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Wyszukujesz frazę "overlap" wg kryterium: Temat


Tytuł:
A patient with overlap syndrome: systemic lupus erythematosus, dermatomyositis, and Sjögren’s syndrome – a rare overlapping diseases case report
Autorzy:
Sokołowska, Aldona
Iwański, Mateusz
Dąbrowski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/29519533.pdf
Data publikacji:
2023-09-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
autoimmune diseases
overlap syndrome
self-reactive
Opis:
Introduction and aim. Autoimmune rheumatic diseases are a group of disorders with similar clinical, laboratory and immunological manifestations. Connective tissue diseases include systemic scleroderma, dermatomyositis or polymyositis, Sjögren’s syndrome, rheumatoid arthritis, and systemic lupus erythematosus. If the patient meets the diagnostic criteria for at least two of these diseases and has specific serologic markers, a diagnosis of overlap syndrome is possible. Description of the case. This case describes a 27-year-old man who had a history of paroxysmal fever, night sweats, erythema-like skin lesions on the forearms and lower legs, a feeling of progressive muscle weakness especially in the proximal muscles, and dry mouth. The patient was diagnosed with an overlap syndrome: systemic lupus erythematosus, dermatomyositis, and Sjögren’s syndrome. Conclusion. Overlap syndrome is difficult to treat due to its multisystem nature, requiring a symptomatic therapeutic approach and careful control of medication doses to reduce side effects while controlling disease activity.
Źródło:
European Journal of Clinical and Experimental Medicine; 2023, 3; 659-662
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Blind frequency offset estimation for overlap PCC-OFDM systems in presence of phase noise
Autorzy:
Shentu, J.
Armstrong, J.
Powiązania:
https://bibliotekanauki.pl/articles/307668.pdf
Data publikacji:
2003
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
OFDM
frequency offset
estimation
phase noise
overlap PCC-OFDM
Opis:
This paper presents a technique for frequency offset estimation for polynomial cancellation coded orthogonal frequency division multiplexing with symbols overlapped in the time domain (overlap PCC-OFDM) in the presence of phase noise. The frequency offset estimator is designed based on the subcarrier pair imbalance (SPI) caused by frequency offset. The estimation is performed in the frequency domain at the output of the receiver discrete Fourier transform (DFT). No training symbols or pilot tones are required. Simulations show that this estimator is an approximately linear function of frequency offset. Phase noise does not significantly affect the variance performance of the estimator.
Źródło:
Journal of Telecommunications and Information Technology; 2003, 2; 17-27
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiple roles and sense of identity among women in early and later adulthood
Autorzy:
Pilarska, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/2127760.pdf
Data publikacji:
2019-04-05
Wydawca:
Katolicki Uniwersytet Lubelski Jana Pawła II. Towarzystwo Naukowe KUL
Tematy:
role overlap
sense of identity
multiple roles
self-complexity
Opis:
The article presents the results of a study conducted on a sample of 80 women aged 19-25 and 72 women aged 40-74. The relationships of the two components of self-complexity (the quantity of self-aspects and the amount of overlap between their contents) with the multidimensionally defined sense of identity were examined. Additionally, phase of life differences in the magnitude of these relationships were also investigated. I used the Self-Complexity Questionnaire (SCQ; Barczak, Besta, & Bazińska, 2007) and the Multidimensional Questionnaire of Identity (MQI; Pilarska, 2012). The obtained results showed that the predictive importance of the number of roles for the sense of identity was marginal, whereas the similarity in the content of roles seemed to favor maintaining the sense of identity. In addition, although significant differences were observed in the self--concept structure and the strength of the sense of identity between the two groups of women, the relationships between these areas of personality were not affected by the phase of the life cycle.
Źródło:
Roczniki Psychologiczne; 2016, 19, 2; 349-364
1507-7888
Pojawia się w:
Roczniki Psychologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Increase of high load limit in a gasoline HCCI engine
Autorzy:
Hunicz, J.
Kordos, P.
Gęca, M.
Powiązania:
https://bibliotekanauki.pl/articles/242189.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
HCCI engine
negative valve overlap
high load limit
mechanical boost
Opis:
Engine operation in HCCI mode allows for improvement of thermal efficiency and substantial reduction NOX emission. The most production feasible solution for gasoline HCCI engine is application of exhaust gas trapping using a negative valve overlap. This technique increases thermal energy of a mixture, thus allowing for auto-ignition at moderate compression ratios. However, high exhaust gas re-circulation rate decreases volumetric efficiency. As a result, achievable engine loads are also reduced. Supercharging can be applied in order to improve volumetric efficiency and extend high load limit. However, increase of amount of intake air can lead to reduction of start of compression temperature via decrease of residuals in a mixture. In order achieve HCCI mode of combustion, temperature of start of compression must be kept within narrow limits. In this study experimental and modeling investigations were presented. Experiments were carried out using single cylinder research engine. The engine was equipped with fully variable valvetrain and direct gasoline injection. Application of mechanical boosting allowed for widening achievable load range in HCCI mode of operation. Numerical calculations allowed for determination of admissible valvetrain settings and intake pressure, which guarantee proper temperature of start of compression.
Źródło:
Journal of KONES; 2012, 19, 4; 231-238
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural Aspects of Twin-Spot Laser Welding of Dp-Hsla Steel Sheet Joints
Autorzy:
Stano, S.
Grajcar, A.
Wilk, Z.
Różański, M.
Matter, P.
Morawiec, M.
Powiązania:
https://bibliotekanauki.pl/articles/352264.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DP steel
HSLA steel
weldability
overlap joint
twin-spot welding
Opis:
The article presents the possibility of using twin-spot laser welding (i.e. laser welding with focusing a laser beam on two spots) for making overlap joints made of 0.8-1 mm thick HSLA and DP type high strength steel sheets. Joints were made using a Yb:YAG disc laser having a maximum power of 12 kW and a welding head by means of which it was possible to focus a laser beam on two spots, 0.6 mm and 1 mm away. The angle between focuses amounted to 0° or 90°, whereas the power distribution was 50%-50%. With settings as presented above it was possible to obtain high-quality overlap joints. The geometrical parameters of the joints were primarily affected by beams positions (in relation to each other) and, to a lesser degree, by the distance between the focuses. It was possible to obtain a 10% hardness reduction in the fusion zone of the DPHSLA steel joints if the angle between the beams amounted to 90°. The tests also involved microstructural examinations of individual zones of the joints.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 731-740
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DE-XRT coal preparation image overlapping and adhesion particle segmentation method
Autorzy:
He, Lei
Wang, Shuang
Guo, Yongcun
Powiązania:
https://bibliotekanauki.pl/articles/2175443.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
overlap
adhesion
image segmentation
watershed algorithm
DE-XRT
coal
gangue
Opis:
Accurate segmentation of dual-energy X-ray transmission (DE-XRT) coal and gangue image regions are a prerequisite for feature extraction, identification, localization, and separation. A watershed algorithm based on multi-grayscale threshold segmentation (MGTS) is proposed to mark the foreground for the adhesion and overlap of coal and gangue. The grayscale images of foreground objects are segmented using multiple grayscale thresholds, and the number of connected domains is recorded each time. As the gray threshold value decreases, overlapping and adhering objects are gradually separated. The binary image segmented at the grayscale threshold with the most significant number of connected domains is used as a marker region. This marker region is used as the seed point of the watershed algorithm to find the dividing line. The experimental results show that the segmentation accuracy is 91.35%, and the segmentation accuracy of overlapping adhesions of 2, 3, and 4 targets is higher than 90%.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 155840
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exploring teachers’ and learners’ overlapped turns in the language classroom: Implications for classroom interactional competence
Autorzy:
Cancino Avila, Marco Octavio
Powiązania:
https://bibliotekanauki.pl/articles/780641.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
conversation analysis
classroom discourse
classroom interactional competence
teacher-learner overlap
Opis:
The language choices that teachers make in the language classroom have been found to influence the opportunities for learning given to learners (Seedhouse, 2004; Walsh, 2012; Waring, 2009, 2011). The present study expands on research addressing learner-initiated contributions (Garton, 2012; Jacknick, 2011; Waring, Reddington, & Tadic, 2016; Yataganbaba & Yıldırım, 2016) by demonstrating that opportunities for participation and learning can be promoted when teachers allow learners to expand and finish their overlapped turns. Audio recordings of lessons portraying language classroom interaction from three teachers in an adult foreign language classroom (EFL) setting were analyzed and discussed through conversation analysis (CA) methodology. Findings suggest that when teachers are able to navigate overlapping talk in such a way that provides interactional space for learners to complete their contributions, they demonstrate classroom interactional competence (Sert, 2015; Walsh, 2006). The present study contributes to the literature by addressing interactional features that increase interactional space, and an approach to teacher and learner talk that highlights CA’s methodological advantages in capturing the interactional nuances of classroom discourse.
Źródło:
Studies in Second Language Learning and Teaching; 2019, 9, 4; 581-606
2083-5205
2084-1965
Pojawia się w:
Studies in Second Language Learning and Teaching
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of stator-rotor interspace overlap of meridional contours on the efficiency of high-pressure steam turbine stages
Autorzy:
Rusanov, Andrii
Rusanov, Roman
Powiązania:
https://bibliotekanauki.pl/articles/1845496.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-pressure steam turbine
cavern
overlap
impulse type stage
reactive type stage
Opis:
The results of a systematic study of the influence of meridional contours overlap in the stator-rotor axial interspace of the impulse and reactive type stages of a high-pressure steam turbine on the flow structure and gas-dynamic efficiency of the flow part are introduced. The studied flow parts of the impulse and reactive stages are typical for high-power high-pressure steam turbines. It is shown that the stages that have no overlaps and/or have a smooth shape of meridional contours have the best gasdynamic efficiency, and the most negative effect on the flow part is caused by the presence of caverns in the stator-rotor interspace. For cases where, due to technological limitations, it is impossible to avoid the presence of caverns and overlaps with a sharp (step-wise) change in the shape of the meridional contours, it is recommended to perform overlaps with positive size of overlap values near the rotor blades.
Źródło:
Archives of Thermodynamics; 2021, 42, 1; 97-114
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combustion control in gasoline HCCI engine with direct fuel injection and exhaust gas trapping
Autorzy:
Hunicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/246912.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
homogeneous charge compression ignition
variable valve timing
negative valve overlap
gasoline
direct injection
Opis:
Homogeneous charge compression ignition (HCCI) seems to be the most promising solution for gasoline engines in the light of future emissions regulations. This novel combustion technique allows for significant reduction of fuel consumption and engine-out NOX emissions at low and medium engine load/speed conditions. High heat release rate enables realization of the Otto cycle close to ideal, increasing thermal efficiency. Among different approaches to invoke an auto-ignition of air-fuel mixture, exhaust gas trapping with the use of a negative valve overlap is under intensive investigations. The paper presents research results ofcontrolling an auto-ignition and combustion phasing in a single cylinder gasoline engine with direct fuel injection operated in the negative valve overlap mode. The experiments were performed at variable valvetrain settings, providing a control of EGR rate and volumetric efficiency. Additionally, the combustion process was investigated at variable air-fuel ratio. It was found that volumetric efficiency and EGR ratę are mainly dependent on exhaust valve timing, while a timing of intake valve determined combustion on-set and its duration. The effects of EGR rate and air-fuel ratio on combustion timing and exhaust gas emissions were isolated. The direct fuel injection showed its benefits versus mixture formation outside the cylinder. The application of variable injection timing provided additional possibility to control the combustion timing and exhaust emissions. However, it was found that the fuel injection strategy should be related to the engine load conditions.
Źródło:
Journal of KONES; 2010, 17, 2; 137-144
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Perception of Mixture of Musical Instruments with Spectral Overlap Removed
Autorzy:
Kleczkowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/176638.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound segregation
spectral overlap
spectrogram
auditory scene analysis
time-frequency mask
multiple looks
glimpses
Opis:
The issue of auditory segregation of simultaneous sound sources has been addressed in speech research but was given less attention in musical acoustics. In perception of concurrent speech, or speech with noise, the operation of time-frequency masking was often used as a research tool. In this work, an ex- tension of time-frequency masking, leading to the removal of spectro-temporal overlap between sound sources, was applied to musical instruments playing together. The perception of the original mixture was compared with the perception of the same mixture with all spectral overlap electronically removed. Ex- periments differed in the method of listening (headphones or a loudspeaker), sets of instruments mixed, and populations of participants. The main findings were: (i) in one of the experimental conditions the re- moval of spectro-temporal overlap was imperceptible, (ii) perception of the effect increased when removal of spectro-temporal overlap was performed in larger time-frequency regions rather than in small ones, (iii) perception of the effect decreased in loudspeaker listening. The results support both the multiple looks hypothesis and the "glimpsing" hypothesis known from speech perception.
Źródło:
Archives of Acoustics; 2012, 37, 3; 355-363
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of overlap length on the strength of adhesive joints of steel sheets
Wpływ długości zakładki na wytrzymałość połączeń klejowych blach stalowych
Autorzy:
Doluk, Elżbieta
Rudawska, Anna
Miturska-Barańska, Izabela
Ogrodniczek, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/31232904.pdf
Data publikacji:
2022
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
adhesive joint
shear strength
elongation
overlap length
połączenie klejowe
wytrzymałość na ścinanie
wydłużenie
długość zakładki
Opis:
The study evaluates the shear strength of the single-lap adhesive joints made of C45 carbon steel. The influence of the overlap length on the shear strength of the adhesive joint was tested. The elongation of the samples was also tested. Before the bonding process, the samples were treated with P180 abrasive paper and degreased. The adhesive joints were made using the Epidian 53/Z1/100:10 adhesive composition. The strength tests were carried out on a Zwick/Roell Z150 testing machine. The maximum value of the shear strength was obtained for the lap Lz1 = 13 mm and the minimum for Lz4 = 19 mm.
W pracy dokonano oceny wpływu długości zakładki na wytrzymałość na ścinanie jednozakładkowych połączeń klejonych wykonanych ze stali węglowej C45. Podczas eksperymentu zbadano także wydłużenie próbek. Przed rozpoczęciem procesu klejenia próbki zostały obrobione papierem ściernym P180 i odtłuszczone. Połączenia klejowe wykonano przy użyciu kompozycji klejowej Epidian 53/Z1/100:10. Badania wytrzymałościowe przeprowadzono na maszynie wytrzymałościowej Zwick/Roell Z150. Maksymalną wartość wytrzymałości na ścinanie uzyskano dla długości zakładki Lz1 = 13 mm, a minimalną dla Lz4 = 19 mm.
Źródło:
Technologia i Automatyzacja Montażu; 2022, 4; 3-6
2450-8217
Pojawia się w:
Technologia i Automatyzacja Montażu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Forecasting of the productivity of parts machining by highspeed milling with the method of half-overlap
Autorzy:
Dobrotvorskiy, S.
Basova, Y.
Ivanova, M.
Kotliar, A.
Dobrovolska, L.
Powiązania:
https://bibliotekanauki.pl/articles/328626.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
high-speed milling
processing efficiency
processing strategy
half-overlap
deformation component
obróbka maszynowa
frezowanie
jakość
wydajność
prognozowanie
Opis:
In the article the technology of high-speed milling was observed as a key to the most promising methods of engineering products machining. It is indicated that the correct choice of the strategy for moving the cutting tool in the manufacture of products is the basis for ensuring the desired surface quality of the workpiece and its high processing efficiency. A review of the work devoted to the diagnosis of high-speed processing strategies was performed. Based on the up-to-date knowledge of the physics of the process of establishing of a qualitative surface, the article proposes to consider a new technology of high-speed milling with half-overlap. As the main idea of this technology, it is suggested to consider the work of the deformation component of cutting process as the main component of the complex energy-intensive process of high-speed milling. In addition, the paper suggests a technique for estimating the productivity of machining by the method of high-speed milling with half-overlap. It is theoretically justified that the specific productivity of the proposed technology is quite high Q=12.5÷4.2 cm2 /min and depends on the technological regimes. The place of technology of high-speed milling with half-overlap in the technological process of manufacturing details of any complexity was noted. The area of further research is indicated.
Źródło:
Diagnostyka; 2018, 19, 3; 37-42
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie obliczeń równoległych do klasyfikacji punktów overlap
Application of parallel computing for classification of overlapping points
Autorzy:
Bratuś, R.
Musialik, P.
Pióro, P.
Prochaska, M.
Rzonca, A.
Powiązania:
https://bibliotekanauki.pl/articles/131194.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
punkty typu overlap
przetwarzanie równoległe
klasyfikacja punktów
kąt skanowania
overlapping points
parallel computing
points classification
scan angle
Opis:
Publikacja omawia nowatorskie metody rozwiązania ważnego technologicznie zagadnienia, jakim jest klasyfikacji punktów overlap, czyli punktów w pasie podwójnego pokrycia pomiędzy sąsiednimi szeregami skanowania. Prezentowane podejście oparte jest na wydajnej metodzie obliczeń równoległych na procesorach graficznych GPU, pozwalającej na zastosowanie bardziej zaawansowanego algorytmu podczas analizy i przetwarzania danych. Celem sprawdzenia wydajności przeprowadzono testy badanego narzędzia do klasyfikacji punktów overlap, a wyniki odniesiono do możliwości powszechnie stosowanego programu Terrascan firmy Terrasolid. Proponowane innowacje obliczeniowe mają na celu poprawę jakości danych skaningowych pozyskiwanych przy pomocy latających platform takich jak lekkie samoloty czy wiatrakowce. Podniesienie jakości procesu klasyfikacji punktów typu overlap, wymaga dwóch wstępnych etapów przetwarzania. Pierwszy polega na obcięciu brzegów szeregu ściśle według zadanego kąta od pionu. Zastosowane podejście daje bardziej regularne wyniki niż inne metody. Z kolei drugi, oparty o algorytm rozgęszczenia punktów, prowadzi do usuwania nadmiarowych profili skanowania. Proponowane rozwiązanie to klasyfikacja punktów overlap według kąta padania promienia skanera na teren i obiekty terenowe. Reasumując, w ramach opisanych badań dotychczas stosowane metody klasyfikacji punktów overlap zostały poddane rewizji. Korzystając z praktycznych uwag oraz sugestii ze strony wykonawców, wprowadzono szereg udoskonaleń, których prezentacja i dyskusja jest przedmiotem niniejszej publikacji.
The paper presents innovative methods of solving important technological problem: the classification of LiDAR points located in the overlapping area between two parallel scan strips. The presented approach is based on an efficient method of parallel computation using graphic processors, allowing to apply more sophisticated algorithms for data analysis and processing. The tests of the algorithms were executed in order to verify correctness of the assumption that the innovative solutions presented in the paper might increase the efficiency and correctness of the data, referred to well known and popular technological solutions. The suggested computational innovations are applied to increase the quality of the LiDAR data acquired by light airplanes and gyrocopters. Two approaches to increase the quality of classification of overlapping points have bee, proposed. The first process is cutting-off the points of the strip borders strictly according to defined angle measured from vertical direction. The second process is dissolving of the points to get the regular density of the result point cloud. The title issue is the classification of overlapping points according to the angle of incidence to the terrain and other objects. The normal vectors calculation for each of the scan points is necessary for the analysis. Such solution increases the quality of overlaps classification and guarantees its high efficiency thanks to the parallel computation. In conclusion, during the research three innovative approaches were tested and reviewed against commonly used methods. Parallel computation can improve quality and reduce time of processing for overlap classification problem was confirmed.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2017, 29; 11-26
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie wybranych błędów przejazdów agregatu rolniczego prowadzonego manualnie oraz automatycznie
Comparison of the selected errors of an agricultural aggregate crossings driven manually and automatically
Autorzy:
Garbiak, K.
Jurga, J.
Powiązania:
https://bibliotekanauki.pl/articles/288036.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
GPS
systemy prowadzenia pojazdów rolniczych
nakładka
omijak
rolnictwo precyzyjne
steering systems of farm vehicles
overlap
underlap
precise agriculture
Opis:
W artykule porównane zostały dwa systemy prowadzenia ciągnika rolniczego. Pierwszy z nich, tradycyjny sposób prowadzenia agregatu ciągnikowego, polegający na aktywnej kontroli toru jazdy przez operatora. System automatyczny wykorzystywał nawigację satelitarną i był wyposażony w układ automatycznego prowadzenia pojazdu po polu. Badania zostały przeprowadzone w gospodarstwie rolnym położonym w województwie zachodniopomorskim w kwietniu i maju 2012 roku. Celem pracy było porównanie manualnego oraz automatycznego systemu prowadzenia ciągnika rolniczego pod względem odchyleń odległości od pożądanego toru jazdy po polu oraz pól powierzchni nakładek i omijaków. Na podstawie przeprowadzonych badań stwierdzono, że system automatycznego prowadzenia ciągnika wykorzystujący nawigację satelitarną był dokładniejszy i pozwolił ograniczyć powierzchnię nieobrobioną do 0,20%, zaś dwukrotnie obrobioną do 0,21% powierzchni pola.
Two systems of steering a tractor were compared in the article. The first of them, a traditionalway of driving a tractor, consisting in an active control of the track by an operator. An automatic system used a satellite navigation and was equipped with automatic driving system of a vehicle on a field. The research was carried out in an agricultural farm located in Zachodniopomorksie province in April and May 2012. The objective of the paper was to compare a manual and an automatic system of steering a farm tractor on account of distance deviation from a desired track and surface areas of overlaps and underlaps. On the basis of the research which was carried out, it was determined that the system of automatic steering of a tractor which uses a satellite navigation was more accurate and allowed to limit the undone area to 0.20% and to double the area which was worked twice to 0.21% of the field area.
Źródło:
Inżynieria Rolnicza; 2012, R. 16, nr 4, t. 1, 4, t. 1; 55-63
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Własności zakładkowych złączy spajanych metodą zgrzewania tarciowego z przemieszaniem (FSW – Friction Stir Welding)
Properties of overlap joints welded by the Friction Stir Welding Method
Autorzy:
Kudła, K.
Wojsyk, K.
Kucharczyk, Z.
Powiązania:
https://bibliotekanauki.pl/articles/211415.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Obróbki Plastycznej
Tematy:
zgrzewanie tarciowe przemieszaniem
aluminium
złącza zakładkowe
strefa natarcia
strefa spływu
friction stir welding
overlap joints
advancing zone
retreating zone
Opis:
Praca dotyczy problemu łączenia złączy zakładkowych wykonanych ze stopów aluminium technologią zgrzewania tarciowego z przemieszaniem FSW. Analizie poddano budowę złącza w strefach: natarcia, wpływu ciepła oraz spływu. Wykazano dużą niejednorodność i asymetrię złącza, charakteryzującą się wyraźną granicą między materiałem po rekrystalizacji i odkształceniu termomechanicznym. Próby ścinania ujawniły występowanie obszaru w strefie spływu, w którym występują przyklejenia między łączonymi elementami, obniżając jego wytrzymałość. W obszarze natarcia elementem decydującym o charakterze zniszczenia jest kształt linii styku łączonych materiałów. Dokonano analizy siły docisku oraz położenia narzędzia na jakość zgrzein. Wykazano, że najlepsze efekty łączenia uzyskuje się prowadząc proces zgrzewania z kontrolowaną siłą docisku i z zachowaniem odpowiedniego ustawienia kąta pochylenia oraz głębokości jego zanurzenia w materiale.
This paper regards the problem of creating overlap joints made of aluminum alloys using the technology of friction stir welding, FSW. The structure of a joint was analyzed in the advancing zone, the heat affected zone and the retreating zone. It was shown that the joint is nonuniform and asymmetric. The nonuniformity and asymmetry of the joint are characterized by a distinct border between material that was recrystallized and thermomechanically deformed. Shear tests demonstrated the existence of the area in the retreating zone where bonding between joined elements occurs. This reduces the joint strength. In the advancing zone, the shape of the boundary line between joined materials is the factor determining the character of material failure. The work analyzes the impact of downward force and tool position on the quality of welds. It was shown that for the welding process the best results can be achieved by controlling downward force and maintaining appropriate tilt angle and depth of tool penetration.
Źródło:
Obróbka Plastyczna Metali; 2013, 24, 3; 179-191
0867-2628
Pojawia się w:
Obróbka Plastyczna Metali
Dostawca treści:
Biblioteka Nauki
Artykuł

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