Temat: two stage - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Effect of two-stage stirred pulp-mixing on coal flotation
Autorzy:: Gui, X.
Wang, Y.
Zhang, H.
Li, S.
Tematy:: mixing
stirred
two stage
fine coal
flotation; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110764.pdf Link otwiera się w nowym oknie
Opis:: Stirred pulp-mixing is performed before coal flotation. In this study, a two-stage stirred pulpmixing tank was designed based on the single-stirred process to intensify the mixing effect of pulp and flotation reagents. A tank has a pitched-impeller opening-type turbine. Stirred pulp-mixing and flotation experiments were conducted on a sample of anthracite fine coal (-0.5mm) from the Xuehu Coal Preparation Plant in Henan Province, China. The results of the two-stage stirred pulp-mixing were compared with those of a single-stage stirred pulp-mixing in terms of flotation performance. Compared with the single-stage stirred pulp-mixing, two mixing areas and double-layer impeller were able to strengthen the energy input to the stirred system, thereby improving the mixing efficiency of flotation reagents and coal particles in the pulp. The two-stage stirred pulp-mixing significantly increased the flotation feed rate of the cyclone-static micro-bubble flotation column and concentrate yield, enhanced the combustible matter recovery effect of coarse particles at a suitable flotation feed rate, and ensured the recovery effect of fine particles at high flotation feed rate.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: The Efficiency of Public and Private Higher Education Institutions in Poland
Autorzy:: Brzezicki, Łukasz
Wydawca:: Szkoła Główna Handlowa w Warszawie
Cytata wydawnicza:: Brzezicki, Ł. (2020). The Efficiency of Public and Private Higher Education Institutions in Poland. Gospodarka Narodowa. The Polish Journal of Economics, 304(4), 33-51. https://doi.org/10.33119/GN/128218
Opis:: Changes introduced to Poland’s education system in 2011 and 2014 amid efforts to adjust it to the needs of the labour market had an effect on the country’s institutions of higher learning. This paper provides an analysis of the efficiency of public and private Polish universities and examines the impact of selected factors in the years that followed. To estimate this efficiency, a Banker, Charnes and Cooper (BCC) model of the Data Envelopment Analysis (DEA) method was used. To gauge the impact of environmental variables on the efficiency of universities, a truncated regression analysis was performed. The results of the study indicate that public universities were more efficient in terms of the number of graduates they produced but less efficient when considering the level of graduate salaries. The opposite was true for private institutions. The level of efficiency was affected by variables related to specific universities and the socio-economic situation of the region in which they operate. The study analyses the efficiency of educational activities of public and private universities, both in terms of the number of graduates and the quality of education and in the context of the labour market. The analysis also considers the level of graduate earnings.
Dostawca treści:: Repozytorium Centrum Otwartej Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Simulation of work of an engine working with combustion initiation from ignition dose of fuel
Autorzy:: Sendyka, B.
Mitianiec, W.
Noga, M.
Tematy:: modelling
simulation
combustion engine
HCCI
two stage injection system; Pokaż więcej
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Powiązania:: https://bibliotekanauki.pl/articles/245989.pdf Link otwiera się w nowym oknie
Opis:: The paper presents analysis of fuelling and of the course of combustion process for a two-cycle engine. The main idea of the engine according to patent solution of Prof. B. Sendyka consists in the fact that engine work begins from spark ignition, whereas, at higher load and higher temperature in the cooling system there occurs switching off spark ignition and transition to ignition from an ignition dose injected directly into the combustion chamber. Such an engine possesses two injection systems: one system of multi-point injection which forms homogenous mixture, whereas, the other system of direct injection is used for ignition dose injection only. After injection of the ignition dose of a very small mass combustion is initiated on the basis of formation of auto-ignition centres so as it takes place during knock combustion. Auto-ignition centres initiate combustion of the basic charge. Simulation was carried out in order to perform analysis occurring phenomena of fuel feeding and combustion. Works on it started from elaboration of a computational grid of the engine and subsequently analysis of indicated diagrams of engine work with injection of ignition dose was performed. Analysis was also performed of temperature traces and of traces of charge mass change in the cylinder as well as of participation of the mass of basic fuel dose in the cylinder in function of the crank angle. Moreover visualization of effects of the process of mixture formation and combustion was performed and presented in form of illustrations of charge temperature distribution, fraction of fuel ignition and basic dose vapours in cross-sections of the combustion chamber.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: On Maximization of Estimation Accuracy in Multiparameter Two Stage Sampling
O maksymalizacji dokładności estymacji w wieloparametrowym losowaniu dwustopniowym
Autorzy:: Skibicki, Marcin
Tematy:: two stage sampling
sample allocation
covariance matrix
spectral radius; Pokaż więcej
Wydawca:: Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Powiązania:: https://bibliotekanauki.pl/articles/904926.pdf Link otwiera się w nowym oknie
Opis:: In the paper the problem of sample allocation for both stages in such a way, that the accuracy of an estimation of the means of many variables is maximal and the survey cost is restricted is considered. As the measure of accuracy, value of the spectral radius of covariance matrix of means estimators vector is taken. It was proved that the spectral radius is a convex function of sample sizes. That allows effective solving the problem using known methods adapted to this issue.
W pracy rozważano zadanie ustalenia liczebności prób losowanych na obydwu stopniach losowania tak, aby dokładność estymacji średnich wielu cech populacji była maksymalna przy kosztach obserwacji próby nieprzekraczających zadanego poziomu. Za miarę dokładności estymacji przyjęto wartość promienia spektralnego macierzy kowariancji wektora estymatorów wartości średnich cech. Wykazano, że promień spektralny tej macierzy dla przekształconego zadania jego minimalizacji jest wypukłą funkcją odpowiedniego wektora. Pozwala to na efektywne poszukiwanie optymalnego rozwiązania przy użyciu znanych metod adaptowanych do tego problemu.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Fuzzy-PID control method for two-stage vibration isolation system
Połączenie sterowania rozmytego z regulatorem PID w dwustopniowym układzie wibroizolacji
Autorzy:: Zhao, C-S.
Zhu, S-J.
He, Q-W.
Tematy:: two-stage vibration isolation system
fuzzy-PID control
simulation; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/280755.pdf Link otwiera się w nowym oknie
Opis:: The arithmetic of PID control is simple and the stability of it is good. However, the dynamic characteristics of PID control are poor. The fuzzy logic control method is flexible and adaptive. It does not rely on a mathematical model of the system and can deal with the nonlinearity of parameters and uncertain problems. However, the stability of fuzzy logic control is poor. In this paper, fuzzy logic control combined with PID control is applied to a two-stage vibration isolation system to improve the vibration isolation effectiveness. Simulation results show that the method is effective.
Arytmetyka regulatora PID jest prosta, a jego stabilność dobra. Jednakże charakterystyki dynamiczne PID już tak korzystne nie są. Z drugiej strony, metody sterowania oparte na logice rozmytej są elastyczne i cechuje je duża zdolność adaptacyjna. Nie polegają one na ścisłym modelu matematycznym danego układu i dobrze sobie radzą z nieliniowościami parametrów i słabo zdefiniowanymi zagadnieniami. Niestety stabilność sterowania z logiką rozmytą jest niedostateczna. W pracy zaprezentowano rodzaj kombinacji metody logiki rozmytej z regulatorem PID zastosowanej do dwustopniowego układu izolacji drgań. Przeprowadzone symulacje pokazały efektywność takiego podejścia.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Impact of government policies on Sustainable Petroleum Supply Chain (SPSC): A case study – Part II (The State of Nebraska)
Autorzy:: Ghahremanlou, Davoud
Kubiak, Wieslaw
Tematy:: sustainable petroleum supply chain
two-stage stochastic programming
government policies; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/1818474.pdf Link otwiera się w nowym oknie
Opis:: The accompanying part I (Ghahremanlou and Kubiak 2020) developed the Lean Model (LM), a two-stage stochastic programming model which incorporates Renewable Fuel Standard 2 (RFS2), Tax Credits, Tariffs, and Blend Wall (BW), to study the policy impact on the Sustainable Petroleum Supply Chain (SPSC) using cellulosic ethanol. The model enables us to study the impact by running computational experiments more efficiently and consequently by arriving at robust managerial insights much faster. In this paper, we present a case study of the policy impact on the SPSC in the State of Nebraska using the model. The case study uses available real-life data. The study shows that increasing RFS2 does not impact the amount of ethanol blended with gasoline but it might lead to bankruptcy of the refineries. We recommend that the government consider increasing the BW because of its positive economic, environmental and social impacts. For the same reason, we recommend that the tax credit for blending the US produced ethanol with gasoline be at least 0:189 $/gal and the tariff for imported ethanol be at least 1:501 $/gal. These also make the State independent from foreign ethanol thereby enhancing its energy security. Finally, the change in policy impacts the SPSC itself, most importantly it influences the strategic decisions, however setting up a bio-refinery at York county and a blending site at Douglas county emerge as the most robust location decisions against the policy change in the study.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Impact of government policies on Sustainable Petroleum Supply Chain (SPSC): A case study – Part I (Models)
Autorzy:: Ghahremanlou, Davoud
Kubiak, Wieslaw
Tematy:: sustainable petroleum supply chain
two-stage stochastic programming
government policies; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/1818475.pdf Link otwiera się w nowym oknie
Opis:: Environmental concerns and energy security have led governments to establish legislations to convert Conventional Petroleum Supply Chain (CPSC) to Sustainable Petroleum Supply Chain (SPSC). The United States (US), one of the biggest oil consumers in the world, has created regulations to manage ethanol production and consumption for the last half century. Though these regulations have created new opportunities, they have also added new burdens to the obligated parties. It is thus key for the government, the obligated parties, and related businesses to study the impact of the policies on the SPSC. We develop a two-stage stochastic programming model, General Model (GM), which incorporates Renewable Fuel Standard 2 (RFS2), Tax Credits, Tariffs, and Blend Wall (BW) to study the policy impact on the SPSC using cellulosic ethanol. The model, as any other general model available in the literature, makes it highly impractical to study the policy impact due to the model’s computational complexity. We use the GM to derive a Lean Model (LM) to study the impact by running computational experiments more efficiently and consequently by arriving at robust managerial insights much faster. We present a case study of the policy impact on the SPSC in the State of Nebraska using the LM in the accompanying part II (Ghahremanlou and Kubiak 2020).
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Efficiency measurement in dynamic two-stage network structures with flexible intermediate materials
Autorzy:: Kordrostami, S.
Seyedboveir, S.
Daneshian, B.
Amirteimoori, A.
Tematy:: data envelopment analysis
flexible factors
dynamic two-stage network
efficiency; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/406486.pdf Link otwiera się w nowym oknie
Opis:: Data envelopment analysis (DEA) is a nonparametric method for evaluating the relative efficiency of decision making units (DMUs) described by multiple inputs and multiple outputs. Since DEA was introduced in the 1970s, it has been widely applied to measure the efficiency of a wide variety of production and operation systems, including two-stage production systems with a series or parallel structure. The outputs from the first stage to the next stage are called intermediate factors (or measures). In some real applications, an intermediate material or some part of it can become the final output or input to the second stage of production. Previously existing models cannot be employed directly to measure the efficiency of such systems. The authors introduce a dynamic DEA model that identifies the structure of flexible intermediate factors to maximise the measure of overall system efficiency.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Modeling of a two stages electrostatic air precipitation process using response surface modeling
Autorzy:: Berrached, D.
Tilmatine, A.
Miloua, F.
Bengrit, M.
Tematy:: two-stage ESP
design of experiments
experimental modelling
electrostatic precipitator; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/141038.pdf Link otwiera się w nowym oknie
Opis:: Any industrial process needs to work with the optimal operating conditions and thus the evaluation of their robustness is a critical issue. A modeling of a laboratoryscale wire-to-plane two stages electrostatic precipitator for guiding the identification of the set point, is presented this in paper. The procedure consists of formulating recommendations regarding the choice of optimal values for electrostatic precipitation. A twostages laboratory precipitator was used to carry out the experiments, with samples of wood particles of average granulometric size 10 μm. The parameters considered in the present study are the negative applied high voltage of the ionization stage, the positive voltage of the collection stage and the air speed. First, three “one-factor-at-a-time” experiments were performed followed by a factorial composite design experiments, based on a two-step strategy: 1) identify the domain of variation of the variables; 2) set point identification and optimization of the process.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Analysis of energy consumption of crushing processes – comparison of one-stage and two-stage processes
Autorzy:: Ciężkowski, P.
Maciejewski, J.
Bąk, S.
Tematy:: rock crushing
jaw crusher
crushing efficiency
two stage crushing process; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/178852.pdf Link otwiera się w nowym oknie
Opis:: This paper presents experimental comparison of two machine crushing technologies: one-stage and two-stage. The study was carried on a model double-toggle jaw crusher which allows crushing forces, energy and toggle displacement to be measured. The main aim of the work was to determine the energy consumption of crushing process assuming a given level of fragmentation. Studies were performed on three rocks: granite “Strzegom”, limestone “Morawica” and sandstone “Mucharz”. The material tested had a cubic shape and average dimension of 90 mm. One-stage crushing was carried out for outlet slot e_r = 11 mm, and two-stage crushing for e_r = 24 mm and 11 mm. In the tests special design of variable profile moving jaw was used and fixed jaw was flat. The analysis of the results shows that taking into account energy consumption, it is better to use two-stage crushing process. For given materials energy consumption in the two-stage crushing process was reduced by 30%.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "two stage" wg kryterium: Temat