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Wyszukujesz frazę "size effect" wg kryterium: Temat


Tytuł:
Importance of the Size of Local Government in Avoiding the Fiscal Distress - Empirical Evidence on Communes in Poland
Autorzy:
Galiński, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/16729115.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
fiscal distress
local government
size effect
Opis:
Theoretical background: In the literature on finance there are findings which examine reasons for the fiscal distress of units of the public sector, including local governments. However, this distress might be differently defined. Therefore, it determines both the approach to identify this phenomenon and the types of explanatory variables. Nevertheless, in the field of the business sector in the econometric models concerning the financial distress the size of the unit is considered. In this case there are also some possibilities to apply the correct proxy variable. This results from the fact that the size of local government might determine its fiscal capability as well as the level and structure of expenditures, which affect fiscal distress. Purpose of the article: The aim of this paper is to examine the influence of the size of the local government on the probability of the decrease of the exposure to the fiscal distress. Research methods: The author reviewed the literature in the field of the fiscal distress and introduced a multi-criteria decision analysis as well as a logistic regression modelling to examine this. The research procedure also required the use of the linear ordering to construct the dependent variable of the fiscal distress in order to analyse the “size effect” on the fiscal distress. Main findings: Fiscal distress of local governments is a core issue, which should be constantly analysed. It depends on the financial, economic, social and even political aspects. To identify exposure to this distress the TOPSIS method can be used. However, the fiscal distress can be affected by the size of the unit, which influences lots of budgetary categories. Due to the specificity of dependent and independent variables in the econometric models the “size effect” might be represented through the level of the population or the assets. Using the ordinal logistic regression in the research, the authors should consider that this effect can differ between the units with the disparate exposure. So, the partial proportional odds models can be required. Thus, the growth of the size of the unit, measured by the population, increases the odds of reaching very low exposure to fiscal distress. Simultaneously, there are some other important issues which should be included in this type of research.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia; 2022, 56, 5; 101-113
0459-9586
2449-8513
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on optimization method of flotation kinetic model based on molybdenite particle size effect
Autorzy:
Wan, He
An, Yanni
Qu, Juanping
Zhang, Chonghui
Xue, Jiwei
Wang, Sen
Bu, Xianzhong
Powiązania:
https://bibliotekanauki.pl/articles/24085892.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle size effect
molybdenite
mathematical model
method of correction
Opis:
Flotation kinetic models can be applied to describe the flotation process and to predict mineral recoveries. However, the size composition of the target minerals in the feed ore fluctuates considerably, resulting in insufficient accuracy with flotation kinetic models. There have been many studies that focus on the investigation of flotation kinetics with different particle sizes, while the optimization methods for flotation kinetic models based on particle size effects have not been reported. In this paper, flotation tests, optical microscope observations, and particle size analysis were used to identify the reasons for the decrease in accuracy of the flotation kinetic model due to changes in the composition of molybdenite particle size. Additionally, an optimization method for the flotation kinetic model was developed based on the particle size effect. The test results show that the accuracy of the flotation kinetic model for fixed particle size minerals is very high, but the predicted results for flotation recoveries of different particle size mineral mixtures have large deviations. The poor accuracy might be due to the autogenous carrier effect caused by the particle size composition fluctuating considerably. The optimization method for the flotation kinetic model is based on the particle size effect. The model can accurately describe the flotation process of molybdenite with different size compositions of molybdenite and predict the flotation recovery of molybdenite.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 163004
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane wskaźniki wielkości efektu w badaniach psychologicznych
Autorzy:
Prajzner, Arkadiusz
Powiązania:
https://bibliotekanauki.pl/articles/33951763.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
effect size
null hypothesis
statistical analysis
psychological research
wielkość efektu
hipoteza zerowa
analiza statystyczna
badania psychologiczne
Opis:
Odzwierciedlając zmieniającą się praktykę statystyczną w badaniach psychologicznych, w której dominuje testowanie hipotez zerowych z wykorzystaniem decyzji o poziomie istotności wyników, wskazano zalecenia dotyczące raportowania w pracach wielkości efektu. W opracowaniu przedstawiono pojęcie wielkości efektu oraz wskazano miejsce, jakie zajmuje w analizie danych w odniesieniu do istotności wyników. Celem pracy jest opisanie wybranych wskaźników wielkości efektu, a także wskazanie potrzeby zastosowania i poprawnej ich prezentacji i interpretacji w raporcie analiz prac empirycznych z zakresu nauk społecznych. Biorąc pod uwagę ograniczenia podejścia statystycznej analizy danych opartej jedynie na poziomie istotności, w opracowaniu zaprezentowano możliwości umieszczania w analizach danych wskaźnika o większym praktycznym zastosowaniu, jakim jest wielkość efektu. Wykorzystując najbardziej popularne metody analityczne, takie jak testy t Studenta, jednoczynnikowe analizy wariancji w schematach między- i wewnątrzgrupowych, a także analizy testem Wilcoxona, U Manna-Whitneya, H Kruskala-Wallisa, testem Friedmana oraz uwzględniając analizy dla danych jakościowych, zaprezentowano dobrane do planów badawczych wskaźniki wielkości efektu. Ponadto opisano wykorzystanie, sposób obliczania oraz interpretację wybranych wskaźników wielkości efektu, jakimi są wskaźniki: d Cohena, g Hedgesa, delta, rg Glassa, korelacja par dopasowanych rc, eta-kwadrat, omega-kwadrat oraz epsilon-kwadrat, W Kendalla oraz fi, V Cramera czy iloraz szans i ryzyko względne. Prezentację wskaźników wielkości efektu zestawiono z odpowiadającymi im planami badawczymi i rodzajem zebranych danych.
Reflecting the changing statistical practice in psychological research, dominated by null hypothesis testing using a decision about the level of significance of the results, the recommendations are indicated for reporting effect sizes in papers. The study presents the concept of the effect size and indicates its place in data analysis regarding to outcome’s significance. The purpose of the work is to describe selected effect size indicators and to point the need of use and their proper presentation and interpretation in social sciences empirical work data analysis reports. Considering statistical analysis approach limits based on significance level only, the study presents the possibility of including in the data analysis an indicator of a more practical use which is the size of the effect. By using the most popular analysis methods, such as, Student t-test, univariate analyses of variance in between- and within-group schemes as well as Wilcoxon test, Mann-Whitney’s U, Kruskal-Wallis H, Friedman’s test and considering analysis for qualitative data, matched to research plans indicators of the effect size were presented. The paper presents the use, calculation and interpretation of the size effect such as: Cohen’s d, Hedges g, delta, Glass’s rg, matched pairs correlation rc, eta-square, omega-square and epsilon-square, Kendall’s W and fi, Cramer’s V as well as odds ratio and relative risk. The presentation of the effect size indicators was contrasted with the corresponding research plans and the type of data collected.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio J – Paedagogia-Psychologia; 2022, 35, 4; 139-157
0867-2040
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio J – Paedagogia-Psychologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Distillation Conditions for Improved Recovery of Phthalides from Celery (Apium graveolens L.) Seeds
Autorzy:
Kokotkiewicz, Adam
Badura, Anna
Tabaczyńska, Żaneta
Lorenc, Andżelika
Buciński, Adam
Luczkiewicz, Maria
Powiązania:
https://bibliotekanauki.pl/articles/1363267.pdf
Data publikacji:
2021-06-07
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
alkylphthalides
enzyme pretreatment
hydrodistillation
salting-out effect
simultaneous distillation-extraction
size reduction
Opis:
The essential oil of celery (Apium graveolens) is characterized by exceptionally high content of alkylphthalides. The mentioned compounds exhibit a number of biological effects (including hypotensive, lipid-lowering, neuroprotective, and cytotoxic) and are also responsible for distinctive aroma of the plant. In the current work, parameters of conventional hydrodistillation (HD) and simultaneous distillation-extraction (SDE) were optimized to obtain phthalide-enriched fractions of celery seeds. A positive correlation was shown between hydrodistillation time and improved essential oil and phthalide yields. The 6-h HD of comminuted seeds yielded essential oil (2.9%) with a higher total phthalide content (51%), as compared to the samples collected after 1.5-3.0 h, which gave 2.4-2.7% of oil containing 24.6-39.2% of total phthalides. The oil contained sedanenolide (36.7%), 3-n-butylphthalide (13.1%), and sedanolide (1.1%). A further increase in the total phthalide content was achieved by omitting the size reduction step prior to hydrodistillation (68.8%) and utilization of the salting-out effect (84.3%). Enzyme pretreatment had a negligible effect on essential oil and phthalide yields. The change of distillation mode from HD to SDE significantly increased the oil yield of whole seeds (from 2.8 to 5.8% for 6 h processing) while maintaining its high phthalide content (62.5%), which translated to an increase in the total phthalide yield from 19.4 to 36.0 g/kg.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2021, 71, 2; 197-210
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Size effect at testing strength properties of concrete
Autorzy:
Akram, Amanda
Powiązania:
https://bibliotekanauki.pl/articles/1955920.pdf
Data publikacji:
2021
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
concrete
size effect
tensile strength
Opis:
Various strength characteristics of concrete are considered as fracture parameters. The compressive strength of concrete is of paramount importance when designing concrete structures, whereas tensile strength of concrete is the basic property when estimating cracking resistance of a structure and analysing fracture processes in concrete. When testing the compressive strength of concrete, the results are dependent on the shape and dimensions of used specimens. Some findings reported in the literature suggest that size effect exists also when testing such fracture properties of concrete as tensile strength. Unfortunately this problem is much less recognized and described compared to size effect in compressive test results. In this paper, the experimental investigation is presented on how the length of cylindrical specimens influences the tensile splitting strength of concrete obtained by means of the Brazilian method. Additional variable parameters were: type of aggregate (natural gravel and crushed granite) and cement-water ratio (C/W = 1.8 and C/W = 2.6). In conducted laboratory experiments a higher splitting tensile strength of concrete was noted for all specimens with nominal dimensions of 150×150 mm, compared to specimens 150×300 mm in size, regardless of type of aggregate or cement-water ratio.
Źródło:
Budownictwo i Architektura; 2021, 20, 4; 37-45
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of dynamic growth of a micro-scaled void based on strain gradient elasto-plasticity
Autorzy:
Ma, Xinbing
Liu, Jinxing
Wang, Jiadong
Pan, Hao
Powiązania:
https://bibliotekanauki.pl/articles/1839598.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
dynamic void growth
size effect
inertia
thermal softening
Opis:
Void initiation and growth serve as an important mechanism in ductile failures in metals. Particularly, on the micron-level, the extra hardening effect associated with strain gradient is accounted for by adopting strain gradient elasto-plasticity instead of the conventional plasticity. Effects of inertial, strain gradient hardening and thermal softening are formulated analytically for the case where a spherical void expands under external hydrostatic stress. As demonstrated by our results, the inertia effect firstly tends to hinder but then promotes the void growth. The threshold stress required for rapid void growth is lifted due to extra hardening of strain gradient so that the growth of a smaller void is delayed more remarkably. A considerable thermal softening phenomenon is observed here, which is caused by plastic work during the deformation process. The final void growth rate is mainly related to the maximum loading, which is consistent with the prediction based on the classical plastic theory.
Źródło:
Journal of Theoretical and Applied Mechanics; 2020, 58, 4; 927-941
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of pre-tension on torsion of microscale Cu wires: a study via strain gradient theory
Autorzy:
Ma, Xinbing
Liu, Jinxing
Powiązania:
https://bibliotekanauki.pl/articles/280360.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
nonproportional loading
strain gradient plasticity
size effect
cyclic response
Opis:
Nonproportional plastic deformations on the microscale are an emerging topic. A simplified theory of strain gradient elasto-plasticity is developed to study the evolution of yield strength in a copper wire sequentially experiencing tension and torsion. The pre-tension deformation and stress are inherited to the upcoming torsion process, resulting in a nonproportional loading condition. With consideration of the extra hardening effect due to strain gradient, pre-tension weakens the extra hardening effect of the strain gradient and the dependence on the wire radius. Cyclic torsion behavior is also investigated. Anomalous Bauschinger effect and plastic softening are found.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 4; 1055-1065
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On some problems in determining tensile parameters of concrete model from size effect tests
Autorzy:
Marzec, Ireneusz
Bobiński, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/260481.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
concrete
size effect
fracture energy
elasto-plasticity
XFEM
Opis:
The paper presents results of numerical simulations of size effect phenomenon in concrete specimens. The behaviour of in-plane geometrically similar notched and unnotched beams under three-point bending is investigated. In total 18 beams are analysed. Concrete beams of four different sizes and five different notch to depth ratios are simulated. Two methods are applied to describe cracks. First, an elasto-plastic constitutive law with a Rankine criterion and an associated flow rule is defined. In order to obtain mesh independent results, an integral non-local theory is used as a regularisation method in the softening regime. Alternatively, cracks are described in a discrete way within Extended Finite Element Method (XFEM). Two softening relationships in the softening regime are studied: a bilinear and an exponential curve. Obtained numerical results are compared with experimental outcomes recently reported in literature. Calculated maximum forces (nominal strengths) are quantitatively verified against experimental values, but the force – displacement curves are also examined. It is shown that both approaches give results consistent with experiments. Moreover, both softening curves with different initial fracture energies can produce similar force-displacement curves.
Źródło:
Polish Maritime Research; 2019, 2; 115-125
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Physical Properties of Copper Oxide Thin Films Prepared by Electrolysis Method
Autorzy:
Oudah, Mustafa H.
Mazin, H. Hasan
Abd, Ahmed N.
Powiązania:
https://bibliotekanauki.pl/articles/1065248.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
copper oxide
drop-casting method
electrolysis
quantum size effect
thin films
Opis:
The aim of this paper is to study the properties of copper oxide thin films prepared by electrolysis method and deposited on glass substrates by drop-casting method at different annealing temperatures. Copper oxide colloidal was successfully prepared by electrolysis method. The X-ray diffraction confirms the polycrystalline structure of the films. Atomic force microscopy shows that the increase in the annealing temperature improves the surface morphology, increases the grain size and removes the cracks. The best optical transmittance was for the film annealed at 200 ºC. The bandgap decreases from 3.35 eV to 3.15 eV as a result of increasing the annealing temperature. The wide bandgap that obtained in this study is due to quantum size effect.
Źródło:
World Scientific News; 2019, 135; 59-70
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A shifted Wald decomposition of the numerical size-congruity effect: Support for a late interaction account
Autorzy:
Faulkenberry, Thomas J.
Vick, Adriana D.
Bowman, Kristen A.
Powiązania:
https://bibliotekanauki.pl/articles/2129181.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Size congruity effect
response time modeling
accumulator model
shifted Wald distribution
Opis:
Decisions involving comparisons of Arabic number digits often exhibit an interference between the physical size of the digit and the implied numerical magnitude, a phenomenon called the size-congruity effect. Related research over the past four decades has yielded two competing models of the phenomenon: an early interaction account, where interference between numerical and physical magnitude occurs at an early encoding stage, and a late interaction account, where the interference occurs downstream as response competition during the decision process. In the present study, we asked participants to compare the physical sizes of pairs of Arabic digits. We fit the resulting response time distributions with a shifted Wald model, a single boundary accumulator model, which gave us estimates of information accumulation rate (drift rate), response threshold, and nondecision time. We found that incongruity between physical size and numerical magnitude affected the decision-related estimates of drift rate and response threshold. Further, a Bayesian analysis confirmed a null effect of congruity on nondecision time. These results indicate that the observed interference originates from decision-related processes, lending further support for a late interaction account of the size-congruity effect.
Źródło:
Polish Psychological Bulletin; 2018, 49, 4; 391-397
0079-2993
Pojawia się w:
Polish Psychological Bulletin
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carbon nanotubes with controlled length – preparation, characterization and their cytocompatibility effects
Autorzy:
Cendrowski, K.
Jedrzejczak-Silicka, M.
Powiązania:
https://bibliotekanauki.pl/articles/778531.pdf
Data publikacji:
2018
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Multiwalled carbon nanotubes
cutting carbon nanotubes
size effect
mitochondrial activity
biocompatibility
apoptosis
necrosis
Opis:
Multiwalled carbon nanotubes (MWCNTs) have attracted huge attention due to their multifunctionality. Their unique properties allows for covalent and noncovalent modifi cations. The most simple method for functionalization of carbon nanotubes is their decoration with the oxygen containing moieties which can be further simultaneously functionalized for design of new class carriers for targeting and imaging. Here, we present methodology for chopping nanotubes, characterization of MWCNTs, the effect of size on the biocompatibility in culture of L929 mouse fi broblasts using WST-1, LDH and apoptosis assays. The analysis provides the optimal carbon nanotubes length and concentration which can be used for functionalization in order to minimize the effect of the secondary agglomeration when interacting with cells.
Źródło:
Polish Journal of Chemical Technology; 2018, 20, 2; 71-79
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of rootstock on yield quantity and quality of grapevine ‘Regent’ in South-Eastern Poland
Autorzy:
Kapłan, M.
Klimek, K.
Borowy, A.
Najda, A.
Powiązania:
https://bibliotekanauki.pl/articles/11858689.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Tematy:
South-Eastern Poland
plant cultivation
grapevine
grape
Regent cultivar
fruit
fruit quality
fruit size
rootstock effect
yield quantity
yield quality
plant research
Opis:
Globally, the application of rootstocks for grapevine cultivation has been a standard, while in the northern regions, like in Poland where the viticulture tradition is relatively short, the selection of the most suitable rootstock types requires multi-year observation and research. The objective of the present study was to assess the effect of six following rootstock types: ‘101-14 Mgt’, ‘161-49C’, ‘125AA’, ‘5BB’, ‘SO4’, ‘SORI’, and own-rooted vines on yield quantity and quality of ‘Regent’ grapevine in south-eastern Poland. The three-year research period indicates that the vines on ‘125AA’ tended to produce not only the highest yields but had positive influence on the number and weight of clusters and berry weight as well. Whereas the vines grafted onto ‘161-49C’ gave the lowest yields and had the smallest number of clusters per vine. The fruit extract content in ‘Regent’ grapes on ‘101-14 Mgt’ rootstock was found to be significantly lowest among those under study. The extract content and yield of grapevines evaluated in the own-rooted vines and those grafted to the rootstocks which formed one group, did not differ.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2018, 17, 4; 117-127
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inner Size Effect in Layered Films with Eutectic Interaction of Components
Autorzy:
Dukarov, S.
Petrushenko, S.
Sukhov, V.
Churilov, I.
Samsonik, A.
Skryl, O.
Powiązania:
https://bibliotekanauki.pl/articles/1030004.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
inner size effect
multilayer films
interfacial energy
Opis:
The results of the study of melting of Bi-Sn and Pb-Sn polycrystalline layered film systems with the thickness of 200-400 nm on a substrate with temperature gradient are given. Multilayer (each layer is of 10-20 nm) and bilayer films (layers are of 100-200 nm) of the same total thickness have been investigated. Broadening of the melting range in all films and lowering of melting point in multilayer samples compared to the bilayer ones have been observed. The observed phenomena are discussed within existing thermodynamic concepts in consideration of interfacial energy of contacting layers of components and energy of grain boundaries in polycrystalline films.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1186-1190
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inventory management in a manufacturing-remanufacturing system with cannibalization and stochastic returns
Zarządzanie zapasem w systemie produkcyjnym przy występowaniu kanibalizacji i zwrotów stochastycznych
Autorzy:
Okuda, A.
Ishigaki, A.
Yamada, T.
Gupta, S. M.
Powiązania:
https://bibliotekanauki.pl/articles/361798.pdf
Data publikacji:
2018
Wydawca:
Wyższa Szkoła Logistyki
Tematy:
supply chain management
economic efficiency
product recovery
market size
cannibalization effect
zarządzanie łańcuchem dostaw
efektywność ekonomiczna
odzyskiwanie produktu
wielkość rynku
efekt kanibalizacji
Opis:
Background: The design of a remanufacturing system that recovers sold products for reprocessing is needed to meet Japan's environmental objectives. However, to establish closed-loop supply chains for sustainability, it is necessary to consider not only environmental factors but also economic efficiency. Selling remanufactured products at prices lower than new products, may expand market sizes and allow a firm to accrue higher profits. However, a cannibalization effect will occur in which consumers who would have purchased new products, instead purchase remanufactured products at lower prices. The purpose of this study is to design a manufacturing-remanufacturing system in consideration of the cannibalization effect. Furthermore, we evaluate the system including cycle of a product by using the use period of products. Methods: Based on a previous study, we develop a demand model with cannibalization effect using the Bass model. We deal with the demand affected by the different prices of products by introducing a demand function that increases as the price of products decreases. Moreover, by giving the use period of each product, we consider the case that the recovery period of each product is different. Results: In numerical examples, a manufacturing-remanufacturing system using the proposed model is evaluated. The numerical results clarify the influence of the price of remanufactured products, cannibalization rate, and introduction timing of remanufactured products on total profit and remanufacturing rate of our system. Conclusions: This manufacturing-remanufacturing system revealed the influence of cannibalization effect on total profit and the importance of price and the timing of introduction of remanufactured products. In addition, by using the use period of each product, fluctuation in the quantity of reusable products can also be taken into consideration. It is shown that it is necessary to sell remanufactured products according to product recovery.
Wstęp: System produkcyjny odzyskiwania zużytego sprzętu jest bardzo pożądany z punktu widzenia ochrony środowiska. Aby jednak stworzyć ten system w pełni zrównoważony, należy wziąć pod uwagę nie tylko aspekty ekologiczne ale także ekonomiczne. Przy sprzedaży używanych produktów w cenach niższych aniżeli wyroby nowe, wielkość rynku zbytu może ulec zwiększeniu a firmy są w stanie osiągnąć wyższe zyski. Jednak istnieje niebezpieczeństwo pojawienia się efektu kanibalizacji, czyli zjawiska nabywania przez klientów produktów używanych zamiast nowych. Celem pracy było opracowanie modelu produkcyjnego uwzględniającego tej efekty jak również cykl życia produktu. Metody: W oparciu o wcześniejsze został opracowany model popytu uwzględniający efekt kanibalizacji przy użyciu modela Bassa. Określenie popytu w zależności od ceny produktu następowało poprzez zastosowanie funkcji popytu rosnącej przy malejącej cenie produktu. Równolegle, przypisując odpowiedni okres każdemu produktowi, uwzględniono różny czas odtworzenia, specyficzny dla każdego z produktów. Wyniki: Zaproponowany model został przedstawiony w przykładach numerycznych. Ich wyniki wskazują na wpływ ceny odzyskanych produktów, wskaźnik kanibalizacja oraz okresu odtworzeniowego na całkowity zysk uzyskany w opracowanym modelu. Wnioski: Zaproponowano produkcyjny model odzysku zużytego sprzętu uwzględniający efekt kanibalizacji przy użyciu modelu popytu ze zmienną niezależną w postaci ceny produktu. Wykryto efekt kanibalizacji na całkowity zysk oraz istotność ceny i okresu odtworzenia zużytych produktów. Dodatkowo, poprzez zróżnicowanie okresu odtworzenia dla różnych produktów wykazano potrzebę sprzedaży odzyskiwanych produktów.
Źródło:
LogForum; 2018, 14, 1; 113-125
1734-459X
Pojawia się w:
LogForum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Simulations of the Effects of Droplet Size and Concentration on Vapour-Droplet JP-10/Air Detonations
Autorzy:
Liu, L.
Zhang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/358150.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
multiphase detonation
discrete phase model
evaporation and breakup model
droplet size effect
initial concentration effect
Opis:
Two-dimensional simulations were conducted for JP-10 mono-dispersed vapour-droplet detonation in air, based on the detonation mechanism for clouds and validation of the extending critical droplet size limits in previous tests. In the simulations, the discrete phase model combined with the droplet evaporation and droplet breakup models was used. Utilizing a wide range of mono-dispersed droplet sizes and initial droplet concentrations, all cases of JP-10 droplets with a certain amount of pre-vaporized fuel can successfully achieve the deflagration to detonation transition. Detonation velocities at the equivalent concentration with droplet diameters no larger than 50 μm are in good agreement with the theoretical detonation velocities. The effects of droplet size and initial droplet concentration on the detonation behaviour were also investigated. Detonation velocities attained with droplet diameters below 50 μm appear to decrease very slightly with droplet size, but are almost equal to the velocity in gases. When the droplet diameter is above 50 μm, there is a decrease in simulated detonation velocity compared with fine droplets, and no secondary pressure peak was observed. For fuel-rich combustion, detonation velocities decrease rapidly with an increase in initial droplet concentration, and post-wave pressure fluctuation was obviously irregular, caused by the secondary local explosion of the droplets.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 1; 175-190
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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