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Wyświetlanie 1-11 z 11
Tytuł:
Cadmium effects on growth and photosynthetic pigment content of Chaetoceros gracilis
Autorzy:
Ferdian, Ferdian
Hindarti, Dwi
Permana, Rega
Powiązania:
https://bibliotekanauki.pl/articles/1030841.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Carotenoids
Cell density
Chaetoceros gracilis
Chlorophyll-a
Toxicity test
Opis:
Cadmium wastewater released by human activities will eventually enter the aquatic environment. Living organism that lives around could potentially exposed by these cadmium, including C. gracilis which play a critical role as a primary producer. Cadmium can reduce the growth rate and pigment content in C. gracilis. Therefore, toxicity testing becomes important to do considering that C. gracilis has many benefits such as shrimp feed and have active compounds for antibacterial and biodiesel. Toxicity test was performed in 96-hours with a series of concentration 0, 0.56, 1.0, 1.8, 3.2, 5.6 mg/L. IC50 cadmium results in concentrated cell density and chlorophyll-a C. gracilis were 1.62 mg/L and 3.4 mg/L, while carotenoids were not in accordance with the contribution of cadmium. NOEC and cadmium LOEC to C. gracilis cell density were 0.56 mg/L and 1.0 mg/L.
Źródło:
World Scientific News; 2020, 145; 245-255
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling Microcystis Cell Density in a Mediterranean Shallow Lake of Northeast Algeria (Oubeira Lake), Using Evolutionary and Classic Programming
Autorzy:
Arif, Salah
Djellal, Adel
Djebbari, Nawel
Belhaoues, Saber
Touati, Hassen
Guellati, Fatma Zohra
Bensouilah, Mourad
Powiązania:
https://bibliotekanauki.pl/articles/2174666.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
microcystis cell density
Multiple Linear Regression
Support Vector Machine
Particle Swarm Optimization
Genetic Algorithm
Bird Swarm Algorithm
Opis:
Caused by excess levels of nutrients and increased temperatures, freshwater cyanobacterial blooms have become a serious global issue. However, with the development of artificial intelligence and extreme learning machine methods, the forecasting of cyanobacteria blooms has become more feasible. We explored the use of multiple techniques, including both statistical [Multiple Regression Model (MLR) and Support Vector Machine (SVM)] and evolutionary [Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Bird Swarm Algorithm (BSA)], to approximate models for the prediction of Microcystis density. The data set was collected from Oubeira Lake, a natural shallow Mediterranean lake in the northeast of Algeria. From the correlation analysis of ten water variables monitored, six potential factors including temperature, ammonium, nitrate, and ortho-phosphate were selected. The performance indices showed; MLR and PSO provided the best results. PSO gave the best fitness but all techniques performed well. BSA had better fitness but was very slow across generations. PSO was faster than the other techniques and at generation 20 it passed BSA. GA passed BSA a little further, at generation 50. The major contributions of our work not only focus on the modelling process itself, but also take into consideration the main factors affecting Microcystis blooms, by incorporating them in all applied models.
Źródło:
Geomatics and Environmental Engineering; 2023, 17, 2; 31--68
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On continuous time version of two-phase cell cycle model of Tyrcha
Autorzy:
Zwoleński, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/748777.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
cell cycle
transport equations
invariant density
Markov operators
Opis:
We consider a model of two-phase cell cycle in a maturity-structured cellular population, which consists of a system of first order linear partial differential equations (transport equations). The model is based on similar biological assumptions as models of Lasota-Mackey, Tyson-Hannsgen and Tyrcha. We examine behavior of the solutions of the system along characteristics, give conditions for existence of invariant density, and compare results with outcomes of generational model.
Źródło:
Mathematica Applicanda; 2013, 41, 1
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved adhesion and growth of vascular smooth muscle cells in cultures on polyethylene modified by plasma discharge
Autorzy:
Parizek, M.
Kasalkova, N.
Bacakova, L.
Kolarova, K.
Lisa, V.
Svorcik, V.
Powiązania:
https://bibliotekanauki.pl/articles/284295.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomateriały
inżynieria tkankowa
Ar plasma discharge
high density and low density polyethylene
cell adhesion
cell proliferation
vascular smooth muscle cells
biomaterials
tissue engineering
Opis:
The attractiveness of synthetic polymers for cell colonization can be affected by physical and chemical modification of the polymer surface. In this study, high density polyethylene (HDPE, m.w. 0.952g/cm3) and low density polyethylene (LDPE, m.w. 0.922g/cm3) were modified by an Ar plasma discharge using Balzers SCD 050 device (exposure time 10, 50, 150 and 400 seconds, discharge power 1.7W). The material was then seeded with rat aortic smooth muscle cells (RASMC; passages 8 to 9, 17 000 cells/cm3) and incubated in a DMEM medium with 10% of fetal calf serum. On day 1 after seeding, the number of initially adhered cells was significantly higher on all modified HDPE and LDPE samples. On day 2, this difference persisted in HDPE, whereas in LDPE only the values on the samples modified by 150 and 400 seconds were significantly higher. On the 5th and 7th day, there were no significant differences in cell number among all LDPE samples. However, on the HDPE foils, significant differences were still apparent on the samples modified for 400 seconds. The cell spreading areas measured on day 1 after seeding were significantly larger on all modified LDPE samples, and, on day 2, on the HDPE samples exposed for 150s. The increased cell colonization was probably due to the formation of oxygen-containing chemical functional groups in the polymer. These results suggest that the responsiveness of the cell to the changes in physiochemical surface properties was more pronounced in HDPE than in LDPE. On both types of polyethylene, the most appropriate exposure time for the enhancement of cell adhesion and growth seemed to be 150 and 400 seconds.
Źródło:
Engineering of Biomaterials; 2007, 10, no. 67-68; 1-4
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD modelling of hydrogen starvation conditions in a planar Solid Oxide Fuel Cell
Autorzy:
Pianko-Oprych, P.
Zinko, T.
Jaworski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/779053.pdf
Data publikacji:
2017
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
planar Solid Oxide Fuel Cell
fuel starvation
current density
CFD modelling
Opis:
The aim of this study was to highlight the interest of using CFD technique as a diagnostic tool of a malfunctioning Solid Oxide Fuel Cells. Hydrogen starvation of a SOFC due to nitrogen dilution is one of the cell dysfunctions and can lead to its degradation. Identification of the starvation point allows to improve cell performance and establish the best conditions for degradation tests. To illustrate a potential of the CFD tool, several simulations of a single planar SOFC and its behaviour under hydrogen starvation were performed and analysed. The results showed that at lower cell voltage values of 0.3 and 0.5 V significant gradients in the electric current were noticed due to a local reduction in hydrogen concentration. The CFD analysis allowed defining desirable mass flow rate of hydrogen to SOFCs to avoid fuel starvation. The model constitutes a helpful tool for optimizing cell design and operational conditions.
Źródło:
Polish Journal of Chemical Technology; 2017, 19, 2; 16-25
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expression of vascular endothelial growth factor and microvessel density in oral squamous cell carcinoma and its correlation with various clinico-pathological parameters
Autorzy:
Panigrahi, Ranjita
Jha, Narendra Kumar
Hota, Subhransu Kumar
Powiązania:
https://bibliotekanauki.pl/articles/38695726.pdf
Data publikacji:
2024-03-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
microvessel density
oral squamous cell carcinoma
vascular endothelial growth factor
Opis:
Introduction and aim. Angiogenesis, which is accomplished by capillary sprouting, is the process by which new vessels are created from pre-existing ones. In tumor, once their initial blood supply is depleted, a tumour is unable to grow without additional blood flow. Additionally, a tumor’s microvasculature, or microvessel density (MVD), increases along with its capacity to produce angiogenesis. We aimed to observe the relationship between the expression of vascular endothelial growth factor (VEGF) and MVD (using CD34) in oral squamous cell carcinoma (OSCC). Material and methods. The expression of VEGF and CD34 antibodies was analysed using immunohistochemistry method on 50 cases of histopathologically proved OSCC. The expression was correlated with clinicopathological parameters. Results. A significant correlation was observed between VEGF expression and gender, LVSI. No correlation between any other factors and the difference in VEGF expression was statistically significant. Similarly, the MVD expression was not found to be statistically significant in any of the pathological parameters. Conclusion. VEGF positivity as well as MVD were found to be independent of the tumor pathology. Tumor MVD was found to be independent of the expression of VEGF. Further studies in a larger study group may establish a significant association so that antiangiogenic targeted therapy may be initiated.
Źródło:
European Journal of Clinical and Experimental Medicine; 2024, 22, 1; 82-87
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Heating of Woven Carbon Fiber Fabrics Using Thin-Film Solar Cells
Autorzy:
Yan, Taohai
Shi, Yajing
Zhuang, Huimin
Lin, Yu
Ke, Huizhen
Zhu, Chenxi
Lu, Dongdong
Cao, Shengbin
Zhu, Lvtao
Powiązania:
https://bibliotekanauki.pl/articles/2171982.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
thin-film solar cell
woven sample
heating line
carbon fibre
fabric density
Opis:
This study attempted to fabricate heating fabrics using thin-film solar cells. A lightweight and flexible thin-film solar cell was used as the power supply, and fabric samples made of carbon fiber heating lines were used as heating elements. Single-factor experiments of three factors (solar cell voltage, heating time, and carbon fiber heating line arrangement) were conducted, and their influence on the heating effect was analysed. Orthogonal experiments and variance tests were used to determine the influence of the three factors and the optimal heating process. All influential factors were shown to be statistically significant. This kind of heating fabric can be used in warm clothing or for heated clothing.
Źródło:
Fibres & Textiles in Eastern Europe; 2022, 2 (151); 61--67
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vascular smooth muscle cells in cultures on low density polyethylene modified with plasma discharge and biofunctionalization
Autorzy:
Parizek, M.
Kasalkova, N.
Bacakova, L.
Kolarova, K.
Lisa, V.
Svorcik, V.
Powiązania:
https://bibliotekanauki.pl/articles/285087.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
Ar plasma discharge
biomaterials
low-density polyethylene
cell adhesion
cell proliferation
grafting
tissue engineering
vascular smooth muscle cells
Opis:
Low density polyethylene (LDPE) was modified by an Ar plasma discharge and then grafted with glycine (Gly), bovine serum albumin (BSA) or polyethylene glykol (PEG). Some plasma-treated samples and samples grafted with BSA were exposed to a suspension of colloidal carbon particles (C, BSA+C). Pristine LDPE and tissue culture polystyrene dishes (PSC) were used as control samples. The materials were seeded with rat aortic smooth muscle cells and incubated in a medium DMEM with 10% of fetal bovine serum. On day 1 after seeding, the cells on LDPE modified with plasma only, Gly, BSA and BSA+C adhered in similar numbers as on PSC, while the values on non-modified and PEG-modified samples were significantly lower. On day 5, the highest cell numbers were found again on LDPE with Gly, BSA and BSA+C. On day 7, the highest number of cells was found on LDPE modified only with plasma. The latter cells also dis-played the largest cell spreading area. The increased cell colonization was probably due to the formation of oxygen-containing chemical functional groups after plasma irradiation, and also due to positive effects of grafted Gly, BSA and BSA in combination with colloidal C particles.
Źródło:
Engineering of Biomaterials; 2009, 12, no. 89-91; 25-28
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of planar plasma diode
Autorzy:
Wijewardena Gamalath, K. A. I. L.
Samarakoon, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/412368.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Plasma diode
plasma boundary
current density
Particle-In-Cell simulation
anode cathode gap
potential field
Opis:
To investigate the dynamics of a planar plasma diode system (PDS), a model based on the current density equilibrium at the interface was developed. The current densities and plasma boundary variations with the potential fields were obtained by simulating a single square pulse. The variation of an observed overshoot current density with the applied voltage is presented. Planar plasma diode system was also simulated for periodic, sine, square, triangular and saw tooth voltage patterns by varying the amplitude and frequencies. A method to find the lower bound of the electron density of plasma for a specified PDS is presented. Particle-In-Cell simulation technique was used to investigate the plasma particles and electric field distributions over the anode cathode gap for different intensities of external electric fields. The system became stable after few time steps and this time depends upon the intensity and polarization of the external field.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 8, 3; 220-242
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some ecological consequences of soil degradation under Estonian conditions
Ekologiczne konsekwencje degradacji gleby w warunkach estońskich
Autorzy:
Kuht, J.
Nugis, E.
Reintam, E.
Powiązania:
https://bibliotekanauki.pl/articles/807085.pdf
Data publikacji:
2006
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
Estonia
agroecological condition
plant cultivation
barley
cultivated soil
soil degradation
soil compaction
nitrogen fertilization
penetration resistance
soil bulk density
agricultural machine
cell fluid
pH
soil research
agricultural research
Opis:
The extreme soil compaction and standard indices for Estonian soils sted to sustainable crop production are worked out which could be a basis for chracterizing the agro-ecological conditions for some particular soils. Comparison of measurements showed, that increase of subsoil hardness by compaction is mostly visible in soils with relatively weak agro-technical capability (90 and 120 kPa). The penetration resistance of arable soils is quite different depending on Estonian area. We are briefly introducing our results concerning the influence of soil compaction on penetration resistance of different soils in Estonia, on uptake of nutrients and new viewpoints concerning the changes in cellualar fluid pH of barley as depended on the soil compaction. Concerning degree of intracellular fluid pH we could conclude that this method is rather sensitive and allows us to find out plausible relations between the CpH compaction of soil and the level of the nitrogen fertilizer. Our contribution to this work justified itself and allowed us to analyse from a new point of view the positive as well as negative aspects of the effect of soil compaction and level of nitrogen fertilizer. Without nitrogen fertilizer the influence of soil compaction is rather negative. The effect of soil bulk density on cellular fluid pH of barley leaves generally depends on the number of passes. The experiment showed also that stronger decrease of nutrient content started at the same soil bulk densityvalue, at which the cellular fluid pH quickly increased. If the soil bulk density- increased up to level of 1.52-1.54 Mg·m⁻³, the cellular fluid pH increased very quickly.
Opracowano wskaźniki i standardy odnoszące się do maksymalnego, z punktu widzenia zrównoważonej produkcji rolniczej, ugniecenia gleb estońskich. Mogą one stanowić podstawę charakteryzowania warunków agro-ekologicznych dla niektórych gleb. Porównanie wyników badań wykonanych w różnych miejscach wskazuje, że wzrost zwięzłości podglebia w wyniku ugniecenia jest najbardziej widoczny na glebach o stosunkowo słabej nośności agro-technicznej (90 i 120 kPa). Opory penetracji gleb uprawnych różnią się znacznie w zależności od rejonu Estonii. Przedstawiliśmy w skrócie nasze wyniki, dotyczące wpływu ugniecenia gleb na opory penetracji dla rolniczych gleb Estonii i na pobieranie składników nawozowych, a także przedstawiliśmy nasz pogląd dotyczący zmian odczynu pH płynu komórkowego jęczmienia w zależności od ugniecenia gleby. Co się tyczy poziomu odczynu pH płynu komórkowego stwierdziliśmy, że ta metoda jest dostatecznie czuła i pozwala ustalić wiarygodne relacje między CpH, ugnieceniem gleby i poziomem nawożenia azotowego. Nasz wkład w tę pracę był uzasadniony i pozwolił analizować z nowego punktu widzenia zarówno pozytywne jak i negatywne aspekty ugniecenia gleby i nawożenia azotowego. Bez nawożenia azotowego skutki ugniecenia są raczej negatywne. Wpływ gęstości gleby na pH płynu komórkowego liści jęczmienia zależy głównie od liczby przejazdów. Eksperyment wykazał również, że spadek ilości pobranego nawozu rozpoczyna się przy tej samej wartości gęstości gleby, przy której występuje gwałtowny wzrost pH płynu komórkowego. Przy wzroście gęstości gleby do poziomu 1,52-1,54 Mg·m⁻³, pH płynu komórkowego bardzo szybko wzrasta.
Źródło:
Zeszyty Problemowe Postępów Nauk Rolniczych; 2006, 508
0084-5477
Pojawia się w:
Zeszyty Problemowe Postępów Nauk Rolniczych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energetyczna analiza porównawcza zespołów napędowych w zastosowaniu do lekkiego statku powietrznego
Energy comparative analysis of power units for use in light aircraft
Autorzy:
Kuźniar, Michał
Powiązania:
https://bibliotekanauki.pl/articles/314301.pdf
Data publikacji:
2019
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
napęd hybrydowy
ogniwo paliwowe
samolot lekki
motoszybowiec
energia zawarta w paliwie
gęstość energii
hybrid propulsion
fuel cell
light aircraft
motor glider
energy contained in fuel
energy density
Opis:
W nawiązaniu do badań nad ekologicznymi źródłami napędu dla samolotów przeprowadzono energetyczną analizę porównawczą dla zespołów napędowych korzystających z rożnych źródeł zasilania. Do analizy wykorzystano płatowiec motoszybowca AOS-71. Obliczenia przeprowadzono dla różnych zespołów napędowych: spalinowego, elektrycznego, hybrydowego spalinowego oraz hybrydowego z ogniwem wodorowym. Podstawowym założeniem była taka sama masa startowa samolotów wynosząca 660 kg. Dokonano wyznaczenia energii zgromadzonej na pokładzie, a następnie długotrwałości i zasięgu lotu dla każdego rodzaju napędu. Analizę przeprowadzono dla dwóch trajektorii lotu. Wyniki przedstawiono na wykresach i omówiono we wnioskach.
In reference to the research conducted on environmentally friendly sources of propulsion for aircrafts, there was carried out an energetic comparative analysis for power units using various power sources. For this analysis, the AOS-71 glider airframe was used. The calculations were done for different variants: a combustion engine, an electrical engine, a hybrid combustion engine and a hybrid engine with a hydrogen cell. The research was based on the assumption of the same aircraft take-off weight of 660 kg. The energy accumulated on board was determined, and then the duration and range for each type of propulsion for two flight trajectories. The results were presented in diagrams and discussed in the conclusions.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2019, 20, 1-2; 88-92
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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