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Soil organic matter (SOM) plays a major role in agricultural and ecological processes. For this reason, accurate quantification of SOM is important for precision agriculture and environmental management. Inexpensive sensor technology could be a potential approach to achieving the accurate prediction of SOM. The objective of this study was to evaluate inexpensive colour sensor (Nix[TM] Pro) data for prediction of SOM in arid and semiarid areas of Iran. A total number of 85 and 152 soil samples from the soil surface (0-20 cm) were collected from the Semnan (arid area) and Qazvin (semiarid area) regions respectively. The nonlinear random forest (RF) method and linear regression were conducted to predict SOM using Nix[TM] pro colour sensor data. The partial least-squares approach was also utilised to reduce the dimensions of the dataset, decrease the number of input variables and avoid multi-collinearity. Soil colour was measured in moist and dry conditions. Root mean square error (RMSE), correlation coefficient (r), r-square ([R.sup.2]), mean square prediction error (MSPE) and ratio of performance to interquartile distance (RPIQ) were used to assess the RF and the linear regression models for prediction of SOM. Moist sample data was used for estimation of the SOM because of the larger correlation between SOM and colour sensor data in moist than dry samples. In estimation of SOM, the RF model represented lower dispersion between the estimated and the actual values of SOM (RMSE = 0.42, 0.43, RPIQ = 2.2, 2.06 and MSPE = 0.19, 0.19 in semiarid and arid regions respectively). In contrast, more dispersion was obtained by applying the linear regression model (RMSE = 0.61 and 0.51, RPIQ = 1.47 and 1.76, and MSPE = 0.39 and 0.26 in semiarid and arid regions respectively). The RPIQ values for linear regression in arid and semiarid areas were 1.76 and 1.47 respectively. Hence, the use of a linear regression model for prediction of SOM in arid areas would result in acceptable reliability; however, its utilisation should be avoided in semiarid areas due to less reliable results. Additional keywords: Inexpensive colour sensor, nonlinear models, soil organic matter. Received 25 October 2018, accepted 8 February 2019, published online 29 March 2019, Introduction Soil organic matter (SOM) has an essential role in various agricultural and ecological processes including the carbon cycle, soil fertility and soil physical interactions involving C[O.sub.2] sequestration (Sullivan et [...]

Because of water crises, the cultivation of forage plants is greatly important in arid and semi-arid regions of the world. In order to study the effect of different organic fertilizers and irrigation regimes on the growth and biochemical responses of different Atriplex species, this experiment was performed as a factorial split with three replications in the city of Bandar Abbas in 2017-2018. The main factor included three irrigation regimes (irrigation at 80, 60, and 40% of field capacity) and the sub-factor were different sources of fertilizer (poultry manure and sheep manure about 5 tons per hectare, and chemical fertilizer) and different species of Atriplex (A. canascens, A. leucoclada, and A. lelentiformis). Based on the results, increasing drought stress increased sodium (Na) and proline of the leaf and decreased the concentration of nitrogen, phosphorus, potassium, and soluble carbohydrates. In irrigation of 40% of field capacity, the highest amount of leaf nitrogen was observed in sheep manure (1.47%), representing a significant increase compared to the chemical fertilizer. In irrigation of 80% of field capacity, the highest amount of leaf phosphorus (0.222%) was observed in chemical fertilizer. The highest levels of catalase and peroxides were obtained in poultry and sheep manure. Also, in the irrigation of 40% of field capacity, poultry manure and then sheep manure could show higher levels of soluble protein in the leaf, respectively. In general, this study showed the successful effects of organic fertilizers on increasing nutrient uptake and physiological traits and improving the biological yield of Atriplex. [ABSTRACT FROM AUTHOR]

Multi-input converters are utilised in renewable energy systems including photovoltaic or wind systems. In order to increase efficiency in these converters using soft switching technique is unavoidable. This article presents a multi-input soft-switching converter with coupled inductors. The proposed converter uses only one auxiliary circuit and its operation is simple. Operating modes, design considerations, and loss calculations of the proposed converter are described. Also, a controller circuit is proposed for this converter and its operation has been evaluated. All switches used in this converter are turned on and off under soft switching conditions. Proposed converter efficiency is increased in comparison with similar multi-input converters under the same conditions. The theoretical analysis has been confirmed with the simulation and experimental data of a 200 W prototype converter. [ABSTRACT FROM AUTHOR]

A novel magnetic nanocomposite for removing Cd2+ and Pb2+ was prepared by surface coating of Fe3O4 nanoparticles with (3‐aminopropyl)triethoxysilane (APTES), followed by functionalization with isophthaloyl dichloride and hybridization with nano montmorillonite (MMT). The structure of the resulting nanocomposite was determined. The Fe3O4@SiO2‐APTES@isophthaloyl dichloride/MMT nanocomposite was successfully used to remove Cd2+ and Pb2+ from aqueous solutions. Several tests were designed using response surface methodology and the variables were predicted by the reduced quartic model. Absorption parameters such as time, pH, and initial cation concentration were considered as independent variables. The effects of each on the removal of Cd2+ and Pb2+ ions were examined. The efficiency of the model was evaluated by analysis of variance. [ABSTRACT FROM AUTHOR]

A novel magnetic nanocomposite for removing Cd2+ and Pb2+ was prepared by surface coating of Fe3O4 nanoparticles with (3‐aminopropyl)triethoxysilane (APTES), followed by functionalization with isophthaloyl dichloride and hybridization with nano montmorillonite (MMT). The structure of the resulting nanocomposite was determined. The Fe3O4@SiO2‐APTES@isophthaloyl dichloride/MMT nanocomposite was successfully used to remove Cd2+ and Pb2+ from aqueous solutions. Several tests were designed using response surface methodology and the variables were predicted by the reduced quartic model. Absorption parameters such as time, pH, and initial cation concentration were considered as independent variables. The effects of each on the removal of Cd2+ and Pb2+ ions were examined. The efficiency of the model was evaluated by analysis of variance. [ABSTRACT FROM AUTHOR]