Autor: Jastrzebski, G. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Description of the pneumatic work cycle of the starting unit of the UAV launcher
Autorzy:: Jastrzębski, G.
Powiązania:: https://bibliotekanauki.pl/articles/247898.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: launcher
pneumatic trigger
pneumatic system
Opis:: The publication presents a UAV pneumatic launcher designed and built in ITWL. The basic element of the pneumatic launcher is the launch mechanism. The starting mechanism determines the energy parameters that will be reached on the launch pad. The work of the launch engines used in propulsion systems has been reviewed and their advantages and disadvantages are discussed when used in pneumatic launchers. A detailed description of the author’s solution of the pneumatic launching mechanism from the launcher is presented. In order to determine guidelines for the design of pneumatic starter systems, a description of the cycle of operation of the complex pneumatic system was analysed. The description of the pneumatic system’s work cycle was based on the parameters of the flow of the compressed air C and b (C – the sound conductivity of the pneumatic element, b – the critical pressure of the pneumatic element). A set of equations describing the pressure change in the filled and emptied valve compartment and the equation of motion are presented. The equations of a mathematical model describing the pneumatic component and the replacement value of flow parameters for the pneumatic system of series pneumatic components are presented. For the mathematical model, a calculation algorithm is presented which takes into account the initial conditions and the boundary conditions of the various periods of the pneumatic system cycle. Examples of calculation results for a specific pneumatic trigger mechanism are shown. The results obtained were compared with the results of the pneumatic starter station tests and the mathematical model of the pneumatic starter was evaluated.
Źródło:: Journal of KONES; 2017, 24, 4; 61-70
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Impact of opening time of the take-off pneumatic launcher main valve on take-off pressure losses
Autorzy:: Jastrzębski, G.
Powiązania:: https://bibliotekanauki.pl/articles/243547.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: take-off launcher
pneumatic take-off systems
pressure losses
Opis:: This publication presents UAV rope and pneumatic launchers constructed and operated in the Air Force Institute of Technology. The construction and operating principle were presented, and functional properties of the UAV take-off pneumatic launcher were characterised. Furthermore, a detailed diagram of the take-off pneumatic launcher was shown, and an operating principle of the launcher take-off system and pneumatic control of the take-off procedure were discussed. The operation parameters of the most important operational elements (main ball valve, semi-rotary actuator, pneumatic valves controlling the flow) from the launcher pneumatic system were specified. On the basis of data sheets of pneumatic elements, a calculation model of the mass flow (volumetric flow rate) of compressed air flowing through the main valve (ball valve in the take-off cylinder supply line) of the take-off pneumatic launcher was designed. The possible cracks, through which compressed air leaks and the take-off cylinder dead sections during the main valve opening and shot, were characterised and discussed. The calculation model designed for individual leaks and total compressed air leaks in the take-off line of the pneumatic launcher was presented. Based on the mass flow model (volumetric flow rate) of compressed air flowing through the main valve, and total compressed air leaks, the relationship of compressed air energy losses depending on opening time of the main valve of the take-off pneumatic launcher was determined. In the paper, the results of simulation studies for the times shorter than data sheets of the main valve opening were presented. In addition, the change of the compressed air disposable energy losses was defined. Based on the results of simulation studies, the opening time of the take-off launcher main valve for the acceptable disposable energy loss level of the take-off pneumatic launcher was specified.
Źródło:: Journal of KONES; 2016, 23, 4; 175-182
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Experimental method of determining characteristics of power and torque engine for low-power unmanned aerial vehicles
Autorzy:: Jastrzębski, G.
Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/245545.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
internal combustion engines
motor test
motor braking
Opis:: The article presents an analytical determination of power and torque of internal combustion engines of small power. It measured actual power and torque characteristics of internal combustion engines of small power. Three types (methods), braking (receiving power via a hydraulic pump, generator and a package of propellers with variable angle of attack. For each method of receiving power (braking) determined the characteristics of torque and power. There is the summary of results for one engine with different ways of braking. There have been evaluation of the presented methods inhibit combustion piston engines of small power as methods for determining power internal combustion engines. The analysis methods presented in the perspective of the braking engine selection for light unmanned aircraft, and the use of parameters derived from research into engine control. Subject to the evaluation method of adjustment (increase) charged, increasing the load on a liquid or ankle. The criterion for comparing methods for inhibition of internal combustion engines of small power load assumed dependence on the rotational speed n, and obtain maximum power on the motor shaft when the throttle, a reflection of the actual engine operating parameters in its target applications.
Źródło:: Journal of KONES; 2011, 18, 3; 135-142
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Methods for determining the take-off speed of launchers for unmanned aerial vehicles
Autorzy:: Jastrzębski, G.
Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/243050.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aviation
unmanned aerial vehicle
take-off launcher
take-off speed
acceleration recorder
lotnictwo
bezzałogowy statek powietrzny
prędkość startu
rejestrator przyspieszenia
Opis:: Unmanned aerial vehicles (UAV) are currently a very rapidly developing type of aviation. The problem of support during the take-off with the use of, i.e. take-off launchers arose along with their development, especially for UAVs with weights and dimensions preventing manual take-off. One of the major issues associated with UAV take-off launchers is for its UAV accelerating element to obtain its initial speed. The article presents three methods of determining launcher take-off speeds for unmanned aerial vehicles, i.e. the concentrated very oblique projection method, the high-speed camera methods, and the acceleration recorder method. The take-off launcher carriage speed in the oblique projection method is determined from a formula. This method involves “ejections” of concentrated masses from the UAV mass range and measuring the component values resulting from the used formula, which contains the range of the oblique projection, the elevation of the projection and its angle. The method using the high-speed camera involves recording the course of ejections of the concentrated mass from the launcher. The average take-off speed is determined on the basis of a take-off run length (section of the launcher race, where the unit accelerates) and defining the start and end frame of the carriage movement. The third method for the determination of the take-off speed utilizes an acceleration recorder. The method with the recorder involves registering a change in the accelerations when the take-off carriage is being accelerated by a system fixed on the carriage or the accelerated object. The article presents the methodology of dynamic tests of object acceleration on a launcher, necessary for the determination of speed with the mentioned methods. Selected results from actual tests with the use of the 01/WS/2015 launcher, which is an element of the ZOCP JET2 set, were presented. The test results are presented in a tabular form. The methods for the determination of the take-off speed were compared on the basis of performed tests. Based on the obtained results, the factors impacting the accuracy of each of the methods were identified.
Źródło:: Journal of KONES; 2018, 25, 1; 170-176
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: The analysis of working liquid flow in a hydrostatic line with the use of frequency characteristics
Autorzy:: Ułanowicz, L.
Jastrzębski, G.
Powiązania:: https://bibliotekanauki.pl/articles/200309.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: aviation
unmanned aerial vehicle
hydrostatic drive
servomechanism
hydrostatic line
Opis:: One of the little described problems in hydrostatic drives is the fast changing runs in the hydraulic line of this drive affecting the nature of the formation and intensity of pressure pulsation and flow rate occurring in the drive. Pressure pulsation and flow rate are the cause ofthe unstable operation of servos, delays in the control system and other harmful phenomena. The article presents a flow model in a hydrostatic drive line based on fluid continuity equations (mass conservation), maintaining the amount of Navier-Stokes motion in the direction of flow (x axis), energy conservation (liquid state). The movement of liquids in a hydrostatic line is described by partial differential equations of the hyperbolic type, so modeling takes into account the wave phenomena occurring in the line. The in hydrostatic line was treated as a cross with two inputs and two outputs, characterized by a specific transmittance matrix. The product approximation was used to solve the wave equations. An example of the use of general equations is presented for the analysis of a miniaturized hydrostatic drive line fed from a constant pressure source and terminated by a servo mechanism.
Źródło:: Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 949-956
0239-7528
Pojawia się w:: Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Examination of hydraulic amplifiers in the aspect of lifetime prediction
Autorzy:: Jastrzębski, G.
Ułanowicz, L.
Powiązania:: https://bibliotekanauki.pl/articles/244003.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: hydraulic amplifier
distributing slider
hydrodynamic radial force
insensitivity (dead) zone of a hydraulic amplifier
durability (lifetime)
Opis:: The paper presents the lifetime analysis for a hydraulic amplifier and considers two types of the flow distributing devices, i.e. a linear distributings lider and a rotarys lider. Description of essential properties associated with operation of distributing devices in hydraulic amplifiers is included with particular attention to analysis of processes that affect wear and tear of hydraulic amplifiers and influence quality of their operation. In that context a set of parameters that determine operation quality of hydraulic amplifiers was found out where mutual independence of the parameters, their unambiguousness and measurability served as the criteria for selection there of two methods of analysis were used that took account for the foregoing assumption, i.e. the method of maximum informative capacity of the parameter and the method that assumes maximum alteration of the technical condition due to execution of the test. The completed examinations made it possible to find out characteristic curves for hydraulic amplifiers with a linear distributing slider as well as with a rotary slider with regard to their accumulated operation time. Further predictions of the hydraulic amplifier lifetime take advantage of the assumption that the deterioration effect of functional parameters attributable to hydraulic amplifiers is represented by a series of time-related values (y1,y2.....yn)i.e. a set of discrete observations {y1=ksi(teta)} associated with an unsteady stochastic process ksi(teta). The relationships how functional parameters o f a hydraulic amplifier vary in pace with its operation time t are described by means of the Gaussian distribution with the assumption that the course of a functional parameter deterioration corresponds to its aggregated characteristic curve that represents resistance of a distributing device embedded into a hydraulic amplifier to wear and tear processes. Wear of crucial parts within a hydraulic amplifier is measured in terms how functional parameters of that part associated with its accuracy, sensitivity and switching speed are getting worse and worse as time goes by.
Źródło:: Journal of KONES; 2010, 17, 3; 165-172
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: A method of investigating internal leakages in aircraft hydraulic units
Autorzy:: Szczepaniak, P.
Jastrzębski, G.
Jóźko, M.
Powiązania:: https://bibliotekanauki.pl/articles/242288.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aircraft hydraulic unit
internal leakage
precision hydraulic pair
Opis:: Methods of diagnosing technical condition of aircraft hydraulic systems have been analysed. Associated precision pairs of aircraft hydraulic systems have been presented. The most essential features of operating conditions and the loads that affect distributor components of sliding pairs have been identified. The structure of BU intensifier with a sliding distributor has been illustrated. Equation for internal leakages for a precision hydraulic pair with a concentric annular gap (clearance) has been presented. Illustrated and discussed are instances of examining internal leakages occurring in hydraulic systems (with direct methods applied). Findings of research into these issues have been presented as based on measurements taken on the hydraulic system of the Su-22 operated by the Air Force of the Republic of Poland. The technique of examining the problem consists in taking and recording measurements of the drop in pressure in the hydraulic system. The relationship between time of pressure-drop and total leakage for hydraulic systems of particular Su-22 aircraft has been illustrated. The results of research direct and indirect methods have been presented and analysed. Both methods have been compared from the aspect of assessing technical condition of the aircraft hydraulic system. Potential factors that could affect measurements with a given method have been identified.
Źródło:: Journal of KONES; 2014, 21, 4; 471-478
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Selenium concentration in dairy cows and its influence on production traits
Stężenie selenu u krów mlecznych oraz ustalenie jego wpływu na kształtowanie się cech użytkowych
Autorzy:: Ramisz, A.
Balicka-Ramisz, A.
Jastrzebski, G.
Powiązania:: https://bibliotekanauki.pl/articles/44870.pdf
Data publikacji:: 2012
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Opis:: The aim of this study was to determine selenium concentration in the blood serum of dairy cows and to establish its influence on the level of production and reproduction traits. The study was performed on the farm located inWestern Pomerania and involved 140 cows, which were selected using the analogue method on the basis of their physiological state, lactation number, milk yield, age and genotype. The following indices were analyzed in individual groups: milk yield (kg), milk fat yield (kg), milk fat content (%), milk protein yield (kg), milk protein content (%). Selenium concentration in the blood serum was determined with the spectrofluorometric method. The obtained results showed that 23.6% cows had selenium deficiency, 39.3% had threshold concentration and 37.1% had physiological concentration. The mean milk fat and protein contents were the highest in animals with the threshold concentration of selenium and differed statistically (P≤0.01) from those of the group with the deficiency or physiological concentration of this element. The study revealed that the problem of selenium deficiency is still present in some dairy cattle herds in Western Pomerania.
Celem pracy było określenie stężenia selenu w surowicy krów mlecznych oraz ustalenie wpływu na kształtowanie się cech użytkowych i reprodukcyjnych. Badania przeprowadzono w gospodarstwie położonym na terenie Pomorza Zachodniego. Ogółem objęto badaniami 140 krów, które zostały dobrane metodą analogów, uwzględniającą stan fizjologiczny, kolejność laktacji, wydajność mleczną, wiek oraz genotyp. W poszczególnych grupach przeanalizowano następujące wskaźniki: wydajność mleczną (kg), wydajność tłuszczu (kg), zawartość tłuszczu w mleku (%), wydajność białka w mleku (kg), zawartość białka w mleku (%). Zawartość Se w surowicy oznaczono metodą spektofluorymetryczną. Z uzyskanych wyników badań wynika, że u 23,6% krów stwierdzono niedobór selenu, stężenie graniczne występowało u 39,3%, a stężenie fizjologiczne u 37,1%zwierząt. Średnia zawartość tłuszczu i białka w mleku krów była największa u zwierząt z granicznym stężeniem selenu i różniła się statystycznie (P≤0,01) w stosunku do grupy z niedoborem i fizjologicznym stężeniem selenu. Badania wykazały, że problem niedoboru selenu nadal istnieje w niektórych stadach bydła mlecznego na Pomorzu Zachodnim.
Źródło:: Acta Scientiarum Polonorum. Zootechnica; 2012, 11, 1
1644-0714
Pojawia się w:: Acta Scientiarum Polonorum. Zootechnica
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: New approach to modeling geometric errors in precision manufacturing machines
Nowe podejście do modelowania błędów geometrycznych precyzyjnych maszyn technologicznych
Autorzy:: Majda, P.
Szwengier, G.
Jastrzębski, R.
Powiązania:: https://bibliotekanauki.pl/articles/951470.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: machine tool
volumetric error
FEM
geometric errors
błędy geometryczne
obrabiarka
błąd przestrzennego pozycjonowania
MES (metoda elementów skończonych)
Opis:: This paper presents a new approach to modeling geometric errors in machine tools with linear rolling guideways. Modeling was performed using a finite element method. The results of the modeling were a visualization of deformations of a virtual milling machine with a cross table and with known characteristics of guide geometric errors. The simulation results show that the machine table is subject to a complex state of strain. This implies that the Abbe error during milling machine measurements can assume values dependent on the location of metrological device elements on the machine table. The calculation results were verified experimentally using real milling machines. The predictions of the computer simulation were confirmed.
W artykule przedstawiono nowe podejście do modelowania błędów geometrycznych obrabiarek wyposażonych w liniowe toczne połączenia prowadnicowe. Modelowanie przeprowadzono z użyciem metody elementów skończonych. Efektem modelowania jest wizualizacja odkształceń frezarki poziomej ze stołem krzyżowym, która ma znane charakterystyki błędów geometrycznych połączeń prowadnicowych. Analiza wyników procesu symulacji wykazała, że stół takiej obrabiarki podlega złożonemu stanowi odkształcenia. Ma to istotne znaczenie praktyczne, ponieważ podczas wykonywania pomiarów błędów geometrycznych obrabiarek – błąd Abbego może przyjmować różne wartości w zależności od usytuowania przyrządów pomiarowych na stole frezarki. Wyniki obliczeń zweryfikowano doświadczalnie na rzeczywistych frezarkach. Potwierdzono przewidywania symulacji komputerowej.
Źródło:: Advances in Manufacturing Science and Technology; 2013, 37, 3; 33-44
0137-4478
Pojawia się w:: Advances in Manufacturing Science and Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Modeling the effect of geometric errors on the static characteristics of guide rail systems
Modelowanie wpływu błędów geometrii tocznych podzespołów prowadnicowych na ich charakterystyki statyczne
Autorzy:: Jastrzębski, D.
Pawełko, P.
Szwengier, G.
Powiązania:: https://bibliotekanauki.pl/articles/175768.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: prowadnica toczna
błędy geometryczne
sztywność
modelowanie
rolling guideway
geometric errors
stiffness
modelling
Opis:: The paper presents modeling of geometric errors in guide rail systems and how these errors affect their static characteristics. The finite-element method was used for computational analysis, supplemented with technical modeling of butt joints. Different types of geometric errors were assigned to individual elements of guide rail systems, with variations in distributions of clearances and preloads. Selected results of the computational analysis are presented.
W artykule przedstawiono sposób modelowania błędów geometrycznych występujących w tocznych podzespołach prowadnicowych. Celem modelowania było ustalenie wpływu tych błędów na charakterystyki statyczne podzespołów. Zastosowana metoda elementów skończonych, wzbogacona o efektywną opcję technicznego modelowania połączeń stykowych, była podstawowym narzędziem analizy obliczeniowej. Przyjęto hipotezę przypisywania poszczególnych rodzajów błędów geometrycznych do odpowiednich elementów konstrukcyjnych podzespołu tocznego - uzmiennione rozkłady wartości luzów lub zacisków wstępnych. Zaprezentowano przykład prowadzonej analizy obliczeniowej.
Źródło:: Advances in Manufacturing Science and Technology; 2012, 36, 2; 31-41
0137-4478
Pojawia się w:: Advances in Manufacturing Science and Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Monazite Th-U-total Pb geochronology and P-T thermodynamic modelling in a revision of the HP-HT metamorphic record in granulites from Stary Gierałtów (NE Orlica-Śnieżnik Dome, SW Poland)
Autorzy:: Budzyń, B.
Jastrzębski, M.
Kozub-Budzyń, G. A.
Konečný, P.
Powiązania:: https://bibliotekanauki.pl/articles/2060006.pdf
Data publikacji:: 2015
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:: monazite
Th-U-total Pb dating
thermodynamic modelling
granulite
Orlica-Śnieżnik Dome
Bohemian Massif
Opis:: Thermodynamic modelling and monazite Th-U-total Pb dating via electron microprobe were used to improve the pressure, temperature and timing constraints of the HP-HT metamorphic record in granulites from Stary Gierałtów (NE Orlica-Śnieżnik Dome (OSD), SW Poland). The thermodynamic calculations constrained the P-T conditions to 20-22 kbar and ca. 920ºC in the felsic to intermediate granulites and 20-22 kbar and ca. 970ºC in the mafic granulite. These conditions are considered to closely represent the peak temperatures experienced by these rocks. In the intermediate granulite, the matrix monazite and monazite inclusions in garnet and allanite yielded an age of 349±2.5 Ma. An HP-HT metamorphic event with temperature conditions exceeding 900ºC, which are greater than the closure temperatures of most geochronometers, must have disturbed and completely reset the isotopic systems, including the Th-U-Pb system in the monazite. Consequently, this resetting prevented us from constraining the age of potential earlier metamorphic events or the igneous protolith. The 349±2.5 Ma age reflects the timing of the late-stage HP-HT event and cooling below 900ºC related to the initial exhumation of the granulites. A comparison of the new P-T-t constraints with previous data from the NE Orlica-Śnieżnik Dome indicates that the activation of the channels that exhumed the HP rocks to mid-crustal depths most likely initiated at ca. 350 Ma, and all the metamorphic rocks in the OSD likely shared a common Variscan evolution after ca. 340 Ma.
Źródło:: Geological Quarterly; 2015, 59, 4; 700--717
1641-7291
Pojawia się w:: Geological Quarterly
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Response of the coagulation system after application of hemostatic dressings in an animal model
Autorzy:: Jastrzebski, P.
Adamiak, Z.
Pomianowski, A.
Krystkiewicz, W.
Holak, P.
Sawicki, S.
Przyborowska, P.
Zhalniarovich, Y.
Gudzbeler, G.
Powiązania:: https://bibliotekanauki.pl/articles/30833.pdf
Data publikacji:: 2014
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:: The objective of this study was to determine the response of hemostatic dressings. Coagulation and fibrinolytic systems, red blood cell parameters, platelet and leukocyte counts were evaluated after the application of hemostatic dressings: QuikClot, Chitoauze and Celox gauze. The experiment was performed on ten pigs
Źródło:: Polish Journal of Veterinary Sciences; 2014, 17, 4
1505-1773
Pojawia się w:: Polish Journal of Veterinary Sciences
Dostawca treści:: Biblioteka Nauki

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