Science Collected Works - Research Publications

Permanent URI for this collection

Search Results

Now showing 1 - 4 of 4
  • Item
    No Preview Available
    Anatomical comparison of branches and trunks of seven commercial wood species
    Rahmanto, RGH ; Damayanti, R ; Agustiningrum, DA ; Oktapiani, C ; Satiti, ER ; Tutiana, ; Dewi, LM ; Krisdianto, ; Andianto, ; Djarwanto, ; Pari, G ; Karlinasari, L ; Bramasto, Y ; Aminah, A ; Novriyanti, E ; Siregar, IZ ; Teruno, WP ; Huda, MA ; Rohmadi, ; Yusuf, A ; Nugraha, H (IOP Publishing, 2021-11-26)
    Abstract Indonesia is a mega-biodiversity country that grows about 4000 timber producer tree species in tropical rain forest. The comprehensive information of wood properties and quality is important in managing the natural resources sustainably. However, stem in basic properties studies of wood from the natural forest is limited because of some difficulties in harvesting until the transportation process. Hence, study the wood branches becomes a solution, as sometimes wood core samples are not adequate. The question was whether the branch properties could represent the main stem properties? Wood anatomy is an important wood property that can predict the other properties, for instance, the physical and mechanical properties, that determine the effective use of this material. This paper aims to present the comparison of wood anatomical properties of branches and main stem of seven commercial wood species. Quantitative and qualitative anatomical structures were investigated according to the International Association of Wood Anatomist (IAWA) Committee. Result shows that the quantitative wood anatomy of four samples (Mimba, Leda, Jabon, and Bintangur) was statistically different, while only one parameter in Tusam, Mindi, and Khaya was different. Accordingly, it can be concluded that studying the wood properties could be carried out using branch effectively.
  • Item
    No Preview Available
    Fossil wood diversity record from Merangin region, Jambi, Indonesia
    Andianto, ; Damayanti, R ; Dewi, LM ; Ismanto, A ; Oktariani, H (IOP Publishing, 2021-11-26)
    Abstract Merangin is a region in Jambi province, Indonesia, which well-known for its geodiversity. As part of geodiversity, fossil woods play an important role in reconstructing the ancient trees during geological history. Since the study on fossil wood origin Merangin Regency, Jambi, is still limited, this study was conducted to determine fossil wood identity through anatomical features observation and estimate the age of fossil wood samples through geological analysis. The anatomical characteristics were observed using a light microscope to identify the botanical identity of the discovered fossil wood samples. The description of anatomical features refered to the IAWA list of microscopic features for hardwood identification. The result showed that all fossil woods had similarities with the modern wood from the Dipterocarpaceae family, namely Dryobalanoxylon sp. (Kamper), Hopenium sp. (Merawan/Hopea), Shoreoxylon sp. (Meranti), and Cotylelobioxylon sp. (Giam/Resak). These fossil woods were found in different estimated geological age namely Late Permian/Perem age (254-252 million years old), Late Miocene age (7.24-5.33 million years old); Late Pliocene to Early Pleistocene age (3.60-2.58 million years old); and Holocene age (11,700 years old - present). Another approach by using Global Mapper 11 resulted that all the fossil woods were estimated grown in Permian age (290 - 250 million years).
  • Item
    Thumbnail Image
    WGCN: Graph Convolutional Networks with Weighted Structural Features
    Zhao, Y ; Qi, J ; Liu, Q ; Zh, R (ASSOC COMPUTING MACHINERY, 2021)
    Graph structural information such as topologies or connectivities provides valuable guidance for graph convolutional networks (GCNs) to learn nodes' representations. Existing GCN models that capture nodes' structural information weight in- and out-neighbors equally or differentiate in- and out-neighbors globally without considering nodes' local topologies. We observe that in- and out-neighbors contribute differently for nodes with different local topologies. To explore the directional structural information for different nodes, we propose a GCN model with weighted structural features, named WGCN. WGCN first captures nodes' structural fingerprints via a direction and degree aware Random Walk with Restart algorithm, where the walk is guided by both edge direction and nodes' in- and out-degrees. Then, the interactions between nodes' structural fingerprints are used as the weighted node structural features. To further capture nodes' high-order dependencies and graph geometry, WGCN embeds graphs into a latent space to obtain nodes' latent neighbors and geometrical relationships. Based on nodes' geometrical relationships in the latent space, WGCN differentiates latent, in-, and out-neighbors with an attention-based geometrical aggregation. Experiments on transductive node classification tasks show that WGCN outperforms the baseline models consistently by up to 17.07% in terms of accuracy on five benchmark datasets.
  • Item
    Thumbnail Image
    Imaging the ignition of dense, inhomogenous liquid fuel sprays at elevated temperatures and pressures
    Han, M ; Gordon, R ; Talei, M ; Brear, M ; Lacey, J (The University of Queensland, 2020)
    This paper investigates the forced ignition of inhomogeneous, dense liquid fuel sprays. The fuel spray is pure n-Heptane, injected with a prototype gasoline direct injector designed by Delphi for the Engine Combustion Network’s Spray G research. This spray is ignited by a laser spark, delivered by a custombuilt high precision laser traverse system. The spray ignition process is recorded with a high-repetition rate schlieren imaging system. The impact of changes in chamber pressure and temperature on ignition probability statistics are investigated. Ignition probability is reduced by increasing chamber pressure and promoted by increasing chamber temperature. At a constant laminar flame speed, the impact of chamber temperature increase is greater than that of chamber pressure increase.