Research in Agricultural Engineering, 2021 (vol. 67), issue 1
Effect of drying temperature in hop dryer on hop qualityOriginal Paper
Adolf Rybka, Petr Heřmánek, Ivo Honzík
Res. Agr. Eng., 2021, 67(1):1-7 | DOI: 10.17221/61/2020-RAE 
One of the qualitative characteristics of both green and dried hops is the content of hop essential oils which are contained in a quantity of 0.5 to 3.5%, depending on the hop variety. These essential oils are heat labile substances because the temperature has an influence on their content. Hop cones, dried either in belt or chamber dryers, are exposed to a drying medium temperature of 55 °C to 60 °C for the entire duration of drying, i.e. for 6-8 hours. Under current drying conditions there is a loss of approx. 15 to 25% of the total content of essential oils present in hops before drying. In case of special aroma...
Energy and exergy analyses of okra drying process in a forced convection cabinet dryerOriginal Paper
Abiodun Okunola, Timothy Adekanye, Endurance Idahosa
Res. Agr. Eng., 2021, 67(1):8-16 | DOI: 10.17221/48/2020-RAE
A forced convection automatic cabinet dryer integrated with a data logger was designed and fabricated. The okra samples were dried in the dryer at drying temperatures of 50, 60, and 70 °C and at three different load densities of 200, 300, and 400 g at a continuous air velocity of 0.7 m.s-1. Energy and exergy analyses of the drying process were performed. The obtained results showed that the energy efficiency, energy utilisation, and utilisation ratio increased from 26.59 to 68.24%, 5.47 to 114.36 W, and 0.36 to 0.71 as the temperature increased to 70 °C, respectively. The inflow, outflow, and exergy losses were in the range of 7.02 to 26.14...
Forces and loosening characteristics of a new winged chisel ploughOriginal Paper
Mahmood Reza Salar, Seyed Hossein Karparvarfard, Mohammad Askari, Hoda Kargarpour
Res. Agr. Eng., 2021, 67(1):17-25 | DOI: 10.17221/71/2020-RAE
This study was devoted to verifying the performance of various configurations of a winged chisel plough (WCP) in a soil bin. The performance of the new tool was assessed at three wing depths (5, 10 and 15 cm), three bend angles (10, 20 and 30 °), and three rake angles (7.5, 15 and 22.5 °) with three replications using a completely randomised design at a constant depth and speed of 30 cm and 1 m.s-1, respectively. The draught and vertical forces, soil disturbed and upheaved areas plus the efficiency of the soil loosening were measured during the tests. The results revealed that the draught and vertical forces were significantly increased by increasing...
Moisture - Influenced friction properties of ackee apple (Blighia sapida) seedsOriginal Paper
Olajide Ayodele Sadiku, David Omogunsoye
Res. Agr. Eng., 2021, 67(1):26-33 | DOI: 10.17221/75/2020-RAE
The friction properties of ackee apple (Blighia sapida) seeds at an 11.9, 17, 22, 27, and 32% (w.b.) seed moisture were determined, which are vital for designing their processing techniques and equipment to replace the present manual methods. The ackee apple grows in many West African countries, especially Nigeria. The ackee seeds were harvested at Lanlate, Oyo State, Nigeria, where ackee trees are predominant. Standard experimental methods were adopted to determine the properties. The data were analysed using an ANOVA and the least significant difference (LSD) at P ≤ 0.05. As the moisture increased, the static coefficient of...
A study on the influence of the loading rate and orientation on some mechanical properties of cassava tubers of different agesOriginal Paper
Olawale Ogunnigbo, Dare Adetan, Tunde Morakinyo, Olusola Olusunmade, Bolaji Ojerinde
Res. Agr. Eng., 2021, 67(1):34-44 | DOI: 10.17221/57/2020-RAE
The study determined the effects of the speed of loading and the loading orientation on some selected mechanical properties of the TME 419 cassava tuber variety at different ages of the tuber which are essential in the design and construction of the processing and handling equipment of a cassava peeler. The properties considered include the bioyield and rupture points, compressive and rupture strengths, toughness and firmness, and moduli of stiffness and toughness, which were carried out in the transverse and longitudinal loading direction using an Instron Universal Testing Machine (UTM). As the loading rate increased from 5.00 to10.00 mm.min-1...
Comparative analysis of the physical properties of two varieties of periwinkle relevant to the design of processing equipmentShort Communication
Inemesit Edem Ekop, Kayode Joshua Simonyan, Udochukwu Nelson Onwuka
Res. Agr. Eng., 2021, 67(1):45-50 | DOI: 10.17221/58/2020-RAE
The physical properties of agricultural products are essential in designing machines, equipment, and systems for efficient processing operations. Two periwinkle varieties, viz Tympanotonus fuscatus (Linnaeus, 1758) and Pachymelania aurita O. F. Müller, 1774, were utilised in this study to investigate and determine their physical properties relevant to the design of efficient processing equipment. The geometric (axial dimensions, mean diameters, surface area, sphericity, aspect ratio) and gravimetric (bulk and true densities, mass, and porosity) properties were measured. The averages for the major diameter, arithmetic mean...