Physical, mechanical and hydration kinetics of particleboards manufactured with woody biomass (Cupressus lusitanica, Gmelina arborea, Tectona grandis), agricultural resources, and Tetra Pak packages

<p>Costa Rica cuenta con madera de varias especies proveniente de plantaciones forestales para abastecer la demanda de madera. Sin embargo, no se tienen los valores de esfuerzos admisibles para grados estructurales de estas maderas. El presente trabajo tiene como objetivo, mostrar los valores de diseño derivados de madera libre de defectos para nueve especies de plantación utilizadas en la reforestación comercial. Los esfuerzos analizados fueron flexión estática, compresión paralela y perpendicular al grano y cortante y tensión paralela al grano. Los resultadosen la madera libre de defectos mostró que Tectona grandis, Terminalia oblonga y Acacia mangium presentaron los más altos valores en MOE y MOR en flexión. En compresión paralela y perpendicular, T. grandis presentó la más alta resistencia, A. mangium y T. grandis fueron las especies con la mayor resistencia en tensión paralela al grano. A. mangium y Cupressus lusitanica mostraron los más altos valores en cortante paralela al grano. Vochysia guatemalensis y Bombacopsis quinata mostraron la resistencia más baja en todas las propiedades medidas. La derivación<br />de los esfuerzos de diseño permitió establecer tres grupos de especies. El grupo 1 está formado por Acacia mangium, T. grandis, Terminalia amazonia y T. oblonga con los más altos valores admisibles. El grupo 2, con valores intermedios de valores admisibles, lo componen Gmelina arborea y C. lusitanica. El grupo 3, con los valores admisibles más bajos, compuesto por<br />Alnus acuminata, B. quinata y V. guatemalensis.</p>

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CHEMICAL AND EXTRACTIVES COMPATIBILITY OF EMPTY BUNCH FRUIT OF Elaeis guineensis, LEAVES OF Ananas cumosos AND TETRAPAK WITH WOOD USED IN PARTICLEBOARDS IN TROPICAL AREAS

Latin American Applied Research - An international journal ◽

10.52292/j.laar.2015.356 ◽

2015 ◽

Vol 45 (1) ◽

pp. 1-10

Author(s):

R. MOYA ◽

D. CAMACHO ◽

R. SOTO ◽

J. F. MATA-SEGREDA ◽

J. VEGA-BAUDRIT

Keyword(s):

Infrared Spectrum ◽

Elaeis Guineensis ◽

Lignin Content ◽

Chemical Characterization ◽

Woody Species ◽

Tectona Grandis ◽

Chemical Compositions ◽

Timber Species ◽

Cupressus Lusitanica ◽

Tetra Pak

Tropical countries produce a great variety of lignocellulosic residues from small-area planted crops. Large amount of “Tetra Pak” package are also produced without any disposal treatment. In order to give solutions for waste management, residues must be incorporated in other processes, such as the manufacture of particleboards. The main objective of this work was to evaluate chemical compositions, extractives in different solvent, chemical characterization of extracts in polar and un-polar solvent utilizing infrared spectrum analysis. A second aim of this study was to test the compatibility between chemical composition and extractives of empty bunch fruit of Elaeis guineensis (BPF), the leaves of Ananas cumosos (PL) and “Tetra Pak” packages with three timber species (Gmelina arborea, Tectona grandis and Cupressus lusitanica).. Results showed that cellulose, ashes and lignin content of BPF, PL and “Tetra Pak” differ from those of the woody species. Similar result was obtained for pH and for the amount of substances extracted with different solvents. Infrared spectrum of water (polar), and ethanol-toluene (un-polar) solutions showed that the greatest differences in extracts were found in BPF and PL, this in relation to the studied woody species. Finally, HCMA showed that residues from BPF and “Tetra Pak” packages are slightly different, considering chemical compositions and extract content, to other woody species used for particleboard manufacture. Moreover, PL has the least compatibility with the woody species.

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Insectos barrenadores del xilema en especies forestales comerciales en Costa Rica

Revista Mexicana de Ciencias Forestales ◽

10.29298/rmcf.v7i35.76 ◽

2017 ◽

Vol 7 (35) ◽

pp. 079-089 ◽

Cited By ~ 1

Author(s):

Marcela Arguedas Gamboa ◽

María Rodríguez Solís

Keyword(s):

Costa Rica ◽

Acacia Mangium ◽

Tectona Grandis ◽

Gmelina Arborea ◽

Cordia Alliodora ◽

Cupressus Lusitanica ◽

Vochysia Guatemalensis ◽

Hyeronima Alchorneoides ◽

Alnus Acuminata

Insectos de varias familias producen daños a la madera de árboles en pie, lo que causa importantes pérdidas económicas en proyectos de reforestación comercial. Desde 1984, en el Instituto Tecnológico de Costa Rica se ha elaborado el diagnóstico nacional de plagas forestales. Al respecto, en este estudio se sistematiza la información referente a los barrenadores del xilema. Las muestras dañadas se recolectaron y llevaron al laboratorio de Sanidad Forestal del Instituto Tecnológico de Costa Rica para obtener los adultos en forma directa o mediante crianza; los cuales fueron identificados en instituciones por especialistas en taxonomía de insectos. Se registraron daños en 41 especies arbóreas, algunas de ellas son de gran importancia en los programas de reforestación comercial en Costa Rica como: Acacia mangium, Alnus acuminata, Bombacopsis quinata, Cordia alliodora, Cupressus lusitanica, Gmelina arborea, Hyeronima alchorneoides, Tectona grandis, Terminalia spp. y Vochysia guatemalensis. Asimismo, se identificaron 84 especies de insectos barrenadores comprendidas en 12 familias entomológicas: 36 % Cerambycidae, 29 % Curculionidae: Scolitinae, 10 % Hepialidae y 25 % otras. Sin embargo, no se informa de mortalidad causada por estos barrenadores, pero sí que afectan drásticamente la calidad de la madera, y por tal razón, deben ser considerados como plagas de gran impacto en la actividad forestal del país.

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Influence of the relative humidity on the hydration kinetics of concrete

2nd International RILEM Symposium on Advances in Concrete through Science and Engineering ◽

10.1617/2351580028.048 ◽

2006 ◽

Cited By ~ 1

Author(s):

Thomas Adam

Keyword(s):

Relative Humidity ◽

Hydration Kinetics ◽

Kinetics Of

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Hydration kinetics of little millet and proso millet grains: effect of soaking temperature

Journal of Food Science and Technology ◽

10.1007/s13197-019-03789-4 ◽

2019 ◽

Vol 56 (7) ◽

pp. 3534-3539

Author(s):

Sagar Patil Balkrishna ◽

R. Visvanathan

Keyword(s):

Hydration Kinetics ◽

Proso Millet ◽

Little Millet ◽

Kinetics Of ◽

Soaking Temperature

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Cement-Based Renders Manufactured with Phase-Change Materials: Applications and Feasibility

Advances in Materials Science and Engineering ◽

10.1155/2016/7254823 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 10

Author(s):

Luigi Coppola ◽

Denny Coffetti ◽

Sergio Lorenzi

Keyword(s):

Compressive Strength ◽

Phase Change ◽

Phase Change Materials ◽

Residential Buildings ◽

Setting Time ◽

Drying Shrinkage ◽

Hydration Kinetics ◽

Mechanical Performances ◽

Entrapped Air ◽

Kinetics Of

The paper focuses on the evaluation of the rheological and mechanical performances of cement-based renders manufactured with phase-change materials (PCM) in form of microencapsulated paraffin for innovative and ecofriendly residential buildings. Specifically, cement-based renders were manufactured by incorporating different amount of paraffin microcapsules—ranging from 5% to 20% by weight with respect to binder. Specific mass, entrained or entrapped air, and setting time were evaluated on fresh mortars. Compressive strength was measured over time to evaluate the effect of the PCM addition on the hydration kinetics of cement. Drying shrinkage was also evaluated. Experimental results confirmed that the compressive strength decreases as the amount of PCM increases. Furthermore, the higher the PCM content, the higher the drying shrinkage. The results confirm the possibility of manufacturing cement-based renders containing up to 20% by weight of PCM microcapsules with respect to binder.

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