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Cellulose based micro- and nanocomposites

Çetin N. S., Özmen N.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 76, nr 1

9--14

EN

Purpose: In this study, the comparative role of micro-and nano- sized cellulose powder in exploring the influence on the mechanical properties of high density polyethylene (HDPE) composites was investigated. Design/methodology/approach: For production of alpha-cellulose and nanocrystalline cellulose, pulp was produced from Turkish pine (Pinus brutia Ten.) sapwood by Kraft pulping technique. Firstly, alpha-cellulose was isolated from Turkish pine pulp. After that, microcellulose and nanocrystalline cellulose were produced from this alpha-cellulose by grinding and acid hydrolysis technique, respectively. In order to compare the effect of micro-cellulose or nanocrystalline cellulose (CNC) as a filler, micro-cellulose or CNC and HDPE composites were produced with 3 different wt% cellulose containing (1.5 and 10 wt%). Findings: The nanocrystalline cellulose-filled HDPE had a significantly higher tensile and impact strength than the micro-cellulose-filled HDPE composites.

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Carbon-13 in alpha-cellulose of oak latewood (Jędrzejów, Southern Poland) during the Maunder Minimum

Pazdur A., Korput S., Fogtman M., Szczepanek M., Hałas S., Krąpiec M., Szychowska-Krąpiec E.

Geological Quarterly

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2005

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Vol. 49, No. 2

165-172

EN

We have studied the δ13C signature in latewood alpha-cellulose of an ancient oak (Quercus robur L.) from a Cisterian Abbey belfry in Jędrzejów (Southern Poland). The time scale for the delta 13C record during 1631-1765 AD was built on the basis of detailed dendrochronology studies. Techniques available for extraction of alpha-cellulose from small samples have been used, the mean value of alpha-cellulose extraction efficiency being ca. 35%. In the delta 13C record of alpha-cellulose the cooling between 1650-1700 AD is clearly visible as a decrease of about 1.5‰. This period is consistent with the interval of the lowest solaractivity between 1645 and 1715 AD, which is known as the Maunder Minimum. Anti-correlation between δ13C and δ13C during the Maunder Minimum was observed but δ13C record is delayed by about 30 years with respect to the Maunder Minimum.

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Delta 13C in tree rings alfa-cellulose. A methodology of measurements and interpretation: state of the art

Pawełczyk S., Pazdur A.

Geochronometria

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2000

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Vol. 18

15-18

EN

The development of a tree is dependent upon the climatic and environmental conditions under which it grows. Formed growth rings represent integration of these variables during each growing season. More parameters other than ring-width are required to produce satisfactory reconstruction of past environmental changes. Stable isotope variations within the growth rings may provide other parameters. The variation of delta13C indices in the latewood alpha-cellulose is highly correlated with combined July and August environmental variables. Investigation of isotopic carbon composition in annual tree rings from Upper Silesia and ecologically clean Augustów Wilderness region were recently undertaken in the 14C Laboratory in Gliwice. In that time a series of radiocarbon concentration measurements in single tree rings and delta13C in the entire organic matter were carried out. Such evaluated values of delta 13C are used to correct radiocarbon concentration. However they cannot be used to reconstruct climatic and environmental conditions.