جستجوی مقالات مرتبط با کلیدواژه "ایران" در نشریات گروه "مکانیزاسیون کشاورزی"

The purpose of this research is to investigate the current status of articles of Iranian universities and institutions in the field of vaccine in the ISI Web of Science international citation database based on quantitative and qualitative scientometric indicators.

In this study, scientometric methods and citation analysis were used.

The findings of the research show that 1781 articles with at least one author's organizational affiliation related to Iranian universities and institutions are indexed in this database. Razi Vaccine and Serum Research Institute is the most cited with an average of 12.88 citations per article and also has the lowest author self-citation among universities and institutions with 2.5%. Iranian writers had the most co-authorship and international collaboration with their counterparts from the United States, Germany and England, respectively.

Because most Iranian articles are published in Q3 and Q4 journals with a low impact factor, the average citation of Iranian articles in the field of vaccine is much lower than the global average and the average of other countries. In terms of co-authoring and international collaboration, Iranian researchers, same as other countries, have collaborated the most with their counterparts from America, Germany, England and Canada.

The world’s growing population has led to an inevitable increase in energy demand, and this, in addition to the depletion of non-renewable energy sources, can lead to several environmental issues. Wind power has proven to be a reliable and sustainable source of electricity, particularly in light of the pressing need to mitigate environmental impact and promote the use of renewable energy. The purpose of this research is to investigate and compare the environmental effects of electricity production from two wind power plants, Aqkand and Kahak, using wind turbines with a capacity of 2.5 megawatts for a period of three different lifetimes (20, 25, and 30 years).

The present study investigates the environmental effects of electricity generation during the life cycle of wind farms (Kahak and Aqkand) during the construction and operation of these power plants and the cumulative exergy demand index. The specifications of the wind turbines used in the current research are: turbine capacity of 2.5 MW, rotor diameter of 103 meters, rotor weight of 56 tonnes, three blades, each blade is 50.3 meters long and weighs 34.8 tonnes. The turbines are manufactured by Mapna and used in dry conditions. A functional unit of one kilowatt of electricity was selected and the data were analyzed in SIMAPRO software using IMPACT2002+ method with 15 midpoint indicators and four final indicators.

The results showed that the stage of raw materials and production has the highest impact on the creation of midpoint indicators, which is due to extraction, manufacturing, and production of parts such as steel casting using non-renewable energy and activities such as high-temperature welding. The total environmental index of Aqkand and Kahak wind power plants for 1 kWh of generated electricity was 5.84 and 4.45 μPt respectively, more than half of which belongs to the damage to human health category. The investigation of the ionizing radiation index showed that the use of diesel fuel in the installation phase resulted in the highest amount of emissions in both of the power plants, so the share of pollutant emissions in the raw materials and production phase is more than 40%, and in the installation phase due to diesel fuel consumption was more than 48%. The investigation of the eutrophication index showed that the raw materials and production stage accounted for more than 95% of the damage to the ecosystem quality category, and in the meantime, copper and electrical components had the highest amount of contribution to the raw materials and production stage. Additionally, diesel fuel accounted for the largest part of the result in the installation stage, and the transportation and maintenance stage included less than 1% of this result. The investigation of the renewable energy consumption index showed that the stage of raw materials and turbine production in the Aqkand power plant with a share of 68% and the Kahak power plant with a share of 70% had the greatest effect on the category of resource damage. Also, the installation and commissioning phase was the second most effective factor in the category of resource damage due to the use of diesel fuel. The study of the cumulative exergy demand index showed that non-renewable-fossil resources had the largest share in exergy demand (0.15 MJ) to produce one kilowatt of electricity generated from power plants.

In this study, the results showed that in both plants, about 70% of various respiratory effects, 60% of human health issues, and 25% of acidification and global warming are caused in the raw materials and manufacturing phase. Furthermore, the installation phase is responsible for 17% and 16% of climate change in the Aqkand and Kahak power plants respectively, and between 14% and 26% of other environmental factors.

This article follows a descriptive-analytical investigation in proposing a conceptual model for establishing a modern agricultural education system based on smart electronic learning based on knowledge management. Currently, systematic communication has made a tremendous evolution in knowledge sharing. The evolutions are the improvement of knowledge management systems based on expert systems. In fact, this modern education method is based on the foundations of smart learning. Knowledge sharing through using smart technologies has led us to modern education. The new education is a platform for the application of innovative foundations and smart technologies to increase flexibility, efficiency, adaptability, collaborative engagement, motivation, and inclusive feedback. The field of agricultural sciences has gained a significant impact on new situations. Agricultural education in Iran should follow the recent global developments. The research adapted system analysis and design methods to develop the proposed conceptual model. The main research finding is to propose a practical conceptual model for developing modern smart agricultural education based on knowledge management. The conceptual models can be applied in the development of smart learning at various levels of education, higher education institutes, universities, and educational affairs in the other sectors in Iran.

In order to identify, register, certify, control and protect the country's livestock and poultry genetic reserves, a comprehensive system should be designed, which consists of the sub-sections like “preparing a comprehensive atlas”, “distribution map”, “accurate statistics and monitoring of the existing populations of the country's indigenous livestock and poultry genetic reserves”. . Therefore, this study has been conducted to introduce the population and breeds of livestock and poultry of the country aiming at designing of the "Atlas of genetic resources of livestock and poultry of the country" application program. In this application, the users can easily get to know the livestock and poultry breeds of each geographical region and observe their breed and breeding characteristics. Also, this app has a user-friendly search feature. The information can be updated from the application panel. In this application, there is a section called "Registration of new species" that can be obtained from the population and breeds of livestock and poultry all over the country with the voluntary participation of people. This information will be used in the database after filtering on the management panel.

The overall goal of this research is to identify the status of scientific information production by Iranian researchers in the field of agricultural biodiversity using scientific metrics from the beginning to the end of 2020 in the Scopus database. 1053 scientific works of Iranian researchers have formed the statistical community of the research. To conduct the research, first, the characteristics of scientific works related to the subject area of biodiversity were extracted and then the obtained results were analyzed. The scientific outputs of Iranian researchers in the field of biodiversity are indexed in the form of 9 types of information sources in the Scopus citation database, and the most type of information resources were in the form of research articles with 936 titles (88.89%). University of Tehran with 214 article titles (20.32%) have had the most participation in the publication of scientific production in the field of biodiversity. Most of the articles of Iranian researchers in the field of biodiversity have been published in Journal of Environmental Studies with 4 quartiles and 36 article titles. The results of the research showed that the process of producing articles in this field is increasing.

This research has been carried out in the field of scientometrics and its main purpose is to identify the scientific production of Iranian researchers in three thematic areas of weeds plant pests and plant diseases, until 2017 in Scopus database. Quantitative indicators have been used to conduct this research. The statistical population of the study is 5002 scientific works produced by Iranian researchers. To conduct the research, first the specifications of the scientific works related to these three subject areas were extracted and refined, and then the obtained results were analyzed. On average, the annual production of scientific works by researchers is 87.7. More than 84.3% of scientific papers have been prepared in groups and only 15.7% of articles have been written by one author. About 65% of articles are written by two or three authors. The results of the research show that the growth of articles is increasing.

The main purpose of this article is to study and analyze the status of Iranian researchers' scientific production of plant pests from the beginning to the end of 2017.Research

This is a scientometrics research method. The statistical population of this study consists of 744 titles of scientific works produced by Iranian researchers extracted from Scopus database.

A total of 744 scientific works were produced by 159 Iranian researchers, the most of which (106) were produced in 2017.The research paper with a total of 682 titles are the type of works and the subject area of agriculture (550 works) covers the most. Tehran University with 150 works, Islamic Azad University with 67 works and Tarbiat Modarres University with 64 works were the most collaborated. Researchers in the United States (23), England (14) and Canada (13 articles) had the most collaboration. About 93% of the scientific works were co-authored and 7% were single authored. The 3 authors with 189 works and the 4 authors with 188 works constitute the most produced works.

The results show that the scientific output of Iranian researchers has a relatively growing trend. Interaction of Iranian researchers with their domestic counterparts and external researchers has been acceptable. Out of 744 works, 93% have been produced collaboratively and co-authored, and 27% of them have been collaborated with foreign production researchers.

Introduction The loess-paleosol sequences in Northern Iran are important archives that represent several cycles of Quaternary climate change and can be used to complete the information gap on loess between Europe and central Asia. Last interglacial soils derived from loess in northern Iran is represented by strongly developed Bt horizons of forest soils. In Golestan and Mazandaran area, soils under the forest are mainly classified as Alfisols or Luvisols. Interestingly, E horizons are generally not found in these soils. In the Caspian Lowlands, a pronounced precipitation gradient is reflected in mean annual precipitation rates decreasing from about 1850 mm at Bandar Anzali in the west to about 435 mm at Gonbad- e Kavoos in the east. The results of the loess climosequence in Northern Iran showed that with increasing precipitation, soil pH and calcium carbonate contents decrease, whereas soil organic carbon, clay content, and cation exchange capacity increase. For years, many efforts to quantify the soil properties led to the provision of indices of soil development. Among these indices are forms and ratios of iron, morphological, and micromorphological indices. Many studies have been carried out on the loess-paleosol sequences and modern loess soils in Northern Iran with focus on micromorphology, mineralogy, and dating but more investigation is needed with an emphasis on the forest soils with well-pronounced clay illuviation as a proxy for paleo-moisture. For this purpose, we used micromorphology and soil color indices to report the effects of precipitation gradient on the variability in the formation of soils under forest vegetation. Materials and Methods The study area is located at the northern slopes of Alborz Mountain Ranges, covered with Caspian or Hyrcanian deciduous forests. Field sampling started in summer 2015. More than ten soil pedons with loess parent material were investigated based on former studies. Finally, six representative modern pedons were selected and dug in an east-west direction on loess deposits. The climate data shows that precipitation varies from 500 mm in Qapan (Pedon 1) to up to 800 mm in Neka. Physiochemical properties of soils were studied using standard methods. Thin section prepared for soil micromorphological studies were studied and interpreted based on Bullock et al. and Stoops guideline using a polarizing microscope. The micromorphological index of soil development (MISECA), suggested by Khormali et al (2003), was calculated. Also, color indices were calculated based on Hurst (1977), Torrent (1983), and Alexander (1985) by using the Munsell color chart. In all color indices, Munsell color hue converts to a single number. Results and Discussion The results showed that the downward decalcification and the subsequent clay illuviation were the main criteria influencing the assessment of soil development in this study. So, all of the soils host argillic and calcic horizons and are classified as Alfisols and Mollisols. Micromorphological studies confirmed the morphology studies in the field and the results of physico-chemical analyses. MISECA index showed pedological changes in different pedons in the studied areas. A significant positive relationship between climate gradient (increasing rainfall) and MISECA index was found. The area and thickness of clay coatings show an increasing trend with rainfall. Occurrence and preservation of clay coatings are more pronounced in more humid regions with illite and vermiculite as the dominant clay minerals. These minerals reduce the shrink/swell potential and increase the number of clay coatings present. In Argillic horizons of all pedons, except Toshan, dominant b-fabric is speckled due to carbonate leaching, while in Toshan, it is striated b-fabric. In calcite horizon, b-fabric is crystallitic. The correlation of various forms of iron with three color indices of Hurst, Torrent, and Alexander showed that Torrent and Alexander indices were better than the other one for the study area. Moreover, there was a good correlation between MISECA and Torrent color index. Conclusion The results showed that the soil evolution in the studied areas is strongly influenced by soil formation factors, especially in a climate which shows a change in the micromorphological characteristics of soils. With increasing the rainfall from the east to the west in this gradient, the amount and thickness of clay coating, as well as secondary calcium carbonate accumulation, change significantly. In addition, the micromorphological and color indices of soil evolution can be used as two indicators for assessing the effects of rainfall gradient on soil formation in northern Iran. On the other hand, knowledge of the development of modern loess-derived soils could help to better understand the paleoenvironment.

Introduction Loess sediments of northern Iran represent several cycles of climate change and evolution of the landform for the mid-to-late Quaternary. Climate change in elevations of Iran and its surrounding areas is very controversial in the mid and late Quaternary, and has been discussed in the past according to rainfall and rainfall periods and between rainfall, glacial and inter-glacial. Paleomegnatic results also indicate that these sediments have accumulated between, 1.8 to 2.4 million years ago. However, pedogenic processes and the effects of past climate in these soils still have not been fully investigated. The loess deposits in northern Iran are a valuable archive of regional paleoclimatic and paleoenvironmental information. Extensive sedimentological and chronological studies have been carried out on the middle to upper Pleistocene loess during the past decades, but it is necessary to do a comparative research on the older loess deposits. So, this study aimed to conduct a mineralogical and physicochemical investigation on the early Pleistocene loess and to compare it with modern loess soils in Agh-Band, Yelli-Badrag and Qareh-Agach in loess plateau of eastern Golestan.
Materials and Methods The study area is located in a hot and dry climate in loess Plateau east Golestan. According to the previous studies, a total of six profiles were excavated and studied. Then, physicochemical properties such as soil texture, acidity (pH), electrical conductivity (EC), saturation moisture (SP), organic carbon (OM), cationic exchange capacity (CEC) and calcium carbonate equivalent (CCE) were measured in the laboratory. Clay separation was carried out with a specific method to separate the clay as well as identification of clay minerals. After preliminary field observations and determining the horizons for each profile in the region, soil classification was done based on soil taxonomy and WRB. Then, soil samples were prepared from each horizon for physicochemical and mineralogical studies in sufficient quantities.
Results and Discussion Comparing the results of physicochemical properties (such as color, lime percentage, the cation exchange capacity and the ratio of iron, etc.) in paleosol and modern loess soils indicates that in paleosol soils, soil forming processes have passed several stages. Clay mineralogy is a good indicator for past climate change studies in loess.The existence of the arglic horizons and the evolved calcic in paleosols and their absence, in comparison with the modern soils in which they are present, indicate the change in soil formation conditions. The change in the color of paleosols also represents the soil moisture and the more suitable conditions of the past climate (temperature, and especially rainfall) in comparison with the present climate of the region, this color change was due to activation of soil formation processes in paleosols. All paleosol samples had a higher clay content than the late modern loess soils of the Pleistocene, suggesting favorable climatic conditions for soil formation processes and the development of more ancient soil than parent materials. Decrease in the amount of annual precipitation in the region, compared to the past, has led to decreased smectit and increased chlorite. Therefore, presence of smectit cannot be attributed to the present situation of the region. The presence of these clay minerals in paleosols can be due to wet weather conditions as well as weathering of clay mineral deposits. On the other hand, the dominance of less weathered clay minerals such as illite and chlorite in the late Pleistocene modern loess soils is correlated with the present dry climatic conditions.
Conclusion The simultaneous presence of modern and old loess soils in the studied areas demonstrates the general evolution of geographical and climatic conditions during the Pleistocene period which has altered the properties of these layers and ultimately left out the effects of high clay conditions, which is a combination of climatic evidence and intermittent pedogenic soil formation processes. The presence of early Pleistocene loess soils between late Pleistocene loess sediments in Golestan province and the conditions of the study provided pedological and mineralogical comparisons of modern and paleosols in these areas and the results clarified a part of the climate change in northern Iran. The past climate study allows for prediction of the current and future climate change process. Therefore, a more accurate study of clay minerals as the key to all soil behaviors and past climate change in different parts of the eastern Golestan plateau can be very useful in completing studies of evidence of past climate change in paleosol soils

The true bugs (Insecta: Heteroptera) are one of the most important insects which included several pest and beneficial species (predators and parasitoids) and therefore have important role in agroecosystems. The fauna of aquatic and semi-aquatic Heteroptera was studied in paddy fields and around aquatic ecosystems in some regions of Iran through 2004-2009. Totally 58 species from 14 families including, Aphelocheiridae, Corixidae, Gerridae, Hebridae, Hydrometridae, Leptopodidae, Mesovelidae, Naucoridae, Nepidae, Notonectidae, Ochteridae, Pleidae, Saldidae and Veliidae were collected ad determined. Among the collected species, four species including, Sigara nigrolineata nigrolineata (Fieber, 1848), Sigara scripta (Rambur, 1840), Saldula orthochila (Fieber, 1859) and Saldula xanthochila (Fieber, 1859) are new records for Iran.

The majority of hydraulic processes under a natural condition in a field are carried out under unsaturated flow conditions. The soil moisture retention curve (SMRC) is the most important hydraulic characteristic of an unsaturated soil whose knowledge is of prime importance in soil-water studies such as soil conservation, soil erosion, land evaluation, soil reclamation, and water resources management. SMRC can be determined by two different direct and indirect methods. While there are noticeable developments on direct methods, they are still time- and labor-consuming. As a result, researchers are focusing more on indirect methods. The present research has evaluated some common PTFs for predicting the SMRC for a number of soils in Iran. Fifty soils, the majority of which were loam and clay loam, were taken from Karaj, Amol, and Babol in the north of Iran. Soil water contents corresponding to matric potentials of 0, -5, -33, -100, -500, and -1500 kPa were determined by a pressure plate apparatus. Four common PTFs of Rawls and Brakensiek (RB), Vereeken et al. (VMFD), Wosten (W), and Wosten et al. (WLNL) were used in this study. To evaluate these PTFs, the GMER (Geometric mean error ratio), GSDER (Geometric standard deviation of error ratio), and RMSE (Root mean square error) indices were considered. The results showed that these PTFs functioned better for loam-textured soils. VMFD and WLNL PTFs performed better, while VMFD was better than the others for clay loam soils. In general, better fit was found as the matric potential increased.