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Tytuł:
A Level-Based Approach to Prioritize Telecommunications R&D
Autorzy:
Fialho, J.
Godinho, P.
Costa, J. P.
Afonso, R.
Regalado, J. G.
Powiązania:
https://bibliotekanauki.pl/articles/307952.pdf
Data publikacji:
2008
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
multicriteria decision support
R&D project evaluation
Opis:
In this paper, an approach to evaluate R&D projects in telecommunications is presented. These Project have particular features that cannot be properly incorporated by classical evaluation methods. This approach incorporates different criteria, both quantitative and qualitative, and also management flexibility and uncertainty. Thus, it is an approach that can be applied to real data of R&D projects in a telecommunications company.
Źródło:
Journal of Telecommunications and Information Technology; 2008, 4; 40-43
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling Tyre-Road Noise with Data Mining Techniques
Autorzy:
Freitas, E.
Tinoco, J.
Soares, F.
Costa, J.
Cortez, P.
Pereira, P.
Powiązania:
https://bibliotekanauki.pl/articles/177590.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
tyre-road noise
data mining
model
texture
damping
surface characteristics
Opis:
The research aimed to establish tyre-road noise models by using a Data Mining approach that allowed to build a predictive model and assess the importance of the tested input variables. The data modelling took into account three learning algorithms and three metrics to define the best predictive model. The variables tested included basic properties of pavement surfaces, macrotexture, megatexture, and unevenness and, for the first time, damping. Also, the importance of those variables was measured by using a sensitivity analysis procedure. Two types of models were set: one with basic variables and another with complex variables, such as megatexture and damping, all as a function of vehicles speed. More detailed models were additionally set by the speed level. As a result, several models with very good tyre-road noise predictive capacity were achieved. The most relevant variables were Speed, Temperature, Aggregate size, Mean Profile Depth, and Damping, which had the highest importance, even though influenced by speed. Megatexture and IRI had the lowest importance. The applicability of the models developed in this work is relevant for trucks tyre-noise prediction, represented by the AVON V4 test tyre, at the early stage of road pavements use. Therefore, the obtained models are highly useful for the design of pavements and for noise prediction by road authorities and contractors.
Źródło:
Archives of Acoustics; 2015, 40, 4; 547-560
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wspomaganie wzrostu komórek kostnych na hydrożelach z gumy gellan za pomocą mineralizacji enzymatycznej
Promotion of bone cells growth on gellan gum hydrogels by enzymatic mineralization
Autorzy:
Pietryga, K.
Costa, J
Pereira, P.
Douglas, T. E. L.
Pamuła, E.
Powiązania:
https://bibliotekanauki.pl/articles/285546.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
hydrożel
kompozyt
mineralizacja
fosfataza alkaliczna
hydrogel
composite
mineralization
alkaline phosphatise
Opis:
Enzymatyczna mineralizacja hydrożeli jest obiecującym sposobem uzyskiwania materiałów do leczenia ubytków tkanki kostnej. Dzięki wytworzeniu wewnątrz materiału fosforanów wapnia (CaP), hydrożele stają się sztywniejsze, przez co bardziej odpowiednie do regeneracji tkanki kostnej. W przedstawionych badanych hydrożele z gumy gellan (GG) zawierające enzym – fosfatazę alkaliczną (ALP, 0,5 mg/ml) były mineralizowane poprzez inkubację w roztworze glicerofosforanu wapnia (CaGP). Porównano trzy różne stężenia GG: 0,7; 1,2 i 1,6%. W celu oceny zawartości CaP oznaczono suchą masę mineralizowanych próbek. Rozmieszczenie fazy mineralnej obserwowano w mikroskopie świetlnym na przekrojach. Przeprowadzono również testy mechaniczne w próbie ściskania. W badaniach komórkowych komórki osteoblastopodobne MG-63 hodowano na powierzchni materiałów jak i na przekrojach w okresie 1 oraz 7 dni. Żywotność komórek oznaczono przy pomocy barwienia live/dead. Badania mechaniczne wykazały znacznie wyższy moduł Younga w przypadku materiałów zmineralizowanych w porównaniu z czystymi hydrożelami jednak wzrost ten nie był tak wyraźny dla hydrożeli o wyższym stężeniu GG. Z powodu wypłukiwania ALP, rozmieszczenie fazy mineralnej w obrębie próbek nie było jednorodne: większość CaP tworzyła się wewnątrz materiału. Obecność fazy mineralnej sprzyjała adhezji komórek MG-63 do materiału, ich rozpłaszczeniu jak również przeżywalności.
Enzymatic mineralization of hydrogels is a promising approach to obtain new materials for the treatment of bone tissue defects. Thanks to creation of calcium phosphates (CaP) inside the material, the hydrogel becomes more rigid and therefore more suitable for bone tissue replacement. In this study, gellan gum (GG) hydrogels containing the enzyme alkaline phosphatase (ALP, 0.5 mg/ml) were mineralized by incubation in mineralization solutions of calcium glycerophosphate (CaGP). Three different concentrations of GG were compared: 0.7, 1.2 and 1.6% (w/v). In order to assess amount of CaP formed, dry mass percentage was calculated while distribution of mineral phase was observed by light microscopy. Mechanical tests in compression mode were also carried out. Osteoblast-like MG-63 cells were cultured for 1 and 7 days on the surface and cross-sections of mineralized and non-mineralized samples. Viability of cells was measured by live/dead staining. Mechanical testing revealed that Young’s modulus of mineralized hydrogels was much higher than unmineralized hydrogels. However, this increase was not particularly pronounced for samples of higher GG content. Due to ALP leaching, the distribution of minerals was inhomogeneous: most of the mineral phase was formed inside the material. The presence of CaP in mineralized samples promoted attachment, spreading and viability of MG-63 cells.
Źródło:
Engineering of Biomaterials; 2014, 17, 125; 6-12
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Shot Peening With Glass Microspheres on the Fatigue Behavior of a Low Carbon Steel
Autorzy:
de Lacerda, J. C.
Pereira, I. R.
Costa, J. M. G.
Pinto, J. S.
Souza, H. F. M.
Fonseca, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/352156.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fatigue
shot peening
Wöhler curve
low carbon steel
glass microspheres
Opis:
The present work has the objective of studying the effect of shot peening with glass microspheres on SAE 1020 steel in its resistance to fatigue. Fatigue tests were carried out by rotary bending with load control and loading on balance in specimens with and without shot peening. A rotation speed of approximately 750 rpm (12.5 Hz) was employed in the fatigue tests. Vickers microhardness tests were performed in order to verify the surface hardening produced by shot peening with glass microspheres. Analysis of the steel surface and fatigue fractures was performed using scanning electron microscopy (SEM). Fatigue tests were performed in order to obtain S-N curves (Wöhler curves). It was observed that shot peening with glass microspheres improved the fatigue strength of the steel at high cycle.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1513-1518
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Can concurrent teaching promote equal biomechanical adaptations at front crawl and backstroke swimming?
Autorzy:
Costa, M. J.
Barbosa, T. M.
Morais, J. E.
Miranda, S.
Marinho, D. A.
Powiązania:
https://bibliotekanauki.pl/articles/307054.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ekspertyza
kinematyka ruchu
pływak
expertise
kinematics
swimmer
Opis:
Purpose: The biomechanical adaptations in front crawl and backstroke swimming, as influenced by the implementation of a concurrent teaching programme were analysed. Methods: Sixteen participants (19.75 ± 1.13 years) underwent a 30 weeks intervention characterized by an increasing complexity to accomplish motor skills in the following order: (i) lower limbs propulsion; (ii) lower limbs propulsion synchronized with breathing cycle; (iii) lower limbs propulsion synchronized with one upper limb action; (iv) lower limbs propulsion synchronized with both breathing cycle and one upper limb action; (v) full swimming stroke; (vi) motor trajectory of the arms stroke. Performance and biomechanics were measured at front crawl and backstroke during three time points throughout the programme. Results: There were improvements in performance over time at front crawl (21.49 s to 19.99 s, p < 0.01) and backstroke (27.15 s to 24.60 s, p = 0.01). Significant improvements were found for velocity at front crawl (1.13 m/s to 1.22 m/s, p < 0.01) and backstroke (0.92 m/s to 1.00 m/s, p < 0.01). Stroke frequency increased at backstroke (0.64 to 0.73 Hz, p = 0.01), while the intra-cyclic variation of the velocity decreased at front crawl (0.13 to 0.12%, p = 0.02). There was also a moderate-high inter-subject variability in response to the programme. Conclusions: These findings prove that a programme of 30 weeks teaching concurrently front crawl and backstroke is effective to promote similar biomechanical adaptations in low-tier swimmers. However, each subject shows an individual response to better adapt the biomechanical actions and to reach a higher level of expertise.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 81-88
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relationship between performance, dry-land power and kinematics in master swimmers
Autorzy:
Espada, M. C.
Costa, M. J.
Costa, A. M.
Silva, A. J.
Barbosa, T. M.
Pereira, A. F.
Powiązania:
https://bibliotekanauki.pl/articles/307228.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pływanie
kinematyka
energia
master swimmers
kinematic
dry-land power
performance
Opis:
The purpose of the study was to analyze the relationships between sprint swimming performance, dry-land power, and kinematics in master swimmers. Twenty-two male master swimmers were separated in two groups based on their chronological age: (i) 30–39 years and; (ii) 40–49 years. Maximum dry-land power was determined through counter movement jump and 3 kg medicine ball throwing (Hmax and Tmax, respectively). Kinematic determinants of performance were measured during a maximal bout of 15, 25 and 50 m front crawl (T15, T25, T50). Stroke frequency (SF), stroke length (SL) and stroke index (SI) were calculated as kinematical aspects of the stroke. In the 30-39 group, SI25 was correlated to T25 (r = –0.76, p < 0.01, η2 = 0.96), the same was observed between SI50 and T50 (r = –0.83, p < 0.01, η2 = 0.96). Only SI50 was significantly correlated to T50 (r = –0.86, p < 0.01, η2 = 0.97) in the 40–49 years age cohort. In dryland power variables, Hmax and Tmax were only correlated in the younger master swimmers group (r = –0.87, p < 0.01, η2 = 0.97). There were no significant differences (p < 0.05) between younger (30–39 years) and older (40–49 years) swimmers groups in dry-land tests (Hmax 28.5 ± 5.9 vs. 26.5 ± 3.9 cm and Tmax 4.2 ± 1.0 vs. 4.2 ± 1.1 m). Our results suggest that swimming performance in younger master swimmers (30–39 years) seem more dependent on kinematic swimming variables than on strength parameters, which were most related to swimming performance in the older master swimmers (40–49 years).
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 2; 145-151
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tracking young talented swimmers : follow-up of performance and its biomechanical determinant factors
Autorzy:
Morais, J. E.
Saavedra, J. M.
Costa, M. J.
Silva, A. J.
Marinho, D. A.
Barbosa, T. M.
Powiązania:
https://bibliotekanauki.pl/articles/951824.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
prepubescent swimmers
longitudinal assessment
kinematics
drag force
anthropometrics
efficiency
kinematyka
efektywność
pływak
biomechanika
Opis:
The aim of the study was to follow-up the stability of young talented swimmers’ performance and its biomechanical determinant factors (i.e., anthropometrics, kinematics, hydrodynamics and efficiency) during a competitive season. Thirty three (15 boys and 18 girls) young swimmers (overall: 11.81 ± 0.75 years old and Tanner stages 1–2 by self-evaluation) were evaluated. Performance, anthropometrics, hydrodynamics, kinematics and efficiency variables were assessed at three moments during a competitive season. Performance had a significant improvement (with minimum effect size) and a moderate-very high stability throughout the season. In the anthropometrics domain all variables increased significantly (ranging from without to minimum effect size) between moments and had a moderate-very high stability. Hydrodynamics presented no variations between all moments and had a low-very high stability throughout the season. In the kinematics domain, there were no variations between moment one and three, except for an increase in stroke frequency (without size effect). Speed fluctuation remained constant, with no significant variations. All kinematic variables had a low-very high stability. Efficiency variables did not present variations between moment one and three and had a low-moderate stability. Overall, young swimmers showed a minimum improvement in performance and in anthropometric factors; and a moderate stability of performance and its determinant factors (i.e., anthropometrics, hydrodynamics, kinematics and efficiency) during the competitive season.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 129-138
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, characterization and catalytic properties of SAPO-11 molecular sieve synthesized in hydrothermal media using di-isopropylamine as template
Autorzy:
Chellappa, T.
Costa, M. J. F.
Nascimento, W. A.
Ferreira De Lima, L.
Bassan, I. A.
Tavares, M.
Fernandes, V. J.
Menezes, A.
Guilherme Meira, L.
Telesforo Nóbrega De Medeiros, J.
Maribondo Do Nascimento, R.
Powiązania:
https://bibliotekanauki.pl/articles/200372.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microporous materials
SAPO-11
characterization
catalytic activity
molecular sieves
Opis:
A microporous SAPO-11 Molecular sieve was successfully synthesized by the hydrothermal method, using a single agent, as an organic template: di-isopropylamine (DIPA). The obtained solid was calcined at 550◦C for three hours, after which the flow of nitrogen was exchanged for that of synthetic air and submitted for another ten hours of calcination, so as to remove the single agent: di-isopropylamine, which after the removal of the template could be observed by the high crystallization of the sample. Furthermore, the molecular sieve was characterized by XRD, SEM, TG-DTG and N2 adsorption desorption (BET analysis). The obtained catalyst proved to have a high potential catalytic activity and selectivity, through the obtained characterization results, exhibiting good hydrothermal stability. The catalytic performance of SAPO-11 was tested by the deactivation/regenerability of the coked sample, furthered by cracking of n-hexane reaction and high olefins selectivity was obtained.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 3; 481-488
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The content of anthocyanin in potato plants in an in vitro culture on the media with different humic products
Autorzy:
Klocek, J.
Costa, G.
Mioduszewska, H.
Powiązania:
https://bibliotekanauki.pl/articles/951217.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
anthocyanin content
potato plant
in vitro culture
plant hormone
humic substance
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Application of Optimal Control Theory to the Design of Theoretical Schedules of Anticancer Drugs
Autorzy:
Boldrini, J. L.
Costa, I. S.
Powiązania:
https://bibliotekanauki.pl/articles/908297.pdf
Data publikacji:
1999
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
chemioterapia
odporność na działanie leków
sterowanie optymalne
chemotherapeutic treatments
drug resistance
optimal control
Opis:
A system of differential equations for the control of tumor growth cellsin a cycle non-specific chemotherapy is analyzed. Spontaneously acquired drug resistance is taken into account by means of a mutation rate non-decreasingly dependent on time and the drug kill rate is supposed to depend on the growth rate of sensitive cells. For general tumor growth and drug kill rates the optimal treatment consists in maximizing the allowable drug concentration throughout.
Źródło:
International Journal of Applied Mathematics and Computer Science; 1999, 9, 2; 387-399
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A sixth-order finite volume method for the 1D biharmonic operator: Application to intramedullary nail simulation
Autorzy:
Costa, R.
Machado, G. J.
Clain, S.
Powiązania:
https://bibliotekanauki.pl/articles/330268.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
finite volume method
polynomial reconstruction operator
harmonic operator
biharmonic operator
high order method
Opis:
A new very high-order finite volume method to solve problems with harmonic and biharmonic operators for one-dimensional geometries is proposed. The main ingredient is polynomial reconstruction based on local interpolations of mean values providing accurate approximations of the solution up to the sixth-order accuracy. First developed with the harmonic operator, an extension for the biharmonic operator is obtained, which allows designing a very high-order finite volume scheme where the solution is obtained by solving a matrix-free problem. An application in elasticity coupling the two operators is presented. We consider a beam subject to a combination of tensile and bending loads, where the main goal is the stress critical point determination for an intramedullary nail.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 3; 529-537
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Expert System Coupled With a Hierarchical Structure of Fuzzy Neural Networks for Fault Diagnosis
Autorzy:
Calado, J. M. F.
Costa, I. S.
Powiązania:
https://bibliotekanauki.pl/articles/908283.pdf
Data publikacji:
1999
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
rozpoznanie błędu
wykrywanie błędu
system ekspertowy
sieć neuronowa rozmyta
fault diagnosis
fault detection
fault isolation
shallow knowledge
deep knowledge
expert system
fuzzy neural network
abrupt faults
incipient faults
Opis:
An on-line fault diagnosis system, designed to be robust to the normal transient behaviour of the process, is described. The overall system consists of an expert system cascade with a hierarchical structure of fuzzy neural networks, corresponding to a multi-stage fault detection and isolation system. The fault detection is performed through the expert system by means of fault detection heuristic rules, generated from deep and shallow knowledge of the process under consideration. If a fault is detected, the hierarchical structure of fuzzy neural networks starts and it performs the fault isolation task. The structure of this diagnosis system was designed to allow for the diagnosis of single and multiple simultaneous abrupt and incipient faults from only single abrupt fault symptoms. Also, it combines the advantages of both fuzzy reasoning and neural networks learning capacity. A continuous binary distillation column has been used as a test bed of the current approach. Single, double and triple simultaneous abrupt faults, as well as incipient faults, have been considered. The preliminary results obtained show a good accuracy, even in the case of multiple faults.
Źródło:
International Journal of Applied Mathematics and Computer Science; 1999, 9, 3; 667-687
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environmental radiological impact by a fertilizer complex in the Ebro river (Spain)
Wpływ przemysłu produkcji nawozów sztucznych na skażenia promieniotwórcze środowiska naturalnego na przykładzie rzeki Ebro (Hiszpania)
Autorzy:
Costa, E.
Sanchez-Cabeza, J.
Garcia, J.
Masque, P.
Grimaltb, J.
Powiązania:
https://bibliotekanauki.pl/articles/340306.pdf
Data publikacji:
2004
Wydawca:
Główny Instytut Górnictwa
Tematy:
skażenie wody
rzeka Ebro w Hiszpanii
skażenie radonem
skażenie torem
water contamination
Ebro river in Spain
radon contamination
thorium contamination
Źródło:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa; 2004, 1; 33-33
1643-7608
Pojawia się w:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust control of depth of anesthesia based on H∞ design
Autorzy:
Caiado, D. V.
Lemos, J. M.
Costa, B. A.
Powiązania:
https://bibliotekanauki.pl/articles/229439.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
depth of anesthesia
model uncertainty
robust control feedback
H∞ design
μ-synthesis
Opis:
This paper presents a case study on the design of a robust controller for the depth of anesthesia (DoA) induced by the drug propofol. This process is represented by a linear model together with a non-parametric uncertainty description that is evaluated using a patient model bank with 20 patients undergoing sedation. By using H∞ methods, the controller is aimed to comply with robust stability and performance specifications for the class of patient models considered. A minimization problem of sensitivity and complementary sensitivity is made to design the controller. The controller that results from this procedure is approximated by a controller with a lower order, that in turn is redesigned in discrete time for computer control application. The resulting controller is evaluated in simulations using a realistic nonlinear model of DoA.
Źródło:
Archives of Control Sciences; 2013, 23, 1; 41-59
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extraction of Ziziphus lotus fruit syrups: effect of enzymatic extraction and temperature on their rheological and chemical properties
Autorzy:
Letaief, T.
Mejri, J.
Ressureicao, S.
Abderrabba, M.
Costa, R.
Powiązania:
https://bibliotekanauki.pl/articles/2083051.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
Ziziphus lotus L.
syrup
shear-thinning
rheology
enzymatic extraction
Opis:
Fruit syrups are attracting increasing interest in the food industry. Ziziphus lotus fruit syrups were elaborated through the traditional and enzymatic methods with 30, 50 and 70° Brix. A chemical analysis revealed that Ziziphus lotus fruit powder and syrups present a potential source of energy through their relatively higher content of carbohydrates. Rheological oscillatory tests showed that syrups of 30°Brix demonstrate a viscous type of behaviour, the 70°Brix syrups possess an elastic behaviour, while the 50°Brix syrups present a mixed behaviour over the temperature range of 20 to 80°C. These syrups did not demonstrate any thixotropy or time dependence of viscosity. The complex viscosity was described successfully with a mathematical model that incorporates both independent variables, with an Arrhenius-type dependence on temperature, with an activation energy of 21.94 kJ mol-1 for the whole Brix range. The flow behaviour evaluation of the 30 and 50°Brix showed that these are shear-thinning fluids, tending to Newtonian fluids at higher temperatures. The dynamic viscosity was well described by the power law and the dependence of its parameters on temperature was adequately described by a Turian approach. The syrups of Ziziphus lotus fruit demonstrated a potential for further beneficial research with a view to obtaining a commercial food product.
Źródło:
International Agrophysics; 2021, 35, 1; 31-40
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
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