Drying Characteristics, Kinetic Modeling, Energy and Exergy Analyses of Water Yam (Dioscorea alata) in a Hot Air Dryer

In this study, drying characteristics, kinetic modelling, energy and exergy analyses of a convective hot air dryer are presented for water yam. The drying experiments were carried out at temperature levels of 50, 60, and 70 ◦C and slice thicknesses of 3, 6, and 9 mm. The effects of drying variables on the drying rate (DR), moisture diffusivity (Deff), activation energy (Ea), energy utilization (EU), energy utilization ratio (EUR), exergy loss (EXL), exergy efficiency (EXeff), improvement potential (IP), and exergetic sustainability index (ESI) were investigated. The results showed that increasing air temperature increased the DR, Deff, EU, EUR, EXL, EXeff, IP, and ESI, while increasing the slice thickness increased Deff and Ea, but decreased the DR. The highest Deff and Ea values were 4.2 × 10−8 m2/s, and 53 KJ/mol, respectively. EU and EUR varied from 10 to 150 J/s and 0.39 to 0.79, respectively. EXL and EXeff varied between 2 and 12.5 J/s and 58 to 75%, respectively. Midilli’s model had the best performance in predicting the moisture ratio of water yam with coefficient of determination (R2 = 0.9998), root mean square error (RMSE = 0.0049), and sum of square error (SSE = 0.0023). Keywords: exergy efficiency; exergy sustainability index; water yam; drying rate; exergy los

Development and Process Optimization of a Ready-to-Eat Snack from Rice-Cowpea Composite by a Twin Extruder

A central composite rotatable design with four independent variables viz. blend ratio (broken rice flour and cowpea flour): 90:10–70:30, moisture content (10–18% wet basis), barrel temperature (110–150 ◦C), and screw speed (280–360 rpm) were varied in the development of ready-to-eat snacks using a twin extruder for a broken rice–cowpea product. The effects of the independent variables on specific mechanical energy, water absorption index, water solubility index, total color, hardness, bulk density, expansion ratio, and overall acceptability of the extruded snack were investigated using regression analysis. The results showed that the physical qualities of the ready-to-eat snacks were significantly affected by the extrusion parameters (i.e., blend ratio, barrel temperature, moisture content, and screw speed). From the findings, it was observed that screw speed and moisture contents affected hardness, while water absorption index was affected by all the extrusion parameters. However, the water solubility index and overall acceptance were majorly affected by the moisture content; extrudate produced with barrel ratio of 85:15, 12% moisture content, barrel temperature of 140 ◦C, and screw speed of 300 rpm was the most acceptable, at 6.73 on a 9 point hedonic scales. The blend ratio and barrel temperature influenced the expansion. Furthermore, the combination of cowpea and broken rice to produce nutritious ready-to-eat snacks has high acceptability and is a promising panacea for food security. Keywords: broken rice; cowpea; extrusion; food security and ready-to-eat snack

Wpływ wybranych właściwości mechanicznych ziarna kukurydzy cukrowej na stopień jego odcięcia od rdzeni kolb

Research results on the quality of work of a seed cutter for selected cultivars of sweetcorn were presented. Measurements were carried out at the rotational speed of a head of 1600 rot. min.·-1 and a linar velocity of the cob conveyor of 0.31 m·s-1 . A statistically significant relation between the degree of cutting the seed mass and the selected mechanical properties of grain were determined. Differences between cultivars at the level of approximately 43% for the force of perforation of the pericarp Fp.Przedstawiono wyniki badań jakości pracy obcinarki ziarna dla wybranych odmian kukurydzy cukrowej. Pomiary przeprowadzono przy prędkości obrotowej głowicy wynoszącej 1600 obr·min-1 i prędkości liniowej podajnika kolb - 0,31 m·s-1. Stwierdzono istotny statystyczny wpływ między stopniem odcięcia masy ziarna, a wybranymi właściwościami mechanicznymi ziarna. Zaobserwowano różnice pomiędzy odmianami na poziomie około 42% dla siły przebicia okrywy owocowonasiennej Fp, około 27% dla odporności na przebicie Rp, około 31% dla deformacji L i około 14% dla stopnia odcięcia ziarna S od

Influence of Silver Nanoparticles, Laser Light and Electromagnetic Stimulation of Seeds on Germination Rate and Photosynthetic Parameters in Pumpkin (Cucurbita pepo L.) Leaves

The study aimed to determine the impact of laser light (L), magnetic stimulation (p) and silver nanocolloid (AgNC) on pumpkin seeds on the germination rate and content of photosynthetic pigments as well as the efficiency of photosynthesis and greenness index in the plant’s development stages. Seeds germinated after the use of various combinations of different refining techniques. The best results were observed for the alternating magnetic field, where the germination energy increased significantly by 20% relative to the control. A similar effect was observed in terms of germination capacity which increased by 4%. A decrease in terms of emergence rate was observed in all study groups. Leaves grown from seeds soaked in nanocolloidal silver on platters were characterised by a significantly higher content of chlorophyll a and b by, respectively, 53 and 11%, as well as 79% higher carotenoid content. The leaves of potted plants contained 42 and 43% more chlorophyll a in groups p and AgNC. In addition, 66 and 81% more carotenoids in groups L and p. At the stage of the onset of flowering of pumpkin, an improvement in terms of photosynthetic efficiency and greenness index was observed in all study groups. The highest improvement was recorded for seeds soaked in silver and reached 23% (intensity of photosynthesis) and 11% (greenness index SPAD)

O zmianie koncepcji i ogólnej strukturze budowy ciągników rolniczych

Conclusions on the analysis of the state of development in the tractor industry are formulated, aspects of the forecasting concept of transformation, general layout solutions and the theory of promising tractor units with new propulsion systems are considered, a general approach to the pre-design substantiation of new generation tractors is presented.Sformułowano wnioski z analizy stanu opracowań i tendencji w budowie ciągników. Rozpatrzono aspekty prognozy transformacji koncepcji, ogólnej struktury rozwiązań konstrukcyjnych i teorii perspektywicznych ciągnikowych agregatów maszynowych z nowymi układami napędowymi. Przedstawiono możliwe tendencje w przedprojektowym uzasadnieniu koncepcji budowy ciągników nowej generacji

Influence of Blanching Time on Moisture, Sugars, Protein, and Processing Recovery of Sweet Corn Kernels

The objective of this work is to determine the influence of blanching time on moisture content, sugars, protein, and processing recovery (degree of cut corn) of sweet corn kernels. Sweetcorn cobs of the Jubilee variety were blanched in the water at the temperature 85 °C during the period of 2, 4, 6, and 8 min. Non-blanched cobs were used as control samples. Blanched cobs were made subject to a mechanical process of cutting-off the kernels. It was stated that the blanching time has significant statistical influence on the content of moisture, sugars, and protein in kernel as well as on the quantity of the cut-off kernel mass

Impact of Pre-Sowing Red Light Treatment of Sweet Corn Seeds on the Quality and Quantity of Yield

This paper presents the results of a study on the effects of red light treatment of sweet corn seeds on the quantity and quality of the subsequent yield (total and marketable), as well as the length of cobs and thousand kernel weight. The respective groups of kernels were exposed to light: 1—once (K1), 2—twice (K2), and 3—thrice (K3); the control seeds were untreated. The light treatment had a positive impact on the analyzed values. Relative to the control, we observed a yield increase of approx. 5% for the Basin cultivar and approx. 25% for the Shaker and Powerhouse cultivars under the K2 mode. We also recorded an increase in the percentage of marketable yield of approx. 20%, 45%, and 48%, respectively for the Shaker, Powerhouse, and Basin cultivars. Positive effects were also observed in terms of cob length and thousand kernel weight for all treatment modes and cultivars analyzed. The obtained results support the inclusion of this method in the scope of recommendable agrotechnical practices aimed at improving the quantity and quality of yields of various crops and vegetables

Extension Experts‘ Intentions to use Precision Agricultural Technologies, a Test with the Technology Acceptance Model

Precision agriculture (PA) is a farm management strategy that relies on various technologies to improve the productivity and sustainability of farming operations. The adoption of PA entails on-farm and off-farm benefits; however, the adoption rates remain low in Iran. Using the socio-psychological framework of the technology acceptance model (TAM), this study examined agricultural extension experts‘ intentions to use precision agricultural technologies (PATs) in Ardabil province, Iran. Structural equation modelling (SEM-PLS) was used to map the components of the TAM (perceived usefulness, perceived ease of use, and attitudes toward PATs). All the components of the TAM showed a significant effect on experts‘ intentions, confirming the importance of socio-psychological variables in predicting agricultural experts‘ decision to apply PATs. Experts perceived PATs as helpful and relatively easy to use. In addition, they had positive attitudes toward PATs and intended to use most PA technologies. The TAM posits that two attitudinal components of perceived usefulness (PU) and perceived ease of use (PEU) determine acceptance and use. PU is the degree to which one believes using technology would enhance job performance, while PEU is the degree to which using technology is free of effort. The results showed that PEU and PU had a positive impact on attitudes. The three constructs positively affected behavioural intention toward the application of PATs and explained 68.8% of the variance of this construct. Due to the novelty of PA in the country, PEU was the most critical determinant of intention

Pyrolysis oil blended n-butanol as a fuel for power generation by an internal combustion engine

The article discusses results from the investigation of the n-butanol-pyrolysis oil blend, which can be considered a potential fuel for the internal combustion spark-ignition engine operating in a power generation set. The n-butanol-pyrolysis oil blends were prepared at two ratios of 3:1 (25%) and 1:1 (50%) by volume, respectively. As reference fuels for combustion tests in the engine, regular gasoline (gasoline EU 95) and n-butanol were proposed. The combustion tests were conducted on the single-cylinder research engine at a compression ratio of 11:1 and an equivalence ratio of 1. The experimental analysis was focused on engine performance, combustion phases, knock occurrence, and exhaust emissions. As observed, combustion got slower for butanol-pyrolysis oil blends. CO emission was similar to tests with reference fuels. Unburnt hydrocarbons increased with pyrolysis oil increased to 50% in a blend. NO emissions were reduced. It was found that n-butanol blended pyrolysis oil at a ratio of 3:1 can be successfully applied as the fuel to the spark-ignition engine. Additionally, it was found that this blend is more resistant to combustion knock compared to regular gasoline 95. Hence, the engine can work at a higher compression ratio without any malfunctions caused by combustion knock