnts of human’s life and its spreading has been a social issue. For discovering the origin of for ementionedissue , it is necessary to investigate its historical background. As ghajar are has been exposed to many challenges of traditional and modern values , it can be producer of all types of ambivalences;therefore this issue has been investigated from the point of view of English travel writers who have had association with people and specilly with ghajarcouqp at that time. the population (statistical society) of this research includes all of the itineries written by Englishmen who have traveled to Iran in Ghajar career. That from among them 34 itineraries have been selected as sample (through purposeful sampling) investigating of all types of sociological ambivalence and psychological ambivalence has been done through Robert merton, typological approach in sociological ambivalence theory , also these typs have been investigated and classified by using historical investigation techniques and content analysis . The results show that: from among 6 kinds of sociological and psychological ambivalence, all kinds except 3 type have been refered to in mentioned intineration in ghajar; are highest amount of sociological ambivalence is dedicated to type 5 (alteraction between cultural structure and social structure ) that has been manifested in “aberrant behavior” (psychological ambivalence) in the next level, the 6 type of sociological ambivalence (different collections of cultural values) has been mostly dedicated to imitation of court from western lifestyle . The mentioned ambivalences have been mostly observed among “Iranian base and in “cultural –political field “ and in “naseredin shah” and then “fathali shah” ghajarera. Regarding content analysis of itineraries ,the final analysis of shows the effect of specific feature of social – cultural structure of ghajar are on the spreading of ambivalence.
Volume 5, Issue 4 (4-2021)
Abstract
Research Subject: Global energy demand is increasing, so enhanced oil recovery techniques have incorporated in production processes. Water flooding is a common technique in oil recovery processes. One of the major challenges in this technique is heterogeneity of the reservoir structure which results in increased water production and reducing the oil recovery factor. Moreover, long-term water or chemical injection might lead to the increased horizontal and vertical heterogeneities in the reservoir. Selective blockage of high permeability areas and consequently improved production from low permeability regions is important for increasing the oil recovery factor. In recent years, using hydrogels in injection processes, has been associated with various field successes, indicating the ability of these materials for selectively blocking the areas of high permeability. Hydrogels are injected after water or polymer flooding to conduct the injected fluid to low permeability areas.
Research Approach: In this paper, hydrogel injection process was simulated in glass micromodels using Comsol Multiphysics software. Hydrogel functionality was studied in low permeability areas in porous media. Moreover, the optimized conditions for water flooding process was studies. For this purpose, after model validation, sensitivity analysis was performed on effective parameters on oil recovery factor and a mathematical model was presented to predict the oil recovery factor.
Main Results: Oil recovery factors obtained from experimental and simulation studies, were in good agreement with each other with absolute error values of 2.29% and 4.06%, for water and hydrogel flooding, respectively.
Four parameters of injection rate, contact angle, oil viscosity, and injection fluid viscosity were considered as effective parameters on oil recovery factor. Among them, contact angle was the most important parameter. In water flooding, the most important interacting parameters are viscosity and contact angle and the least important parameters are injection temperature and rate. In water flooding simulation studies, the thickness of the contact surface was obtained hmax/5, where
Volume 7, Issue 1 (6-2019)
Abstract
One of the very consequences of language contacts is the presence of loanwords in a language. A great number of linguistic researches have focused on loanword studies through sociolinguistic approaches. In case of literary texts, the frequent and conscious use of loanwords reflects the style and the implicated purposes of the author which must definitely be transferred in translation. The present study aims to investigate the role of loanwords in literary texts, and their representations in translations. To this end, 148 loanwords were extracted from the American novel, Funny in Farsi by Firoozeh Dumas, then their representations in the Persian translation were studied considering three variables: the donor language, the semantic fields of loanwords and the translation strategies. The results revealed that ‘equivalence’ and ‘definition’ were the priorities of the translator among the translation strategies, and this has led to lose some cultural aspects of the literary text in translation.
Volume 8, Issue 1 (4-2017)
Abstract
In recent years a lot of researches have been carried out about sensitivity of the living organisms to magnetic fields and nanoparticles. Therefore, to evaluate the effect of the magnetic field and silver nanoparticles on photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids), proline, glycine betaine, soluble sugars and proteins, nitrate and nitrate reductase activity and protein electrophoresis pattern on Calendula officinalis L., in 2015 experiments were performed in the Department of Biology, University of Urmia. Seedlings were grown for 30 days in four treatments including: control, magnetic field with B = 3 mT for an hour per day, silver nanoparticles (50 ppm), and magnetic field (B = 3mT) plus silver nanoparticles (50 ppm). The results showed that plants treated with magnetic field, silver nanoparticles and magnetic field + silver nanoparticles photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids) content, compatible solutions content such as proteins and soluble sugar, proline andglycine betaine and nitrate content and nitrate reductase activity were significantly (P<0.05) increased compared to control group. Electrophoretic pattern of proteins investigated the maximum bands visible on gel electrophoresis were for treated groups with silver nanoparticles + magnetic field.
Volume 8, Issue 1 (1-2019)
Abstract
Health and environmental side effects of chemical insecticides and development of resistant population of Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) to pesticides have resulted in increasing demands for non-chemical control approaches against this pest. In this research, the efficacy of two biological control agents were studied under field condition. Treatments consisted of releasing Habrobracon hebetor (Say) (Hymenoptera: Braconidae), Trichogramma evanescence Westwood (Hymenoptera: Trichogrammatidae) and combination of H. hebetor + T. evanescence (HABROBRACON-TRICO). The results revealed significant differences in the number of infested tomato fruits among treatments and harvesting times. The infested fruits was the lowest (2.68 ± 0.14%) in plots treated by HABROBRACON-TRICO. Moreover, the highest (3.36 ± 0.50%) and the lowest (2.88 ± 0.22%) damaged fruits was recorded in the second and fourth harvesting times, respectively. There was significant interaction between harvesting times and treatments. Regarding the tomato yield in treatments, findings revealed significant difference among treatments in both main harvesting times. However, there was no significant differences in total yield in treatments. It could be concluded that biological control agents can be used as a promising alternative for synthetic insecticides in control of H. armigera in tomato farms without significant crop losses.
Volume 8, Issue 4 (8-2019)
Abstract
White-Spotted Stink bug, Eysarcoris ventralis (Westwood) (Hem.: Pentatomidae) was reported as one of the major destructive pests attacking rice worldwide. In Iran, it has been recorded on weeds, grape, alfalfa and wheat. In a survey on rice pests in Guilan province (Northern Iran) during 2017-2018, a large number of adult stink bugs were collected on rice panicles feeding on grains. The sucking on rice grains by adults as well as nymphs caused various symptoms, either empty glumes or spots around the feeding site. This is the first report of the damage symptoms caused by E. ventralis on rice in Iran (Guilan province).
Volume 9, Issue 1 (1-2009)
Abstract
The higher frequency transient signals generated as a result of a power system fault or disturbance provide the basis for an alternative approach to power system containing connectors and cables result in unsuitable operation of the system. However one major challenge is the need to ensure that the transients to be neutralized by electromagnetic compatibility (EMC) issues and cabling routes. This paper proposes novel method for optimal cable routings and connectors; a combinatorial design Algorithm, to choose the best path when two or more physical paths are available. The best path from EMC point of view can be chosen based upon various criteria such as monetary cost minimization, voltage drop and quality (electromagnetic compatibility) parameters. This paper initially provides a numerical 2D and 3D resolution of the problems of radiation generated by current sources. The approach is based on the finite element method (FEM) associated with absorbing boundary conditions. The presented model makes it possible to consider wave propagation and their effects in heterogeneous mediums in transient which can be applied in EMC for the simulation of radiation. First, the formulations of the electromagnetic problem are detailed. The simulation results are used for the cabling routes with respect to undesirable field distribution in the specified regions. Finally by the use of AHP optimal routes for cabling based upon the above mentioned criteria are chosen. The proposed method is successfully implemented on two different types of power systems, "high voltage substation and current injection system".