جستجوی مقالات مرتبط با کلیدواژه « Electrical Conductivity » در نشریات گروه « منابع طبیعی »

Salinity stress reduces seed quality, but suitable concentrations of silicon and nickel can improve germination indices in the produced seeds. This study was conducted in a factorial arrangement based on randomized complete block design (RCBD) in 2018 in Haji Abad city, Hormozgan, Iran. The experimental treatments consisted of four safflower varieties as the first factor, including Soffeh, Local Isfahan, Padideh, and Golmehr; and seven spraying levels, including nickel (100, 200 and 300 mg L-1) and silicon (100, 150, and 200 mg L-1) as the second factor. The results demonstrated that the foliar application of 100 mg/l Nickle and 200 mg/l silicon increased potassium by 10% and 18%, respectively. The foliar application of 200 mg/l silicon increased the activity of alpha and beta amylase enzymes by 17% and 12%, respectively. In addition, Golmehr and Safe varieties obtained from a mother plant recorded higher germination and rate percentage, as well as seed vigor, while Padideh variety showed the lowest values of the same traits. The foliar application of 200 mg/l silicon, compared to the control, increased the seed vigor as well as Soffeh and Golmehr cultivars by 23% and 25%, respectively; however, the Nickle concentration of 300 mg/l resulted in a decrease of 24% and 19% in these cultivars.On the other, this trait decreased with increasing nickel concentration significantly. Generally, foliar application of silicon at concentrations of 150 and 200 mg L-1 was found to improve seed quality of different safflower varieties under salinity stress.

In this experiment, physical and chemical characteristics of sugar beet seed and its relationship with germination traits was studied. This traits were evaluated on 10 sugar beet singles crosses that obtained from three locations including Ardabil, Firuzkuh, and Karaj. Results showed that bulk density, true density and electrical conductivity are influenced by environment and genotype. Percentage of solids soluble in sugar beet pericarp (germination inhibitors) it was only affected by the seed production environment. Both genetics and environmental conditions on the maternal plant during seed development and maturing were effective on germination percentage, germination velocity and mean germination time. But the germination uniformity of sugar beet seeds was only affected by genotype. On the other, the correlation between bulk density, true density, electrical conductivity, porosity and percentage of solids in pericarp solution of sugar beet seeds with some germination traits was significant. But, the germination uniformity had no correlation with the physical and chemical properties of seed. Increased density of the seed pericarp caused decrease of seed quality factors including electrical conductivity and percentage of solids solution on pericarp. Therefore, germination uniformity, which is less affected by the environment, can be used in breeding programs as indicator of seed quality selection. Physical and chemical traits that was a significant correlation with germination traits, in the management of sugar beet seed production with the aim of increasing the extraction coefficient and quality of sugar beet seeds are recommended.

The improper harvesting time can result in producing poor quality seed because leakage from the seed coat increases under these conditions. As such, it is critical to determine the proper seed moisture at the harvesting time. This study is included two years conducted in 2018 and 2019 as a factorial in the form of a randomized complete design under three replications. The first factor contains three corn varieties (Simon, AS71 and KSC703) whereas the second factor contains four harvesting times in terms of the seed moisture content (30, 35, 40 and 45%). The obtained results indicate that the highest electrical conductivity is observed in the early harvest treatment with 45% moisture, whereas the lowest electrical conductivity is observed in the treatment with 30% moisture at the harvesting time. The early harvest with 45% moisture decreases the viability as well as the percentage and germination rate of corn seeds. The highest viability of corn seeds at 35% moisture at the harvesting time is observed in AS71 varietie. Moreover, the germination of seeds of the Simon and KSC703 varieties did not reveal a statistically significant difference in the treatment of 30% moisture at the harvesting time with 35% and 40% moisture. The treatment with 45% moisture delayed the germination rate. In general, due to the reduction in the germination response at high moisture content at maturity time for standard and aging acceleration test, 30 and 35% moisture content at maturity time were found to be appropriate to produce high quality corn seeds.

Multiphase flow systems are important parts of industrial processes, including the food, pharmaceutical, oil and petrochemical industries and also agriculture. In order to monitor and control these systems, it is necessary to determine its characteristics such as mass flow of materials, mass concentration, volumetric concentration, density, velocity and homogeneity distribution of fluid. Magnetic induction tomography is one of the new methods of monitoring fluid in pipelines. Its main advantage is that MIT sensors have no contact with the fluid flow. In this research, design and performance simulation of applied current magnetic induction tomography (AC-MIT) system was studied. The system included two annular electrodes as a transmitter sensor and 196 coils as a receiver sensor. In order to performance simulation of the system, three positions (R=0, R=0.35, R=0.65) were considered for the target object and the image reconstructed using Landweber iterative algorithm with Tikhonov regularization method. To evaluate the quality of the reconstructed image, size error (SE) and root mean square error (RMSE) were calculated in different regularization coefficients. The results showed that RMSE increases with increasing regularization coefficient and decreases when the target object approaches the cross-sectional wall. SE parameter decreases as the target object approaches the cross-sectional wall. The minimum and maximum values of the calculated SE were related to R=0.65 and middle position, equal to 0.13 % and 5.72%, respectively.

Germination of seeds, one of the most critical stages of plant cycle is greatly influenced by drought stress. In this way, the effects of ascorbic acid to improve germination and antioxidant enzyme activities in sheep fescue seeds under drought stress were studied. A factorial experiment based on completely randomized design with three replications was done. None- primed seed (control group) and priming of different concentrations of ascorbic acid (0, 1 and 2 mM) under 0, -0.4, -0.8 and -1.2 MPa drought stress levels were evaluated. The results showed that seed priming with ascorbic acid in different drought levels increased some traits such as germination percentage, vigour index, plumule and radicle length, soluble carbohydrates and protein contents and antioxidant enzymes activities (catalase, superoxide dismutase and ascorbate peroxidase). While it decreased mean germination time, electrical conductivity and malondialdehyde content in comparison to nonprime seeds. So seed priming with 1 and 2 mM of ascorbic acid in -1.2 MPa level increased vigour index, soluble carbohydrates and proteins, respectively by 167.03, 22.26, 35.77, 187.91, 22.61 and 30.20% compared to nonprimed seeds. Also, it increased activity of catalase, superoxide dismutase and ascorbate peroxidase, respectively by 11.85, 22.81, 12.25, 13.83, 31.33 and 9.93% compared to non-primed seeds. Therefore, the use of 1 and 2 mM ascorbic acid concentrations to reduce the negative effects caused by drought stress is recommended.

Mapping soil salinity changes on a large scale is very costly and time consuming. One of the most cost-effective ways to map soil salinity is to use satellite imagery. Investigation of spectral characteristics of soils with saline surfaces and determining the extent of areas affected by this phenomenon, by using new images with relatively high spatial and spectral resolution can be used in preparing soil salinity maps. In recent years, many indicators have been developed to detect and extract the characteristics of saline surfaces from satellite images, most of which have been studied based on the spectral reflection of these surfaces in different bands of satellite images or intermediate ratios. The purpose of this study is to estimate the salinity changes from 2001 to 2016 in Miandoab region located in West Azerbaijan province. For this purpose, 42 samples with appropriate distribution were taken from the area. The samples were then transferred to the laboratory to measure soil salinity parameters. To evaluate soil salinity, in addition to sampling of topsoil, the NDSI, IBI, NDVI, SI7 and NIR, RED, SWIR2 bands of Landsat 7 for 2001 and Landsat 8 for 2016 were used. The regression equation for determining soil salinity for 2001 showed that soil salinity has a positive and significant correlation with NDSI index at the level of 5%, While for 2016, the highest significant correlation at the 5% level was with the RED and NIR bands of the Landsat 8 image. In 2001, the highest and lowest lands in the region were non-saline lands (39%) and very saline lands (12%), respectively; While in 2016, the highest and lowest lands in the region are relatively saline lands (35%) and non-saline lands (18%). The results of the present study showed that the salinity of the region can be easily calculated using Remote sensing indices. Due to its proximity to Lake Urmia, the study area faces soil salinity problems, so the identification and classification of saline areas is necessary for land management.

This research in order to study on post-harvest process effect on 2 soybean commercial Williams and Saba (L17) in Moghan region was conducted as a 2×5, two cultivars× 5 post-harvest process stages including after harvest, after drying, after cleaning after packing and stacking and storage, factorial experiment based on completely randomized design by 3 replications. Studied traits were normal seedlings percent in standard germination test and after accelerated ageing test, seedling weight vigour index after standard germination test, broken seeds percent, cracked coat seeds percent and electrical conductivity. Results revealed Williams cultivar had more normal seedlings percent after accelerated ageing test and seedling weight vigour index after standard germination test and less cracked coat seeds percent. Also the least normal seedlings percent in standard germination test, normal seedlings percent after accelerated ageing test and seedling weight vigour index after standard germination test and the most broken seeds percent, cracked coat seeds percent and electrical conductivity investigated. Based on this research results Williams cultivar seeds had more germination ability and vigour preservation potential during post-harvest process stages than Saba (L17) cultivar. Also germination ability and vigour decrease after drying and storage stages revealed seed drying unsuitability.

This experiment was conducted to study the effect of different packages on oil rapeseed varieties produced in Qom province. The studied cultivars were RGS, Talaieh and Okapi and packaging cover types were three andndash;layer paper bag ,4-layer paper bag , propylene bag,propylene+paper and flaxen bag which was studied using factorial experiment on the basis of randomized complete block design in 3 replications. The seed containing bags were stored in the ware house of agricultural and natural resources center of Qom province for 1 year and standard sampling of each treatment and replication was done at the end of the storage period then seeds germination was tested. Also electrical conductivity test ,average time for germination cold test and accelerated aging test have been conducted for estimating seed vigor. The results showed no significant difference between cultivars and cultivars reaction to the exerted treatments was the same, but seeds storage in the various bags had a significant effect on seed vigor as seeds in four layer and three layer paper bags had the most vigor and seeds in propylene bags and paper propylene bag had the least vigour.Also the results showed that various seed storing covers have significant effect on the average time of seeds germination ,electrical conductivity and vigor after cold test and accelerated aging test and in all cases three and four layer paper bags showed the best resulting. However propylene and paper propylene bags had more deteriorating effect on seed quality. Since in the warehouse the temperature had increased up to 45anddeg;c and air relative humidity up to 85% in some months of the year, and with considering that high temperature may accelerate the incidence of some hydraulic reactions and either seed deterioration, so the temperature has more effect on propylene and propylene paper bags.