African baobabs with double closed ring-shaped structures and two separate false cavities : radiocarbon investigation of the baobab of Golconda Fort

Author Posting. © Studia Chemia, 2016. This article is posted here by permission of Studia Chemia for personal use, not for redistribution. The definitive version was published in Studia Chemia 2016, no. 4 (2016): 21-30.The article discloses the results of radiocarbon investigation of the baobab of Golconda Fort, Hyderābād, India, which is the largest African baobab outside Africa. Two wood samples were collected from the large inner cavity; of these we extracted several segments for AMS (accelerator mass spectrometry) radiocarbon dating. The oldest sample segment had a radiocarbon date of 342 ± 22 BP, which corresponds to a calibrated age of 430 ± 20 yr. We estimate that the oldest part of the baobab has an age of 475 ± 50 yr. The investigation of the baobab of Golconda Fort revealed that it consists of 6 + 2 fused stems. Six stems build two rings that close two distinct false cavities, while two additional stems are located outside the rings. We called this new type of architecture double closed ring-shaped structure with two separate false cavities.The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76

Radiocarbon dating of the old ash of Aiton, Romania

Author Posting. © Studia Chemia, 2018. Studia Universitatis Babes-Bolyai Seria Chemia is an Open Access Journal (read, download, copy, distribute, print for research use, search, or link to the full texts of articles). The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia 63, no. 3 (2018): 41-48, doi:10.24193/subbchem.2018.3.03.The article reports the AMS (accelerator mass spectrometry) radiocarbon investigation results of the old common ash of Aiton. Five wood samples were collected from the trunk of the tree. The deepest ends of the samples were analysed by AMS radiocarbon. We found radiocarbon dates between 165 ± 20 BP and 240 ± 18 BP, which correspond to calibrated ages of 230 – 360 years. These results, combined with a ring counting estimate, indicate an age of 330 ± 30 years for the ash of Aiton. By this value, the ash of Aiton becomes the oldest known common ash with accurate dating results.The research was funded by the Romanian Ministry of Research and Innovation CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2016-0776, Nr. 90/2017

Radiocarbon dating of Makuri Le boom, a very old African baobab from Nyae Nyae, Namibia

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Patrut, R. T., Patrut, A., Rakosy, D., Rakosy, L., Lowy, D. A., Von Redenf, K. F., & Bodis, J. Radiocarbon dating of Makuri Le boom, a very old African baobab from Nyae Nyae, Namibia. Studia Universitatis Babes-Bolyai Chemia, 65(2), (2020): 149-159, doi:10.24193/subbchem.2020.2.12.The article reports the AMS (accelerator mass spectrometry) radiocarbon dating results of Makuri Lê boom, a very large African baobab from Nyae Nyae Conservancy, Namibia. The investigation of this superlative baobab shows that it consists of 12 independent stems of different dimensions, which belong to three generations. Makuri Lê boom has an open ring-shaped structure, a type of architecture which allows baobabs to reach very large sizes and old ages. The oldest sample has a radiocarbon date of 1602 ± 17 BP, which corresponds to a calibrated age of 1520 ± 35 calendar yr. By this value, Makuri Lê boom becomes one of the oldest dated baobabs and angiosperms with accurate dating results.The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2016-0776, Nr. 90/2017

Radiocarbon dating of a very large African baobab from Limpopo, South Africa : investigation of the Sagole Big Tree

Author Posting. © Studia Chemia, 2017. This article is posted here by permission of Studia Chemia for personal use, not for redistribution. The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia 62, no. 2, Tom 2 (2017): 355-364, doi:10.24193/subbchem.2017.2.28.The article reports the AMS (accelerator mass spectrometry) radiocarbon dating results of Sagole Big tree, a giant African baobab from Limpopo, South Africa. Several wood samples were collected from the walls of its inner cavity and dated by radiocarbon. The age values along the cavity samples increase with the distance into the wood. This anomaly shows that the cavity is a false one. The oldest sample segment had a radiocarbon date of 781 ± 29 BP, which corresponds to a calibrated age of 740 ± 15 yr. We estimate that the oldest part of the Sagole baobab has an age of 800-900 yr. We determined that the tree has a closed ring-shaped structure, which consists of a large unit with six fused stems and of two additional leaning stems.The research was funded by the Romanian Ministry of Scientific Research CNCSUEFISCDI under grant PN-II-ID-PCE-2013-76

African baobabs with a very large number of stems and false stems : radiocarbon Investigation of the baobab of Warang

Author Posting. © Studia Chemia, 2017. This article is posted here by permission of Studia Chemia for personal use, not for redistribution. The definitive version was published in Studia Universitatis Babes-Bolyai, Seria Chemia 62, no. 1 (2017): 111-120, doi:10.24193/subbchem.2017.1.09.The article presents the AMS (accelerator mass spectrometry) radiocarbon dating results of the baobab of Warang, Senegal. The investigation of the baobab revealed that it consists of 18 partially fused stems, which represents the largest number of stems reported for an African baobab. Three stems build the ring that closes a false cavity, while 15 stems grow outside the ring. Seven wood samples were collected from the false cavity and from the outer part of other stems. The dating results evinced that the stems belong to four different generations, out of which the first generation is around 500 years old. We also documented the presence of false stems, which emerge from a large adjacent stem, are triangular in horizontal section and act as an anchor. The baobab of Warang possesses 12 ordinary stems and 6 false stems.The research was funded by the Romanian Ministry of National Education CNCS-UEFISCDI under grant PN-II-ID-PCE-2013-76

Interactions of water and methanol with MeAPO-5: FTIR microspectroscopic study on single crystals

Water and methanol were chosen as small polar probe molecules. Their interactions with the framework of AFI type molecular sieves in the form of single large crystals were investigated with FTIR microspectroscopy. Water molecules interact with framework Al cations of AlPO4-5. Hydrogen bonds between water molecules themselves as well as between water and framework oxygen have been inferred from the absence of free stretching OH vibrations. Methanol exhibited weaker interactions with AlPO4-5 than water. The both polar molecules on MeAPO-5 materials interacted primarily with the bridging OH groups. Strongly polar molecules revealed a bimodal distribution of acid strength of the bridging OH groups. Two adsorbate species have been found to occur, both bound via hydrogen bonds of different strength dependent on the adsorption site. The interactions between the probe molecules and the framework are stronger in the confined environment of the narrow channels than in the wide channels. All these interactions are weak and do not lead to structure changes as, e.g., in ZSM-5