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Tytuł:
Conditions of economic efficiency of industrial enterprises in the enterprise life cycle stages
Uwarunkowania efektywności ekonomicznej przedsiębiorstw przemysłowych w fazach cyklu życia przedsiębiorstwa
Autorzy:
Żurakowska-Sawa, J.
Powiązania:
https://bibliotekanauki.pl/articles/2051458.pdf
Data publikacji:
2019
Wydawca:
Akademia Bialska Nauk Stosowanych im. Jana Pawła II w Białej Podlaskiej
Tematy:
industrial enterprise
enterprise condition
economic efficiency
enterprise
life cycle
conditioning
macroeconomic situation
Opis:
Subject and purpose of work: The purpose of the study is to determine the variables determining the level of synthetic measure of economic efficiency in listed companies of the industry sector as part of their enterprise life cycle. Materials and methods: The article uses data from annual unitary financial statements of industrial enterprises according to the classification of the Warsaw Stock Exchange and data describing the macroeconomic situation of the state economy. The research period covered the years 1999-2012. In order to examine which factors determine the level of economic efficiency at each stage of the life cycle of enterprises, estimation of econometric models was carried out. Results: In the models obtained for companies in the growth and maturity stage, statistically significant determinants were obtained only in the field of internal factors. In the models estimated for companies in the stages of launch, shake-out and decline, statistically significant conditions were identified, both in terms of external factors and in the area of internal factors. Conclusions: A comprehensive assessment of the conditions for the level of economic efficiency of enterprises should take into account both factors dependent on the enterprise (microeconomic) as well as those determined by the environment (macroeconomic) and beyond its control. It is therefore necessary for managers of enterprises to have extensive and up-todate knowledge of factors and conditions that are significant in shaping the level of economic efficiency.
Źródło:
Economic and Regional Studies; 2019, 12, 3; 287-301
2083-3725
2451-182X
Pojawia się w:
Economic and Regional Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving the effective efficiency of a spark ignition engine through the use of a fully independent valve control system
Autorzy:
Żmudka, Zbigniew
Postrzednik, Stefan
Powiązania:
https://bibliotekanauki.pl/articles/2097609.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
SI engine
theoretical cycle
charge exchange
engine efficiency
independent valve control
silnik ZI
cykl teoretyczny
wymiana ładunku
sprawność silnika
niezależne sterowanie zaworami
Opis:
The article presents theoretical research of the proposed system of fully independent valve control (FIVC) of the SI engine. The analysis included controlling the movement of the intake valves, which results in adjusting the mass of the fresh charge to the current engine load, as well as the movement of the exhaust valves, where the main aim is to keep the rest of the exhaust gas in the cylinder, i.e. implementation of internal EGR. The open theoretical Seiliger-Sabathe cycle with the classic throttle regulation of load is the reference cycle for assessment of benefits and study of the effectiveness of obtaining work as a result of application of the FIVC system. A comparative analysis of the effectiveness of application of the proposed system was carried out based on the selected quantities: fuel dose, cycle work, relative work of charge exchange and cycle efficiency. The use of the FIVC to regulate the SI engine load makes it possible to eliminate the throttle and thus reduce the charge exchange work, especially in the partial load range. And this then leads to an increase in internal and effective work, which in turn results in an increase in the effective energy efficiency of an engine operation.
Źródło:
Combustion Engines; 2021, 60, 4; 30--35
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late intake valve closing as a way of the throttleless control of SI engine load
Autorzy:
Żmudka, Z.
Postrzednik, S.
Przybyła, G.
Powiązania:
https://bibliotekanauki.pl/articles/247952.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
spark-ignition engine
variable valve actuation
late intake valve closing
open Atkinson-Miller cycle
charge exchange process
cycle efficiency
Opis:
The paper tackles the problems connected with the charge exchange in internal combustion engines. The theoretical analysis of the charge exchange process in the SI engine has been presented. The realization of the charge exchange process is connected with the necessity of overcoming the flow resistances, then with the necessity of doing a work, so-called the charge exchange work. The flow resistance caused by throttling valve is especially high at the partial load running of an engine. A system with independent, late intake valve closing has been analysed. The use of the analysed system to governing of an engine load will enable to eliminate a throttling valve from inlet system and reduce the charge exchange work, especially within the range of partial load. The decrease of the charge exchange work leads to an increase of the internal and effective works, which results in an increase of the effective efficiency of the spark ignition engine. The open, theoretical Atkinson-Miller cycle has been assumed as a model of processes proceeding in the engine with variable intake valve actuation. The system has been analysed individually and comparatively with open Seiliger-Sabathe cycle, which is theoretical cycle for the classic throttle governing of engine load. Benefits resulting from application of the system with late intake valve closing have been assessed on the basis of the selected parameters: a fuel dose, a cycle work, relative charge exchange work and cycle efficiency.
Źródło:
Journal of KONES; 2012, 19, 1; 491-499
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Throttleless control of SI engine load by fully flexible inlet valve actuation system
Autorzy:
Żmudka, Z.
Postrzednik, S.
Przybyła, G.
Powiązania:
https://bibliotekanauki.pl/articles/133835.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
spark-ignition engine
variable valve actuation
early inlet valve closure
theoretical cycle
charge exchange process
cycle efficiency
silnik o zapłonie iskrowym
cykl teoretyczny
wydajność cyklu
Opis:
A system with independent, early inlet valve closure (EIVC) has been analysed. The open, theoretical cycle has been assumed as a model of processes proceeding in the engine with variable inlet valve actuation. The system has been analysed individually and comparatively with open Seiliger-Sabathe cycle which is theoretical cycle for the classic throttle governing of engine load. The influence of EIVC on fuel economy, cycle work, relative charge exchange work and cycle efficiency has been theoretically investigated. The use of the analysed system to governing of an engine load will enable to eliminate a throttling valve from inlet system and reduce the charge exchange work, especially within the range of partial load. The decrease of the charge exchange work leads to an increase of the internal and effective works, which results in an increase of the effective efficiency of the spark ignition engine.
Źródło:
Combustion Engines; 2016, 55, 1; 44-48
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena sprawności cyklu roboczego pojazdu do usuwania odpadów z pojemników na podstawie danych eksploatacyjnych
Working cycle efficiency evaluation of Refuse Collection Vehicle based on exploitation data
Autorzy:
Wysocki, O.
Zajdziński, T.
Czyżewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/309906.pdf
Data publikacji:
2018
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
śmieciarka
zużycie energii
zużycie paliwa
efektywność cyklu roboczego
pojazd do usuwania odpadów z pojemników
energy consumption
fuel consumption
working cycle efficiency
waste collection vehicle
refuse collection vehicle
Opis:
W artykule przedstawiona została metoda oceny sprawności cyklu roboczego śmieciarki. Wykorzystując dane eksploatacyjne wyznaczono dwa reprezentatywne cykle i na ich podstawie obliczono zarówno sprawność całego cyklu, jak i jego poszczególnych faz. Porównano wartości energii potrzebnej do opróżniania pojemników, energii do zagęszczania odpadów oraz energii z paliwa. Przedstawiono przebiegi mierzonych i obliczonych wartości w czasie obrazując w ten sposób rzeczywiste przebieg parametrów układu hydraulicznego i obciążenia silnika spalinowego poczas rzeczywistej pracy pojazdu.
In this paper a method of efficiency evaluation of working cycle of Refuse Collection Vehicle is presented. Using real world data, two representative working cycles were analyzed. Total cycle efficiency was calculated, as well as the efficiency of particular cycle phases. Then, energy needed to collect, energy needed to compact the waste and energy from fuel were compared. Measured and calculated values vs time were shown on the diagrams illustrating hydraulic system parameters and the real load applied to the chassis combustion engine.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2018, 19, 9; 188-192
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simple tank-to-wheels analysis tool for future vehicle powertrains
Autorzy:
Vavra, J.
Macek, J.
Takats, M.
Cerovsky, Z.
Powiązania:
https://bibliotekanauki.pl/articles/243520.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
vehicle powertrain efficiency
internal combustion engine
fuel cells
simulation
driving cycle
Opis:
The future powertrains have to be properly assessed in early stages of vehicle design using simple and fast but reliable tools. The aim of the paper is to develop a simulation tool suitable for any of current transient cycles for finding of upper limits of tank-to-wheel efficiencies of recent or future vehicle powertrains in different concepts of vehicles to assess their potential, to find gaps between the state-of-the-art and to find ways to bridge them. The simulation philosophy and procedure may be described in the following steps. The testing cycle power demands on vehicle movement are analyzed and the optimum operation efficiency of a primary mover (engine, fuel cell, electric motor) is assigned to them. Dynamic torques at powertrain are accounted for. Speed, speed slip (driving machine/wheels) and load dependencies of transmission efficiency are simulated by simple models. In the case of a hybrid solution, charging and discharging efficiencies of energy accumulators and additional losses (e.g., in converters and inverters) are considered. The clear modular structure of the simulation tool enables the researcher to amend new features of powertrain components. The links to more detailed simulation tools are prepared. The simulation tool is described by regression and algebraic models (based on the results of higher level simulation tools) in a way giving immediate response during sensitivity analysis. The examples of tool calibration for different powertrains and results comparing powertrain potential are presented for lower medium class passenger car. The current simulation tool creates a useful link between detailed and accurate but CPU time demanding 1-D tools, based on partial differential equations, and rules-of-thumb, used sometimes for initial potential assessments. Moreover, the described tool does not require detailed data on the powertrain during early stage of design but it shows its potential for further development.
Źródło:
Journal of KONES; 2008, 15, 3; 525-534
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effective efficiency in car engine as a function of reduction ratio during energy-aying speed control
Autorzy:
Ubysz, A.
Powiązania:
https://bibliotekanauki.pl/articles/246247.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
power efficiency
driving cycle
effective engine efficiency
B. S. F. C.
load torque
Opis:
The study examines the effect of transformation ratio in power transmission system on engine efficiency as a function of passenger vehicle velocity (m = 1400 kg) with energy-saving vehicle drive. The study also presents working range in driving phases for energy-saving speed control up to 120 km/h for a simplified overall engine performance map for SI engine. Understanding of the presented considerations can be facilitated through relating with advantages of application of non-driving phases in low engine load phases (field 4 in overall engine performance map). Working points of SI engines in engine performance maps were divided in terms of energy-saving vehicle speed control into 4 ranges. Zone l is the most economic whereas zones 3 and 4 are the least energy-saving, which was also discussed by the author in other works. The study presents the location of engine working points in overall engine performance map during energy-saving vehicle speed control within the range of 30-120 km/h using two different 6-gear gearboxes. Working range for CI engine in simplified overall characteristics in truck, the impact of speed control upon fuel consumption in real traffic conditions, sum and difference characteristics of components of drive engine unitary power, area of maximal rise in overall engine efficiency after reduction of rotational speed, simplified SI engine performance maps, covering with economic zone of working point in energy-saving drive of vehicles are presented in the paper.
Źródło:
Journal of KONES; 2010, 17, 4; 547-552
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The energy - efficient two - phase driving cycle (eta n greather than 1) can efficiency eta n in vehicles be higher than 1.0 ?
Autorzy:
Ubysz, A.
Powiązania:
https://bibliotekanauki.pl/articles/242928.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
efficiency
driving cycle
overall engine efficiency
Opis:
The study presents an important part of fourth chapter of the monograph 'Energy Consumption in Relation to Fuel Efficiency Under Complex Driving Conditions' (2003) concerning opportunities to improve vehicle drive efficiency through application, during one phase of driving in neutral in two-phase driving cycle. Theoretical simulation of total energy consumption in vehicles with SI engine provided explanation of a relatively low fuel efficiency observed under real driving conditions in serial cars [1]. The study cites the original method of calculations developed by the author in order to calculate the efficiency of vehicle power unit in two-phase driving cycle assuming that one of the phases might be non-driving. The calculations were made for complex driving conditions, i.e. simulated changes with predefined steps for road slope (-3.5o to 3.5o), acceleration (-0.36-0.36 m/s2) and average speed (60-140 kmph) for a distance of 2x500 m. The results of calculation variants for each type of a drive system of a car proved that there are significant limitations of optimising the fuel consumption of cars. The first one is conditioned by the fact that the engine works at full dynamic load and the second one by the fact that idle running is against the 'Highway Code'.
Źródło:
Journal of KONES; 2012, 19, 4; 633-642
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of transcritical carbon dioxide cycles with heat regeneration
Autorzy:
Trela, M.
Kwidziński, R.
Butrymowicz, D.
Powiązania:
https://bibliotekanauki.pl/articles/239921.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CO2 thermodynamic cycle
near-critical region
heat regeneration
thermal efficiency
CO2
cykl termodynamiczny
obszar około-krytyczny
regeneracja ciepła
sprawność cieplna
Opis:
The paper presents an efficiency analysis of two transcritical CO2 power cycles with regenerative heaters. For the proposed cycles, calculations of thermal efficiency are given for selected values of operating parameters. It was assumed that the highest working temperature and pressure are in the range from 600 to 700°C and 40 to 50 MPa, respectively. The purpose of the calculations was optimization of the pressure and mass flows in the regenerative heaters to achieve maximum cycle efficiency. It follows that for the assumed upper CO2 parameters, efficiency of 51-54% can be reached, which is comparable to the efficiency of a supercritical advanced power cycle considered by Dostal.
Źródło:
Archives of Thermodynamics; 2013, 34, 3; 197-217
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rotating combustion chambers as a key feature of effective timing of turbine engine working according to Humphrey cycle – CFD analysis
Autorzy:
Tarnawski, Piotr
Ostapski, Wiesław
Powiązania:
https://bibliotekanauki.pl/articles/2173712.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pressure gain combustion
Humphrey cycle
turbine engine
CFD analysis
valve timing system
isochoric combustion
engine energy efficiency
sealing system
ciśnienie spalania
cykl Humphreya
silnik turbinowy
analiza CFD
układ rozrządu
spalanie izochoryczne
sprawność energetyczna silnika
system uszczelniający
Opis:
The paper presents a concept of a new turbine engine with the use of rotating isochoric combustion chambers. In contrast to previously analyzed authors’ engine concepts, here rotating combustion chambers were used as a valve timing system. As a result, several practical challenges could be overcome. An effective ceramic sealing system could be applied to the rotating combustion chambers. It can assure full tightness regardless of thermal conditions and related deformations. The segment sealing elements working with ceramic counter-surface can work as self-alignment because of the centrifugal force acting on them. The isochoric combustion process, gas expansion, and moment generation were analyzed using the CFD tool (computational fluid dynamics). The investigated engine concept is characterized by big energy efficiency and simple construction. Finally, further improvements in engine performance are discussed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 5; art. no. e143100
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The hybrid concept of turboshaft engine working according to Humphrey cycle dedicated to variety power demand - CFD analysis
Autorzy:
Tarnawski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/24202460.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
pressure gain combustion
Humphrey cycle
turbine engine
CFD analysis
valve timing system
isochoric combustion
engine energy efficiency
sealing system
spalanie powodujące wzrost ciśnienia
cykl Humphreya
silnik turbinowy
analiza CFD
układ rozrządu
spalanie izochoryczne
sprawność energetyczna silnika
system uszczelniający
Opis:
The paper presents a new concept of the turbine engine in the area of pressure gain combustion (PGE). The engine works according to Humphrey’s cycle. Minor modification in construction has allowed power generation of 500 kW, 700 kW, 1000 kW, and 1800 kW. The concept successfully resolved the challenges related to the temporary opening and closing of the combustion chamber. The presented valve timing system has ensured effective gas flow and what stands behind it, an effective process of conversion of a high-pressure gas impulse into mechanical energy. Rotating combustion chambers enabled the application of an effective sealing system. The concept characterizes simple construction and potentially low power-to-weight coefficient. The CFD numerical analysis of the presented engine concept showed very promising effective efficiency and low specific fuel consumption.
Źródło:
Combustion Engines; 2023, 62, 2; 129--136
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Koszty bezpieczeństwa jako produktu usługowego
The costs of security understood as the service product
Autorzy:
Szykuła-Piec, B.
Piec, R.
Powiązania:
https://bibliotekanauki.pl/articles/136924.pdf
Data publikacji:
2017
Wydawca:
Szkoła Główna Służby Pożarniczej
Tematy:
bezpieczeństwo
poczucie bezpieczeństwa
produkt
cykl życia produktu
finanse jednostek samorządu terytorialnego
metoda ABC
efektywność
koszty działań
security
sense of security
product
life cycle of product
finance
local government units
ABC method
efficiency
costs of activities
Opis:
We współczesnej rzeczywistości bezpieczeństwo otrzymało pierwszeństwo. Obecna sytuacja na świecie skłania do rozważań, czy ludzie czują się bezpiecznie, czy jako naród żyją w poczuciu, że państwo jest w stanie zapewnić im bezpieczeństwo i utrzymać je na akceptowalnym przez obywateli poziomie. Nasuwają się kolejne pytania o to, czy w przypadku prowadzonej polityki, nakładającej na samorządy lokalne obowiązki związane z zapewnieniem bezpieczeństwa swoim mieszkańcom, posiadają one wystarczające środki na ten cel. Czy ponoszone koszty są mierzone i poddawane analizom? Jedną z metod analizy kosztów wykonywaną w ramach zarządzania finansami jest metoda ABC – rachunek kosztów działań. Niniejsze opracowanie jest propozycją zaadaptowania tej metody na potrzeby identyfikacji kosztów działań na rzecz bezpieczeństwa. W kontekście podnoszenia efektywności alokacji środków, bezpieczeństwo zostało zdefiniowane jako produkt wytwarzany przez władze publiczne, co umożliwia zaimplementowanie tej metody. Teoretyczne studia nad etapami analizy rachunku kosztów działań stanowią wprowadzenie do procesu planowania zadań w obszarze bezpieczeństwa.
In contemporary reality the security has received the priority... The current situation of the world forces us to consider whether we, as a nation, feel safe. Is the state able to provide us safety and keep it at an acceptable level by citizens? There are further questions as to whether, with the policies imposing the local government obligations on the security of their citizens, they have sufficient resources for this purpose. Whether they are rationally used, considering the limited access. Whether the costs incurred are measured and subjected to analysis. One of the cost analysis methods, used in financial management, is the ABC method – activity cost accounting. This study is a proposal to adapt the method for the identification of the safety actions cost. In the context of increasing the efficiency of resource allocation, the security is defined as a product produced by the public authority, which makes it possible to implement this method. Theoretical studies on the steps of activity cost analysis are the introduction to the security planning process.
Źródło:
Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej; 2017, 2, 62; 153-169
0239-5223
Pojawia się w:
Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekonomiczna analiza przedsięwzięcia budowlanego w systemie partnerstwa publiczno-prywatnego na podstawie kosztów docelowych
Economic analysis with using target costing of construction project in public private partnership
Autorzy:
Sobotka, A.
Żelazna-Blicharz, A.
Blicharz, P.
Powiązania:
https://bibliotekanauki.pl/articles/350319.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
partnerstwo publiczno-prywatne
koszty docelowe
efektywność inwestycji
cykl życia
droga
public-private partnership
target costing
investment efficiency
life cycle
road
Opis:
Partnerstwo publiczno-prywatne (PPP) jest stosowanym na świecie systemem realizacji przedsięwzięć inwestycyjnych dla celów publicznych. Stanowi rozwiązanie, które w Polsce powinno być wykorzystywane w powiązaniu z uwzględnieniem funduszy unijnych. Jednym z podstawowych problemów, które należy rozwiązać, podejmując inwestycje w jakimkolwiek modelu systemu PPP, jest trafne oszacowanie kosztów przedsięwzięcia inwestycyjnego i przeprowadzenie rachunku efektywności inwestycji. Musi on obejmować zarówno wszystkie etapy cyklu inwestycyjnego (tzn. od pomysłu do oddania do eksploatacji), jak i uwzględniać okres eksploatacji zasobów, objęty kontraktem na świadczenie usług i zarządzanie nimi przez partnera prywatnego. Autorzy w artykule przedstawiają metodę analizy ekonomicznej na przykładzie hipotetycznej inwestycji drogowej, jaką jest obwodnica miasta. Wykorzystuje ona tradycyjne narzędzia, używane w ocenie ekonomicznej opłacalności przedsięwzięć inwestycyjnych, takie jak NPV (zaktualizowana wartość netto) oraz rachunek kosztów docelowych (target costing). Ten ostatni stanowi podstawowy element w kalkulacji kosztów i odnosi się do całego cyklu życia produktu. Przykład poprzedzony jest krótką charakterystyką partnerstwa publiczno-prywatnego oraz metody rachunku kosztów docelowych.
Public Private Partnership (PPP) is the system of realizing investment - enterprises for public purposes that is practiced in the world. It is the solution that should be practiced in Poland, also with the usage of the funds from the European Union. One of the main problems, that should be solved while undertaking investments in any model of the system Public Private Partnership (PPP), is a right estimation of costs of the investment - enterprise and making the calculation of the investment efficiency. This calculation has to include both all the stages of the investment cycle (i.e. from the idea into the exploitation) and the exploitation cycle of the resources that is contracted for lendering services and managing the resources by the private partner. The authors of this article present the method of economic analysis on the example of the hypothetical road - investment of a ring-road. This method uses the traditional tool that is practiced in the economic estimation of the profitability of the investment - enterprises, e.g. NPV (updated net value) and the account of target costing that is the fundamental element of cost calculation and refers to the whole life cycle of the product. The example is prefaced by a short characteristics of Public Private Partnership (PPP) and the method of target costing.
Źródło:
Górnictwo i Geoinżynieria; 2006, 30, 4; 103-119
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Test bed studies of an engine with combustion initiation from ignition dose of fuel
Autorzy:
Sendyka, B.
Noga, M.
Powiązania:
https://bibliotekanauki.pl/articles/245825.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
two-cycle engine
compression ignition
spark ignition
total efficiency of engine
Opis:
Results of test bed studies of combustion engine with work possibility with application of spark ignition and combustion from ignition dose injected directly into the combustion chamber were described in this article. In engine working according to the patent solution of Prof. B. Sendyka, during start and work at low rotational speed and low load a system realizing spark ignition of homogenous mixture formed in classical way in the intake manifold is active. For higher rotational speeds and heavy load the ignition system is switched off whereas, injectors of ignition dose injecting fuel by the end of the compression stroke directly into the working space of the engine are activated. The fuel dose injected into the combustion chamber undergoes auto-ignition and in this way the combustion process in the whole volume of the homogenous combustion charge accumulated in the cylinder is initiated. The mass of ignition dose of fuel constitutes about 5 – 10% of the whole fuel mass per working cycle what differs decisively the presented solution from other known engines working according to similar principles. Application of two combustion system in four stroke combustion engine aims at combining the advantages of spark ignition a compression ignition engines. The engine is characterized by easy starting and during work at higher rotational speed and higher load in the mode of ignition from pilot dose exploitation efficiency of energy contained in fuel is higher than for spark ignition engine, this finds direct reflection in increase in total efficiency by over 9% as related to the base value.
Źródło:
Journal of KONES; 2011, 18, 4; 427-509
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The description of the total efficiency of 2SZ-FE engine with the variable valve timing
Autorzy:
Sendyka, B.
Sochan, A.
Noga, M.
Rodak, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/243046.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
silnik spalinowy
obieg Atkinsona
spalanie
sprawność ogólna
silnik
combustion engine
Atkinson cycle
combustion
total efficiency
engine
Opis:
In this paper there were conducted tests of the combustion engine with the Atkinson cycle and with applying variable valve timing. There was described the 2SZ-FE engine characteristics and assigned the total efficiency before and after application of the phase shifter. Secondly, there was determined the thermal efficiency of the single engine work cycles and also engine 's total efficiency by using the optoelectronic pressure sensor and mathematical programme. After that, it was available to present the range of the variable valve timing. Atkinson system, phases of 2SZ-FE engine timing gear, the total efficiency distribution during 75 % of throttle opening and when inlet valves are open, the total efficiency increase during 75 % of throttle opening, the total efficiency distribution during 50 % of throttle opening and when suction valves are open, the total efficiency increase during 50 % of throttle opening, the total efficiency distribution during 25 % of throttle opening and when inlet valves are opened, the total efficiency increase during 25 % of throttle opening, the total efficiency distribution with application of phases shifter are presented in the paper.
Źródło:
Journal of KONES; 2007, 14, 2; 401-407
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
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