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Wyniki wyszukiwania dla: propulsion shaft fatigue
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Negative impact of constant RPM control strategy on ship NOx emission in waves
PublikacjaIn severe wave conditions, the ship propulsion system is loaded with high fluctuations due to external disturbances. The highly fluctuating loads enforce radical changes in the main engine torque, which in turn demands variation of the fuel rate injected into the cylinders if a constant rotational speed strategy is applied. Therefore, the temperature of gases varies to a large extent during the combustion process in the cylinders....
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Axial-Flux Permanent-Magnet Dual-Rotor Generator for a Counter-Rotating Wind Turbine
PublikacjaCoaxial counter-rotating propellers have been widely applied in ships and helicopters for improving the propulsion efficiency and offsetting system reactive torques. Lately, the counter-rotating concept has been introduced into the wind turbine design. Distributed wind power generation systems often require a novel approach in generator design. In this paper, prototype development of axial-flux generator with a counter-rotating...
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Lessons learned during SRAD hybrid motor development
PublikacjaStudent Researched and Developed (SRAD) hybrid rocket motor H-15 with total impulse of 15 $kNs$ was built. First version of the engine has average thrust of 3 $kN$, the second, improved one is prepared with an aim to have average thrust of 5 $kN$. Engine development was started from scratch and went through phases of: definition of design assumptions and constraints, numerical modelling to predict engine performance, CAD and CAM...
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Kompensacja skoków ciśnienia w pompie tłoczkowej o zmiennej wydajności z rozrządem krzywkowym
PublikacjaPrzedmiotem rozprawy doktorskiej jest opis matematyczny, badania i symulacja mechanizmu kompensacji skoków ciśnienia w pompie tłoczkowej z rozrządem krzywkowym typu PWK. W rozprawie przedstawiono istniejące rozwiązania konstrukcyjne pomp tłokowych, kładąc szczególny nacisk na przedstawienie stosowanych w nich mechanizmów rozrządu i kompensacji skoków ciśnienia. Ponadto szczegółowo opisano budowę i zasadę działania pompy PWK będącej...
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Modelling of the Baumann turbine stage operation Part II. Free and kinetic vibrations
PublikacjaIn this paper has been presented a methodology of validation a novel mathematical model dedicated to evaluation and prediction of material degradation and demage of steam turbine elements such as blades, valves and pipes due to three mechanisms: stress-corosion, high-temperature creep and low-cyclic fatigue. The validation concept is based on an experimental setup manufactured in the Laboratory of Faculty of Mechanical and Power...
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Modern GFRP Composite Footbridges
PublikacjaApplication of GFRP composites in civil engineering is still not large but already noticeable. Advantages of this material, such as: low volume weight, relatively high stiffness and strength, well fatigue resistance, easiness in shaping, high material damping and high environmental resistance, make it attractive for bridge and in particular foot-bridge designers. It is estimated that nowadays in the world there are realized hundreds...
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Asphalt pavement structure optimization with alternative materials
PublikacjaThe paper briefly describes modern method assessment of the pavement structure based on the simplified viscoelastic continuum damage (S-VECD) model. The method was used to compare two types of pavement structures. There were analysed classical cstructures with asphalt concretes with neat bitumen and innovative one- or two layered structures with SMA 16 with highly polymer modified bitumen (HiMA). Pavement structures using SMA 16...
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Myelodysplastic syndrome, NOS - Male, 65 - Tissue image [11290630017295671]
Dane BadawczeThis is the histopathological image of HEMATOPOIETIC AND RETICULOENDOTHELIAL SYSTEMS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Myelodysplastic syndrome, NOS - Male, 65 - Tissue image [11290630017293721]
Dane BadawczeThis is the histopathological image of HEMATOPOIETIC AND RETICULOENDOTHELIAL SYSTEMS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Myelodysplastic syndrome, NOS - Male, 65 - Tissue image [11290630017298631]
Dane BadawczeThis is the histopathological image of HEMATOPOIETIC AND RETICULOENDOTHELIAL SYSTEMS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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INFLUENCE OF TIME ON THE BEARING CAPACITY OF PRECAST PILES
PublikacjaOne of the most popular types of foundations in layered subsoil with very differentiated soil shear strengths are precast piles. One of the reasons is a fact that we can well control the driving process during the installation of these piles. The principles of the assessment of bearing capacity and settlements of the piles given by Eurocode 7, concentrate on two main methods, i.e. Static Pile Load Tests (SPLT) and Dynamic Driving...
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Real-time hybrid model of a wind turbine with doubly fed induction generator
PublikacjaIn recent years renewable sources have been dominating power system. The share of wind power in energy production increases year by year, which meets the need to protect the environment. Possibility of conducting, not only computer simulation, but also laboratory studies of wind turbine operation and impact on the power system and other power devices in laboratory conditions would be very useful. This article presents a method...
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Geometric working volume of a satellite positive displacement machine
PublikacjaThis article describes a method for determining the geometric working volume of satellite positive displacement machines (pump and motor). The working mechanism of these machines is satellite mechanism consisting of two non-circular gears (rotor and curvature) and circular gears (satellites). Two variants of the satellite mechanism are presented. In the first mechanism, the rolling line of the rotor is a sinusoid "wrapped" around...
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Friction Resistances in Internal Gear Pump with Modified Sickle Made of Plastic
PublikacjaThis paper presents modifications of the sickle insert (constructional and material) made in a gear pump with internal meshing. The introduced design change consists in making an incision in the sickle insert. Due to this treatment, the races of the insert are pressed against the apex wheels of the gears. The introduced compensation causes a smaller drop in pump efficiency with increasing discharge pressure. The article describes...
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DETERMINATION OF SEAKEEPING PERFORMANCE FOR A CASE STUDY VESSEL BY THE STRIP THEORY METHOD
PublikacjaThe increase of seakeeping performance is of particular importance for car and passenger ferries, service ships in the gas and oil extraction industry and offshore wind power farm industry, as well as for special purpose ships (including military applications). In the water areas of the Baltic Sea, North Sea, and Mediterranean Sea, which are characterised by a short and steep wave, the hull shape has a substantial impact on the...
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The experience of movement in orbital space architecture: A narrative of weightlessness
PublikacjaBased upon a combination of architectural theories, the knowledge of space environment, and psychology of isolated and confined environments, this qualitative research aims to study orbital space settlement in a way to get the built space congenial to the human experience of movement. In this sense, sensors, self-propulsion or mechanical actuators, the inhabitant’s mental and visual capacity for movement, as well as the represented...
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The experience of movement in orbital space architecture: A narrative of weightlessness
PublikacjaBased upon a combination of architectural theories, the knowledge of space environment, and psychology of isolated and confined environments, this qualitative research aims to study orbital space settlement in a way to get the built space congenial to the human experience of movement. In this sense, sensors, self-propulsion or mechanical actuators, the inhabitant’s mental and visual capacity for movement, as well as the represented...
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Application of unmanned USV surface and AUV underwater maritime platforms for the monitoring of offshore structures at sea
PublikacjaThe operation of offshore structures at sea requires the implementation of advanced systems for their permanent monitoring. There is a set of novel technologies that could be implemented to deliver a higher level of effective and safe operation of these systems. A possible novel solution may be the application of a new maritime unmanned (USV) surface and underwater vehicles/platforms (AUV). Application of such vehicles/platforms...
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The voltage on bus bars of the main switchboard of the ro-ro ship electrical power system during a layover at the port
Dane BadawczeThe dataset is part of the research results on the quality of supply voltage on bus bars of the main switchboard of the ship's electrical power system in different states of ship exploitation. The attached dataset contains the measurement results carried out onboard a ro-ro ship during a layover at the port.
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Magnetic field maps of an astable multivibrator in frequency range from 30 MHz to 3 GHz – selective detection
Dane BadawczeThe data presents a result of near field measurements of electromagnetic emissions radiated from the PCB of a small electronic device. An efficient method of modelling the magnetic and electric field emissions is the measurements in the near field using electric and magnetic probes. The attached files contain magnetic field maps created on based measurements...
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ADAPTATION OF ENGINEERING FEA-BASED ALGORITHMS TO LCF FAILURE AND MATERIAL DATA PREDICTION IN OFFSHORE DESIGN
PublikacjaThere is an ever growing industrial demand for quantitative assessment of fatigue endurance of critical structural details. Although FEA-based calculations have become a standard in engineering design, problems involving the Low-To-Medium cycle range (101-104) remain challenging. This paper presents an attempt to optimally choose material data, meshing density and other algorithm settings in the context of recent design of the...
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Structural Health Monitoring of Overhead Power Transmission Lines
PublikacjaStructural Health Monitoring (SHM) is a novel and continuously developing branch of science and technology that draws attention of scientists all over the world. It creates opportunities to detect, localize and identify structural damage of various types such as: line breakage, permissible sag, bolt loosening, fatigue cracking or insulator contamination. On the other hand the methods used to estimate the remaining operational...
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Experimental comparison of hydrodynamic thrust bearings with different pad surface materials
PublikacjaBabbitt is the material most frequently used as the pad surface material for hydrodynamic bearings operating at usual operating conditions. It shows many advantages important for safe bearing operation, as for example: low friction coefficient, corrosion resistance, fair mechanical properties and outstanding conformability. On the other hand, it is not free from disadvantages, such as limited fatigue strength or limited resistance...
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The Use of Direct Shear Test for Optimization of Interlayer Bonding Under a Poroelastic Layer
PublikacjaPoroelastic Road Surfaces (PERS) are characterised by porous structure with air void content of 20% or higher and stiffness almost 10 times lower than that of a standard asphalt course. Such properties enable noise reduction by up to 12 dB in comparison to SMA 11 mixture. However, the disadvantage of a poroelastic pavement is its low durability, which partially results from delamination from the lower layer. The paper aims to investigate...
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Chemical Theory of Machines, basic principles of strength with examples of calculations
PublikacjaThis book encompasses the essential range of information on technical aspects of mechanical design. It was written primarily for the students and staff of chemistry faculties of technical universities, yet it may also be utilized by everyone, who ether would like to try or already enjoys designing, but cannot take advantage of typical stress & machine construction handbooks. These handbooks often require familiarity with the concepts...
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Effect of presence of lifting pocket on the THD performance of a large tilting-pad thrust bearing
PublikacjaHydrostatic assistance is a commonly used method to improve limited load carrying ability of tiltingpad thrust bearings during transient states of operation of vertical shaft hydro-generators. Despite of special hydraulic equipment (as pumps, valves, etc.), it also requires manufacturing of special recesses/pockets at pad sliding surfaces, into which oil is injected under high pressure. It allows to lift the rotor before start-up...
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Water-Lubricated Sintered Bronze Journal Bearings—Theoretical and Experimental Research
PublikacjaWater lubricated bearings are used from many years in shipbuilding, hydro power and other industries because of their advantages such as: extensive serviceable life, low coefficient of friction, longevity of shaft sleeve, good abrasion resistance, low maintenance required, unit simplicity, no danger of pollution and low price. Various types of water lubricated sliding bearings have been tested at the Technical University of Gdansk...
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FEM modelling of screw displacement pile interaction with subsoil
PublikacjaPredicting the-settlement characteristics of piles is an important element in the designing of pile foundations. The most reliable method in evaluating pile-soil interaction is the static load test, preferably performed with instrumentation for measuring shaft and pile base resistances. This, however, is a mostly post-implementation test. In the design phase, prediction methods are needed, in which numerical simulations play an...
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EMISJA AKUSTYCZNA JAKO SYGNAŁ DIAGNOSTYCZNY ODWZOROWUJĄCY ZMĘCZENIOWE ZUŻYCIE WARSTW ŚLIZGOWYCH PANWI ŁOŻYSK GŁÓWNYCH I KORBOWYCH SILNIKÓW O ZAPŁONIE SAMOCZYNNYM
PublikacjaW artykule przedstawiono wyniki badań laboratoryjnych, z których wynika, że emisja akustyczna (EA) może być uznana za sygnał diagnostyczny, przydatny do identyfikacji stanu technicznego łożysk głównych i korbowych okrętowych silników o zapłonie samoczynnym. Wykazano w nim bowiem, że parametry emisji akustycznej takie jak: czas rejestracji, energia sygnału, amplituda sygnału, ilość przekroczeń poziomu dyskryminacji, czas narastania,...
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Caring for Children with Dravet Syndrome: Exploring the Daily Challenges of Family Caregivers
PublikacjaWhile Polish studies focus on the symptoms, causes and treatment of people suffering from Dravet syndrome (DS), much less is known about the situation of the family caregivers of DS children. This study was designed to explore the experiences, daily challenges and needs related to caring for DS children. An anonymous self-administered online questionnaire was developed. Thesurvey was completed by 75 family caregivers affiliated...
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Impact of overloaded vehicles on load equivalency factors and service period of flexible pavements
PublikacjaOverloaded vehicles occur less frequently in comparison to properly loaded vehicles but due to their greater potential to cause damage they significantly contribute to the distress of pavement structure. As the studies show, the phenomena of vehicles overloading intensifies when the control of traffic is poor and the average percentage of overloaded vehicles on analyzed roads varies from 6% to 23%. The main goal of the ar-ticle...
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Influence of the notch rounding radius on estimating the elastic notch stress concentration factor in a laser welded tee joint
PublikacjaIn recent years an increased interest of industry in sandwich-type metal structures can be observed. These structures consist of thin plates of 2.5 mm in thickness separated by stiffeners of different shapes and forms. Welds joining the plates and stiffeners are made on the outer side of the plates using laser welding technique. A locally focused source of heat causes the plate to melt creating a very narrow and elongated joint....
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Evaluation of the Effectiveness of Compression Therapy Combined with Exercises Versus Exercises Only Among Lipedema Patients Using Various Outcome Measures
PublikacjaThe treatment of lipedema remains challenging, largely due to widespread misconceptions. Selecting the appropriate treatment method necessitates the use of accurate outcome measures. This study aims to evaluate the effectiveness of compression therapy combined with exercises versus exercises alone in lipedema patients using various outcome measures. Twenty-four women with lipedema were divided into two equal groups: one group received...
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MINERAL CONTENT OF TREE SAP FROM THE SUBCARPATHIAN REGION
Publikacjabut also as medicinal substance in folk medicine. Traditionally, it was used to treat various conditions, mostly anaemia and chronic fatigue. This study has been designed to establish the content of metallic elements (sodium, potassium, calcium, magnesium, zinc and copper) in sap collected from eight different species (silver birch, downy birch, hornbeam, Norway maple, boxelder maple, black walnut, black alder and white willow)...
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Effect of processing parameters on the cyclic behaviour of aluminium friction stir welded to spark plasma sintered aluminium matrix composites with bimodal micro-and nano-sized reinforcing alumina particles
PublikacjaUnderstanding the cyclic behaviour of Alumina reinforced Aluminium composites (Al-A2O3) was of critical importance, for their further application in the different industrial sectors. The present study is focussing on the cyclic behaviour of the Al-Alumina nanocomposite produced through the combination of spark plasma sintering (SPS) method and friction stir welding (FSW). The added Alumina with total content of 10% is the combination...
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Effect of aeration of antibiotic-loaded bone cement on its properties and bactericidal effectiveness
PublikacjaBACKGROUND: Antibiotic-loaded bone cements are now widely used in medicine. They are able to locally deliver antibiotic particles and they allow treat or protect against infection. It is assumed that the bactericidal effectiveness of bioactive bone cements depend on the parameters of its production. Hence, the aim of this study was to check the effect of aeration of bone cement before mixing the components on its properties as...
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Bitumen Aging—Laboratory Simulation Methods Used in Practice and Selected Directions of Research on New Methods
PublikacjaChanges in the properties of bitumen binders that occur as a result of aging have a huge impact on the durability of products produced from them. In particular, asphalt pavements, which constitute the most common use of petroleum bitumen, are susceptible to damage resulting from the increasing stiffness of the bitumen during its life cycle. Increased stiffness of asphalt pavements reduces the pavement resistance to low-temperature...
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Exploring the trends in flux-cored arc welding: scientometric analysis approach
PublikacjaFlux-cored arc welding (FCAW) is a universal group of welding methods in terms of the scope of application and automation possibilities, the share of which in various industries in many countries is still increasing. The paper presents the results of bibliographic analyses (scientometric analysis with the use of VOSviewer, Bibliometrix and CitNetExplorer tools) of a data set of 993 publications indexed in the Web of Science database...
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Nonlinear Control of a Doubly Fed Generator Supplied by a Current Source Inverter
PublikacjaNowadays, wind turbines based on a doubly fed induction generator (DFIG) are a commonly used solution in the wind industry. The standard converter topology used in these systems is the voltage source inverter (VSI). The use of reverse-blocking insulated gate bipolar transistor (RB-IGBT) in the current source inverter topology (CSI), which is an alternative topology, opens new possibilities of control methods. This paper presents...
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Displacements of bones during bending test of first metatarsophalangeal joint after arthrodesis with medially or dorsally positioned locking plate and lag screw.
Dane BadawczeThe Dataset contains the values of displacements of bone control points during the bending test of first metatarsophalangeal (MTP1) joint specimens after arthrodesis.
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Instantaneous power signal measurements for bearing diagnostics
Dane BadawczeBearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous current and voltage power supplied to the engines. Bearing damage causes the appearance of deformations, which are in the form of additional harmonic components...
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Analysis of the instantaneous power signal for bearing diagnostics -bearing damaged
Dane BadawczeThe attached dataset contains the measurement results of the instantaneous values of current and voltage, recorded during the diagnostics of a damaged bearing. Bearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous...
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Analysis of the instantaneous power signal for bearing diagnostics - bearing undamaged
Dane BadawczeThe attached dataset contains the measurement results of the instantaneous values of current and voltage, recorded during the diagnostics of an undamaged bearing. Bearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous...
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A Comparative Study of Fuzzy SMC with Adaptive Fuzzy PID for Sensorless Speed Control of Six-Phase Induction Motor
PublikacjaMulti-phase motors have recently replaced three-phase induction motors in a variety of applications due to the numerous benefits they provide, and the absence of speed sensors promotes induction motors with variable speed drives. Sensorless speed control minimizes unnecessary speed encoder cost, reduces maintenance, and improves the motor drive’s reliability. The performance comparison of the fuzzy sliding mode controller (FSMC)...
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A Comparative Study of Fuzzy SMC with Adaptive Fuzzy PID for Sensorless Speed Control of Six-Phase Induction Motor
PublikacjaMulti-phase motors have recently replaced three-phase induction motors in a variety of applications due to the numerous benefits they provide, and the absence of speed sensors promotes induction motors with variable speed drives. Sensorless speed control minimizes unnecessary speed encoder cost, reduces maintenance, and improves the motor drive’s reliability. The performance comparison of the fuzzy sliding mode controller (FSMC)...
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Longitudinal Motion Due to Action of Tunnel Thrusters
PublikacjaTunnel thrusters are propulsion and active control devises that provide a side force, or transverse thrust, to support mooring operations or position keeping. They shorten the time of manoeuvring, reduce the cost of towage and since inception, manoeuvrability specifically in ports has become a lot easier. Tunnel thrusters can either be operated manually or with the help of Dynamic Positioning systems which makes it even more efficient. Theoretically,...
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Using differential pressure sensor to measure nitrous oxide level in a tank
PublikacjaA method for measuring the level of liquid nitrous oxide oxidizer in a hybrid rocket motor oxidizer tank is proposed. Presented approach is more accurate than the most commonly used method of this measurement, which employs weighting of the whole sounding rocket or an oxidizer tank. In our solution we use a differential pressure sensor to measure the change of pressure at the bottom of an oxidizer tank in comparison to the pressure...
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Field Evaluation of High Modulus Asphalt Concrete Resistance to Low-Temperature Cracking
PublikacjaHigh-modulus asphalt concrete has numerous advantages in comparison to conventional asphalt concrete, including increased resistance to permanent deformations and increased pavement fatigue life. However, previous studies have shown that the construction of road pavements with High Modulus Asphalt Concrete (HMAC) may significantly increase the risk of low-temperature cracking. Those observations were the motivation for the research...
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Analysis of diagnostic informativeness of the exhaust temperature of a naval gas turbine
PublikacjaThe conducted investigations aimed to carry out an analysis of the possibility that the failures identification in the automatic control system of a gas turbine engine could be worked out on the basis of measurements of the exhaust stream temperature behind the gas generator. The exhaust temperature represents a basic control parameter, enabling technical state evaluation of the engine within the operation process, which is observed...
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Pile Model Tests Using Strain Gauge Technology
PublikacjaOrdinary pile bearing capacity tests are usually carried out to determine the relationship between load and displacement of pile head. The measurement system required in such tests consists of force transducer and three or four displacement gauges. The whole system is installed at the pile head above the ground level. This approach, however, does not give us complete information about the pile-soil interaction. We can only determine...