Research in Agricultural Engineering, 2023 (vol. 69), issue 1
Thin layer drying characteristics of alligator pepper, ginger and turmericOriginal Paper
Adebayo Olasunkanmi Salau*, Babatunde Sunday Ogunsina, Adewale Waliu Adebayo, Adekunle Felix Okunade
Res. Agr. Eng., 2023, 69(1):1-8 | DOI: 10.17221/71/2021-RAE 
The delightful pungency, aromatic compounds and phytochemicals in some spices make them indispensable in local food systems and native medicine, hence, driving a robust market in many parts of the world. The understanding of their drying characteristics is very important for processing and adding value, and a thin layer drying study is a proven method for achieving this. In this study, changes in the moisture content, moisture ratio, drying rate and effective diffusivity of alligator peppers, ginger and turmeric were investigated at three drying temperatures 50, 60, and 70 °C following standard procedures. Five models were proposed to simulate the...
Model development and optimisation of the disc plough efficiency on loamy-sand soil in South-East NigeriaOriginal Paper
Okechukwu Oduma, Precious Ehiomogue, Dilibe Ifanyi Ntunde
Res. Agr. Eng., 2023, 69(1):9-17 | DOI: 10.17221/72/2021-RAE
This study was conducted to model and optimise the efficiency of a disc plough on loamy-sand soil in South-East Nigeria to aid farmers to examine and choose the right ploughing implement based on the soil type for an effective and bountiful production. The operational speed and cutting depth were taken as factors for the study of the plough efficiency. The results revealed that the highest field efficiency of 80% was noted when the plough worked at the cutting depth of 30 cm and a speed of 5 km·h–1 while the lowest efficiency of 68.10% was achieved at a speed of 9 km·h–1 and a depth of 10 cm. The quadratic...
Influence of the excavator hydraulic system efficiency on the productivityOriginal Paper
Michal Jùza, Petr Heømánek
Res. Agr. Eng., 2023, 69(1):18-27 | DOI: 10.17221/77/2021-RAE
This paper presents the experimental research of factors influencing the UDS 214 excavator efficiency. The hydraulic oil flow rate is measured in hydraulic circuits for controlling the moving of the bucket of the UDS 214 excavator. From the measured values, the total power losses of the individual hydraulic circuits and their efficiencies are evaluated by calculations and measurements. Furthermore, the times of the excavator cycles during a soil excavation and loading of the transport vehicle were measured. From the measured operating cycle times of the excavator, the average value of the operating cycle time was evaluated and, from this average time,...
Dielectric properties of materials for 3D printing at high frequenciesOriginal Paper
Tomá¹ Pícha, Stanislava Pape¾ová
Res. Agr. Eng., 2023, 69(1):28-35 | DOI: 10.17221/10/2022-RAE
3D printing is widely used method. In the term of developing of components for electronic devices, it is important to provide the good physical properties of the used dielectric. The main parameters are optional and stable value of the relative permittivity and the minimum dielectric losses of the material. The paper is focused on testing of loss factor and relative permittivity of following materials: polylactic acid (PLA, in two dye modifications), polyethylene terephthalateglycol (PET- G) and acrylonitrile butadiene styrene (ABS) in the frequency range of 1-100 MHz. It was proven, that the values of permittivity of the tested materials were 2.9-4.2...
Estimation of corn coefficients with vegetation indices using multispectral camera and droneOriginal Paper
Christos Dimitrios Papanikolaou*, Maria Andreas Sakellariou-Makrantonaki
Res. Agr. Eng., 2023, 69(1):36-47 | DOI: 10.17221/19/2022-RAE
Optimum irrigation scheduling and new technologies are the key to the successful practice of modern agriculture and natural resources, such as water management. Α three-year research project was conducted at Velestino, Magnesia, Greece. The aim was to study whether vegetation indices can be used to estimate the crop coefficients of corn in order to apply an intelligent method of irrigation using drones in the future. The normalised difference vegetation index (NDVI), the soil-adjusted vegetation index (SAVI), the renormalised difference vegetation index (RDVI) and a new index [difference infrared – green vegetation index (DIGVI)] were calculated...
Development and evaluation of a low-cost evaporative cooling system for agricultural product storageShort Communication
Natesan Kapilan, Vijay Kumar Patil
Res. Agr. Eng., 2023, 69(1):48-53 | DOI: 10.17221/41/2021-RAE
Agricultural products are highly perishable and, hence, we need to preserve these products after harvest. India is an agricultural country and, thus, the post-harvest storage of perishable agricultural products is important to reduce the gap between the demand and supply. Cold storage technologies have been developed and are used in India; however, these technologies are not popular in rural and remote areas due to the higher initial cost and the electrical energy requirement. Therefore, a number of low-cost technologies have been developed and, among these technologies, the evaporative cooling technology is gaining in popularity due to its simple...