AgriEngineering — Open Access Journal

Plant leaf diseases can affect plant leaves to a certain extent that the plants can collapse and die completely. These diseases may drastically decrease the supply of vegetables and fruits to the market, and result in a low agricultural economy. In the literature, different laboratory methods of plant leaf disease detection have been used. These methods were time consuming and could not cover large areas for the detection of leaf diseases. This study infiltrates through the facilitated principles of the convolutional neural network (CNN) in order to model a network for image recognition and classification of these diseases. Neuroph was used to perform the training of a CNN network that recognised and classified images of the maize leaf diseases that were collected by use of a smart phone camera. A novel way of training and methodology was used to expedite a quick and easy implementation of the system in practice. The developed model was able to recognise three different types of maize leaf diseases out of healthy leaves. The northern corn leaf blight (Exserohilum), common rust (Puccinia sorghi) and gray leaf spot (Cercospora) diseases were chosen for this study as they affect most parts of Southern Africa’s maize fields. Full article

Water flow and sedimentation processes have been significantly erratic at the Chókwè Irrigation Scheme (CIS) and have affected its hydraulic performance. Given its expansion there is need to understand these processes taking place on-site and along the channels of the scheme. CIS being the biggest project of its kind in Mozambique requires proper management of water flow and sedimentation processes. Therefore, the effect of water flow, sediment transport and deposition parameters on the performance of the CIS is needed. In order to determine the effect of spatial and temporal water flow and sediment distribution trends along the irrigation canals, there is need to establish a correlation between these parameters. Determining the influence of water flow velocity on sediment settling rate at different depths along the canal reaches is important in managing the CIS. In addition, a developed decision-support tool to predict sediment deposition is required. For this reason, it is therefore crucial to carry out a timely assessment of water flow and sedimentation processes in CIS in a review concept. From the current review, some gaps that exist for more focused research on Chókwè Irrigation Scheme have been identified. In this regard therefore, there is need to develop an effective support tool for managing water flow and sediment deposition along the canal reaches with a view to increasing crop production in CIS. Full article

A scale-up protocol for rosmarinic acid extraction from Orthosiphon stamineus was developed using the concept of constant power dissipation for a similar kinetic profile. Rosmarinic acid is the bioactive compound in the herb and therefore, large scale extraction for that compound is important for commercial application. The first-order kinetic equation which was established in the preparative scale extraction was used to describe the extraction of rosmarinic acid from the herb. The agitation speed of the pilot large-scale extractor (451 rpm) was determined based on the constant power dissipation to meet the minimal required speed, namely just-suspended speed (N_js), 450.84 ± 0.88 rpm. The experimental data was fitted well to the proposed kinetic equation with a high correlation coefficient, R² 0.88, and a low root mean square error, RMSE 3.85. This indicates the good performance of the scale-up approach based on the dynamic criterion. Therefore, the use of constant power dissipation to obtain a similar kinetic profile could be applied for phytochemical extraction from herbal plants. Full article

This research aims to solve the problem of the raw milk collection and transportation system which can be interpreted as a special case of the vehicle routing problem. In the proposed problem, the factory will send the trucks, multiple fleets composed of several compartments, to collect the raw milk from the raw milk farms. The objective of this research is to minimize the total transportation cost and the trucks’ and tanks’ cleaning costs. The transportation cost directly depends on the fuel usage. The fuel usage occurs during the transportation of the milk and during the waiting times when it arrives at the factory and cannot transfer the raw milk into the production tank. We develop the modified differential evolution algorithm (MDE) to solve the proposed problem. The original process of the Differential Evolution algorithm (DE) has been modified in two folds which are as follows: (1) In the recombination process, the 2nd order of trial vectors has been generated using 3 different strategies and compared with the 1st order trial vector; the better from the 1st and the 2nd order of trial vectors will move to the selection process. (2) The probability function has been used to select the new target vector from one of two sources which are the trial vector and the current target vector so that the worse solution can be accepted in order to increase the diversity of the original DE. The computational result shows that the modified DE (MDE) outperforms the original DE in finding a better solution. Full article

The efficient use of water should involve decisions for balancing green water (GW) and blue water (BW) use for sustainable development. More specifically, the focus of irrigation water management should be redirected from a BW perspective toward considering the full water balance, including GW flow. This study presents a modelling approach in a system dynamic platform for minimizing the BW to GW ratio in a water basin while maximizing total agricultural profit. The paper considers the compromise between any reduction in the GW to BW ratio and the possible changes in the economic achievement of the region through varying land use and cropping patterns. This paper explores and presents the possibilities of reducing the BW to GW ratio in the Zarrinehrud River-basin for moderate, dry, and wet years using the water footprint concept. Results show that under all combinations of economic objective and BW to GW ratio addressed by water footprint measures, the hydro-economic performance of the river basin may substantially be improved as compared with the current practice. Either weights may systematically be changed or multiple objective optimization algorithms may be employed if a more precise tradeoff between the objectives is needed. Full article

Future climate change is projected to have significant impacts on water resources availability in many parts of the world. This research evaluated climate change impacts on runoff, aquifer infiltration, renewable water resources, and drought intensity in Salt Lake sub-basin, Iran, by the Soil and Water assessment tool (SWAT) model and the Standardized Precipitation Index (SPI) under A1B, A2, and B1 climatic scenarios for 2011–2030, 2046–2065, and 2080–2099, using 1986–2016 as the reference period. The model was calibrated and validated by the SWAT-CUP software and SUFI-2 algorithm. Nash–Sutcliffe (NS) coefficients (0.58 and 0.49) and the determination coefficients (R²) (0.65 and 0.50) were obtained for the calibration and validation periods, respectively. In order to study the climatic condition in the study basin, drought intensity was calculated. Then, drought intensity was predicted using the SPI index for the period 2011–2030. The results showed that runoff, infiltration, as well as renewable water resources will decrease under all climatic scenarios. Renewable water resources will be approximately reduced 100 Mm³ by the year 2100. The future projections suggest a regional increase of 2 °C in temperature and a 20% decrease in precipitation in the sub-basin. In particular, drought intensity will be increased in the future. In 2015, this index was −1.31, and in 2016, the SPI index was lower than −2. These projection scenarios should be of interest to water resources managers in tropical regions. Full article

For the first time, a steady state computational simulation for the production of biodiesel from meat processing dissolved air flotation sludge via an integrated process of in-situ hydrolysis and esterification technologies has been investigated. Important thermophysical properties of the intrinsic lipids of dissolved air flotation sludge were estimated using chemical constituent fragment methods. The environmental performance and the economic performance of the biodiesel production process were assessed via the estimation of the net energy ratio (NER) and the unit production cost, respectively. Since electrical energy requirements may be satisfied via either non-renewable (case A) or renewable sources (case B), the NER was determined for both scenarios. To enhance the robustness of the study results, uncertainties in the NER and the unit cost of the biodiesel production process due to the variability of the underlying study assumptions were also assessed. Uncertainty analysis indicated that the likely range of the NER for the biodiesel production process for cases A and B are 1.76 to 3.32 and 1.82 to 3.36, respectively, at 95% probability. Uncertainty analysis also showed that the likely range of the unit production cost for biodiesel is $US0.41/kg-biodiesel to $US0.71/kg-biodiesel at 95% probability. The results that were obtained in this study therefore provide evidence of both the environmental sustainability and the economic viability of biodiesel production from dissolved air flotation sludge via the proposed integrated process of in-situ hydrolysis and esterification. Full article

Successful data acquisition on mobile platforms, such as tractors, requires the provision of protection for the sensitive electronics, as these platforms are inherently rife with electrical transients that have sufficient energy to cause damage to unprotected instrumentation. Unfortunately, though there are many protection options for industrial applications (i.e., those installed at 120VAC), off-the-shelf products for mobile protection are extremely limited and, after a survey, were determined to provide insufficient protection. The objective of this study was to identify the requirements for the protection of mobile platform instrumentation and equipment, and/or identify circuits that can perform this function. A literature review of electrical transients typical to automotive electronics was performed and circuit simulations were performed using open source software. Off-the-shelf circuit components were tested, via simulation, in various configurations until a design emerged that provided adequate protection from all surge classes. To ensure protection of valuable data, one of the design criteria was to ensure the circuit would continue to supply power to the personal computer (PC), and electronics, even during a load-dump event. The circuit was also designed to provide protection from electrical fast transients and electrostatic discharges. The reported circuit is capable of protecting a computer and data acquisition electronics installed on 12 VDC mobile equipment. This simple, inexpensive design meets Automotive Electronics Council requirements and uses readily available components without a specially fabricated circuit board. Full article