Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

2 Technical Sciences / University of Warmia and Mazury in Olsztyn

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Design concept and parameters of a conical bar separator

100%

Jadwisieńczak B. , Kaliniewicz Z.

tom nr 20(3)

275--288

The process of adapting a screen separator to seeds of a given species and variety requires a corresponding set of replaceable screens. Screen replacement is a time-consuming process. Screens are often selected from the available size range, therefore, cleaning and separation processes are not always optimized. This study proposes a design concept of a new device for cleaning and separating seeds, which features a conical bar screen that rotates around its own axis. The screen has grooves whose width is smallest at the beginning of the screen and increases along the screen surface. Seeds can be sorted into various size fractions by changing the position of collecting buckets under the screen. The functional parameters of the separating device were designed based on a review of publications describing the size of the most popular agricultural seeds. The basic geometrical relationships in the proposed conical bar screen were described. The geometrical parameters of the screen were selected on the assumption that the radius at which bars are fixed to the screen can range from 200 mm to 400 mm and that bar diameter can range from 5 mm to 10 mm. Two variants of the device were proposed as a replacement for one universal separating screen. The first variant will be used to sort small seeds, including seeds of small-seeded legumes, seeds of major cereal species and medium-sized seeds with dimensions similar to cereal seeds, whereas the second variant will be applied to separate large seeds, including seeds of large-seeded legumes and plumper seeds from the medium-size fraction. The width of grooves at the beginning and end of the screen should equal 1 mm and 5 mm in the first variant and 2.5 mm and 13 mm in the second variant, respectively.

Correlations between germination capacity and selected physical properties of perennial ryegrass cv. Maja seeds

80%

Kaliniewicz Z. , Jadwisieńczak K. , Jadwisieńczak B. , Potkaj Ł.

tom nr 19(1)

5--16

Perennial ryegrass is one of the most valuable pasture grasses. The species is recommended for sodding various types of land in Poland due to its fast growth and the ability to produce large numbers of vegetative shoots. Seedling emergence and biomass yield are largely determined by seed quality. This study analyzes the correlations between the basic physical properties of seeds of perennial ryegrass cv. Maja and their germination capacity. The basic dimensions (length, width and thickness) and mass of each of the 150 seeds were determined, and their arithmetic mean diameter, geometric mean diameter, aspect ratio, sphericity index and density were calculated. The seeds were germinated for 14 days, and the results were recorded daily, which enabled to determine germination time for each seed. The relationships between the evaluated parameters were determined by the Student’s t-test for independent samples and correlation analysis. The analyzed physical properties of seeds had no significant effect on the germination rate index. Germinated and non-germinated seeds differed significantly in width, length and arithmetic mean diameter, but they should not be sorted based on their plumpness to improve the quality of seed material because it could lead to a high loss of viable seeds.