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Tytuł:
Exergetic Analysis For A Complete Node Of Fluidised-Bed Drying Of Poppy Seeds
Autorzy:
Skoneczna-Łuczków, J.
Ciesielczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/185488.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fluidised drying
efficiency
exergy
poppy seed
suszenia fluidalnego
wydajność
egzergia
Opis:
The article presents an experimental-theoretical analysis of fluidised-bed drying of poppy seeds directed on minimisation of energy. The analysis was performed for a complete drying node incorporating a heat exchanger and a fan. Two complementary factors were used in the exergetic evaluation: exergy efficiency and unit consumption of exergy. An analysis of drying in stationary bed was carried out for comparison purposes. Results of the exergetic analysis can become a basis for innovative works focused on decreasing energy consumption of a technological node being analysed, e.g. by the use of recirculation of fluidising-drying medium.
Źródło:
Chemical and Process Engineering; 2015, 36, 4; 437-447
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Design Features of Compressor Casing Treatment
Badanie charakterystyk projektowych obróbki obudowy kompresora
Autorzy:
Nezym, V
Powiązania:
https://bibliotekanauki.pl/articles/950694.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
axial compressor
stall range
efficiency
casing treatment
grooves
kompresor
rowki obwodowe
wydajność
Opis:
Casing treatment in the form of circumferential grooves over a rotor blade tips is used for improvement of an axial compressor performance. Usually, these grooves extend compressor’s stall range (stable operational range) but decrease its efficiency. In the paper, there are presented main results of investigations on grooves that influence positively efficiency of compressor. There were investigated traditional (typical) and newly developed groove configurations. Certain grooves combine increase in efficiency with extension in stall range.
Obróbka obudowy kompresora, polegajacą na wykonaniu obwodowych rowków ponad szczytem łopaty wirnika, jest stosowana dla poprawy własciwosci roboczych kompresora. Zwykle rowki takie zwiekszaja zakres przeciagania kompresora (zakres stabilnego działania), ale pogarszaja sprawność. W artykule zaprezentowano główne wyniki badan nad rowkami, które wpływaja pozytywnie na sprawnosc kompresora. Badano zarówno tradycyjne (typowe) konfiguracje rowków, jak i konfiguracje ostatnio opracowane. Niektóre z nich zapewniają zarówno wzrost sprawności jak zakresu przeciągania.
Źródło:
Archive of Mechanical Engineering; 2014, LXI, 1; 153-161
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of external cooling system on the performance of supercritical steam turbine cycles
Autorzy:
Kosman, W.
Powiązania:
https://bibliotekanauki.pl/articles/240233.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
para nadkrytyczna
schładzanie
turbina parowa
wydajność
cooling
efficiency
steam turbine
supercritical steam
Opis:
The problem presented in this paper refers to the concepts applied to the design of supercritical steam turbines. The issue under the investigation is the presence of a cooling system. Cooling systems aim to protect the main components of the turbines against overheating. However the cooling flows mix with the main flow and modify the expansion line in the steam path. This affects the expansion process in the turbine and changes the performance when compared to the uncooled turbine. The analysis described here investigates the range of the influence of the cooling system on the turbine cycle. This influence is measured mainly through the change of the power generation efficiency. The paper explains the approach towards the assessment of the cooling effects and presents results of the modeling for three supercritical steam cycles.
Źródło:
Archives of Thermodynamics; 2010, 31, 3; 131-144
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical thermodynamic optimization of supercritical coal fired power plant with support of IPSEpro software
Autorzy:
Elsner, W.
Kowalczyk, Ł.
Marek, M.
Powiązania:
https://bibliotekanauki.pl/articles/240118.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optymalizacja termodynamiczna
siłownia nadkrytyczna
symulacja
wydajność
efficiency
simulation
supercritical power plant
thermodynamic optimization
Opis:
The paper presents a thermodynamic optimization of supercritical coal fired power plant. The aim of the study was to optimize part of the thermal cycle consisted of high-pressure turbine and two chosen high-pressure feed water heaters. Calculations were carried out using IPSEpro software combined with MATLAB, where thermal efficiency and gross power generation efficiency were chosen as objective functions. It was shown that the optimization with newly developed framework is sufficiently precise and its main advantage is the reduction of computation time on comparison to the classical method. The calculations have shown the tendency of the increase in efficiency, with the rise of a number of function variables.
Źródło:
Archives of Thermodynamics; 2012, 33, 3; 101-110
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filling model for the working multi-disc biomass grain grinding unit
Model wypełnienia zespołu roboczego, wielotarczowego rozdrabniacza ziaren biomasy
Autorzy:
Tomporowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/139718.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rozdrabnianie
rozdrabniacz wielotarczowy ziaren biomasy
biomasa
wydajność
grinding
multidisc biomass grain grinding unit
biomass
efficiency
Opis:
Efficiency, functionality and performance of the grain grinding process are significantly influenced by phenomena that are difficult to describe and occur in the working area of the grinder. In a machine-based, multi-disc grinding of grain biomaterials, the design of the quasi-cutting unit, volumes, sections of transport/grinding holes, their motion and the design features of the discs (the grinding unit) must facilitate the functions of grinding in the inter-hole space (with minimum energy-consumption of the process and maximum efficiency) and minimising undesirable phenomena related to mixing and transport. The pre-requisite for optimisation of the quasi-cutting unit design is a mathematical model. Among many aspects of the problem, this study describes a sample procedure resulting in a filling model for a biomass grain quasi-cutting unit including an initial verification of the same under conditions of the evaluation of maize and triticale grain grinding efficiency, using an innovative multi-hole 5-disc and 7-disc grinder.
Istotny wpływ na wydajność, funkcjonalność i sprawność procesu rozdrabniania ziaren zbóż mają trudne do opisania zjawiska, zachodzące w przestrzeni roboczej rozdrabniacza. W maszynowym wielotarczowym rozdrabnianiu biomateriałów ziarnistych, należy tak dobrać konstrukcję zespołu quasi-ścinającego, objętości, przekroje otworów transportowo-rozdrabniających, ich ruch i cechy konstrukcyjne tarcz (zespołu rozdrabniającego), aby zostały zrealizowane założone funkcje: rozdrabnianie w przestrzeni międzyotworowej (przy minimalnej energochłonności procesu i maksymalnej wydajności) oraz minimalizacja zjawisk niepożądanych związanych z mieszaniem i transportem. Warunkiem optymalizacji konstrukcji zespołu quasi-ścinającego jest model matematyczny. Wśród wielu warstw problemu, w pracy przedstawiono przykładowe postępowanie, prowadzące do modelu wypełnienia zespołu quasi-ścinającego ziarna biomasy wraz z wstępną jego weryfikacją w warunkach badania wydajności rozdrabniania ziaren kukurydzy i pszenżyta na innowacyjnym rozdrabniaczu wielootworowym, 5-cio i 7-mio tarczowym.
Źródło:
Archive of Mechanical Engineering; 2012, LIX, 2; 155-174
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical performance attributes of Thai automotive supply chains
Autorzy:
Satayapaisal, A.
Takala, J.
Wiriyacosol, S.
Chansa-ngavej, C.
Powiązania:
https://bibliotekanauki.pl/articles/407337.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
przemysł motoryzacyjny
łańcuch dostaw
wydajność
supply chain performance
performance measurement
critical factor index
Thai automotive industry
Opis:
The Thai automotive industry has been ranked one of the top ten of the Thai export products for several years. Effective supply chain management has become a key strategy for the industry to stay competitive. Performance measurement has thus become a crucial issue in automotive supply chains. The purpose of the research is to gain insight into the relevant performance attributes that affect the automotive supply chains. The critical factor indexes (CFIs) are calculated in order to determine which of the performance attributes are considered to be the strength and which ones need to be specially focused, so that precautions could be made in developing the performance measurement system. Based on the CFIs, companies in Thai automotive supply chains can support their decision making under scarce resources with valid data. A set of questionnaires with different performance attributes is used comprising of two separate parts, one intended for the first tier supplier companies and the other for the automakers. Each performance attribute in the questionnaires is assessed on how important the company sees them from their perspective, how well the tasks measured by each performance attribute have been carried out in their companies, how they see themselves compared to their competitors, and how they see each performance attribute developing compared to the situation 1 to 2 years before. The results provide a guideline to the companies in Thai automotive supply chains to measure the right performance attributes for making the right decision in a competitive environment.
Źródło:
Management and Production Engineering Review; 2012, 3, 2; 36-48
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The method for increasing the efficiency of equipment’s maintenance in railway traction power supply systems
Autorzy:
Matusevych, O.
Kuznetsov, V.
Sychenko, V.
Powiązania:
https://bibliotekanauki.pl/articles/223664.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
railway traction
power systems
efficiency
maintenance equipments
traction substation
trakcja kolejowa
systemy zasilania
wydajność
konserwacja urządzeń
Opis:
Purpose. To develop the method for increasing the efficiency of the equipment’s maintenance and repair system, ensuring necessary level of operational reliability of the equipment, safety and reliability of the electric equipment with minimal expenses on operation. Relevance. Aging of the power equipment in railway power supply systems sharply raised a need for assessment of its states and degree of risk for operation outside rated service life. In critical conditions of technological processes and operational modes of the railways it is necessary to increase the equipment’s operational reliability. The scheduled maintenance and repair system whose main technical and economic criterion is the minimum of equipment’s downtimes on the basis of a rigid regulation of repair cycles, in the conditions of market regulations in the field of repair in many cases does not provide the optimal decisions due to insufficient financing. The solution of this problem is possible by improvement of the maintenance and repair system. Under these conditions the main direction for supporting the operational reliability of power electric equipment on TS is a development of the modern methods based on individual supervision over real changes of technical condition of power equipment. Scientific novelty. In this article the authors proposed an integrated approach, on the basis of which can be developed the effective maintenance and repair system for traction power supply systems. Proposed approach allowed to react quickly to changes of service conditions on traction substations, to control the technical condition of power electric equipment under the conditions of uncertainty, to establish interrelation between quality of service and operational reliability of the equipment, to choose a service strategy on traction substations. Practical importance. The validity of the developed method was confirmed by the results of calculations and practically by choosing the optimal maintenance's option for transformer TDTN-25000/150-70 U1 (ТДТН-25000/150-70 У1) on traction power supply substation.
Źródło:
Archives of Transport; 2018, 47, 3; 39-47
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of different organic fluids on performances of binary slag washing water power plants
Autorzy:
Li, Z.
Liu, Y.
Dong, P.
Zhang, Y.
Xiao, S.
Powiązania:
https://bibliotekanauki.pl/articles/240438.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
slag washing water
efficiency
organic fluids
binary power cycle
wydajność
płyn organiczny
podwójny cykl zasilania
Opis:
In this paper, 3 typical organic fluids were selected as working fluids for a sample slag washing water binary power plants. In this system, the working fluids obtain the thermal energy from slag washing water sources. Thus, it plays a significant role on the cycle performance to select the suitable working fluid. Energy and exergy efficiencies of 3 typical organic fluids were calculated. Dry type fluids (i.e., R227ea) showed higher energy and exergy efficiencies. Conversely, wet fluids (i.e., R143a and R290) indicated lower energy and exergy efficiencies, respectively.
Źródło:
Archives of Thermodynamics; 2017, 38, 3; 49-62
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The literature review of Supply Chain performance measurement in the manufacturing industry
Autorzy:
Sillanpää, I.
Kess, P.
Powiązania:
https://bibliotekanauki.pl/articles/407345.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
przemysł przetwórczy
łańcuch dostaw
wydajność
zarządzanie
supply chain
performance measurement
supply chain management
manufacturing industry
strategy
operations
Opis:
The article addresses the issues of Supply Chain (SC) performance measurement - the process of qualifying the efficiency and effectiveness of the supply chain. The aim of this study is to present a supply chain measurement approaches for manufacturing industry. The research is based on a review of the current understanding of supply chain management and literature related to supply chain performance measurement. This study creates a framework for supply chain measurement by presenting the main theory framework of supply chain performance measurement. It is stated that supply chain performance measurement is extremely important in developing supply chain. The measurement framework in this study offers guidelines for measuring the supply chain in manufacturing industry.
Źródło:
Management and Production Engineering Review; 2012, 3, 2; 79-88
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resource-saving technologies of railway transportation of grain freights for export
Autorzy:
Kozachenko, D.
Vernigora, R.
Kuznetsov, V.
Lahvinova, N.
Rustamov, R.
Papahov, A.
Powiązania:
https://bibliotekanauki.pl/articles/223476.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rail transportation
grain export
efficiency
consignor routing
concentration of loading
cluster analysis
transport kolejowy
eksport zboża
wydajność
Opis:
The research objective is to increase the efficiency of export railway transportation of grain freights in Ukraine by the introduction of consignor routing, a concentration of loading of grain on junction elevators and the organization of the movement of grain routes according to the schedule. According to the researchers in USA and EU, one of the effective directions for decreasing the expenses in a logistic chain of grain delivery to ports is consignor routing of railway transportation. Consignor routing of transportations of grain freights provides a concentration of their loading at junctions. The choice of junctions is proposed to be carried out on the basis of methods of the cluster analysis. For formation of regions for a concentration of grain loading the theory of sets and multicriteria optimization are used. As a result, on the basis of the modified simplex method are chosen 24 regions of possible concentration of grain loading that cover 70 stations on Ukrainian railways providing 7,5 million t consignor routing for grain in a year with minimal additional expenses. The assessment of the efficiency of railway transportation routing of grain freights is calculated with use of the developed simulation model. Researches showed that application of consignor routing allows to reduce a turn-round cycle for grain wagon in a logistic chain of deliveries up to 27%, and application of the schedule for consignor routes allows to reduce a turn-round cycle up to 62%, in comparison with transportation by car loading. Thus, as showed the calculations executed for one of the directions of grain transportation for export, the necessary operation park of grain-carrier wagons is reduced twice, thereby allowing to cut logistic expenses on a delivery of the Ukrainian grain through seaports to the world markets.
Źródło:
Archives of Transport; 2018, 45, 1; 63-74
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parallel anisotropic mesh refinement with dynamic load balancing for transonic flow simulations
Autorzy:
Gepner, S.
Majewski, J.
Rokicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/202281.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
parallel CFD
adaptation
dynamic load balancing
mesh refinement
parallel efficiency
CFD
dostosowanie
dynamiczne obciążenia
wydajność
modele siatkowe
Opis:
The present paper discusses an effective adaptive methods suited for use in parallel environment. An in-house, parallel flow solver based on the residual distribution method is used for the solution of flow problems. Simulation is parallelized based on the domain decomposition approach. Adaptive changes to the mesh are achieved by two distinctive techniques. Mesh refinement is performed by dividing element edges and a subsequent application of pre defined splitting templates. Mesh regularization and derefinement is achieved through topology conserving node movement (r-adaptivity). Parallel implementations of an adaptive use the dynamic load balancing technique.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 2; 195-207
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The simultaneous effect of the operating temperature and solar radiation on the efficiency of photovoltaic panels
Jednoczesny wpływ temperatury pracy oraz promieniowania słonecznego na wydajność ogniw fotowoltaicznych
Autorzy:
Heim, D.
Powiązania:
https://bibliotekanauki.pl/articles/231179.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
temperatura pracy
promieniowanie słoneczne
wydajność
ogniwo fotowoltaiczne
symulacja
operating temperature
solar radiation
efficiency
photovoltaic cell
simulation
Opis:
The proper designing of PV systems requires the use of advanced building energy simulation techniques. It allows to design the best position of the PV array, as well as the right quantity of produced energy in different cases. On the other hand the PV efficiency is not only a constant value but changes according to temperature and solar radiation. This paper is devoted to estimate the simultaneous effect of both weather factors on PV efficiency. The task was achieved by numerical simulation and ESP-r software. Computer simulations have been carried out with the use of the Typical Meteorological Year data for Warsaw (52°N 21°E). The greatest influence of temperature on the efficiency of solar energy conversion was observed for crystalline silicon cells. The influence of the boundary conditions assumed in the study is ignored for amorphous silicon cells in the summer period and regardless of the material type in the winter period.
Fotowoltaika jest najbardziej popularnym systemem konwersji energii promieniowania słonecznego na prąd elektryczny. Energia elektryczna produkowana przez systemy PV może być spożytkowana na potrzeby danego użytkownika, zaś jej ewentualna nadwyżka sprzedana bezpośrednio do sieci elektroenergetycznej. Prawidłowe zaprojektowanie systemu PV wymaga użycia zaawansowanych technik symulacji energetycznych budynków. Pozwalają one na wybór najlepszego usytuowania oraz dają prawidłową informacje na temat możliwej do uzyskania ilości energii. Z innej jednak strony, systemy PV nie posiadają stałej wydajności a jest ona zależna od temperatury pracy oraz docierającego do ogniwa promieniowania słonecznego. Wpływ temperatury na wydajność ogniw PV jest dobrze znana z literatury przedmiotu. Artykuł ten ma natomiast na celu oszacowanie jednoczesnego wpływu temperatury i promieniowania na wydajność ogniw. Główny cel osiągnięty został poprzez obliczenia symulacyjne z zastosowaniem zaawansowanego narzędzia obliczeniowego, programu ESP-r. Obliczenia przeprowadzono dla danych meteorologicznych Warszawy. Uwzględniono zarówno promieniowanie bezpośrednie jak i rozproszone. Wyznaczono ilość wyprodukowanej energii dla wybranych tygodni oraz wpływ temperatury i promieniowania słonecznego na wydajność ogniw PV. Największy wpływ temperatury na wydajność konwersji energii słonecznej zaobserwowano latem dla ogniw wykonanych z krzemu krystalicznego. Dla ogniw wykonanych z krzemu amorficznego w okresie lata oraz bez względu na rodzaj materiału w okresie zimy wpływ temperatury dla przyjętych warunków obliczeniowych był pomijany. Istotny natomiast był wpływ zmieniającego się natężenia promieniowania, którego spadek znacznie obniża zdolność konwersji fotoelektrycznej zarówno w okresie zimy jak i lata.
Źródło:
Archives of Civil Engineering; 2011, 57, 3; 261-274
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Novel Extraction Process Of Rare Earth Elements From NdFeB Powders Via Alkaline Treatment
Nowy sposób ekstrakcji pierwiastków ziem rzadkich z proszków NdFeB w roztworach alkalicznych
Autorzy:
Chung, K. W.
Kim, C.-J.
Yoon, H.-S.
Powiązania:
https://bibliotekanauki.pl/articles/355324.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
recycling
NdFeB magnet
alkaline treatment
leaching
selective leaching efficiency
recykling
magnes neodymowy
obróbka alkaliczna
ługowanie
wydajność
Opis:
The alkaline treatment of NdFeB powders in NaOH solution at various equivalent amounts of NaOH at 100°C was performed. The resultant powders were then leached in 0.5M H2SO4 solution at 25°C for 2 minutes. At 5 equivalents of NaOH, neodymium in NdFeB powders was partially transformed to neodymium hydroxide. The transformation of neodymium to neodymium hydroxide actually occurred at 10 equivalents of NaOH and was facilitated by increasing the equivalent of NaOH from 10 to 30. In addition, iron was partially transformed to magnetite during the alkaline treatment, which was also promoted at a higher equivalent of NaOH. The leaching yield of neodymium from alkaline-treated powders was increased with an increasing equivalent of NaOH up to 10; however, it slightly decreased with the equivalent NaOH of over 10. The leaching yield of iron was inversely proportional to that of rare earth elements. NdFeB powders treated at 10 equivalents of NaOH showed a maximum leaching yield of neodymium and dysprosium of 91.6% and 94.6%, respectively, and the lowest leaching yield of iron of 24.2%, resulting in the highest selective leaching efficiency of 69.4%.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1301-1305
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of waste heat energy sources of a conventional steam propulsion plant of an LNG carrier
Autorzy:
Adamkiewicz, Andrzej
Grzesiak, Szymon
Powiązania:
https://bibliotekanauki.pl/articles/240754.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
waste heat energy
steam turbine
efficiency
propulsion plant
energia cieplna odpadowa
silnik parowy
wydajność
instalacja napędowa
Opis:
This paper presents the origins of marine steam turbine application on liquefied natural gas carriers. An analysis of alternative propulsion plant trends has been made. The more efficient ones with marine diesel engines gradually began to replace the less efficient plants. However, because of many advantages of the steam turbine, further development research is in progress in order to achieve comparable thermal efficiency. Research has been carried out in order to achieve higher thermal efficiency throughout increasing operational parameters of superheated steam before the turbine unit; improving its efficiency to bring it nearer to the ideal Carnot cycle by applying a reheating system of steam and multi stage regenerative boiler feed water heating. Furthermore, heat losses of the system are reduced by: improving the design of turbine blades, application of turbine casing and bearing cooling, as well as reduction in steam flow resistance in pipe work and maneuvering valves. The article identifies waste energy sources using the energy balance of a steam turbine propulsion plant applied on the liquefied natural gas carrier which was made out basing on results of a passive operation experiment, using the measured and calculated values from behavioral equations for the zero-dimensional model. Thermodynamic functions of state of waste heat fluxes have been identified in terms of their capability to be converted into usable energy fluxes. Thus, new ways of increasing the efficiency of energy conversion of a steam turbine propulsion plant have been addressed.
Źródło:
Archives of Thermodynamics; 2019, 40, 3; 195-210
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The performance of tramway service from the users viewpoint: A comparative analysis between two Moroccan cities
Autorzy:
Zehmed, Karim
Jawab, Fouad
Powiązania:
https://bibliotekanauki.pl/articles/2067395.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
tramway service
performance
perceived quality
satisfaction
Morocco
comparative analysis
komunikacja tramwajowa
wydajność
postrzegana jakość
Maroko
analiza porównawcza
Opis:
The Moroccan government has recently promoted sustainable public transport projects such as tramway services namely in the two largest cities of country, Casablanca and Rabat-Salé. Since its launch, the tramway service is increasingly present in citizens' daily lives in both cities. To maintain its attractiveness, operators and transport authorities should examine the performance of tramway service from user’s point of view. That is, an in-depth understanding of how passengers perceive service quality and what make them satisfied. The purpose of this study is to compare the performance of tramway service in the two cities based on the opinions of a sample size of 613 and 435 individuals in each city. The outcome of this peer comparison allows to determine the strengths and weaknesses of provided service and identify priorities for improvement in each city. Regarding the methodology, we adopted a two-step approach to achieve our research purpose. The first stage intends to compare users' perceptions regarding Service Quality Attributes (SQAs) and overall satisfaction and to identify any significant differences between the two cities. To this end, we applied, in the first stage, a student t-test of two independent samples. The second stage employs an ordered probit regression model to identify the most important SQA; i.e., which most influence the overall satisfaction, and improvements priorities for the current service tramway. The results showed that, in average, passengers found service quality as good and are satisfied with tramway service in both cities. Tram vehicles’ is the best appreciated service attribute in both cities while Comfort in Rabat-Salé and Lines’ connectivity in Casablanca are the least appreciated. Moreover, the service performance of Rabat-Salé tramway exceeds that of Casablanca tramway in terms of service Availability, service Reliability, Fares level, Tram vehicle, Drivers’ competence, Lines’ connectivity, and overall satisfaction. On the other hand, we found that among top six important attributes, Reliability and Administrators should be prioritized for improvement in Casablanca; and staff, Lines, Comfort, and Administrators in Rabat-Salé. Results showed that improvements in all these service aspects would increase significantly overall user’s satisfaction.
Źródło:
Archives of Transport; 2021, 60, 4; 7--21
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 24

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