Enhancement of Agricultural Materials Separation Efficiency Using a Multi-Purpose Screw Conveyor-Separator

The technological process of agricultural production is inextricably linked to the movement of a large number of goods, ranging from the supply of raw materials to their conversion and delivery of finished products. In the implementation of freight flows at the enterprises of agro-industrial complexes and the complex mechanization of raw material conversion processes, the main role is played by systems of transport and technological machines, which include screw conveyors with the ability to convert materials. For this purpose, the simultaneous performance of transportation and separation processes has been studied. The results of the investigation include the construction and study of the mathematical model of the system «a screw of the screw conveyor—grain mixture and separation process» involving further experimental research. The study of the effectiveness of separating agricultural materials with a multifunctional screw conveyor-separator showed that for effective sifting, the selected rational values of the parameters lie within the following limits: angle of inclination of the sieve was 0–14°, and frequency of rotation of the working body was 300–700 rpm. Some rational parameters were obtained during the grain mixture separation process on the basis of an experimental study, namely: n = 380 rpm; q = 0.9–4.7 kg/h·cm2, γ = 0–14°; P = 0.22–0.7 kW, depending on the size of the working sieve (100 × 200 mm). These rational parameters will make it possible to increase the efficiency of agricultural materials separation by a screw conveyor separator, to achieve maximum productivity, and to reduce energy consumption compared to other sorting devices

Tribological Study of Chisel Knives in Sandy Soil

This paper presents the interaction system within the mechanical soil processing process, consisting of two large elements, the metal of the tool and the soil. Due to the two main forces acting on the chisel knives—friction and impact with the sandy soil—the wear of these chisel knives was determined. To determine the wear, a stand was used which allowed testing chisel-type knives in laboratory conditions by changing their functional parameters: working depth, angle of the knives to work the soil, working speed, humidity and granulation of the test environment. The present paper presents an application of the Archard-type wear law to the contact between a chisel-type knife and sandy soil (wet and dry sand). The theoretical model regarding the Archard wear coefficient considered three forms of surface damage (shake down, ratcheting and micro-cutting). The sand was considered spherical and rigid and the surface of the knife was flat. The experimental model considered real steel knives with different surface hardness and operation under controlled conditions of sand granulation, humidity, attack angle, depth of penetration and speed of sliding. The theoretical and experimental results highlight the wear behavior of chisel knives (Archard coefficient) in wet and dry sand

Evaluation of essential oil and hydrolate from a new hyssop variety (Hyssopus officinalis L.)

The main objective of this study was to evaluate the quality of essential oil (EO) and hydrolate (HY) obtained from a new Romanian variety of hyssop (Hyssopus officinalis L., Lamiaceae family), namely ‘Cătălin’. The chemical composition and the concentration of the compounds was established by gas chromatography coupled to mass spectrometry (GC/MS). The main constituents identified in hyssop EO and HY were cis-pinocamphone (34.63% and 67.00%), trans-pinocamphone (11.72% and 14.58%), thujenol (1.39% and 6.05%). The evaluation of the antioxidant capacity was performed by three methods (DPPH, ABTS and FRAP), EO proving a higher oxidizing activity compared to HY one. The antimicrobial activity of the essential oil was evaluated in vitro, in order to detect its ability to inhibit G- phytopathogenic bacteria (Pseudomonas syringae) and plant pathogenic fungi (Fusarium oxysporum). Eugenol, linalool and estragole standards were used as reference volatile compounds. Regarding Pseudomonas syringae (LMG5090) bacterium, assays showed that hyssop oil does not inhibit its growth. Estragole and eugenol showed pronounced antibacterial activity in all tested concentrations, both in the first 24 hours of incubation and after 3 days. Linalool instead has bacteriostatic activity only at high concentrations (50% and 100%), an inhibitory activity that is maintained only in the first 24 hours of incubation. The results obtained against Fusarium oxysporum reveal that the EO tested has no fungicidal activity but only fungistatic, and it is able to delay mycelial growth and the degree of inhibition depending on the concentration used

RELATIONSHIP BETWEEN THE INFLUENCE FACTORS OF THE SOIL TILLAGE PROCESS

It is known that the soil tillage process for the sowing of the crops is one of the most important agricultural works involving both large energy consumption and high costs. The quality of seed-bed preparation influences the degree of germination and crop productivity. The soil tillage process is influenced by many factors. Usually, these factors are: pedological factors (soil texture, organic matter, clay mineralogy, soil structure, soil bulk density, moisture content, respectively: external friction, soil- metal adherence, soil cohesion, soil resistance to penetration), technological factors (forward speed, working depth, working width), and constructive factors (type of tool, geometry of tool, technical condition of tool, adjustment mode of tool). All these factors determine the mechanical energy necessary to effectuate the soil tillage process, energy which contain the following terms: energy required to cut the soil, energy required to overcome the external friction forces, energy required to move the soil, energy required to overcome the adhesion forces, energy required for displacement of the tools, and the energy required to overcome the inertia forces (if the speed of the agricultural machine is not constant). In this paper, more complex scheme of the soil tillage process and the relationships between the factors of influence are presented, with concrete application for the agricultural vibro-cultivator used in conservation tillage systems, which can make the preparation of the seedbed for sowing in one pass with minimum consumption of energy, without causing the degradation of agricultural soil

Chemical Composition, Antioxidant and Antimicrobial Effects of Essential Oils Extracted from Two New <i>Ocimum basilicum</i> L. Varieties

Recent agricultural research aims to identify novel applications for plant extracts as efficient defenses against weeds, insects, or phytopathogenic agents. The main goal of the present study was to evaluate two new varieties of basil (Ocimum basilicum L., fam. Lamiaceae), Yellow basil, “Aromat de Buzau” variety and Red-violet basil, “Serafim” variety. The basil varieties were studied under different aspects regarding biochemical characterization using GC-MS, antioxidant activity evaluated under three methods (DPPH, ABTS, FRAP), and antimicrobial properties (for three G-bacteria: Perctobacterium carotovorum, Pseudomonas marginalis, Pseudomonas syringae and three phytopathogenic fungi: Rhizoctonia solani, Fusarium oxysporum, Botrytis cinerea). The results showed that linalool (39.28%; 55.51%), estragole (31.48%; 9.78%), and eugenol (5.42%; 7.63%) are the main compounds identified in the extracts, validating the high antioxidant activity of the studied essential oils and floral waters. When applied in high concentrations, essential oils have shown a potential bactericidal effect on P. carotovorum as well as a potential fungicidal effect on R. solani and B. cinerea

Contributions to the Mathematical Modeling of the Threshing and Separation Process in An Axial Flow Combine

The paper presents a mathematical model that characterizes the process of threshing and separation from the threshing machine with an axial flow of a thresher, taking into account the following input parameters: material flow, rotor speed, distance between rotor and counter rotor, mean density of processed material, feed speed, length of thresher and separating surface. Output parameters, such as the distribution function of separated seeds, distribution density function of separated seeds and distribution function of free seeds in the threshing space, as well as the distribution function of unthreshed seeds, together with the value of evacuation losses, were used to control the modeling process

Chemical Composition, Antioxidant and Antimicrobial Effects of Essential Oils Extracted from Two New Ocimum basilicum L. Varieties

Recent agricultural research aims to identify novel applications for plant extracts as efficient defenses against weeds, insects, or phytopathogenic agents. The main goal of the present study was to evaluate two new varieties of basil (Ocimum basilicum L., fam. Lamiaceae), Yellow basil, &ldquo;Aromat&nbsp;de Buzau&rdquo; variety and Red-violet basil, &ldquo;Serafim&rdquo; variety. The basil varieties were studied under different aspects regarding biochemical characterization using GC-MS, antioxidant activity evaluated under three methods (DPPH, ABTS, FRAP), and antimicrobial properties (for three G-bacteria: Perctobacterium carotovorum, Pseudomonas marginalis, Pseudomonas syringae and three phytopathogenic fungi: Rhizoctonia solani, Fusarium oxysporum, Botrytis cinerea). The results showed that linalool (39.28%; 55.51%), estragole (31.48%; 9.78%), and eugenol (5.42%; 7.63%) are the main compounds identified in the extracts, validating the high antioxidant activity of the studied essential oils and floral waters. When applied in high concentrations, essential oils have shown a potential bactericidal effect on P.&nbsp;carotovorum as well as a potential fungicidal effect on R. solani and B. cinerea

Contributions to the Mathematical Modeling of the Threshing and Separation Process in An Axial Flow Combine

The paper presents a mathematical model that characterizes the process of threshing and separation from the threshing machine with an axial flow of a thresher, taking into account the following input parameters: material flow, rotor speed, distance between rotor and counter rotor, mean density of processed material, feed speed, length of thresher and separating surface. Output parameters, such as the distribution function of separated seeds, distribution density function of separated seeds and distribution function of free seeds in the threshing space, as well as the distribution function of unthreshed seeds, together with the value of evacuation losses, were used to control the modeling process

Research on the Identification of Some Optimal Threshing and Separation Regimes in the Axial Flow Apparatus

Starting from the influencing parameters of threshing and separation and implicit seed losses that occur within this process, this paper searched for and identified the optimal threshing regimes to minimize losses depending on the process parameters. The evacuation losses (pev) depend on threshing rotor speed (n) and implicit rotor peripheral speed (vp), material feed speed (va), the space between the rotor and counter-rotor (δ), material feed flow (Q), material density (ρ), and the length of the threshing apparatus (L). As the parameters ρ and L are constant, the variation of losses in relation to each of the arguments was followed: vp, Q, ρ, and va, respectively, for the minimization of losses by the variation of the loss function by two arguments each (represented graphically); the four arguments targeted being: vp, va, ρ, and Q. Using these input parameters, it was possible to determine the optimal threshing regimes for the variation of losses in relation to the rotor peripheral speed, the feed flow, the space between the rotor and the counter-rotor, and the feed speed, so as to obtain a seed separation percentage (Ss) as close as possible to 100% (and implicitly the smallest threshing losses—towards zero) in relation to these parameters

Morphological, Physiological and Quality Performances of Basil Cultivars under Different Fertilization Types

The prospect of replacing traditional chemical fertilization with organic and microorganism-based fertilization meets the current demand for more sustainable cropping systems and healthy food. In this respect, research was carried out to evaluate the effects of the factorial combination between four basil cultivars (‘Aromat de Buzau’, ‘Macedon’, ‘Cuisoare’ and ‘Serafim’) and three types of fertilization, namely chemical fertilization (with a solid chemical fertilizer), organic fertilization (with chicken manure formulate) and microorganisms’ fertilization (with microorganisms formulate), on basil yield, biochemical and physiological parameters and essential oil composition. The results showed that the biometric parameters (plant height, number of stems and leaves and leaf area) were significantly influenced by the cultivar; ‘Macedon’ obtained the highest values of plant height (64.7 cm) and number of stems (20.33) and leaves (618.3) and ‘Serafim’ the largest leaf area (4901.7 cm2 per plant), while the type of fertilization did not affect these parameters. Regarding the biomass, the influence of the cultivar was not significant on fresh biomass but was significant on dry biomass, with ‘Macedon’ showing the highest value (56.4 g·plant−1 dry biomass). The mentioned parameters were significantly influenced by the type of fertilization, with the highest values recorded with chemical fertilization. Both the cultivar and the fertilization type significantly influenced the physiological parameters (the total content of assimilatory pigments and photosynthesis). Five phenolic compounds were quantified from leaf extracts by HPLC-MS (caffeic acid, hyperoside, isoquercitrin, rutin and quercitrin). Hyperoside was identified only in ‘Macedon’, while the rest of the compounds were found in all the cultivars and varied depending on the cultivar and fertilization type. Regarding the composition of the essential oil, variation was found depending on the cultivar and fertilization type. In ‘Aromat de Buzau’, the main compounds were methyl chavicol and β-linalool; in ‘Macedon’, geranial and neral; and in ‘Cuisoare’ and ‘Serafim’, β-linalool. Moreover, the PCA showed that the ‘Serafim’ cultivar has exclusive properties compared to the other cultivars. Our results highlight that identifying the most effective interaction between genotype and fertilization type allows to optimize yield and quality targets for sweet basil