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1

The process of increasing the functionality of poly(glycidyl azide) GAP

Chmielarek Michał, Nowosielska Julia

Materiały Wysokoenergetyczne

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2022

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T. 14

93−-106

EN

Poly(glycidyl azide) (GAP) is a synthetic polymer with energetic properties due to the presence of an azide group in its structure. It is used in industry primarily as a component of binders for rocket fuel. Classically produced GAP has secondary hydroxyl groups, which react much more slowly with the crosslinking agents diisocyanates found in high-energy materials. It has been confirmed that methods can be used which modify the structure of GAP thereby obtaining a polymer with an increased number of functional groups. Furthermore, such processes produce a polymer with more desirable primary hydroxyl groups. Using such a polymer is economically advantageous and allows easier control of processes using GAP. Attempts were made to obtain such a modified polymer. The polymers obtained were subjected to FTIR analysis, viscosity measurements and hydroxyl group values.

PL

Poli(azydek glicydylu) to syntetyczny polimer o właściwościach energetycznych, które zawdzięcza posiadaniu w swojej strukturze grupy azydkowej. Znajduje zastosowanie w przemyśle przede wszystkim jako składnik lepiszczy do paliw rakietowych. Klasycznie wytwarzany GAP posiada drugorzędowe grupy hydroksylowe dużo wolniej reagujące z występującymi w materiałach wysokoenergetycznych czynnikami sieciującymi – diizocyjanianami. Potwierdzono możliwość zastosowania metod, które pozwalają zmodyfikować strukturę GAP i uzyskać polimer ze zwiększoną ilością grup funkcyjnych. Ponadto w procesie tym wytwarzany jest polimer o bardziej pożądanych pierwszorzędowych grupach hydroksylowych. Używanie takiego polimeru jest korzystne ekonomicznie i pozwala na łatwiejszą kontrolę procesów z użyciem GAP. Podjęto próby otrzymania tak zmodyfikowanego polimeru. Otrzymane polimery poddano analizie FTIR, pomiaru lepkości i wartości grupy hydroksylowej.

2

Driving factors affecting spatial and temporal variations in the structure of phytoplankton functional groups in a temperate reservoir

Ćirić M., Gavrilović B., Subakov-Simić G., Krizmanić J., Vidović M., Zebić G.

Oceanological and Hydrobiological Studies

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2015

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Vol. 44, No. 4

431--444

EN

During the twenty-five years of existence, water quality has declined and severe blooms of cyanobacteria have occurred in the Grlište Reservoir. Changes in phytoplankton functional groups over time and along horizontal and vertical gradients were investigated in the course of a one-year study in this water-supply reservoir. We identified 19 dominant taxa, classified into 12 phytoplankton associations. The presence of the codons C, P, D and S1 differentiated the transitional from the lacustrine part of the reservoir. The nitrogen-fixing cyanobacteria Dolichospermum viguieri dominated the phytoplankton community in the epilimnion during August and September, when the reservoir showed P-limitation, but the bloom was not observed. The driving factors that accounted for the main variability in phytoplankton functional groups along the seasonal and vertical profile were identified using the direct gradient analysis (RDA). Our results revealed the importance of two bipolar factors. The first factor explained the variability in phytoplankton due to thermal stratification and physical mixing, each process affecting the algal community in contrasting ways. The second factor was interpreted as reduction vs. oxidation processes. Positive correlation between stratification and water pumping by a drinking water plant indicated that human activities were not severe enough to break down the thermal stability of the reservoir and to cause a cyanobacterial bloom.

3

Functional traits and plasticity of plants in ecological research and education

Masarovičová E., Májeková M., Vykouková I.

Chemistry-Didactics-Ecology-Metrology

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2015

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R. 20, NR 1-2

59--65

EN

Plant functional traits are any morphological, physiological and phenological features, which indirectly affect plant fitness through their three basic components of plant individual performance - growth, reproduction and survival. These features represent also a keystone for plant functional groups, which are similar in three aspects - function on the level of organism, response to environmental factors and effect on ecosystems. Functional approach in ecology and vegetation study enables to evaluate plant communities on the base of species function in a community, and to relate functional structure of plant communities to particular environmental gradients. Species plasticity has many aspects that mirror species adaptations to the environmental conditions and which then also translate into functional structuring of plant communities. This approach is thus a novel and exciting mode how to carry on plant ecology, both in research and education at universities.

PL

Charakterystyczna funkcjonalność roślin zależy od ich cech morfologicznych, fizjologicznych i fenologicznych, które pośrednio wpływają na kondycję roślin poprzez trzy podstawowe elementy ich indywidualnego rozwoju, tj. wzrost, reprodukcję i przetrwanie. Cechy te stanowią również podstawę funkcyjnych grup roślinnych, które są podobne w trzech aspektach - funkcje na poziomie organizmu, odpowiedź na czynniki środowiskowe i wpływ na ekosystemy. Podejście funkcjonalne w ekologii i w badaniach roślin umożliwia ocenę zbiorowisk roślinnych w oparciu o funkcje gatunków w społeczności i odniesienie funkcjonalnej struktury zbiorowisk roślinnych do poszczególnych gradientów środowiskowych. Plastyczność gatunków ma wiele aspektów, które odzwierciedlają ich przystosowanie do warunków środowiskowych, a które następnie przekłada się także na funkcjonalną strukturę zbiorowisk roślinnych. Takie podejście jest więc nowym i interesującym sposobem rozumienia ekologii roślin, znajdującym zastosowania zarówno w badaniach, jak i w edukacji uniwersyteckiej.

4

Temporal fluctuations of the phytoplankton community in an isolated floodplain lake (North Mollaköy Lake) of the Sakarya River (Northern Turkey)

Sevindik T. O., Tunca H., Önem B., Tamer S. A.

Oceanological and Hydrobiological Studies

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2014

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Vol. 43, No. 4

381--392

EN

The aim of this study was to determine the spatial and temporal variation of phytoplankton and water quality in response to the hydrological regime in an isolated floodplain lake (North Mollaköy Lake) of the Sakarya River. Variations in the composition, biomass and functional groups of phytoplankton and environmental parameters were monthly analyzed in sub-surface samples collected from the pelagic zone at four stations from July 2012 to June 2013. A total of 109 taxa were identified, and the species which contributed the most to the phytoplankton biomass were grouped into 14 functional groups (FGs). The distribution of FGs was linked to the transition (T1 and T2), high (HW) and low (LW) water periods in North Mollaköy Lake. FGs J, MP, N, G, X1, X2, Y, W1, W2, S1, H1, B and C were the contributors to the phytoplankton biomass during the low-water period (LW) and the transition periods (T1 and T2), while Lo contributed the most during the high-water period (HW). RDA revealed that the most important factor affecting the temporal distribution of FGs was the water discharge and that there are some differences between stations in terms of Si, pH values and the distribution of FGs.

5

Zinc ion adsorption on carbon nanotubes in an aqueous solution

Ansari A., Mehrabian M. A., Hashemipour H.

Polish Journal of Chemical Technology

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2012

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Vol. 14, nr 3

29-37

EN

The literature devoted to numerical investigation of adsorption of heavy metal ions on carbon nanotubes is scarce. In this paper molecular dynamics is used to simulate the adsorption process and to investigate the effect of the infl uencing parameters on the rate of adsorption. The predictions of the molecular dynamics simulation show that the adsorption process is improved with increasing the temperature, pH of solution, the mass of nanotubes, and surface modifi cation of CNT using hydroxyl and carboxyl functional groups. The results predicted by the model are compared with the experimental results available in the literature; the close agreement validates the accuracy of the predictions. This study reveals that the water layers around the carbon nanotubes and the interaction energies play important roles in the adsorption process. The study also shows that electrostatic force controls the attraction of zinc ions on the nanotube sidewall.

6

Effect of young midfield shelterbelts development on species richness of macrofungi communities and their functional structure

Kujawa K., Kujawa A.

Polish Journal of Ecology

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2008

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Vol. 56, nr 1

45-56

EN

The aim of the study was to recognize features characterizing development of macrofungi communities occurring in afforestations planted in crop fields and to evaluate the role of these habitats in conservation of macrofungi and preserve high species richness. The study was carried out in 1998-2006 and covered four shelterbelts (planted in 1993-1996) located in the area of the Dezydery Chłapowski Landscape Park (western part of Poland). The shelterbelts were colonized by macrofungi just after planting. During first years of their growth a total of 174 species were recorded. Species composition changed significantly between initial (1998-2000) and final (2004-2006) period of study. Similarity of macrofungi communities (expressed as the Sorensen's index) between these two periods in studied shelterbelts ranged between 37 and 46%. In spite of high similarity in tree species composition between studied afforestations (69-80%), the communities of macrofungi differed strongly between these sampling plots (Sorensen's index was equal to about 40%). Pattern of changes in percentage share of functional groups, i.e. parasitic, mycorrhizal and saprotrophs (humicolous, lignicolous, litterinhibiting and muscicolous ones) in individual afforestations was different but the diversity of the communities measured with the Shannon-Weaver H' index on the basis of share of functional groups tended to increase with ageing of afforestations. On average, the share of fungi growing on soil (ectomycorrhizal and humicolous saprotrophic species) was highest among all distinguished groups. Species composition of particular functional group was changing during the study period. A species representing new groups (lignicolous saprotrophs and parasites) were appearing in some shelterbelts in successive years. There were recorded some species rare in Poland, eg. Psilocybe (Stropharia) melanosperma (Bull. ex Pers.: Fr.) Noordel., Clavariadelphus fistulosus (Holmsk.: Fr.) Corner, Thelephora caryophyllea (Schaeff): Fr., Agrocybe arvalis (Fr.) Singer, Galerina clavata (Velen.) Kuhner, Lachnella alboviolascens (Alb. & Schwein.: Fr.) Fr., Macrocystidia cucumis f. minor Joss, Mycena amicta (Fr.) Quel., Psilocybe (Stropharia) inuncta (Fr.: Fr.) Noordel., Trichophaea gregaria (Rehm) Boud. and Typhula filata (Pers.) Herter. Occurrence of rare and threatened species in young shelterbelts indicates that such afforestations, planted in crop fields but not treated by agricultural practices, contribute to the protection of species richness of macrofungi associated with tree communities and they are important substitute habitats for many species.

7

The oil polymeric resins with epoxy groups in side chains

Pochapska I., Bratychak M.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2003

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Vol. 52, nr 25

576-578

EN

The oil polymetric resins (OPRs) with functional groups are synthesized. The influence of 2.2'-azo-bis-izo-butyric nitrile amount, temperature, time of co-oligomerization and glycidilmethacrylate amount on the yield and characteristics of obtained OPRs with functional groups are investigated. The resins (OPRs obtained are combined with other co-polymers and used as active additives to the polymeric compostions.

PL

Otrzymano polimerowe zywice olejowe (OPR-y) zawierajace grupy funkcyjne. Zbadano wpływ 2,2'-azo-bis-izobutyronitrylu, temperatury i czasu ko-oligometryzacji z metakrylanem glicydlu na wydajność i właściwości OPR-ów. Otzrymane zywice w kombinacji z innymi kopolomerami mogą być stosowane jako aktywne dodatki w kompozycjach polimerowych.

8

Oil polymeric resins with functional groups on the basis of the C9 fraction

Bratychak M.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2003

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Vol. 52, nr 25

253-256

EN

It is proposed to obtain the oil polymeric resins (OPRs) with functional groups by the initiative copolymerization using aliphatic azodinitrillic compounds with epoxy, hydroxy, carboxy and peroxy groups and also peroxides and hydroperoxides with epoxy and unsaturated double bonds as initiators. OPRs are used as substitutes of vegetable oils in lacquer-varnish industry and as colophony at a paper production, at the production of rubber-technical products.

PL

Zaproponowano sposób otrzymywania polimerowych żywic olejowych (OPR) zawierających grupy funkcyjne drogą rodnikowej kopolimeryzacji z alifatycznymi związkami posiadającymi grupy epoksydowe, hydroksylowe, karboksylowe i nadtlenkowe. OPR-y mogą być używane jako zamienniki olejów roślinnych w przemyśle farb i lakierów oraz w przemyśle gumowym i papierniczym.