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Wyszukujesz frazę "Kaliniewicz, Z" wg kryterium: Autor


Tytuł:
The Effect of the Impurity Content of Buckwheat Nutlets on Product Purity after Cleaning in a Grader with Indented Pockets
Wpływ stopnia zanieczyszczenia surowca ziaren gryki na czystość produktu po czyszczeniu w tryjerze z wgłębieniami kieszonkowymi
Autorzy:
Kaliniewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/298223.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
gryka
rzodkiew świrzepa
stopień zanieczyszczenia
tryjer
buckwheat
wild radish
impurity content
grader
Opis:
This study analyzed four mixtures of buckwheat nutlets and wild radish siliques with impurity content (wild radish siliques) of 2.5, 5.0, 7.5 and 10.0%. Buckwheat nutlet yield, the efficiency of wild radish silique removal, the efficiency of mixture separation and product purity were determined at two depth settings of indented pockets (2.4 and 2.8 mm), three factors of static load of the cylinder with the mixture (0.1, 0.2 and 0.3 of full load) and five angles of the working edge of the trough (10, 20, 30, 40 and 50°). The obtained results indicate that the impurity content of raw material significantly affects the purity of the separated product.
Do badań wykorzystano cztery mieszaniny ziaren gryki i łuszczyn rzodkwi świrzepy o udziale: 2,5, 5,0, 7,5 i 10,0% składnika zanieczyszczającego - łuszczyn rzodkwi świrzepy. Wyznaczano uzysk ziarna gryki, skuteczność wydzielania łuszczyn rzodkwi świrzepy, skuteczność rozdzielania mieszaniny i czystość produktu na dwóch głębokościach wgłębień kieszonkowych (2,4 i 2,8 mm), przy trzech wskaźnikach statycznego obciążenia cylindra mieszaniną (0,1, 0,2 i 0,3 pełnego obciążenia) oraz pięciu kątach ustawienia roboczej krawędzi rynienki (10, 20, 30, 40 i 50°). Stwierdzono, że stopień zanieczyszczenia surowca wpływa istotnie na czystość produktu czyszczenia.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2011, 14(1); 5-12
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Theoretical Analysis of Cereal Seed Screening in a String Sieve
Autorzy:
Kaliniewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/298351.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
string sieve
modelling
seeds
angle of inclination
Opis:
The conditions of the screening process in a fixed string sieve designed by the author have been formulated. The string sieve was designed for separating seeds of 5 cereal species (wheat, rye, barley, oats and triticale). The width of the separating groove was set at 1 mm at the beginning of the screen and 5 mm at the end of the screen. It has been assumed that seeds have a spheroidal shape and that their motion is initiated by positioning the string sieve at an appropriate angle. The results of a theoretical analysis revealed that at the given parameters of a string sieve, the above angle is determined only by the thickness and width of separated seeds. The sieve’s angle of inclination should be set at 45° to propel seeds into motion and at 50° to ensure the continuity of the screening process. Such a large setting angle is not recommended because it increases the sieve’s height and deteriorates the quality of the separation process. The problem can be solved by setting the separator bucket into motion and separating seeds at a small inclination angle of the string sieve.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2013, 16(3); 234-247
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two mathematical formulas for assessing seed separation efficiency
Autorzy:
Kaliniewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/297999.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
seeds
separation process
indicators
comparison
Opis:
Two mathematical formulas for assessing the efficiency of seed mixture separation were analyzed. Increases in the crop seed yield and the efficiency of impurity separation were accompanied by higher seed separation efficiency regardless of the adopted formula. One of the examined formulas carried more information, and it could be used to determine the improvement in the purity of the separated product relative to the raw material. The difference in the analyzed formulas’ ability to determine the efficiency of seed separation was minimized when the separation process was more efficient, i.e. when the value of partial indicators of separation efficiency was closer to 1. Both formulas could be successfully used to describe seed separation efficiency because in most practical applications, the error generated by the evaluated formulas did not exceed 1.5%.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2013, 16(2); 109-117
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
String sieve: design concept and parameters
Autorzy:
Kaliniewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/298037.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
seed
cleaning
sorting
geometric parameters
string sieve
Opis:
This paper presents the design concept and the parameters of a new device for cleaning and-or sorting seeds and grain produced in a conventional farm. The discussed device is a string sieve where the groove between adjacent strings is minimal at the beginning of the screen and increases towards the end of the screen. The proposed sieve poses an alternative to a screen separator comprising a set of differently-sized mesh screens with longitudinal openings. In view of the average size of farm-produced seeds, the width of the separating groove should be set at 1mm at the beginning of the screen and 11 mm at the end of the screen. In sieves not designed for grading large seeds or vetch seeds, the width of the separating groove can be set at 1 mm and 5 mm, respectively.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2013, 16(2); 119-129
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A movable string sieve - analysis of seed screening
Autorzy:
Kaliniewicz, Z.
Domański, J.
Powiązania:
https://bibliotekanauki.pl/articles/298132.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
string sieve
modeling
physical properties
Opis:
The conditions of seed movement in a string sieve set into reciprocating motion have been formulated for cereal, vetch, pea, lupine and faba bean seeds. In the analyzed string sieve, seed movement was determined by a combination of the following parameters: angular velocity of the crank, crank radius, seed size, seed’s coefficient of external friction, string diameter and angle of inclination of the separator screen. A string sieve for cleaning and sorting most farm-produced seeds was analyzed. The width of the separating groove was set at 1 mm at the beginning of the screen and 11 mm at the end of the screen, and the strings had the diameter of 4 mm. Our results indicate that seeds cannot be effectively graded in the modeled string sieve. The angular velocity of the crank exceeds the velocity which is applied to power conventional separator buckets, and it could damage the separator. A reduction in the angular velocity of the crank to the recommended level caused seeds to become jammed directly before the screening site. The above problem can be solved by propelling seeds into motion with the use of special sweeping brushes.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2013, 16(4); 253-264
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design concept and parameters of a conical bar separator
Autorzy:
Jadwisieńczak, B.
Kaliniewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/298140.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
seeds
cleaning and separation
separator
geometrical relationships
Opis:
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.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2017, 20(3); 275-288
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of saw chain type and wood species on the kickback angle of a chainsaw
Autorzy:
Kaliniewicz, Z.
Maleszewski, Ł.
Krzysiak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/297817.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
chainsaw
kickback
saw chain
wood
correlation
Opis:
Wood processing operations, in particular debarking, can pose a significant hazard for the chainsaw operator when performed without due caution. The most common hazards with potentially fatal consequences include kickback which occurs when the chainsaw’s guide bar is violently thrown backwards towards the operator. The aim of this study was to determine the influence of wood species and different saw chain brands on the kickback angle of a chainsaw. The kickback angle of a combustion chainsaw was analyzed in a self-designed test stand with the use of a digital level gauge accurate to 0.1°. Four differently priced saw chain brands, including two standard chains and two chains with anti-kickback features, were evaluated. Kickback was analyzed on five wood species (pine, spruce, birch, alder and oak) at three engine speeds (50%, 75% and 100% of maximum rotational speed). Kickback was significantly determined by wood species and saw chain type, and it was less influenced by the rotational speed of the chainsaw engine. The average kickback angle was largest in alder and smallest in spruce. The analyzed parameter was not always reduced by saw chains with anti-kickback features. In some cases, low-priced saw chains with anti-kickback features offer less protection than more expensive standard chains. Chainsaw buyers should decide whether it is worthwhile to compromise on safety in exchange for a lower price.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2018, 21(4); 323-334
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of cereal seed shape with the use of sphericity factors
Autorzy:
Kaliniewicz, Z.
Biedulska, J.
Jadwisieńczak, B.
Powiązania:
https://bibliotekanauki.pl/articles/298142.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
seeds
dimensions
mass
shape
correlations
Opis:
Shape is one of the key discriminating factors in seeds. It plays a major role in seed cleaning and sorting, and it influences the bulk behavior of seeds. The shape of seeds can be described with the use of sphericity factors. In this study, the thickness, width, length and mass of principal cereal seeds (wheat, rye, barley, oats and triticale) were determined. The geometric parameters of seeds were used to calculate five sphericity factors for each seed type. The results of measurements and calculations were processed statistically by analysis of variance, correlation analysis and linear regression analysis. In the group of the analyzed cereal seeds, the lowest values were noted for sphericity factor K5 in the range of 0.046 to 0.275, and the highest values - for sphericity factor K3 in the range of 0.359 to 0.650. The shape of cereal seeds was mostly highly correlated with: thickness in barley seeds, width in wheat seeds, width and thickness in rye and triticale seeds, and length in oat seeds. All of the analyzed sphericity factors can be used interchangeably to describe the shape of cereal seeds, and the relationships between those factors can be described with linear equations.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2015, 18(4); 237-246
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of sonication on the mechanical properties of organic mixed grain bread
Wpływ sonikacji na właściwości mechaniczne ekologicznego chleba mieszanego
Autorzy:
Batia-Strynkowska, M.
Wesołowski, A.
Kaliniewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/93722.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
ultrasonic technique
bread
mechanical properties
TPA
technika ultradźwiękowa
chleb
właściwości mechaniczne
Opis:
The aim of this study was to determine the effect of ultrasound waves on mechanical properties of organic bread. Mixed grain bread baked at a local bakery according to its original recipe was the material subjected to testing. Prior to baking, the dough was sonicated at frequencies of 20 kHz and 40 kHz for 3 minutes, and at a frequency of 100 kHz for 3 minutes and 6 minutes. The mechanical properties of the bread (compression test, penetration test and TPA) were examined after 24 h, 48 h and 72 h following the baking process. The maximum work obtained in the compression test after 24 h following the baking ranged from 616 N to 668 N. On the next day following the baking, the maximum work value ranged from 750 N to 898 N, while after 72 hours, it ranged from 988 N to 1135 N. In the penetration test, the following results were obtained: after 24 hours, the force value ranged from 2.71 N to 3.17 N; after 48 hours following the baking, it ranged from 4.90 N to 6.35 N; and after 72 hours following the baking, from 3.98 N to 6.88 N. As regards elasticity, the obtained results fell within the following ranges: after 24 hours following the baking, from 0.53 to 0.58; after 48 hours following the baking, from 0.43 to 0.55; and after 72 hours following the baking, from 0.40 to 0.45. Gumminess measured after 24 hours following the baking ranged from 8.75 N to 18.71 N; after 48 hours, from 10.83 N to 15.48 N; and after 72 hours, the gumminess values ranged from 15.57 N to 19.06 N. As regards chewiness, the following results were obtained: after 24 hours following the baking, from 8.00 N to 17.59 N; after 48 hours following the baking, from 9.77 N to 13.87 N; and after 72 hours following the baking, from 12.56 N to 16.85 N. The frequencies and durations of sonication applied changed no mechanical properties of the tested bread.
Celem pracy było określenie wpływu ultradźwięków na właściwości mechaniczne chleba ekologicznego. Badaniom poddano chleb mieszany wypieczony w lokalnej piekarni zgodnie jej recepturą. Przed wypiekiem ciasto zostało poddane sonikacji o częstotliwości 20 kHz i 40 kHz przez 3 minuty oraz częstotliwości 100 kHz przez 3 min i 6 minut. Właściwości mechaniczne chleba (test ściskania, test penetracji oraz TPA) zbadano po 24 h, 48 h i 72 h od wypieku. Maksymalna praca uzyskana w teście ściskania po 24 h od wypieku mieściła się w granicy od 616 N do 668 N. W kolejnej dobie po wypieku wartość pracy maksymalnej wyniosła od 750 N do 898 N, natomiast po 72 h wynosiła od 988 N do 1135 N. W teście penetracji uzyskano następujące wyniki po 24 h wartość siły mieściła się w granicach 2,71÷3,17 N, 48 godzin po wypieku 4,90÷6,35 N oraz 3,98÷6,88 N po 72 godzinach od wypieku. W przypadku sprężystości otrzymano wyniki mieszczące się w następujących granicach 24 h po wypieku 0,53÷0,58, 48 h po wypieku 0,43÷0,55, 72 h po wypieku 0,40÷0,45. Gumiastość mierzona 24 h po wypieku mieściła się w granicach od 8,75 N do 18,71 N, po 48 h od 10,83 N do 15,48 N, a po 72 h wartości gumiastości mieściły się w przedziale od 15,57 N do 19,06 N. W przypadku żujności otrzymano następujące wyniki 24 h po wypieku 8,00÷17,59 N, 48 h po wypieku 9,77÷13,87 N, 72 h po wypieku 12,56÷16,85 N. Zastosowane częstotliwości oraz czas sonikacji nie wpłynęły na zmianę właściwości mechanicznych badanego chleba.
Źródło:
Agricultural Engineering; 2018, 22, 4; 5-13
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlations between germination capacity and selected physical properties of perennial ryegrass cv. Maja seeds
Autorzy:
Kaliniewicz, Z.
Jadwisieńczak, K.
Jadwisieńczak, B.
Potkaj, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/297989.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
seeds
physical parameters
germination rate index
correlation
Opis:
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.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2016, 19(1); 5-16
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability and correlation of the selected physical properties of pumpkin seed (Cucurbita pepo L.)
Zmienności i korelacja wybranych cech fizycznych pestek dyni zwyczajnej (Cucurbita pepo L.)
Autorzy:
Kaliniewicz, Z.
Jadwisieńczak, K.
Zalewska, K.
Sosińska, E.
Powiązania:
https://bibliotekanauki.pl/articles/93817.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
pumpkin
seeds
separation
physical properties
dynia
nasiona
wydzielanie
cechy fizyczne
Opis:
Basic dimensions (length, width and thickness), critical velocity of transporting seeds, sliding friction angle and the mass of pumpkin seeds, obtained from four fruit of various mass were determined. Based on the measurements, volume and thickness of each seed and its spherical index were calculated. Interdependence between the tested properties and indexes was evaluated based on the test for independent samples, analyses of variance, correlation and regression. It was found that the seeds mass is the most variable property and their length is the least variable. Empty and full pumpkin seeds should be separated with a pneumatic separator, where a vertical air stream of velocity approx. 5 m·s-1 is a separating element. Length and mass of seeds may be used at separation of seed material into quality fractions. As a result of separating the smallest seed fraction, a seed material may be obtained in which after the process of removing the fruit-seed coat, 95% of ripe seeds will be available.
Określono podstawowe wymiary (długość, szerokość i grubość), prędkość krytyczną unoszenia, kąt tarcia poślizgowego i masę pestek dyni zwyczajnej, pozyskanych z czterech owoców o różnej masie. Na podstawie pomiarów obliczono objętość i gęstość każdej pestki oraz jej wskaźniki sferyczności. Współzależność między badanymi cechami i wskaźnikami oceniono na podstawie testu t dla prób niezależnych, analizy wariancji, korelacji i regresji. Stwierdzono, że cechą fizyczną o największej zmienności jest masa pestek, a o najmniejszej – ich długość. Puste i pełne pestki dyni najlepiej jest rozdzielać za pomocą separatora pneumatycznego, gdzie elementem rozdzielczym jest pionowy strumienia powietrza o prędkości ok. 5 m·s-1. Przy rozdzielaniu materiału nasiennego na frakcje jakościowe można wykorzystać jako cechę rozdzielczą długość lub masę pestek. W wyniku oddzielania najmniejszej frakcji pestek można uzyskać materiał nasienny, w którym po procesie usuwania okrywy owocowo-nasiennej znajdować się będzie ok. 95% nasion dorodnych.
Źródło:
Agricultural Engineering; 2014, 18, 2; 65-75
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Correlations between Selected Physical Attributes of Scots Pine Seeds
Analiza współzależności wybranych cech fizycznych nasion sosny zwyczajnej
Autorzy:
Kaliniewicz, Z.
Grabowski, A.
Liszewski, A.
Fura, S.
Powiązania:
https://bibliotekanauki.pl/articles/298218.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
sosna zwyczajna
nasiona
cecha rozdzielcza
czyszczenie
sortowanie
Scots pine
seeds
separation properties
cleaning
sorting
Opis:
Critical transport velocity, the thickness, width, length and the angle of sliding friction of Scots pine seeds harvested from three seed banks (conservation seed stand, commercial seed stand and seed plantation) were determined. The investigated attributes were compared by single classification analysis of variance, correlation, single-variable and multivariate regression analysis. The analyzed seed traits differed significantly between the specimens from the examined seed banks. The equations describing the correlations between the studied attributes were characterized by relatively low percentages of explained variation, which renders them unfit for designing seed and separation models.
Wyznaczono prędkość krytyczną unoszenia, grubość, szerokość, długość i kąt tarcia ślizgowego nasion sosny zwyczajnej, zebranych z trzech odmiennych baz nasiennych (wyłączony drzewostan nasienny, gospodarczy drzewostan nasienny i plantacja nasienna). Porównywano te cechy, wykorzystując analizę wariancji z klasyfikacją pojedynczą, korelację oraz regresję jednej zmiennej i wielu zmiennych. Stwierdzono, że w większości przypadków analizowane cechy nasion z odmiennych baz nasiennych różnią się statystycznie. Równania współzależności między określanymi cechami charakteryzują się stosunkowo niskim procentem wyjaśnionej zmienności, co właściwie wyklucza ich zastosowanie do budowania modeli nasion i procesów rozdzielczych.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2011, 14(1); 13-22
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Frictional properties of selected seeds
Autorzy:
Kaliniewicz, Z.
Markowski, P.
Anders, A.
Jadwisieńczak, K.
Powiązania:
https://bibliotekanauki.pl/articles/298455.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
physical attributes
coefficient of external friction
relation
Opis:
The thickness, width, length and weight of five seed species (buckwheat, vetch, pea, lupine and faba bean) and their external friction angle were determined on two types of surfaces - steel and rubber. The experiment was performed with the use of a an inclined plane with an adjustable angle of inclination that measures the angle of external friction and the time taken by seeds to travel a given distance, which supports the determination of the coefficient of kinetic friction. The measured parameters were used to calculate arithmetic and geometric mean diameter, aspect ratio and sphericity index. The dimensions, weight and the calculated indicators of the examined seeds did not significantly affect their coefficients of static and kinetic friction or their coefficients of rolling resistance and rolling friction. The studied parameters were largely influenced by the type of friction surface, and significantly lower average values were reported for steel than rubber. In the studied seed species, the static friction coefficient was determined in the range of 0.187 to 0.582, kinetic friction coefficient - 0.134 to 0.479, rolling resistance coefficient - 0.148 to 0.529 and rolling friction coefficient - 0.29 to 1.80 mm.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2015, 18(2); 85-101
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability in and correlations among selected physical properties of European larch (Larix decidua Mill.) seeds
Autorzy:
Kaliniewicz, Z.
Tylek, P.
Anders, A.
Markowski, P.
Rawa, T.
Powiązania:
https://bibliotekanauki.pl/articles/297835.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
seeds
physical properties
coefficients
correlation
Opis:
Selected physical attributes of European larch seeds harvested from 2 seed plantations and 2 commercial seed stands in north-eastern Poland were determined. The physical properties of seeds were measured, and the results were used to calculate indicators of seed weight and the frictional and geometric properties of seeds. Physical attributes and indicators were compared by Student’s t-test for independent samples, analysis of variance, correlation analysis and linear regression analysis. The average values of physical properties and indicators were determined at: critical transport velocity - from 5.93 to 6.13 m • s-1, thickness - from 1.25 to 1.43 mm, width - from 2.29 to 2.71 mm, length - from 3.71 to 4.57 mm, angle of sliding friction - from 27.85 to 31.98o, weight - from 4.03 to 6.14 mg, coefficient of sliding friction - from 0.54 to 0.63, arithmetic mean diameter - from 2.42 to 2.90 mm, geometric mean diameter - from 2.20 to 2.60 mm, aspect ratio - from 59.60 to 62.38%, sphericity index - from 57.27 to 59.40%, specific weight - from 1.81 to 2.33 g • m-1, volume - from 4.60 to 7.59 mm3 and density - from 0.82 to 0.91 g • cm-3. The material harvested in seed plantations differed from seeds from commercial seed stands in all parameters, excluding critical transport velocity. Seed weight was most correlated with the remaining parameters. The highest value of the correlation coefficient and the equation with the highest value of the coefficient of determination were reported for the dependence between seed weight and seed length. Seed weight was also relatively highly correlated with seed width, therefore, the use of mesh screens with round openings and/or cylindrical grain graders is recommended in seed sorting processes.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2014, 17(2); 123-134
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł

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