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Search results for: underwater wet welding
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Laboratory station for research of the innovative dry method of exhaust gas desulfurization for an engine powered with residual fuel
PublicationContemporary methods of exhaust gas desulfurization in marine engines are all expensive methods (4-5 million euro). This is, among other reasons, due to the limited market audience, but primarily due to the monop-olized position of manufacturers offering fabrication and assembly of this type of marine ship installations. Proposed as part of a research project financed by the Regional Fund for Environmental Protection and Maritime...
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Atmospheric opacity estimation based on IWV derived from GNSS observations for VLBI applications
PublicationThermal emission of atmospheric water vapor has a great influence on the calibration of radio astronomical observations at millimeter wavelengths. The phenomenon of an atmospheric water vapor emits noise signal and attenuates astronomical emission. At 22 GHz, integrated water vapor (IWV) obtained from global navigation satellite systems (GNSS) is strictly related to atmospheric opacity (τ0), which is a crucial parameter for data...
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Analysis of Organic Rankine Cycle efficiency and vapor generator heat transfer surface in function of the reduced pressure
PublicationIn the paper presented is analysis of the influence of reduced pressure on efficiency and heat transfer area of vapor generator of Organic Rankine Cycle (ORC) in case of subcritical and supercritical parameters of operation. Compared are two cases of subcritical and supercritical ORC featuring a similar arrangement of heat source supply and heat removal, that is featuring the same temperatures of working fluid before the turbine,...
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On design and analysis of flow characteristics of the last stage of gas-steam turbine
PublicationResearch regarding blade design and analysis of flow have been conducted for over a century. Meanwhile new concepts and design approaches were created and improved. Advancements in information technologies allowed to introduce computational fluid dynamics (CFD) and computational flow mechanics (CFM). Currently a combination of mentioned methods is used for design of turbine blades. These methods enabled us to improve flow efficiency...
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Influence of Material Thickness on the Ductile Fracture of Steel Plates for Shipbuilding
PublicationIn the shipbuilding industry, the risk of brittle fractures is relatively high because some units operate in arctic or subarcticzones and use high thickness (up to 100 mm) steel plates in their structures. This risk is limited by employing certifiedmaterials with a specific impact strength, determined using the Charpy method (for a given design temperature) and byexercising control over the welding processes (technology qualification,...
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The Effects of Pin Profile on HDPE Thermomechanical Phenomena during FSW
PublicationFriction stir welding (FSW) of polymeric materials has recently attracted significant attention. Herein, we present the effect of the tool pin profile on the FSW of high-density polyethylene (HDPE) joints through joint experimental analysis and thermomechanical simulations. For analysis of pin profile effects on the thermomechanical properties of HDPE joints, frustum (FPT), cubic (CPT), and triangular (TPT) pin shapes were selected...
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Influence of the Tool Rotational Speed on Physical and Chemical Properties of Dissimilar Friction-Stir-Welded AA5083/AA6060 Joints
PublicationAluminum alloys have been successfully used in the railroad and automotive industries because of their potential to significantly reduce component weights, and their good mechanical and anti-corrosion properties. Problems with joining aluminum alloys are characterized by low weldability, which influences the need for studies focused on unconventional methods. The environmentally friendly and low-cost friction-stir-welding method...
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Wire Arc Additive Manufactured Mild Steel and Austenitic Stainless Steel Components: Microstructure, Mechanical Properties and Residual Stresses
PublicationWire arc additive manufacturing (WAAM) is an additive manufacturing process based on the arc welding process in which wire is melted by an electric arc and deposited layer by layer. Due to the cost and rate benefits over powder-based additive manufacturing technologies and other alternative heat sources such as laser and electron beams, the process is currently receiving much attention in the industrial production sector. The gas...
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"Raport z wstępnych badań własności stali trudnościeralnej 460HB",. ang "Report on preliminary tests of the properties of wear-resistant steel 460HB"
PublicationMikrostrukturę badanej stali trudnościeralnej 460HB stanowi drobnoziarnisty martenzyt odpuszczony, który jest właściwy dla stali konstrukcyjnych niskowęglowych, niskostopowych ulepszonych cieplnie. W przypadku blach grubych, do których zalicza się badana stal, struktura może ulec zaburzeniu, jeżeli w hutniczym procesie wytwórczym wystąpiła niejednorodność odkształcenia plastycznego i w konsekwencji tworzenie się pasm segregacyjnych,...
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Podstawy i celowość badań i analiz hydroakustycznych pędników okrętowych
PublicationOdpowiednie regulacje i wytyczne projektowe powinny opierać się na lepszym poznaniu wpływu hałasu na ekosystem morski. Problem badawczy polegający na rozpoznaniu źródeł hałasu został rozwiązywany stosunkowo niedawno. Do tej pory zostały wydane zalecenia i normy dotyczące ograniczenia emisji hałasu podwodnego (ang. Underwater Radiated Noise - URN) przez niektóre rodzaje statków, ale relacja między transportem morskim jako grupą...
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Analysis of Methods for Determining Shallow Waterbody Depths Based on Images Taken by Unmanned Aerial Vehicles
PublicationHydrographic surveys enable the acquisition and processing of bathymetric data, which after being plotted onto nautical charts, can help to ensure safety of navigation, monitor changes in the coastal zone, and assess hydro-engineering structure conditions. This study involves the measurement of waterbody depth, identification of the seabed shape and geomorphology, the coastline course, and the location of underwater obstacles....
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Double-stage ORC system based on various temperature waste heat sources of the negative CO2 power plant
PublicationAnalysed is the modification of the thermodynamic cycle with the negative CO2 power plant concept by its combination with the organic Rankine cycle. The analysed power plant operates on a gas produced from the gasification of sewage sludge. The negative emission term comes from the aggregated CO2 balance resulting from the capture of the CO2, while the sewage sludge is one of the inevitable environmental sources of CO2 to be avoided....
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Optimization and Modeling of Cr (VI) Removal from Tannery Wastewater onto Activated Carbon Prepared from Coffee Husk and Sulfuric Acid (H2SO4) as Activating Agent by Using Central Composite Design (CCD)
PublicationThe primary goal of this research is to lower the hexavalent chromium (Cr (VI)) concentration that has occurred from the growth of the tannery industry. As a result, the potential for heavy metal concentration is increasing day by day. Industrial effluent containing Cr (VI) contributes significantly to water pollution. Chromium hexavalent ion (Cr (VI)) in wastewater is extremely hazardous to the environment. It is critical to address...
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Review on robust laser light interaction with titania – Patterning, crystallisation and ablation processes
PublicationTitanium dioxide is regarded as a very promising semiconducting material that is widely applied in many everyday-use products, devices, and processes. In general, those applications can be divided into energy or environmental categories, where a high conversion rate, and energy and power density are of particular interest. Therefore, many efforts are being put towards the elaboration of novel production routes, and improving the...
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Seafloor characterisation using multibeam data: sonar image properties, seabed surface properties and echo properties
PublicationIn the paper, the approach to seafloor characterisation is presented. The multibeam sonars, besides their well verified and widely used applications like high resolution bathymetry and underwater object detection and imaging, are also the promising tool in seafloor characterization and classification, having several advantages over conventional single beam echosounders. The proposed approach relies on the combined, concurrent use...
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Methodology for Processing of 3D Multibeam Sonar Big Data for Comparative Navigation
PublicationAutonomous navigation is an important task for unmanned vehicles operating both on the surface and underwater. A sophisticated solution for autonomous non-global navigational satellite system navigation is comparative (terrain reference) navigation. We present a method for fast processing of 3D multibeam sonar data to make depth area comparable with depth areas from bathymetric electronic navigational charts as source maps during...
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Cement kiln dust
PublicationThe volume of cement production in the world has remained at the level of approxi mately 4.1 billion tons/year. The cement production process is energy intensive and is the world’s leading emitter of carbon dioxide. Therefore, the main activities cement plants are aimed at introducing technologies changes in production of clinkier.The construction industry is responsible for the majority of CO2 emissions to the atmosphere: the...
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P92 steel and inconel 617 alloy welds joint produced using ERNiCr-3 filler with GTAW process: Solidification mechanism, microstructure, mechanical properties and residual stresses
PublicationThe objective of the current study was to analyse the microstructure, mechanical characteristics, and residual stresses of a dissimilar welded joint (DWJ) made of P92 steel and the Inconel alloy 617 (IN617) using the gas tungsten arc welding (GTAW) method. The ERNiCr-3 filler was selected to produce the conventional V groove (VG) and narrow V groove (NVG) butt joint. The filler deficient zones in the weldments, such as the filler...
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Effect of slag coal ash and foamed glass on the mechanical properties of two-stage concrete
PublicationTwo-stage concrete (TSC) is known by various names such as colcrete, Polcrete, preplaced aggregate concrete and prepacked concrete. It is different from traditional concrete in two fundamental ways, namely method of construction and mix proportion. Two-stage concrete (TSC) is defined as firstly, coarse aggregates are placed into the formwork and grout is applied to fill in the between coarse aggregate particles voids. Secondly,...
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Analiza porównawcza metod zwiększania nośności i sztywności stalowych, doczołowych węzłów śrubowych.
PublicationInnowacyjna, w porównaniu z dotychczas stosowanym sposobem, metoda obliczania nośności stalowych węzłów została wdrożona wraz z normami europejskimi. Pozwala ona dokładniej odwzo-rować rzeczywistą pracę poszczególnych części węzła, gdyż wynik obliczeń uzależniony jest od znacznie większej liczby zmiennych. Dzięki postępowi technologicznemu w zakresie metalurgii oraz badaniom naukowym obecnie możliwe jest wzmacnianie połączeń...
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Komputerowo wspomagana analiza elastycznych siłowników elektrostatycznych dla potrzeb implementacji w systemach mechatroniki
PublicationPrzeprowadzone badania naukowe rozpoczęto od szczegółowej analizy układu mechatronicznego dłoni robotycznych, powstałych na przestrzeni ostatnich 40 lat, w celu dokładnego rozpoznania ich głównych wymogów konstrukcyjnych i ograniczeń systemowych. Z uwagi na brak dostępnych narzędzi do symulacji omawianych siłowników, w rozprawie opracowano uniwersalne narzędzie – program do analizy numerycznej. U jego podstawy założono wykorzystanie...