Wyniki wyszukiwania - BazTech

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Multi-criteria evaluation of technological solutions to improve gas distribution station efficiency

Misevičiūtė Violeta, Tučkus Rapolas, Rogoža Artur

Journal of New Technologies in Environmental Science

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2023

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Vol. 7, nr 4

109--120

EN

Due to the global energy crisis, rising energy demand, and climate change, there must be a way to recover energy that is not used for beneficial purposes, reduce primary and final energy consumption, and reduce emissions. The natural gas sector and its transmission networks, including gas distribution stations (GDSs), are an important component of Lithuania's energy sector. Because the gas pressure is reduced by the use of gas pressure regulators (GPR), the energy potential in high pressure gas is not used effectively, the need to heat natural gas is conducted with the use of natural gas boilers, and additional environmental pollution is caused by the use of GDS. The purpose of the study is to analyse GDSs, identify areas where the energy potential is not being exploited and the environment is polluted, and propose reasonable solutions. After reviewing the literature, alternative technological solutions were selected, including turbine expanders, gas preheating systems that were modified from gas boilers to geothermal heat pumps, solar collectors, and photovoltaic solar cells. To evaluate the potential of technological solutions to improve GDS efficiency and reduce emissions, the proposed solutions are analysed according to the multi-criteria analysis that consider solutions proposed from an energy, economic, and environmental perspective. Based on multi-criteria evaluation, the best alternative technological solution for GDS is recommended.

2

Tribological wear of Fe-Al coatings applied by gas detonation spraying

Chrostek Tomasz

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2021

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nr 24(1)

245--256

EN

Comparative tests of gas detonation (GDS) coatings were carried out in order to investigate the influence of spraying parameters on abrasive wear under dry friction conditions. The tests were carried out using the pin-on-disc (PoD) method at room temperature. The microstructure of the coatings was analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDS) methods. The results showed that with certain parameters of the GDS process, the main phase of the produced coatings is the FeAl phase with the participation of thin oxide layers, mainly Al2O3. The tribological tests proved that the coatings sprayed with the shorter barrel of the GDS gun showed higher wear resistance. The coefficient of friction was slightly lower in the case of coatings sprayed with the longer barrel of the GDS gun. During dry friction, oxide layers form on the surface, which act as a solid lubricant. The load applied to the samples during the tests causes shear stresses, thus increasing the wear of the coatings. During friction, the surface of the coatings is subjected to alternating tensile and compressive stresses, which lead to delamination and is the main wear mechanism of the coatings.

3

Structural analysis of Fe-Al coatings applied by gas detonation spraying

Chrostek Tomasz

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2020

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nr 23(3)

221--232

EN

The article analyzes the formation of oxide phases in the structure of intermetallic FeAl coatings applied by gas detonation spraying (GDS). The structural properties of powder charge particles and FeAl coating formed during GDS were determined. The effect of the GDS process on phase changes in FeAl coating applied under controlled conditions was examined. The results indicate that at specific process parameters, FeAl powder particles are strongly oxidized in a hot stream of gases produced during supersonic combustion. Powder particles undergo very strong plastic deformation during the process, and the resulting multiphase coating contains oxide phases that form thin membranes along grain boundaries. The results of structural analyses and microanalyses of chemical composition (SEM/EDS) and phase composition (XRD) indicate that strongly heated FeAl particles undergo surface oxidation during GDS and are transformed into grains (splats) when they collide with a steel substrate. The produced FeAl coating has a multi-layered and multi-phase structure characteristic of the sprayed material, and it contains thin oxide layers, mainly Al2O3.

4

Influence of gas detonation spraying parameters on the geometrical structure of Fe-Al intermetallic protective coatings

Chrostek Tomasz, Bramowicz Mirosław, Rychlik Kazimierz, Wojtkowiak Adam, Senderowski Cezary

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2019

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nr 22(3)

249--262

EN

The paper presents the results of an analysis of the geometrical structure of Fe-Al intermetallic protective coatings sprayed under specified gun detonation spraying (GDS) conditions. Two barrel lengths, two powder injection positions (PIP) at the moment of spark detonation, and two numbers of GDS shots with 6.66 Hz frequency were applied as variable parameters in the GDS process. Surface profile measurements were conducted by contact profilometry with the use of the TOPO-01 system and the Mitutoyo SJ 210 profilometer. The measured parameters were used to analyze surface topography in two-dimensional (2D) and three-dimensional (3D) systems. It was assumed that roughness can be regarded as a non-stationary parameter of variance in surface amplitude which is highly dependent on the sampling rate and spraying distance. Therefore, changes in surface amplitude parameters and functional properties were analyzed across segments with a length (ln) of 1.25, 4 and 12.5 mm. The development of the geometric structure of the surface was analyzed with the RMS (Root Mean Square) fractal method, and the geometric structure of the surface stretched by several orders of magnitude was evaluated based on the correlation between roughness (Rq), segment length (ln) and fractal dimension (D). The RMS method and the calculated fractal dimension (D) supported the characterization of the geometric structure of intermetallic Fe-Al protective coatings subjected to GDS under the specified process conditions based on the roughness profiles of surface segments with a different length (ln).

5

Functional and Fractal Properties of Fe-Al Coatings After Gas Detonation Spraying (GDS)

Chrostek T., Rychlik K., Bramowicz M., Senderowski C.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 4

1993--1999

EN

The paper presents the results and provides an analyse of the geometric structure of Fe-Al protective coatings, gas-treated under specified GDS conditions. The analysis of the surface topography was conducted on the basis of the results obtained from the SEM data. Topographic images were converted to three-dimensional maps, scaling the registered amplitude coordinates of specific gray levels to the relative range of 0÷1. This allowed us to assess the degree of surface development by determining the fractal dimension. At the same time, the generated three-dimensional spectra of the autocorrelation function enabled the researchers to determine the autocorrelation length (Sal) and the degree of anisotropy (Str) of the surfaces, in accordance with ISO 25178. Furthermore, the reconstructed three-dimensional images of the topography allowed us to evaluate the functional properties of the studied surfaces based on the Abbott-Firestone curve (A-F), also known as the bearing area curve. The ordinate describing the height of the profile was replaced by the percentage of surface amplitude in this method, so in effect the shares of the height of the three-dimensional topographic map profiles of various load-bearing properties were determined. In this way, both the relative height of peaks, core and recesses as well as their percentages were subsequently established.

6

Global standards in supply chain management : best practices in consumer goods and retail industry

Popa V.

Polish Journal of Management Studies

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2012

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Vol. 5

172-198

EN

The Global Commerce Initiative (GCI) established the Global Upstream Supply Initiative (GUSI) in order to provide a standard framework for consumer goods manufacturers and their suppliers of ingredients, raw materials and packaging to better integrate across a number of supply chain processes. Without Internal Data Alignment, for example, Global Data Synchronization (GDS) will definitely not improve business performance and will, in fact, magnify the negative impact of poor quality data. What's more, collaborative initiatives such as those included in Efficient Consumer Response (ECR) and Collaborative Planning, Forecasting and Replenishment (CPFR) will not be economically deployable on a wide scale without the consistently accurate and available information that will result from an Internal Data Alignment program. GDS is based on a global network of data pools, or electronic catalogues, which are all inter-operable and compliant with the same business requirements and standards. Interoperability means that a manufacturer can publish a product and partner data on one single Data Pool without having to worry about the fact that customers may select different Data Pools to access the data. Integrated Suppliers is a concept for improving the part of supply chain between manufacturers and the tiers of suppliers of ingredients, raw materials and packaging. By sharing information both parties are able to exercise judgment on costs, quantities and timing of deliveries and productions in order to stream line the production flow and to move to a collaborative relationship.

PL

Global Commerce Initative (GCI) stworzyła Global Upstream Supply Initative (GUSI) aby utworzyć standardowe ramy dla producentów dóbr konsumpcyjnych i ich dostawców surowców, materiałów i opakowań, w celu lepszej integracji procesów zachodzących w łańcuchu dostaw. Bez wewnętrznego dopasowania danych, Globalna Synchronizacja Danych (GSD) nie przyczyni się do poprawy wydajności firmy, w rzeczywistości zwiększy negatywny wpływ informacji charakteryzujących się złą jakością. Co więcej, wspólne inicjatywy takie jak Efficient Consumer Response (ECR) czy Collaborative Planning, Forecasting and Replenishment (CPFR) nie będą miały przełożenia ekonomicznego, gdyż wpływ na to będzie miał brak dokładnych i dostępnych informacji które są uzyskiwane z programu wewnętrznego dopasowania danych. Program wewnętrznego dopasowania danych opiera się na globalnej sieci danych, katalogach elektronicznych, które są w szczególności Interoperacyjne i działają zgodnie z tymi samymi wymaganiami i standardami biznesu. Interoperacyjność oznacza że producent może opublikować informacje o produkcie wraz z partnerami w jednej puli danych, bez konieczności martwienia się tym że klienci mogą wybrać inną pulę danych aby uzyskać dostęp do tych informacji. Koncepcja zintegrowanych dostawców dotyczy poprawy części łańcucha dostaw między producentami i ich dostawcami surowców, materiałów i opakowań. Dzięki dzieleniu się informacjami, obie strony są w stanie wyegzekwować postanowienia w sprawie cen, ilości, terminów dostaw i produkcji w celu uzyskania strumieniowego przepływu produkcji i nawiązać relacje współpracy.