19 research outputs found
Evaluation of Morpho-physiological Responses of Iranian Rice Landraces and Improved Genotypes to Iron Deficiency in Nutrient Solution
Excessive application of P fertilizers, use of the bicarbonated water sources for irrigation concomitant to a low level of organic matter have resulted in widespread iron deficiencies in crop plants in Iran. One of the strategies to overcome this problem is to select tolerant genotypes to iron deficiency (i.e. iron-use-efficient genotypes) or bred genotypes with high-micronutrient-uptake ability. Therefore, this experiment was conducted to study the behavior of twelve Iranian rice landraces and improved genotypes to iron deficiency (Tarom Mahalli, Amol 2, Musa-Tarom, Gharib, Shiroudi, Bejar, Neda, Nogouran, Jozdan, Sazandegi, Zayande Roud, and Kouhrang) as exposed to two levels of chelated iron fertilizers, including 5mM (iron deficiency) and 50mM (no iron deficiency) in Yushida nutrient solution culture. A factorial experiment based on a completely randomized design with four replicates was carried out in Soilless Culture Center at Isfahan University of Technology, Isfahan, Iran in 2013. The results showed that the iron content, shoot and root dry weights, total dry weight, leaf area, root length and volume and the number of tillers were significantly affected by genotypes, iron fertilizer, and their interaction. The mean dry weights were 0.215, 0.138, and 0.255 g per plant in northern landraces, northern improved, and central Iranian genotypes under no iron deficiency condition, but they were decreased by 25.7, 35.2, and 23.0% under iron deficiency condition, respectively. Based on the magnitude of decrease of total biomass under iron deficiency condition, genotypes such as Musa-Tarom, Bejar, and Zayande Roud seemed to be more tolerant in comparison to Jozdan, Amol 2, and Shiroudi
The Combined Effect of Different Nitrogen Levels and Planting Arrangement on Weed Interference with Linseed and Seed Berseem Clover Intercropping
Intercropping is one of the effective components of sustainable agriculture. In order to assess the effects of nitrogen application and planting arrangement on linseed and berseem clover leaf area, light absorption and their yield an experiment was conducted as a split plot based on randomized complete block design with three replications at the Research Farm of College of Agriculture, Isfahan University of Technology in 2012. The main plots included three nitrogen rates (0, 30 and 60 kg/ha of nitrogen) and subplots were different planting arrangement of linseed and berseem clover (monoculture of linseed, 70% linseed: 70% berseem clover, 70% linseed: 50% berseem clover, 50% linseed: 50% berseem clover, 50% linseed: 70% berseem clover, monoculture of berseem clover). The highest weed dry weight (286 g/m2) was obtained in monocultures of linseed when 60 kg/ha nitrogen was applied. The highest percentage of light absorption (85.3%) was achieved at different planting arrangements with application of 30 kg/ha nitrogen. The highest seed yield of linseed (53.19 g/m2) and berseem clover (72.6 g/m2) were obtained in monocultures and 0 and 30 kg/ha nitrogen treatments, respectively. In general, linseed and berseem clover intercropping with application of 30 kg/ha nitrogen were proven beneficial as they led to the greater yield and successful weed control
Evaluation of the mechanical and wear properties of titanium produced by three different additive manufacturing methods for biomedical application
Commercially pure titanium, as a widely used metallic biomaterial, was fabricated using dissimilar additive manufacturing (AM) methods, namely selective laser melting (SLM), laser engineered net shaping (LENS) and wire arc additive manufacturing (WAAM). Microstructures as well as mechanical and wear properties of the produced titanium samples were studied. Diverse microstructural features were related to the different linear energy densities and cooling rates induced by each AM method. Tensile testing evaluation indicated the highest yield and ultimate tensile strengths as well as elastic energy for titanium produced by SLM. However, the maximum ductility was obtained in the WAAM-fabricated titanium due to its larger grain size and slightly higher densification. All the mechanical properties obtained were either superior or comparable to those of cast and powder metallurgy produced titanium. Fracture surface analysis showed the presence of mainly coarse and fine dimples for WAAM and SLM-produced samples, respectively. This was consistent with the grain size of each sample. Wear performances and mechanisms were also examined and the results were in agreement with the values obtained from the hardness to elastic modulus ratios (H/E and H/E)
Nanoindentation and wear properties of Ti and Ti-TiB composite materials produced by selective laser melting
Ti and Ti-TiB composite materials were produced by selective laser melting (SLM). Ti showed an α΄ microstructure, whereas the Ti-TiB composite revealed a distribution of needle-like TiB particles across an α-Ti matrix. Hardness (H) and reduced elastic modulus (Er) were investigated by nanoindentation using loads of 2, 5 and 10 mN. The results showed higher H and Er values for the Ti-TiB than Ti due to the hardening and stiffening effects of the TiB reinforcements. On increasing the nanoindentation load, H and Er were decreased. Comparison of the nanoindentation results with those derived from conventional hardness and compression tests indicated that 5 mN is the most suitable nanoindentation load to assess the elastic modulus and hardness properties. The wear resistance of the samples was related to their corresponding H/Er and H3/Er2 ratios obtained by nanoindentation. These investigations showed that there is a high degree of consistency between the characterization using nanoindentation and the wear evaluation from conventional wear tests
Nanoindentation and wear properties of Ti and Ti-TiB composite materials produced by selective laser melting
Modified Histogram Segmentation Bi-Histogram Equalization
In the application of image processing, contrast enhancement is a major step. Conventional methods which are studied in contrast enhancement such as Histogram Equalization (HE) have not satisfactory results on many different low-contrast images and they also cannot automatically handle different images. These problems result of specifying parameters manually in order to produce high contrast images. In this paper, Modified Histogram Segmentation Bi-Histogram Equalization (MHSBHE) is proposed. In this study, histogram is modified before segmentation to improve the input image contrast. The proposed method accomplishes multi goals of preserving brightness, retaining the shape features of the original histogram and controlling excessive enhancement rate, suiting for applications of consumer electronics. MHSBHE avoids over-enhancement and generates images with natural improvement. Simulation results show that in terms of visual assessment, peak signal-to-noise (PSNR), average information content (entropy) and Absolute Mean Brightness Error (AMBE) the proposed method has better results compared to literature methods. The proposed method enhances the natural appearance of images especially in no static range images and the improved image is helpful in generation of the consumer electronic. © 2020, Springer Nature Singapore Pte Ltd
Hyper-heuristic Image Enhancement (HHIE): A Reinforcement Learning Method for Image Contrast Enhancement
Conventional contrast enhancement methods such as histogram equalization (HE) have not obtained acceptable results on many different low-contrast images and they also cannot automatically handle various images. These problems are a result of specifying parameters manually for the sake of producing high-contrast images. We proposed an automatic image contrast enhancement on Hyper-heuristic. In this study, simple exploiters are proposed to improve the contrast of current image. To select these exploiters appropriately, reinforcement learning is proposed. This selection is based on the functional history of these exploiters. Having multi aim of preserving brightness, retaining the shape features of the original histogram, and controlling on the rate of over-enhancement are the achievements of the proposed method. These objectives are suitable for the application of consumer electronics. By this simulation results, it has been shown that in terms of visual assessment, absolute mean brightness error (AMBE) and peak signal-to-noise (PSNR) of the proposed method are superior to literature methods. © 2020, Springer Nature Singapore Pte Ltd