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Wyszukujesz frazę "core" wg kryterium: Temat


Tytuł:
Examinations of parameters influencing the outflow of two phase air-sand stream from machine chamber and core box filling in shooting process
Badania parametrów wpływających na wypływ dwufazowego strumienia piaskowo-powietrznego z komory nabojowej i wypełnienie rdzennicy w procesie dmuchowym
Autorzy:
Fedoryszyn, A.
Dańko, R.
Tematy:
core production
core shooting
core blowing
rdzennice
strzelarka
nadmuchiwarka
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/356971.pdf  Link otwiera się w nowym oknie
Opis:
The study investigates the key aspects involved in the flow of the air-sand stream from the machine chamber and in the core box filling in the core shooting and core blowing processes. The prevailing tendency to manufacture thin-walled castings with intricate channel structures has become the major determinant of castings quality and production rates. An important parameter of most core sand used in the shooting processes is the ability to eject from the machine chamber and the core-box filling capability. These properties are the key factors determining the feasibility of manufacturing intricate cores and the process efficiency. The research work outlined in this study focuses on establishing the performance criteria of core sand ejection from the machine chamber and of core box filling and sand compaction. The results given below were obtained for several new-generation core sand types, containing organic and inorganic binders, and designed to be used in hot-box, warm box and warm air processes.
W publikacji przedstawiono zagadnienia związane z wypływem strumienia piaskowo-powietrznego z komory nabojowej i zapełnianiem rdzennicy metodami dmuchowymi z wykorzystaniem strzelarek i nadmuchiwarek. Tendencja do konstrukcji odlewów o coraz cieńszych ściankach i skomplikowanych kanałach, sprawia, że produkcja wysokiej jakości rdzeni jest nadal czynnikiem determinujacym jakość oraz wydajność produkcji odlewów. Ważnymi właściwościami ogółu mas rdzeniowych stosowanych w procesach dmuchowych jest ewakuacja masy z komory nabojowej maszyny dmuchowej oraz zdolność do zapełniania i zagęszczania masy w rdzennicy. Właściwości te, decydują często o możliwosci wykonania skomplikowanych rdzeni oraz o efektywności procesu technologicznego. Przedstawione badania dotyczą ustalenia kryteriów oceny ewakuacji masy z komory nabojowej oraz zdolność do wypełniania rdzennicy i zagęszczania kilku nowoczesnych mas formierskich, zarówno organicznych jak i nieorganicznych, pochodzących technologii hot box, warm box, warm air.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of the Influence of the Number and Distribution of Vents on the Production Process of Cores by the Blowing Method
Autorzy:
Dańko, R.
Tematy:
core shooter
core sands
blowing method
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/352765.pdf  Link otwiera się w nowym oknie
Opis:
The results of studies of the cores production by blowing methods with utilising the modified experimental shooting machine SR-3D, are provided in the hereby paper. The core sands from the Cordis technology were applied in the presented investigations. The influence of the number and distribution of vents on the shaped core box filling, filmed by a digital camera, was determined. Investigations were performed for the shooting pressures of 0.4, 0.5 and 0.6 MPa and for three surfaces of the shooting hole, at various numbers and distribution ways of vents in the experimental core box. The selected results of the model investigations were compared with the results of simulations performed previously in the PROCAST programme. The intensity of the core sand outflow from the shooting chamber into the core box of the experimental shooting machine was measured. Technological effects were assessed on the basis of the core sand apparent density in individual parts of the core, in dependence on the character of the pressure increase in the shooting chamber and the pressure value obtained in the core box.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Density Distribution and Resin Migration Investigations in Samples of Sand Core Made by Blowing Method
Autorzy:
Dańko, R.
Jamrozowicz, Ł.
Tematy:
core shooting
core blowing
molding sand
resin migration
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/106993.pdf  Link otwiera się w nowym oknie
Opis:
Resin migration in a core can occur during the core production process performed by blowing methods in which the core sand is transported into the core box as a two-phase sand-air flux characterized by various working parameters (working pressure, shooting time, volumetric concentration). This migration is the result of the resin being blown off from the matrix grain surfaces by compressed air. The methodology of the investigation of this effect developed at AGH University of Science and Technology is presented in this paper. The results of the resin migration tests obtained for cores made with cold-box technology at various working parameters of the shooting process are also shown.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compaction of Cores Made by Blowing Methods – Model Investigations
Autorzy:
Dańko, R.
Tematy:
core shooting
blowing process
core sand
core box
rdzeń wstrzeliwany
masa rdzeniowa
rdzeń odlewniczy
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/380080.pdf  Link otwiera się w nowym oknie
Opis:
The results of model investigations of the influence of the blowing process selected parameters on the distribution of the compaction of the core made by the blowing method, are presented in the hereby paper. These parameters were: shooting pressure, shooting hole diameter, amount and distribution of deaerating holes. Investigations were performed using the horizontal core box of the cuboidal cavity and the same core box into which inner inserts were introduced. These inserts were dividing the primary volume into three sectors differing in their direction, introduction conditions and the character of the core sand flow. As the compaction measure the apparent sand density was assumed. The density was determined in five measuring points in case of uniform cores, and in three measuring points in case of cores obtained in the core box with three separated sectors. The apparent density of the compacted core sand in the core box cavity was determined on the basis of the measurements of masses and volumes of samples cut-out from the determined core places by means of the measuring probe. Investigations were performed at three values of the working pressure equal 0.4, 0.5 and 0.6MPa for two diameters of the shooting hole: 10 and 20 mm. During tests the core box deaeration, controlled by an activisation of the determined number of deaerating vents placed in the core box, was also subjected to changes.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Core Sands Properties in Blowing Process
Autorzy:
Dańko, R.
Tematy:
foundry
core
blowing process
core sand
odlewnictwo
rdzeń odlewniczy
masa rdzeniowa
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/381670.pdf  Link otwiera się w nowym oknie
Opis:
The effects of filling the core box cavity and sand compaction in processes of core production by blowing methods (blowing, shooting) depend on several main factors. The most important are: geometrical parameters of cavity and complexity of its shape, number, distribution and shape of blowing holes feeding sands as well as the venting of a technological cavity. Values of individual parameters are selected according to various criteria, but mostly they should be adjusted to properties of the applied core sand. Various methods developed by several researchers, including the authors own attempts, allow to assess core sands properties on the basis of special technological tests projecting the process into a laboratory scale. The developed criteria defining a degree or a filling ability factor provide a better possibility of assessing the core sand behaviour during flowing and core box filling, which indicate the value and structure of the obtained compacting decisive – after hardening – for strength and permeability. The mentioned above aspects are analysed – on the basis of authors’ own examinations - in the hereby paper.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficacy of Exercise Protocols on Balance in Badminton Players -A Systematic Review & Meta-Analysis
Autorzy:
Indora, Nitin Kumar
Manoj, Malik
Jaspreet, Kaur
Tematy:
badminton
core stability training
Pilates
Plyometric
Swiss ball
core strengthening
balance
Pokaż więcej
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Powiązania:
https://bibliotekanauki.pl/articles/2170348.pdf  Link otwiera się w nowym oknie
Opis:
Objective. the goal of this “systematic review” and meta-analysis is to find out the efficacy of exercise regimes on balance in badminton players. Study design. Systematic review and meta-analysis. data Source. Pub Med, “Cochrane database (Cochrane Central register of controlled Trials)”, google Scholar, Springer, and DoAJ. Eligibility criteria. limits were applied to database searches to identify papers published in English and only human studies were included. results. result of Meta – analysis was statistically significant in “anterior component of Y-balance test” (MD = 2.39, 95% ci = 1.90, 2.89; “p ≤ 0.00001”) with low heterogeneity (i² = 0%, p < 0.41). There was statistically significant improvement in postero-medial component of y- balance (MD = 2.87, 95% ci = 0.55, 5.19; p ≤ 0.02) with “moderate heterogeneity” (i² = 39%, p < 0.19). result showed statistically significant improvement in postero-lateral component of y- balance test (MD = 3.09, 95% ci = 0.64, 5.65; p ≤ 0.02) with “moderate heterogeneity (i² = 38%, p < 0.20)”. There was “statistically significant “improvement in overall balance of y-balance test in “experimental group as compared to control group (MD = 8.49, 95% ci = 4.62,12.36; p ≤ 0.0001) with low heterogeneity (i² = 0%, P < 0.47)”. Conclusion. this systematic and meta-analysis concluded that various exercise protocols may result in improvement in the balance of badminton players. PrOSPErO registration number: crD42020193620.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the relationship between the level of knowledge about Core Stability and the occurrence of injuries among Footballers
Ocena zależności pomiędzy poziomem wiedzy na temat Core Stability a wystepowaniem kontuzji u piłkarzy
Autorzy:
Dąbek, Dominika
Opis:
Wstęp: Stabilizacja centralna określana jako wydolność mięśni core, których zadaniem jest kontrola centrum ciała (kompleksu miedniczno-lędźwiowego) w statyce i dynamice, stanowi główny element programów prewencyjnych kontuzji w piłce nożnej. Pomimo to często w literaturze prezentowana jest błędnie. Dlatego można wywnioskować, iż wiedza na temat core stability może mieć wpływ na występowanie kontuzji wśród zawodników i zawodniczek piłki nożnej. Cel pracy: Ocena korelacji pomiędzy stanem wiedzy na temat mięśni core, a występowaniem kontuzji wśród zawodników i zawodniczek piłki nożnej.Materiał i metody: Grupa badana: 110 osób (50 kobiet i 60 mężczyzn) trenujących piłkę nożną w ligach: ekstraklasa do liga okręgowa, w wieku 20-25 lat. Osoby, które spełniały kryteria włączenia wypełniły autorski kwestionariusz ankietowy. Wyniki badania ankietowego zostały poddane analizie statystycznej. Wyniki: Wykonywanie treningu core powiązane było istotnie statystycznie z płcią i ligą, a także z częstotliwością treningów oraz z wykonywaniem treningów wzmacniających i stabilizacyjnych. Częściej treningi core wykonywały kobiety, osoby trenujące w wyższych ligach i osoby częściej trenujące. Wiedza na temat treningów core powiązana była istotnie statystycznie z płcią, z wykonywaniem treningów wzmacniających i stabilizacyjnych, ale nie była z ligą i częstością treningów. Wyższy poziom wiedzy na temat treningów core miały kobiety, osoby, które wykonywały treningi wzmacniające i stabilizacyjne. Nie wykazano natomiast związku poziomu wiedzy na temat treningów core z doświadczeniem kontuzji χ2 = 0,31; p = 0,855.Wnioski: Nie istnieje zależność pomiędzy stanem wiedzy na temat stabilizacji core, a występowaniem kontuzji wśród zawodników i zawodniczek piłki nożnej.
Introduction: Cora stability defined as core muscle efficiency, whose task is to control the center of the body (pelvic-lumbar complex) in statics and dynamics, is the main training element of injury prevention programs in football. Despite this, it is often presented erroneously in the literature. Therefore, it can be concluded that knowledge about core stability may affect the occurrence of injuries among football players.Aim: To assess the correlation between the state of knowledge about core muscles and the occurrence of injuries among football players.Material and methods: Study group: 110 people (50 women and 60 men) training football in leagues: Ekstraklasa to District League, aged 20-25. Persons who met the inclusion criteria completed an original questionnaire. the results of the survey were subjected to statistical analysis.Results: Core training was statistically significantly related to gender and league, as well as to the frequency of training and to strengthening and stabilization training. Core workouts were more often performed by women, people training in higher leagues and people training more often. Knowledge about core training was statistically related to gender, with strengthening and stabilization training, but it was not with the league and frequency of training. A higher level of knowledge about core training had women, people who performed strengthening and stabilization trainings. However, the level of knowledge about core training was not shown to be related to the experience of injury χ2 = 0.31; p = 0.855.Conclusions: There is no relationship between the state of knowledge about core stabilization and the occurrence of injuries among football players.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Inne
Tytuł:
Core breast biopsy under MR control : preliminary results
Autorzy:
Kleinrok, Krzysztof
Herman-Sucharska, Irena
Tabor, Jacek
Popiela, Tadeusz
Urbanik, Andrzej
Podsiadło-Kleinrok, Beata
Opis:
Background: Breast MR examination is capable of detecting suspected lesions that are not visualized by other imaging techniques, such as mammography or ultrasonography. In all cases such lesions should be verified histopathologically by MR-guided core biopsy. The aim of the study was the determination of effectiveness of MR-guided breast core biopsy in detection of breast pathologies. Material/Methods: Twelve women with suspected lesions detected by MR (GEMS Signa Excite 1.5 T with 4-channel open breast coil manufactured by MRI Devices Corporation) were qualified to MR-guided breast biopsy. Obtained image data were transferred to DYNACAD workstation for calibration, lesion localization, and automatic calculation of target coordinates for MR-guided intervention. Biopsy was performed using automated 14G biopsy needle. Results: MR-guided breast biopsy was performed in 9 women and confirmed lobular and ductal carcinoma in 2 patients respectively, lobular carcinoma in situ (LCIS) in 1, intraductal papilloma in 2, and intraductal hyperplasia without atypia. In 3 patients histopathologic examination revealed benign fibrocystic lesions. Three women were disqualified from biopsy because pre-biopsy MR sequences did not reveal the lesion in 1 case, and due to the target localization out of reach of the biopsy needle in other 2 cases. Conclusions: All non-palpable lesions visualized by MR (contrast-enhanced signal in dynamic examination) should be verified by MR-guided breast biopsy. In each case histopathologic
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Electrochemically Initiated Synthesis of Polyacrylamide Microgels and Core-shell Particles
Autorzy:
Yasmeen, Nabila
Sharma, Piyush Sindhu
Borowicz, Pawel
Kutner, Wlodzimierz
Kalecki, Jakub
Wydawca:
American Chemical Society
Cytata wydawnicza:
Nabila Yasmeen, Jakub Kalecki, Pawel Borowicz, Wlodzimierz Kutner, and Piyush S. Sharma, Electrochemically Initiated Synthesis of Polyacrylamide Microgels and Core-shell Particles, ACS Appl. Polym. Mater. 2022, 4, 452−462. https://doi.org/10.1021/acsapm.1c01359
Opis:
Herein, we developed a simple procedure for synthesizing micrometersized microgel particles as a suspension in an aqueous solution and thin films deposited as shells on different inorganic cores. A sufficiently high constant potential was applied to the working electrode to commence the initiator decomposition that resulted in gelation. Under hydrodynamic conditions, this initiation allowed preparing different morphology microgels at room temperature. Importantly, neither heating nor UV-light illumination was needed to initiate the polymerization. Moreover, thin films of the cross-linked gel were anchored on different core substrates, including silica and magnetic nanoparticles. Scanning electron microscopy and transmission electron microscopy imaging confirmed the microgel particles’ and films’ irregular shape and porous structure. Energy-dispersive X-ray spectroscopy indicated that the core coating with the microgel film was successful. Dynamic light scattering measured the micrometer size of gel particles with different combinations of acrylic monomers. Thermogravimetric analysis and the first-derivative thermogravimetric analysis revealed that the microgels’ thermal stability of different compositions was different. Fourier-transform infrared and 13C NMR spectroscopy showed successful copolymerization of the main, functional, and cross-linking monomers.
European Union Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreement no. 711859 and the Polish Ministry of Science and Higher Education for the implementation of an international co-financed project in the years 2017−2021.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Investigations of the Mechanism of the Sand Shooting into the Core Box
Autorzy:
Dańko, R.
Tematy:
core
core box
sand shooting
deaerating
rdzeń
rdzenie skrzynkowe
piaskowanie
odpowietrzanie
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/379842.pdf  Link otwiera się w nowym oknie
Opis:
The results of investigations of sand shooting into the core box are presented in the hereby paper. The investigations concern the formation of the diphase sand-air flux, its motion, flowing and compaction in the cavity during the core forming. Conditions deciding on the course of individual phases of the process are discussed with taking into consideration the influence of such factors as: the shot pressure, shooting hole diameter, number and distribution of deaerating vents in experimental core boxes (of a single cavity and of multi cavities) on the core sand compaction state. Investigations were performed by means of the modernised experimental shooting machine SR-3D, of the shooting chamber volume of 3.3 dm3, connected with the system of pneumatic supply ensuring the stable pressure supply of values: 0.4 MPa, 0.5 MPa and 0.6 MPa. Two diameters of the shooting hole, equal 10 mm and 20 mm, were applied for filling three experimental core boxes differing in dimensions of cavities and in number and distribution of deaerating vents. The filling process of core boxes was recorded by means of the digital camera PHANTOM V210 with the filming rate of 3000 pictures in second. Simultaneously, during the shot, other values allowing to determine the intensity of the core sand outflow from the shooting chamber to the core box, were tested. The presented in this publication results constitute the important element of the experimental verification of the blowing process simulation calculations which will be performed.
Dostawca treści:
Biblioteka Nauki
Artykuł

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