199 results on '"Roger MOYA"'
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2. Energy Production and its Characteristics from Four Tropical Trees Species Planted in Short Rotation Woody Systems in Costa Rica
- Author
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Carolina Tenorio, Roger Moya, Olman Murillo, and Jonathan Loría
- Subjects
tropical tree ,bioenergy ,firewood ,spacing ,scr ,tropical species ,Biotechnology ,TP248.13-248.65 - Abstract
Short-rotation crop (SRC) systems with woody species have been planted in Costa Rica. However, information about different tree species and spacing is limited. The objective of the present study was to examine biomass production and the physical, energy, and chemical properties of feedstock of four tropical tree species (Cordia alliodora, Dipteryx panamensis, Gmelina arborea, and Tectona grandis) in 34-month-old plants planted at four spacings (0.5x1.0 m, 1.0x1.0 m, 1.0x2.0 m, and 2.0x2.0 m). The highest mortality rate (50%) was found in G. arborea; however, diameter, height, basal area, and biomass production in G. arborea plantations were higher than T. grandis, C. alliodora, and D. panamensis. Spacing effects on diameter, height, basal area, and biomass production were observed in 10-month-olds. Wide spacing presented the highest values in diameter and height, but the highest biomass production was found in the narrow spacing. Also, biomass distribution was different in D. panamensis in relation to other species. Specify gravity, density, and moisture content of biomass showed high variation between species and spacing, but the energy and chemical properties of biomass showed few differences. These results suggest that these four species were uniform in terms of their energy and chemical properties, regardless of the spacing used. Finally, three species (G. arborea, C. alliodora, and T. grandis) presented important potential for use in SRC systems. G. arborea was the species with the highest production but a high mortality rate.
- Published
- 2023
3. Flooring characteristics of thermo-mechanical densified wood from three hardwood tropical species in costa rica
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Carolina Tenorio, Roger Moya, and Angel Navarro Mora
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tropical species ,low density ,spring-back ,flooring properties ,Forestry ,SD1-669.5 ,Manufactures ,TS1-2301 - Abstract
Densification is one method used to modify low-density woods to make them achieve the hardness required for flooring application. The purpose of this study was to investigate the effect of thermo-mechanical densification with pre-heating in wood of Alnus acuminata, Vochysia ferruginea and Vochysia guatemalensis from, seeking to stabilize and reduce spring-back of the densified wood and evaluate its performance in flooring applications. The results showed that the wood of the three species turned dark. This is because brightness diminished and yellowness and redness increased. Weight loss due to pre-heating was statistically higher in V. ferruginea and V. guatemalensis. The final density and spring-back were statistically similar in the three species. The percentage of densification of A. acuminata and V. guatemalensis were statistically higher than for V. ferruginea and the degree of compression was statistically higher in V. guatemalensis. As for flooring evaluation, the percentage of densification, temperature and time of pre-heating affected the behavior of densified wood flooring. The low percentage of densification and high weight loss in the pre-heating stage caused greater values of wear, wear index, residual deformation, residual indentation for the falling ball indentation test, and more damages in the surface indentation test in wood of V. ferruginea.
- Published
- 2021
4. Effect of Thermo-Treatment on the Physical and Mechanical, Color, Fungal Durability of Wood of Tectona Grandis and Gmelina Arborea from Forest Plantations
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Luis Diego MÉNDEZ-MEJÍAS and Roger MOYA
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wood ,thermo-treatment ,dimensional stability ,durability ,shrinking ,color ,densitylity, shrinking, color, density ,Mining engineering. Metallurgy ,TN1-997 - Abstract
This study evaluated the effect of thermo-treatment (THT) at 4 temperatures on the density, shrinking, mass loss, moisture absorption, color, durability in terms of resistance to decay, flexural strength, tensile adhesion of glue line and the infrared spectrum of the wood of Tectona grandis and Gmelina arborea. Sapwood, heartwood and radial and tangential grain patterns were studied. The results showed that the THT temperature decreases the density, the percentage of moisture absorption, the modulus of elasticity and modulus of rupture in the flexure test and the tensile adhesion of glue line. The percentage of shrinking and durability presented irregular behavior relative to the THT temperature. The percentage of mass loss increased with increasing THT temperature in both species. The total color change (∆E*) of thermo-treated wood (THTwood) also increased with increasing THT temperature. Sapwood of T. grandis and G. arborea, having clearer shades, showed a more noticeable color change compared to hardwood; however, no significant differences were obtained between some of the THT temperatures.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17545
- Published
- 2018
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5. Evaluation of Unmanned Aerial Vehicles (UAV) as a Tool to Predict Biomass and Carbon of Tectona grandis in Silvopastoral Systems (SPS) in Costa Rica
- Author
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Javier Hernández-Cole, Edgar Ortiz-Malavassi, Roger Moya, and Olmán Murillo
- Subjects
unmanned aerial vehicles (UAV) ,silvopastoral system (SPS) ,Tectona grandis ,aboveground biomass ,carbon ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 - Abstract
The main objective of this research was to evaluate the use of unmanned aerial vehicles (UAVs) in estimating the aboveground biomass and carbon, and the dasometric characteristics at three different spacings (2.5 m × 1.0 m, 2.5 m × 2.0 m and 2.5 m × 3.0 m) in a silvopastoral system (SPS) for the biomass production of Tectona grandis. A total of 90 trees were sampled, 63 of which were used to perform a dasometric evaluation (vertical and horizontal) in a spacing test in an SPS, and the rest to evaluate the use of UAVs in estimating the aboveground biomass in the spacing test. The results showed significant differences in average diameter at breast height (dbh) between spacings, and in aboveground biomass per tree. The amount of aboveground biomass and carbon per hectare increases at smaller spacings, but the differences were not statistically significant. A logarithmic model was prepared to estimate the dbh based on the crown diameter from the data collected taken in the field, since estimating this variable by means of UAVs is difficult. Significant differences were found in the aboveground biomass estimated using the field data compared to UAV data. The estimation of the crown diameter of the selected trees, hindered by the canopy closure in the SPS, was not adequate, which could influence the amount of aboveground biomass estimated using UAV data.
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- 2021
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6. Characteristics and properties of torrefied biomass pellets from Gmelina arborea and Dipterix panamensis at different times
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Johanna Gaitán-Álvarez and Roger Moya
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Forestry ,SD1-669.5 - Abstract
La torrefacción y peletización se han estudiado en la generación de calor a partir de residuos lignocelulósicos, para incrementar las propiedades energéticas del material. El objetivo del presente trabajo fue torrefaccionar aserrín de Gmelina arborea y Dipteryx panamensis a 200 °C en tres tiempos: 0, 15 y 20 minutos. Con las biomasas obtenidas se fabricaron pellets de 6 mm de diámetro y se evaluaron sus propiedades físicas, el poder calórico, la densidad y la propiedad mecánica de resistencia a la compresión. Ambas especies presentaron características físicas similares con respecto al diámetro (0.50 mm), longitud (21.50 mm) y porcentaje de absorción de agua (6.00 %). El poder calórico aumentó de 9,749 kJ·kg-1 en la biomasa sin torrefaccionar a 18,126 kJ·kg-1 en la biomasa torrefaccionada. Los pellets de D. panamesis presentaron mayor densidad y resistencia a la compresión que los de G. arborea. Con base en los resultados, la resistencia a la compresión del pellet disminuye cuando el tiempo de torrefacción aumenta. Existe correlación positiva entre la densidad de los pellets y la resistencia a la compresión. La especie D. panamensis presenta mejor comportamiento a la torrefacción y peletización que la madera de G. arborea.
- Published
- 2016
7. Gross heating value of various shade-trees wood in coffee plantation in Costa Rica and its relation with extractives and specific gravity
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Roger Moya, Róger Bonilla, and Carlos Zelada Fonseca
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tropical species ,extractives content ,biomass fuelwood ,Agriculture - Abstract
Shade-trees with energy use in coffee plantations are an important alternative to increase profitability in groforestry systems. The aim of this study was to investigate gross calorific value (GCV) of 15 shade-tree species in coffee plantations in Costa Rica. The relationships between specific gravity and extractives content on GCV was evaluated. The results revealed that GCV varied from 15.9 to 21.9 MJ kg-1 for sapwood, and from 15.3 to 21.9 MJ kg-1 for heartwood. No consistency was observed regarding to relation of type of wood (sapwood or heartwood) and GCV. The highest GCV value was found in Pinus caribaea for sapwood and heartwood. However Cupressus lusitanica, presented high GCV in sapwood too. The lowest values were found in Schizolobium parahyba in sapwood and Zygia longifolia and Eucalyptus globulus in heartwood. Carbon content (C) and carbon/nitrogen ratio (C/N ratio) and extractives in sodium hydroxide and dichloromethane were correlated with GCV in sapwood and heartwood. Meanwhile extractives in hot water were correlated in heartwood, and nitrogen content (N) and extractives in cool water were too correlated in sapwood.
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- 2018
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8. Gmelina arborea 'death disease' in fast-growth plantations: Effects of soil and climatic conditions on severity and incidence and its implications for wood quality
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Marcela Arguedas, María Rodriguez-Solis, Roger Moya, and Alexander Berrocal
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death syndrome ,soil management ,tropical species ,pathogen ,Forestry ,SD1-669.5 - Abstract
Aim of study: Plantations are threatened by an emerging disease called “Gmelina death disease”. The objective of this study was measured the incidence and severity of this disease and were correlated with the characteristics of the plantations, micro- and macronutrients in the soil and climatic parameters. Area of study: The present study evaluated 16 symptomatic fast-growth plantations of different age in Costa Rica Material and methods: Fungi were identified from xylem of infected trees. Incidence and severity was measured and correlated with the characteristics of the plantations, micro- and macronutrients in the soil and climatic parameters. Root condition and the quality (specify gravity, mechanical and decay resistance and chemical compositions), of the wood of symptomatic and asymptomatic trees were compared. Main results: Three fungal species (Chaetomella raphigera, Fusarium solani and Rhizomucor variabilis) were identified from diseased samples. Clay content in the soil profile from 10-20 cm deep explained a significant proportion of the variation in the incidence and severity of the disease, and stand density was related to severity. Although two climatic variables, Holdridge’s potential annual evapotranspiration and Thornthwaite’s potential evapotranspiration, showed a relationship between the incidence in the trees and symptoms of the disease. Infected wood turned black in symptomatic trees. Specify gravity and mechanical resistance of infected wood decreased, whereas its natural durability was unaffected. Changes were observed in the quantities of Mg, Fe, Ca, K and Zn in infected wood. Research highlights: Gmelina plantations established in sites with high stand densities and high contents of clay increase susceptibility to this disease.
- Published
- 2018
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9. Effect of nanoclay-treated uf resin on the physical and mechanical properties of plywood manufactured with wood from tropical fast growth plantations
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Freddy Muñoz and Roger Moya
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Adhesive ,Cordia alliodora ,Gmelina arborea ,veneer ,Vochysia ferruginea ,Forestry ,SD1-669.5 ,Manufactures ,TS1-2301 - Abstract
Physical and mechanical properties were evaluated on cross-laminated panels (plywood) fabricated with three plantation species (Cordia alliodora, Gmelina arborea and Vochysia ferruginea) from tropical climates in Costa Rica. The panels were glued with urea-formaldehyde resin modified with nanoclay at four concentrations (0.75, 1.00, 1.50 and 2.00 per cent) and unmodified resin. It was determined that addition of nanoclay to urea-formaldehyde adhesive positively decreased moisture absorption and swelling of the plywood panel with statistical significance. However, nano-modification did not have a significant effect on the density and specific weight of plywood. Nano-modification of urea-formaldehyde resin with nanoclay at 0.75 per cent improved the Module of rupture and Modulus of elasticity in flexure parallel to surface in the three species, also increasing mechanical resistance to strains in parallel tension, shear and compression. By means of electronic microscopy, it was evidenced that the nano-modified adhesive became diffused at the inside of the cellular structure of wood in a better way, allowing for the generation of a transition zone that increased the mechanical properties at the macro level. According to the properties evaluated, it was determined that 0.75 per cent is the optimal percentage to use of nanoclay on urea-formaldehyde resin.
- Published
- 2018
10. Quality of Pellets Made from Agricultural and Forestry Crops in Costa Rican Tropical Climates
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Carolina Tenorio, Roger Moya, Mario Tomazello-Filho, and Jorre Valaert
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Pellet properties ,Biomass ,Fuel ,Short-rotation crops ,Mixture species ,Biotechnology ,TP248.13-248.65 - Abstract
Pellets may be produced with different types of agriculture or forestry crops in Costa Rica. This work evaluated the energy, physical, and mechanical properties of pellets fabricated from 12 types of agricultural and forestry crops (Ananas cumosos, Arundo donax, Coffea arabica, Cupressus lusitanica, empty fruit bunch and oil palm mesocarp fiber of the fruit of Elaeis guineensis, Gynerium sagittatum, Pennisetum purpureum, Phyllostachys aurea, Saccharum officinarum, Sorghum bicolor, and Tectona grandis), and similarities among these crops were established by multivariate principal component analysis. High variation was found in the pellet properties. The energy evaluation revealed that C. lusitanica and P. aurea are the crops with the best qualities for fuel use because of their high calorific values (from 16807 kJ/kg and 19919 kJ/kg, respectively) and low ash content (1.03% and 3.39%, respectively). As for physical properties, most crops exhibited values within the range noted by several authors and standards. All 12 pellet crops displayed high durability (from 72.12% to 92.98%) and compression force (from 295.18 N to 691.86 N). Moreover, the evaluation of crop similarities allowed the determination of four group combinations. Within these groups, C. lusitanica, P. aurea, and G. sagittatum had similar energy qualities and the best caloric characteristics.
- Published
- 2014
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11. Use of coffee (Coffea arabica) pulp for the production of briquettes and pellets for heat generation
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Robert Cubero-Abarca, Roger Moya, Jorre Valaret, and Mario Tomazello Filho
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Resíduos de café ,secagem ,processamento de café ,biomassa ,bio-recursos ,Agriculture (General) ,S1-972 - Abstract
Coffee bean (Coffea arabica) processing generates high amount of residues that are sources of environmental pollution. Therefore, an appropriate solution is needed. The objective of this study was to determine the potential of coffee pulp to produce briquettes and pellets. The study included pulp drying (using air, solar and hot air methods); the production of briquettes and pellets; the evaluation of their energy, physical and mechanical properties; and the evaluation of pellet quality using X-ray densitometry. The results showed that the pulp presented an initial moisture content of 90%, resulting in drying times of 699, 308 and 55 hours for air, solar and hot air drying, respectively, and the calorific values of the pellets and briquettes were 12,501 kJ kg-1 and 11,591 kJ kg-1, respectively. The ash content was 8.68% for the briquettes and 6.74% for the pellets. The density of the briquettes was 1,110 kg m-3, compared with 1,300 kg m-3 for the pellets. The apparent densities were 1,000 kg m-3 and 600 kg m-3 for the briquettes and pellets, respectively, and the water absorptions by the briquettes were 7.90% and 8.10% by the pellets. The maximum horizontal compression effort was 26.86 kg cm-2, measured in the pellets, compared with 4.52 kg cm-2 in the briquettes. The maximum horizontal load was 93.24 kg, measured in the briquettes, compared with 33.50 kg in the pellets. The value of the pellet durability test was 75.54%. X-ray densitometry showed that the pellet was uniform and a few cracks were observed on the pellet surface.
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- 2014
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12. APROVECHAMIENTO E INDUSTRIALIZACIÓN DE DOS PLANTACIONES DE Gmelina arborea DE 15 AÑOS DE EDAD EN DIFERENTES CONDICIONES DE PENDIENTE
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Juliana Espinoza-Durán and Roger Moya
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Forestry ,SD1-669.5 - Abstract
El objetivo principal de este trabajo fue determinar los rendimientos en aprovechamiento e industrialización de dos plantaciones de Gmelina arborea de 15 años de edad sin manejo, en dos grados de pendientes: 30 y 60 %. Los árboles presentaban un diámetro promedio a la altura del pecho (DAP) de 31.23 cm y una altura total de 14.87 m. Se obtuvieron en promedio tres trozas por árbol. Del volumen total en pie, únicamente el 22 % es aprovechable como producto final para la venta en mercado. El desperdicio en la plantación fue de 42.57 %; al trocear el árbol se desperdicia el 14.43 %; al producir el semi-bloque en el aserrío primario se desperdicia el 26.27 % y al obtener las tablas comerciales se desperdicia el 22.10 %. El rendimiento de la troza fue de 53.22 % en madera aserrada en semi-semi-bloque y de 45.88 % en madera aserrada en tablas.
- Published
- 2013
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13. EVALUATION OF DIFFERENT APPROACHES FOR THE DRYING OF LIGNOCELLULOSE RESIDUES
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Carolina Tenorio, and Roger Moya
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Agriculture waste ,Mathematical model ,Costa Rica ,Drying method ,Biotechnology ,TP248.13-248.65 - Abstract
The main objective of this study was to evaluate three methodological approaches for the drying (air drying, solar drying, and hot-air drying) of three lignocelluloses residues in Costa Rica, namely the empty fruit bunches of oil palm (EFB), pineapple plant leaves (PL) with different treatments on this leaf, and sawdust from Gmelina arborea (GAD). The initial moisture content (MCi), the drying times, and the variation of moisture content (MC) with time were determined. A mathematical model of the relation between MC and drying time was also established. The results showed that the MCi was the highest in PL (over 79%), followed by EFB (over 47%), and GAD (lower than 47%). Drying times were higher for air drying, followed by solar drying, and finally hot-air drying. PL showed the longest drying times, followed by GAD and EFB. However, it can be reduced by shortening strands, application of grooves in the cuticle, or crushing the leaf. The MC variation model revealed that the function was Y = ax3 + bx2 + cx + d for all three drying techniques, and the weather conditions where the drying was tested. This model presents high coefficients of determination (over 0.97) and low percentage of errors (1.85-4.73%).
- Published
- 2012
14. Mineral content in relation to radial position, altitude, chemical properties and density of persian ironwood
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Majid Kiaei, Behzad Kord, Ahmad Chehalmardian, Roger Moya, and Mohammad Farsi
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Ash content ,cellulose ,chemical properties ,density ,lignin ,Parrotia persica ,Forestry ,SD1-669.5 ,Manufactures ,TS1-2301 - Abstract
Persian ironwood (Parrotia persica) is native species from Iran and covers 10,54% of the commercial volume. Its wood structure and its chemical composition are affected by growth conditions. The aim of the study was to assess the variation of mineral content (Ni, Fe, Cu, Zn, Pb, Cd), wood density and chemical properties (cellulose, lignin, ash and extractive) of ironwood in relation to altitude above sea level (100, 500 and 700 meter) and pith distance within stem (near to pith and bark and middle point). In addition was investigate the relationship between mineral content with oven-dried density and chemical properties. Results showed that Cd, Cu, Fe, Ni and Zn content (except Pb concentration) increased by increasing of altitude and decreased along radial position within stem from the pith to the bark. Lignin, ash and extractive content increased by increasing altitudes from 100 to 700 meter while cellulose decreased. Radial position had not significant impact on the chemical properties. There are significant relationships between mineral content–chemical properties and between mineral content-wood density (except Cu - density). Forward stepwise regression showed that ash and lignin content had important role on the variation of all of mineral content except on Cd.
- Published
- 2015
15. Physical and Compression Properties of Pellets Manufactured with the Biomass of Five Woody Tropical Species of Costa Rica Torrefied at Different Temperatures and Times
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Johanna Gaitán-Alvarez, Roger Moya, Allen Puente-Urbina, and Ana Rodriguez-Zuñiga
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biomass ,torrefaction ,densification ,tropical woods ,Technology - Abstract
The purpose of the biomass torrefaction and pelletizing processes is to increase its energy properties, be environmentally friendly, decrease shipping costs, and make handling easier. The objective of the present work is to evaluate the density, internal density variation by X-ray densitometry, moisture content, water absorption, and compression force of torrefied biomass pellets of five wood species (Cupressus lusitanica, Dipterix panamensis, Gmelina arborea, Tectona grandis, and Vochysia ferruginea) under three torrefaction temperature conditions (light, middle, and severe) and three torrefaction times (8, 10, and 12 min). The results showed that the bulk density of the pellets was 0.90–1.30 g/cm3. The density variation of the pellets was higher with torrefaction at 250 °C. The moisture content decreased with increasing torrefaction temperature from 3% to 1%. Water absorption was lower in the pellets torrefied at 250 °C. The compression force was lower in the pellets torrefied at 250 °C with approximate loads of 700 N. Based on the above results, it was concluded that pellets made with biomass torrefied at 200 °C have better energy properties and evaluated properties. According to these results, pellets fabricated with the torrefied biomass of tropical species can be used in stove, gas, and hydrogen production because the pellet presents adequate characteristics.
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- 2017
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16. Propiedades mecánicas de vigas 'I' con alas laminadas encoladas en bambú y alma de melina en Costa Rica
- Author
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Viviana Paniagua and Roger Moya
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bamboo I-joists ,flexural strength ,shear strength ,plantation wood ,tropical material ,Guadua angustifolia ,Architecture ,NA1-9428 ,Urban groups. The city. Urban sociology ,HT101-395 - Abstract
Resumen En la búsqueda de elementos estructurales versátiles y eficientes se genera el interés de construir vigas laminadas con plywood de melina (Gmelina arborea) y alas de bambú (Guada angustifolia) laminado encolado, para utilizarlas principalmente en vivienda. En este estudio se analizaron vigas de sección I con alas de bambú laminado encolado y alma de plywood de melina con un peralte de 18,5 cm de altura. Las vigas fueron ensayadas en tamaño natural en flexión estática y cortante. Los resultados mostraron que el módulo de ruptura en flexión promedio de 39,45 MPa y el módulo de elasticidad promedio 17,05 GPa. En la prueba en cortante se encontró que el esfuerzo en la línea de cola fue de 5,95 MPa y en el esfuerzo laminar fue de 6,45 MPa. En relación con los esfuerzos de diseño se determinó que esfuerzo a flexión es de 94,28 kg/cm2 y a cortante de 47,2 kg/cm2. Finalmente, al derivar las tablas de longitud permisibles para usar las vigas en usos de entrepisos o techo, se encontró que estas longitudes pueden variar de 2,6 m a 3,7 m en el caso de entrepisos y de 5 a 7 metros en techos. Abstract The search for efficient and versatile structural elements, leads the interest to fabricate I-joist (6.5 cm × 18.5 cm × 600 cm (width × depth x length) with glue bamboo (Guada angustifolia) in the flanges and Gmelina arborea 12-mm structural plywood in the web. The results showed a modulus of rupture (MOR) of 39. 45 MPa and a modulus of elasticity (MOE) of 17.05 GPa. Shearing in glue line was 5.95 MPa and in laminated strength of 6.45 MPa. Structural design values averaged 9.43 MPa in the bending test and 4.72 MPa in the shear stress according to Costa Rican structural standards. Both resistance value (flexure and shear) was considered satisfactory for structural proposes and I-joist fabricated with bamboo and G. arborea plywood can be compared with “C” structural grade Andean classification group. The use of this I-joist was also shown in roofing and flooring systems. And this beam produce optimum allowable span for the market, from 2 to 7 m in span for roofing systems and from 5 to 7 m for roofing application.
- Published
- 2014
17. Effects of thinning on diameter, heartwood, density and drying defects of gmelina arborea
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Jonathan Vallejos, Roger Moya, and Rafael Serrano
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fast-growth ,plantation wood ,tree morphologic ,wood density ,wood properties ,Forestry ,SD1-669.5 ,Manufactures ,TS1-2301 - Abstract
The effect of three levels thinning intensity in Gmelina arborea plantation on tree diameter, heartwood (diameter and percentage), wood density and drying defects (twist, crook, bow and check) was studied. Wood used for this study was obtained from eight-year-old plantations with thinning intensity of 60, 70 and 80% of initial density. Nine trees were selected from each trial. Results showed that tree diameter and wood density were similar in thinning intensity of 70 and 80%, but tree diameter from the plantation with 60% of thinning intensity was lower than plantation of 70 and 80%. Wood density of trees from 60% thinning intensity plantation was higher than 70 and 80%. Heartwood diameter and its percentage were the highest in 80% of thinning intensity. But not difference was found between 60 and 70% in heartwood (diameter and percentage). Finally, drying defects were not affected significantly by thinning intensity.
18. CHANGES IN YIELD AND CHEMICAL COMPOSITION OF THREE-YEAR-OLD SHORT-ROTATION PLANTATIONS OF Dipteryx panamensis IN COSTA RICA
- Author
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Johana Gaitán-Alvarez, Lidier Tencio, Roger Moya, and Dagoberto Arias-Aguilar
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Tropical species ,Woody crops ,Energy crops ,Forestry ,SD1-669.5 - Abstract
ABSTRACT Research and implementation of energy crops using short-rotation woody species (SRWC) are increasing in Latin America, especially for biomass production and use in bioenergy. For this purpose, one of the main factors to consider is species assessment. Therefore, the objective of the present study was to evaluate the growth characteristics, the production and distribution of biomass, and the chemical, physical, and energetic properties of the biomass of three-year-old Dipteryx panamensis plantations in SRWC in three different spacings (1.0x2.0 m, 1.0x0.5 m and 1.0x1.0 m) and establish the best spacing condition for this tropical species. The results showed that the production of biomass varies between 1.1 and 42.36 t.ha-1, and that 33-44% of the production are concentrated in the leaves. At three years, the SRWC presented 50% mortality, with a diameter of 4.8 cm at 30 cm-height from the ground, with total tree heights ranging from 5.17 to 6.98 meters. The evaluation of the biomass showed a calorific value between 18.9 and 19.4 MJ/kg, less than 1.81% of ash content and 86% of volatile content. As for the effect of the spacing, the green density of the wood and the moisture content increased with increasing spacing, while spacings of 1.0x1.0 m and 1.0x0.5 m showed the best behaviour regarding annual biomass production.
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19. Effect of steaming and furfuryl alcohol impregnation pre-treatments on the spring back, set recovery and thermal degradation of densified wood of three tropical hardwood species
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Ricardo Starbird-Perez, Carolina Tenorio, and Roger Moya
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General Materials Science ,Forestry - Published
- 2022
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20. Production, cost and properties of charcoal produced after logging and sawing, by the earth pit method from Tectona grandis wood residues
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Nadya Berrocal-Mendéz and Roger Moya
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Biomaterials ,Forestry ,Plant Science - Published
- 2022
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21. Annual ring in nine tree species in a Neotropical Island with high precipitation: Coco Island, Costa Rica
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Roger Moya, Carolina Tenorio, and Luis Acosta-Vargas
- Abstract
Coco Island is of volcanic origin with an area of 24 km2, located 530 km from the Pacific coast of Costa Rica and is the furthest Costa Rican Island from the continent and with a rainfall of over 7000 mm years-1. Two types of forest are present, low elevation humid forest and high elevation cloud forest. This study aims to establish different distinctiveness of annual rings and dendrochronological potential (DP) of nine tree species. Any annual ring boundary were not observed in C. pettieri and H. fascicularis; therefore, they did not present any DP. Annual ring type 1 (density variation) was presented in A. compressa, H. succosa, H. odorata, and P. cocosensis, however the annual rings boundary was more defined in A. compressa and H. succosa than other species. O. insularis and S. Holdridgei presented annual rings boundary type 5, fiber band and were adequate distinctiveness. Finally, Eugenia pacifica presented annual ring type 3 (pattern de fiber/parenchyma) and type 4 (vessels distribution), but its distinctiveness was limited. Coco Island´s trees presented seven species with more or less distinctive of annual ring, but three species (A. compressa, E. pacifica, and P. cocosensis) presented low DP. Meanwhile H. succosa, H. odorata, O. insulares, and S. holdridgei showed medium DP. These species growth in the two types of forest in the island and add to abundance and tree diameter, these species have some DP and they can be used to establish a chronology from 50 to 130 years.
- Published
- 2023
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22. Wood Properties of Nine Acetylated Tropical Hardwoods from Fast-Grown Plantations in Costa Rica
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Roger Moya, Johanna Gaitan-Alvarez, Alexander Berrocal, Claudia B. Caceres, and Roger E. Hernandez
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General Materials Science ,Forestry - Published
- 2022
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23. Effect of stem height in variation of bark, heartwood, sapwood and physical properties of wood in Dipteryx panamensis Pittier in a provenance/progeny test
- Author
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Dalina Rodriguez-Perez, Roger Moya, and Olman Murillo
- Subjects
Forestry - Abstract
Dipteryx panamensis is used in reforestation in Costa Rica and a genetic improvement program has been recently started in the country. The objective of the present study was to study the effect of tree trunk height on the variation of bark, sapwood, heartwood, green density (GD), specific gravity (SG) and green moisture content in green condition (MC-G), in a collection of 8-year-old provenances/progenies planted in the town of Florencia in San Carlos in the northern region of Costa Rica The wood of each of 17 families were studied based on 3 of their progenies, evaluating the properties relative to 0, 25%, 50%, 75% and 100% of the commercial height. According to the results, tree diameter and bark thickness showed no statistical differences in their values across trunk. Significant differences were found in diameter and percentage of heartwood and sapwood between provenances and families. The thickness and percentage of sapwood, thickness and percentage of bark, diameter, pith percentage and percentage of pith eccentricity, showed no significant differences between families. SG and the MC-G presented significant variation between provenances, while GD registered differences at above 25 % commercial height. The variation of physical properties, especially SG, between families within each provenance, shows selection potential for genetic improvement, focusing particularly on the bottom section of the tree.
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- 2022
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24. The Effects of Jatropha curcas and Ricinus communis Seeds Addition on Coffee Pulp Waste Pellets as Fuel
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Esteban Díaz-Jiménez and Roger Moya
- Subjects
Environmental Engineering ,Renewable Energy, Sustainability and the Environment ,Waste Management and Disposal - Published
- 2022
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25. Application of the steaming step during kiln drying of lumber of two tropical species with high growth stress presence
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Carolina Tenorio and Roger Moya
- Subjects
General Chemical Engineering ,Physical and Theoretical Chemistry - Published
- 2021
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26. Structure of the secondary xylem and development of a cambial variant in Serjania mexicana (Sapindaceae)
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Kishore S. Rajput, Amit D. Gondaliya, and Roger Moya
- Subjects
Serjania mexicana ,Botany ,Xylem ,Forestry ,Plant Science ,Biology ,Sapindaceae ,biology.organism_classification - Abstract
Summary The lianas in the family Sapindaceae are known for their unique secondary growth which differs from climbing species in other plant families in terms of their cambial variants. The present study deals with the stem anatomy of self-supporting and lianescent habit, development of phloem wedges, the ontogeny of cambial variants and structure of the secondary xylem in the stems of Serjania mexicana (L.) Willd. Thick stems (15–20 mm) were characterized by the presence of distinct phloem wedges and tangentially wide neo-formed cambial cylinders. As the stem diameter increases, there is a proportional increase in the number of phloem wedges and neo-formed vascular cylinders. The parenchymatous (pericyclic) cells external to phloem wedges that are located on the inner margin of the pericyclic fibres undergo dedifferentiation, become meristematic and form small segments of cambial cylinders. These cambia extend tangentially into wide and large segments of neoformations. Structurally, the secondary xylem and phloem of the neo-formed vascular cylinders remain similar to the derivatives produced by the regular vascular cambium. The secondary xylem is composed of vessels (wide and narrow), fibres, axial and ray parenchyma cells. The occurrence of perforated ray cells is a common feature in both regular and variant xylem.
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- 2021
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27. Furfurylation of tropical wood species with and without silver nanoparticles: Part II: Evaluation of wood properties
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Alexander Berrocal, George I. Mantanis, Roger Moya, Charalampos Lykidis, and Johanna Gaitán-Álvarez
- Subjects
Tropical wood ,Chemistry ,General Materials Science ,Pulp and paper industry ,Silver nanoparticle - Published
- 2021
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28. Nanomaterials to Improve the Strength of Wooden Joints
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Carolina Tenorio and Roger Moya
- Published
- 2022
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29. CHARACTERIZATION OF PAULOWNIA TOMENTOSA STEUD TREES GROWN IN A 5-YEAR-OLD PLANTATION IN COSTA RICA
- Author
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Roger Moya and José David Sánchez-Machado
- Subjects
Horticulture ,biology ,Chemistry ,Organic Chemistry ,Materials Chemistry ,biology.organism_classification ,Paulownia tomentosa - Abstract
Paulownia tomentosa is utilized in Costa Rica and other countries for wood production and as feedstock for biomass, though the variation of wood properties for this species is scarcely known. In this work, the specific wood properties of a 5-year-old plantation in Costa Rica were studied. The results showed that bark and pith percentage and wood specific gravity (SG) increased with tree trunk height, while the proportion of heartwood, green wood density and green wood moisture content decreased. The average wood SG was 0.26 and tended to increase from pith to bark. Low wood SG values are related to low mechanical properties, with the advantage that wood shrinkage is low as well, which gives this wood species the potential to be utilized for reforestation purposes in Costa Rica. The gross calorific value of this species was 17809 kJ/kg, which, together with its cellulose and extractives contents, recommend P. tomentosa as a biomass source for energy production.
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- 2021
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30. Physical and Energy Characteristics, Compression Strength and Chemical Modification of Charcoal Produced from Sixteen Tropical Woods in Costa Rica
- Author
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Roger Moya, Víctor Balaguer-Benlliure, and Johana Gaitan-Alvarez
- Subjects
Resistance (ecology) ,Renewable Energy, Sustainability and the Environment ,Carbonization ,Agroforestry ,Geography, Planning and Development ,Biomass ,Forestry ,Management, Monitoring, Policy and Law ,Compressive strength ,Tropical wood ,Bioenergy ,visual_art ,Biochar ,visual_art.visual_art_medium ,Environmental science ,Charcoal ,Food Science - Abstract
Charcoal production from woody species from fast-growth plantations has gained importance in a variety of uses. The objective of the present work is to determine the density, compression resistance...
- Published
- 2021
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31. Ultrasound velocity mapping to evaluate gluing quality in CLT panels from plantation wood species
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Roger Moya, Freddy Muñoz, and Carolina Tenorio
- Subjects
Materials science ,Velocity mapping ,business.industry ,Delamination ,Ultrasound ,General Materials Science ,Forestry ,Plant Science ,Composite material ,Glue line ,business ,Industrial and Manufacturing Engineering - Abstract
Evaluation of the glue line in CLT panels and in other wood composite products in general is of great interest. Non-destructive methods such as determination of the velocity of ultrasound waves going through the materials are commonly applied to evaluate wood products. The present work is aimed at mapping ultrasound velocity (UV) to identify problems of glue line delamination in CLT panels of 3 and 5 layers made from Gmelina arborea and Tectona grandis timber. The results showed higher UV in the 3-layered panels in both timber species, and low UV and the presence of regions of low velocity in UV isocurves of the 5-layered CLT panels, due to separation of glue line, such as un-gluing and delamination. A UV reference value for glue line free of delamination problems of 927 and 1039 m/s was set for CLT panels of G. arborea of 3 and 5 layers, respectively, and of 1073 and 946 m/s for CLT panels of T. grandis of 3 and 5 layers, respectively. Values below the UV reference suggest the presence of some anomalies or problems of delamination, such as gluing defects.
- Published
- 2021
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32. Wood properties comparation of Cedrela odorata from trees in agroforestry and in pure plantation
- Author
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Roger Moya and Beatriz Segura-Elizondo
- Subjects
biology ,Agroforestry ,General Materials Science ,Forestry ,biology.organism_classification ,Cedrela odorata - Published
- 2021
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33. Furfurylation of tropical wood species with and without silver nanoparticles: Part I: Analysis with confocal laser scanning microscopy and FTIR spectroscopy
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Johanna Gaitán-Álvarez, Roger Moya, George I. Mantanis, and Alexander Berrocal
- Subjects
040101 forestry ,0106 biological sciences ,Materials science ,04 agricultural and veterinary sciences ,01 natural sciences ,Silver nanoparticle ,Furfuryl alcohol ,chemistry.chemical_compound ,Tropical wood ,Chemical engineering ,chemistry ,010608 biotechnology ,Confocal laser scanning microscopy ,0401 agriculture, forestry, and fisheries ,General Materials Science ,Fourier transform infrared spectroscopy - Abstract
This work focused on the upgrading of non-durable tropical wood species originating from fast-growing plantations of Costa Rica. Modification of such tropical woods with furfuryl alcohol, although ...
- Published
- 2021
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34. Steaming and Heating Dipteryx panamensis Logs from Fast-Grown Plantations: Reduction of Growth Strain and Effects on Quality
- Author
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Juan David Conde Torres, Roger Moya, and Carolina Tenorio
- Subjects
Reduction (complexity) ,Dipteryx panamensis ,Horticulture ,Strain (chemistry) ,Steaming ,Environmental science ,General Materials Science ,Forestry ,Plant Science - Abstract
Steaming and heating as pretreatments before log sawing reduce the negative effects of growth strain (GS). The object of this work was to study the reduction of GS in logs of Dipteryx panamensis from a fast-growth plantation using steaming and heating treatments and evaluate the effects on the lumber quality. According to the results, the maximum temperature in the center of the log was approximately 90°C after 24 hours for both treatments. GS decreased after heating and steaming. The average value of GS for three treatments was 2,085.61 microdeformation units (με) before the treatment, decreasing to average value to1,692.14 με after the treatments. This reduction in turn produced a reduction of crook due to sawing measured in logs and semilogs and a decrease in the values and incidence of crook, bow, twist, and split. Similarly, color parameters (L*, a*, and b*) were statistically affected by the treatment, except for parameter L* in sapwood. In general, wood darkening was observed. Lastly, both treatments applied to D. panamensis logs showed few differences in GS, in crook due to sawing measured in logs and semilogs, and in the values and incidence of crook, bow, twist, and split. Therefore, both treatments achieved GS reduction in D. panamensis lumber.
- Published
- 2021
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35. Wooden trusses using metal plate connections and fabricated with Gmelina arborea, Tectona grandis and Cupressus lusitanica timber from forest plantations
- Author
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Roger Moya, Monzerrath Rivera-Tenorio, and Angel Navarro-Mora
- Subjects
040101 forestry ,0106 biological sciences ,biology ,Forest management ,Truss ,Forestry ,04 agricultural and veterinary sciences ,Plant Science ,biology.organism_classification ,01 natural sciences ,Biomaterials ,Flexural strength ,Tectona ,010608 biotechnology ,0401 agriculture, forestry, and fisheries ,Gmelina ,Design values ,Cupressus lusitanica ,Mathematics - Abstract
The present work aims at determining the behaviour relative to load applied and displacement and the design values of Howe trusses 7.2 m long fabricated with timber from Gmelina arborea, Tectona grandis and Cupressus lusitanica, using metal plates. The static flexural strength of the trusses was tested by applying the load to three different points, determining the load and the displacement at the central point of the truss, and then these values were used in the SAP2000 program, to define the design values. The results showed design loads at 5.00 kN, 6.34 kN and 5.52 kN and displacements at 1.53 cm, 1.27 cm and 1.71 cm, for trusses fabricated with G. arborea, T. grandis and C. lusitanica timber, respectively. As for the design tables, the values of maximum load diminished with increase in support spans (with 5 m, 6 m, 7 m and 8 m simulated support spans). The load ranged between 59.05 and 186.21 kg/m for G. arborea, 91.38 to 286.39 kg/m for T. grandis and 57.45 to 183.35 kg/m for C. lusitanica. Although truss manufacturing with the three species is viable, T. grandis showed the highest potential.
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- 2020
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36. EQUATIONS FOR PREDICTING HEARTWOOD MERCHANTABLE VOLUME AND TRADABLE SAWLOG IN TECTONA GRANDIS
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Edgar Ortiz-Malavassi, Johanna Gaitán-Álvarez, David Fernández-Sólis, Alexander Berrocal, and Roger Moya
- Subjects
biology ,Volume (thermodynamics) ,Tectona ,Forestry ,biology.organism_classification ,Mathematics - Published
- 2020
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37. Effect of thermo-hydro-mechanical densification on the wood properties of three short-rotation forest species in Costa Rica
- Author
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Carolina Tenorio and Roger Moya
- Subjects
Alnus acuminata ,Rotation forest ,Environmental Engineering ,Static bending ,Materials science ,biology ,Bioengineering ,Young's modulus ,biology.organism_classification ,Positive correlation ,symbols.namesake ,Flexural strength ,symbols ,Composite material ,Waste Management and Disposal ,Compression time ,Vochysia ferruginea - Abstract
Alnus acuminata, Vochysia ferruginea, and Vochysia guatemalensis are three low-density wood species used for reforestation in Costa Rica. The goal of this work was to study a thermo-hydro-mechanical densification process and test the characteristics of densified wood of these species. Twelve densifying treatments based on temperature, compression time, and use/no use of steam were tested. The variables of the densification process and the properties of the densified wood were determined. The results showed that the densification percentage was over 80% for wood of A. acuminata and over 70% for wood of V. ferruginea and V. guatemalensis. In the three species, the densification process was influenced by initial density. The influence of temperature during the densification process affected the heating rate and color change. An increase in the modulus of elasticity and modulus of rupture in static bending and in the hardness of the densified wood relative to the normal wood was observed, as well as a clear positive correlation of the properties with final density and maximum load, the latter being highly correlated with initial density. This showed that initial density was significant in the densification process and affects wood properties.
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- 2020
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38. Density profile and micromorphology variation of densified wood from three fast growth hardwood species in Costa Rica
- Author
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Carolina Tenorio, Mario Tommasiello, and Roger Moya
- Subjects
040101 forestry ,0106 biological sciences ,Materials science ,Forestry ,04 agricultural and veterinary sciences ,Vochysia guatemalensis ,Compression (physics) ,complex mixtures ,01 natural sciences ,Wood tissue ,010608 biotechnology ,Hardwood ,0401 agriculture, forestry, and fisheries ,General Materials Science ,Composite material ,Vochysia ferruginea - Abstract
This study evaluates 1) the effect of the thermo-hydro-mechanical densification process-using three temperatures, two compression times, and the presence or absence of steam, and 2) the effect of initial wood micromorphology on the density profile of densified wood of three low-density fast growing hardwood species in Costa Rica ( Alnus acuminate , Vochysia ferruginea , and Vochysia guatemalensis ). Four density profiles in the densified wood of the three species resulted from the densification temperature and the initial micromorphology of the wood. The initial diameter of the vessels affects the compression stage during the densification process and causes the formation of irregular density profiles. Therefore, this is the most important element in determining the type of the density profile. The wood of A. Acuminata (with smaller-diameter vessels) densified at 180 o C tends to produce more uniform density profiles than the other two species that have larger diameter vessels. The time of compression and the use or not of steam as an initial stage in the densification process did not influence the types of density profiles obtained. Similarly, the type of wood tissue and wood pattern had no effect on the type of density profiles. In conclusion, uniform and regular density profiles in densified wood are more likely to be achieve at high temperatures and with smaller-diameter vessels.
- Published
- 2020
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39. Acetylation of tropical hardwood species from forest plantations in Costa Rica: an FTIR spectroscopic analysis
- Author
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Johanna Gaitán-Álvarez, George I. Mantanis, Alexander Berrocal, Fabio Araya, and Roger Moya
- Subjects
0106 biological sciences ,Softwood ,Hydroxyl groups ,01 natural sciences ,Enterolobium ,Biomaterials ,chemistry.chemical_compound ,010608 biotechnology ,Hardwood ,Lignin ,040101 forestry ,Building construction ,biology ,Wood modification ,Forestry ,04 agricultural and veterinary sciences ,SD1-669.5 ,biology.organism_classification ,Acetic anhydride ,Horticulture ,FTIR spectroscopy ,chemistry ,Tectona ,Samanea ,0401 agriculture, forestry, and fisheries ,Gmelina ,TH1-9745 - Abstract
Acetylation of softwoods has been largely investigated to increase the dimensional stability and biological resistance of wood. However, the knowledge of this technology has not been applied to tropical hardwood species up to date. The objective of this work was to study the effect of acetylation on nine tropical hardwood species, from forest plantations in Costa Rica, by applying acetic anhydride in three different treatment times (1 h, 2.5 h, 4 h), as well as to evaluate this by Fourier-Transform Infrared Spectroscopy (FTIR). Results showed that weight percentage gain (WPG) of wood varied from 2.2 to 16.8%, withVochysia ferrugineaspecies showing the highest WPG, andGmelina arboreaandTectona grandisspecies exhibiting the lowest WPGs. Tropical woods such asEnterolobium cyclocarpum,Hieronyma alchorneoidesandSamanea samanexhibited statistical differences among treatment times, whereas the rest of the species studied showed no significant differences. In general, the most effective acetylation time was 2.5 h for all the species. The ratio of intensity (RI) from the FTIR spectra was greater at the 1732 cm−1, 1372 cm−1and 1228 cm−1peaks for all tropical species, associated with lignin. A good correlation between the RI of those peaks and WPG was found; the same was also found between all RIs and each other. Meanwhile, RI associated to the hemicelluloses and lignin (1592 cm−1and 1034 cm−1peaks, respectively) showed no correlation with WPG, nor between each other or with the other RIs. Furthermore, it was suggested that RI at 1732 cm−1(associated to acetyl groups C=O) can be considered as a reliable indicator of the degree of acetylation for tropical hardwood species. Finally, it was observed that tropical hardwoods having more suitable anatomical features, like larger vessel diameter, higher ray width and frequency, and lesser deposits such as gums and tyloses in the vessels, resulted in significantly higher WPGs.
- Published
- 2020
40. Effect of CaCO3 on the wood properties of tropical hardwood species from fast-growth plantation in Costa Rica
- Author
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Johanna Gaitán-Álvarez, Fabio Araya, Alexander Berrocal, and Roger Moya
- Subjects
Thermogravimetric analysis ,Environmental Engineering ,Absorption of water ,Resistance (ecology) ,Chemistry ,technology, industry, and agriculture ,Bioengineering ,Young's modulus ,Mineralization (biology) ,symbols.namesake ,Horticulture ,Flexural strength ,symbols ,Hardwood ,Precipitation ,Waste Management and Disposal - Abstract
This work aimed to evaluate the effect of the precipitation of CaCO3 via subsequential in-situ mineral formation based on a solution-exchange process of two solution-exchange cycles via impregnation with CaCl2 in ethanol and NaHCO3 in water. The effects were investigated in terms of the structure of the wood and the thermal, physical, mechanical, and decay resistance properties of nine species commonly used in commercial reforestation in Costa Rica. The thermogravimetric analysis results showed that the woods with the highest formation of CaCO3 showed a more pronounced signal at 200 °C in relation to untreated/wood; therefore, they were more thermostable. The fire-retardancy test showed that flame time in CaCO3/wood composites was longer than for untreated/wood in half of the species tested, presenting a positive effect of mineralization. Wood density, decay resistance, modulus of rupture (MOR), modulus of elasticity (MOE) in flexion, and MOR in compression were slightly affected by mineralization. Water absorption increased, but it had no negative effect on the dimensional stability. In general, mineralization can be a chemical treatment to increase the dimensional stability and fire resistance of hardwood species without modifying the wood’s physical and mechanical properties.
- Published
- 2020
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41. Production and Characteristics of Biomass for Arundo donax, Pennisetum purpureum, and P. purpureum × P. glaucum in a Short-Rotation Crop System in Humid Tropical Conditions in Costa Rica
- Author
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Johana Gaitan-Alvarez, Roger Moya, and Estephanía Salazar-Zeledón
- Subjects
biology ,020209 energy ,Crop yield ,Biomedical Engineering ,Soil Science ,Biomass ,Arundo donax ,Forestry ,04 agricultural and veterinary sciences ,02 engineering and technology ,biology.organism_classification ,Crop ,Agronomy ,Bioenergy ,040103 agronomy & agriculture ,0202 electrical engineering, electronic engineering, information engineering ,0401 agriculture, forestry, and fisheries ,Environmental science ,Pennisetum purpureum ,Energy source ,Agronomy and Crop Science ,Pennisetum ,Food Science - Abstract
HighlightsArundo donax, Pennisetum purpureum, and P. purpureum × P. glaucum planted at 103 plants ha-1 were studied.Biomass production and energy characteristics were evaluated at 12, 18, 24, and 30 months.The production of dry biomass varied between 2.52 and 39.25 Mg ha-1.The biomass quality and production of Arundo donax were different from those of Pennisetum ssp.Abstract.The high global demand for fossil fuels has led to the search for alternative sources of renewable energy, such as the production of biomass from short-rotation crops (SRC). This study evaluated three grass species (, , and × ) in SRC systems planted at 103 plants ha-1 in humid tropical conditions in Costa Rica, considering biomass production, moisture content, and energy and chemical properties at four harvest ages (12, 18, 24, and 30 months). The results showed that the height of all species varied between 0.9 and 3.5 m at the different harvests, while the production of dry biomass varied between 2.52 and 39.25 Mg ha-1. As for their chemical properties, the ash content varied between 5.9% and 10.2%, volatile matter varied between 73.3% and 81.9%, and net calorific value varied between 15.86 and 18.94 MJ kg-1. In the three species, the production of biomass was greater at the 12-month and 18-month harvests; at later harvests, biomass production began to decrease, leading to increased moisture and ash contents, lower volatile matter, and lower calorific value. The biomass quality and production of were different from those of . Keywords: Bioenergy, Energetic potential, Forage, Pastures, Short-rotation plantations, Tropical species.
- Published
- 2020
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42. In Situ Synthesis of Fe
- Author
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Roger, Moya, Johanna, Gaitán-Álvarez, Alexander, Berrocal, and Karla J, Merazzo
- Abstract
Magnetic wood is a composite material that achieves harmony between both woody and magnetic functions through the active addition of magnetic characteristics to the wood itself. In addition to showing magnetic characteristics, magnetic wood offers low specific gravity, humidity control and acoustic absorption ability. It has potential for broad applications in the fields of electromagnetic wave absorption, electromagnetic interference shielding, furniture, etc. This work reports on the synthesis of Fe
- Published
- 2022
43. Agronomic Effects of Tectona grandis Biochar from Wood Residues on the Growth of Young Cedrela odorata Plants in a Nursery
- Author
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Roger Moya, Yorleny Badilla Valverde, and Arantxa Rodríguez Solís
- Subjects
biology ,soil fertility ,Biomass ,chemistry.chemical_element ,Agriculture ,biology.organism_classification ,plantation species ,Nitrogen ,Substrate (marine biology) ,Cedrela odorata ,Horticulture ,chemistry ,Tectona ,visual_art ,soil properties ,Biochar ,visual_art.visual_art_medium ,Soil fertility ,Charcoal ,Agronomy and Crop Science ,substrates ,charcoal ,seeding - Abstract
Biochar from agroforestry biomass residues is an alternative source of fertilizers for improving the soil fertility. In Costa Rica, Cedrela odorata is planted in pure plantations and agroforestry systems and different types of substrates are used in the nursery to enhance the growth and performance of the young saplings. The main objective of the present study was to evaluate the growth (in height, diameter, biomass) and distribution of carbon (C), hydrogen (H), and nitrogen (N) for C. odorata plants in a nursery with different application rates of biochar produced from Tectona grandis wood residues. The results showed that the above-measured variables were statistically affected by different application rates of the biochar. The stem diameter, total height, number of leaves, and height increment were statistically significantly higher in the substrate with an application rate of 25–50 tons/ha, in contrast to the 0 and 75 tons/ha application rates, which were statistically the lowest. As for the levels of C, H, and N, there were differences, with the highest values of N and C being in the leaves and stem with the 50 tons/ha application rate and the highest values of H for the 75 tons/ha application rate. The above results showed that applying biochar obtained from T. grandis residues improved soil conditions, resulting in better growth of C. odorata saplings with an application rate of 25 and 50 tons/ha.
- Published
- 2021
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44. Reduction of growth stresses in logs of Hieronyma alchorneoides Allemão from fast-growth plantations using steaming and heating: effects on the quality of lumber
- Author
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Roger Moya and Carolina Tenorio
- Subjects
Hyeronima alchorneoides ,Ecology ,Thinning ,Hieronyma alchorneoides ,Steaming ,food and beverages ,Forestry ,Felling ,humanities ,Internal temperature ,Horticulture ,Wood warping ,Environmental science ,After treatment - Abstract
Growth stresses are usually present in the fast-growing trees of forest plantations and can be evaluated along stem diameter. Growth stresses are relaxed after tree felling and during sawing and drying, and are manifested in the lumber quality. Different methods have been employed to reduce the effect of growth stresses, such as steaming and heating treatments. Excellent growth and yield in forest plantations of Hyeronima alchorneoides were observed, but they showed difficulties in the primary sawing process and a high incidence of wood warping during the drying process. Steam and heat treatments on the log were used to study their effects on H. alchorneoides sawlog and to evaluate lumber quality. Growth stresses in Hieronyma alchorneoides Allemao trees growing under fast-growth conditions show high and negative effects on the lumber quality (increased warps and splits or checks). Therefore, steaming and heating treatments have been applied to reduce these effects on the lumber. The main objective of the present work was to evaluate the effects of steaming and heating treatments on sawlogs of Hieronyma alchorneoides from the fast-growth plantations to reduce the longitudinal surface growth stress. Twenty-six trees ready for felling in the third thinning were sampled and commercial logs measuring 2.5 m long were extracted from them at different heights. These logs were used to investigate the effect of steaming and heating treatments and the growth stresses were measured before and after treatment. Crooking due to sawing, colour and wards, splits and checks were measured. The results showed that the internal temperature of the logs was approximately 85 °C after the heating treatment, and it was nearly 90 °C after the steaming treatment. It resulted in a reduction of 1500 μe (micro-deformations) before the treatment to 1000 μe after the treatment. Therefore, crooking due to sawing decreased significantly in logs or semi-logs. The parameters such as colour, luminosity (L*), redness (a*) and lightness (b*) decreased in heartwood while L* increased and a* and b* decreased in sapwood, which led to the decrease in quality of the lumber, the magnitude and incidence of the defects in treated logs. As compared to untreated logs, the best performance was obtained with steaming treatment, followed by the heating treatment. The difference found between steaming and heating can be attributed to the temperature in the internal part of the log, which was more than 90 °C in steaming treatment; meanwhile, in the heating treatment, the internal temperature of the log was slightly lower (80–85 °C). Therefore, glass transition can be more easily reached by steaming treatment than by the heating treatment.
- Published
- 2021
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45. Propiedades de la biomasa de plantaciones de corta rotación de dos clones de Gmelina arborea Roxb en tres espaciamientos
- Author
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Roger Moya and Carolina Tenorio
- Subjects
woody crops ,especies tropicales ,cultivo de madera ,densidad de plantación ,cultivo energético ,tropical species ,General Medicine ,energy crops ,Fast growth ,plantation density ,Rápido crecimiento - Abstract
Resumen El conocimiento de las propiedades de la biomasa proveniente de clones de Gmelina arborea Roxb en cultivos energéticos en sistemas de corta rotación (SRC en inglés) en Costa Rica es limitado. Los primeros intentos están basados en el uso de clones para la producción de madera, pero plantados en SRC. Así, el presente estudio tuvo como objetivo evaluar las propiedades físicas (peso específico, densidad y contenido de humedad), energéticas (poder calorífico, contenido de cenizas y materiales volátiles) y contenido de carbón de dos clones de G. arborea utilizados para la producción de madera, pero plantados en SRC bajo tres espaciamientos (1,0x1,0 m, 0,75x0,75 m y 1,0x0,5 m), entre 6 y 24 meses de edad. Los resultados muestran que el peso específico básico fue de entre 0,30 a 0,38, la densidad verde de 0,9 a 1,0 g/cm3, el contenido de humedad entre 40 y 70%, el poder calorífico de 18.000 a 20.000 kJ/kg, la cantidad de cenizas fue menor a 4,8% y el contenido de volátiles de entre un 70 a 86%, mientras que el contenido de carbono disminuyo con la edad. Se observaron diferencias entre los dos clones en edades tempranas, pero estás tienden a desaparecer con el aumento de la edad, en especial a la edad de 24 meses, que es cuando se pretende que la plantación sea cosechada, siendo esto una ventaja ya que se tiene una biomasa uniforme si los dos clones son utilizados. Abstract The knowledge of biomass properties from Gmelina arborea clones Roxb in energy crops in short rotation crops systems (SRC) in Costa Rica is limited. The first attempts are based on the use of clones for the production of wood, but planted in SRC. Thus, the present study aimed to evaluate the physical properties (specific gravity, density and moisture content), energy (net calorific value, ash content and volatile materials) and carbon content of two clones of G. arborea used for wood production, but planted in SRC under three spacings (1.0x1.0 m, 0.75x0.75 m and 1.0x0.5 m), between 6 and 24 months of age. Results show that the basic specific gravity was between 0.30 to 0.38, the green density of 0.9 to 1.0 g/cm3, the moisture content between 40 and 70 %, the net caloric value of 18,000 a 20,000 kJ/kg, ash content was less than 4.8 % and the volatile content between 70 and 86%, while the carbon content decreased with age. Differences were observed between the two clones at early ages, but they tend to disappear with increasing age, especially at the age of 24 months, which is when the plantation is intended to be harvested, this being an advantage since we have a uniform biomass if the two clones are used.
- Published
- 2019
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46. The use of X-ray densitometry to evaluate the wood density profile of Tectona grandis trees growing in fast-growth plantations
- Author
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Roger Moya, Alexander Berrocal, and Johana Gaitan-Alvarez
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,Ecology ,biology ,Climate change ,Forestry ,Plant Science ,Limiting ,X ray densitometry ,Visual identification ,biology.organism_classification ,01 natural sciences ,Annual growth % ,Tectona ,Dendrochronology ,Environmental science ,Tree species ,010606 plant biology & botany ,0105 earth and related environmental sciences - Abstract
Tectona grandis (teak) is an important commercial tree species that is widely used in tropical dendrochronology due to the formation of climate-sensitive annual growth rings. However, young trees growing in plantation conditions exhibit poor ring visibility during the first years of growth, limiting the dendrochronology application. In the present study, we use x-ray densitometry to determine the wood density profile between and within annual rings and at the sapwood-heartwood boundary in trees from fast-growth plantations. The resulting wood density profiles (WDP) can be categorized as uniform, stable growth, unstable growth, and false. The annual ring boundaries were indistinct in trees less than 8 years old. In mature trees, the annual ring boundaries are more defined. In relation to the sapwood-heartwood boundary, the WDP showed a decrease in the wood density; however, this decrease is influenced by the annual ring boundary when the two boundaries coincide. The identification of annual rings in trees growing in fast-growth plantations should be combined with X-ray densitometry and visual identification if wood density data are necessary for deriving other analysis, as climate change, from annual ring.
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- 2019
- Full Text
- View/download PDF
47. Biomass production and characteristics of short rotation plantations of clones of Gmelina arborea in three spacings
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Roger Moya, Dagoberto Arias-Aguilar, Juan Carlos Valverde, and Carolina Tenorio
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0106 biological sciences ,020209 energy ,Biomass ,Forestry ,02 engineering and technology ,Biology ,Rotation ,biology.organism_classification ,01 natural sciences ,Plant science ,Agronomy ,0202 electrical engineering, electronic engineering, information engineering ,Genetics ,Gmelina ,010606 plant biology & botany - Abstract
The first attempts to establish energy crops in the tropical region using short rotation species are premised on the utilization of clones for wood production. Therefore, the present study is aimed at examining the growth aspects (survival, diameter and tree height), leaf architecture (leaf area index [LAI], number and angle of the branches and sylleptic branches), biomass production, as well as biomass flow at the age of 24 months of two clones of Gmelina arborea in short rotation crops within three spacings (1.0x1.0 m, 0.75x0.75 m and 1.0x0.5 m). The results showed an increment with age, as the diameter increased from 3.00 cm at six months to 8.0 cm at 24 months, whereas the total height increased from 2.00 m at six months to 10.00 m at 24 months. Clone survival varied from 20 to 60 %, whereas the LAI, branch angle and sylleptic branches increased with age. The differences between clones appeared after 12 months. Biomass production was similar between clones, from 6 ton/ha at six months to 67 ton/ha at 24 months, with clone 2 showing greater biomass flow than clone 1. On the basis of biomass production results and the development of diameter as well as height, clone 1 is recommended for spacing 1.0x1.0 m and clone 2 for spacings 0.75x0.75 m and 1.0x0.5 m.
- Published
- 2019
- Full Text
- View/download PDF
48. Flooring characteristics of thermo-mechanical densified wood from three hardwood tropical species in Costa Rica
- Author
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Angel Navarro-Mora, Carolina Tenorio, and Roger Moya
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Materials science ,Materials Science (miscellaneous) ,Manufactures ,Flooring properties ,Vochysia guatemalensis ,Industrial and Manufacturing Engineering ,TS1-2301 ,High weight ,wear index ,Indentation ,Densification ,Hardwood ,Chemical Engineering (miscellaneous) ,tropical species ,Composite material ,Vochysia ferruginea ,flooring properties ,Alnus acuminata ,biology ,Residual deformation ,Forestry ,SD1-669.5 ,biology.organism_classification ,low density ,Thermo mechanical ,spring-back - Abstract
Densification is one method used to modify low-density woods to make them achieve the hardness required for flooring application. The purpose of this study was to investigate the effect of thermo-mechanical densification with pre-heating in wood of Alnus acuminata, Vochysia ferruginea and Vochysia guatemalensis from, seeking to stabilize and reduce spring-back of the densified wood and evaluate its performance in flooring applications. The results showed that the wood of the three species turned dark. This is because brightness diminished and yellowness and redness increased. Weight loss due to pre-heating was statistically higher in V. ferruginea and V. guatemalensis. The final density and spring-back were statistically similar in the three species. The percentage of densification of A. acuminata and V. guatemalensis were statistically higher than for V. ferruginea and the degree of compression was statistically higher in V. guatemalensis. As for flooring evaluation, the percentage of densification, temperature and time of pre-heating affected the behavior of densified wood flooring. The low percentage of densification and high weight loss in the pre-heating stage caused greater values of wear, wear index, residual deformation, residual indentation for the falling ball indentation test, and more damages in the surface indentation test in wood of V. ferruginea.
- Published
- 2021
49. Wood Properties and Their Variations in Teak
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Carolina Tenorio and Roger Moya
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International market ,Geography ,Tropical wood ,Genetic gain ,Agroforestry ,Natural forest ,Reforestation ,Mechanical resistance ,Silviculture - Abstract
Teakwood is popular in the international market due to its excellent durability, good aesthetic properties and mechanical resistance. Teak has been the priority species in reforestation programs for many years because of its unique features. Since 1900, this species has been planted in areas where it grew naturally. In the present century, it is established as commercial plantations in Africa, America and Oceania, covering a great variety of site conditions. Cloning techniques and intensive silviculture revolutionized teak cultivation. All these factors have resulted in generation of wood with diverse qualities and properties. Thus, this chapter examines variations in teakwood qualities and properties in relation to countries where it grows naturally, variations between plantation and naturally grown wood, variations across countries, sites, provenances and clones. In addition, this chapter addresses aspects of the wood properties related to the commercially known “super teak” trees, heritability, genetic gain and biotechnology. The sources of wood variation are numerous, including anatomical, physical and mechanical properties. The main source of variation is whether the wood comes from natural forests or planted trees. In this regard, intensive silviculture is the most successful way to achieve rapid commercial prospects. Despite the fact that teak has been introduced in many countries, little is known about its wood variations, and wood properties of juvenile teakwood are scarcely studies. It is evident that our knowledge of wood produced under improvement programs is still inadequate, and the same can be applied to genetics and wood engineering, which has only recently begun.
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- 2021
- Full Text
- View/download PDF
50. ALTERAÇÕES NO RENDIMENTO E NA COMPOSIÇÃO QUÍMICA DE PLANTAÇÕES DE TRÊS ANOS DE ROTAÇÃO CURTA DE Dipteryx panamensis NA COSTA RICA
- Author
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Lidier Tencio, Roger Moya, Johana Gaitan-Alvarez, and Dagoberto Arias-Aguilar
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0106 biological sciences ,Plantios energéticos ,Espécies tropicais ,020209 energy ,Tropics ,Biomass ,Forestry ,02 engineering and technology ,SD1-669.5 ,01 natural sciences ,Energy crops ,Energy crop ,Agronomy ,Bioenergy ,Plantios lenhosos ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Woody crops ,Heat of combustion ,Tropical species ,Chemical composition ,Water content ,010606 plant biology & botany ,Woody plant - Abstract
Research and implementation of energy crops using short-rotation woody species (SRWC) are increasing in Latin America, especially for biomass production and use in bioenergy. For this purpose, one of the main factors to consider is species assessment. Therefore, the objective of the present study was to evaluate the growth characteristics, the production and distribution of biomass, and the chemical, physical, and energetic properties of the biomass of three-year-old Dipteryx panamensis plantations in SRWC in three different spacings (1.0x2.0 m, 1.0x0.5 m and 1.0x1.0 m) and establish the best spacing condition for this tropical species. The results showed that the production of biomass varies between 1.1 and 42.36 t.ha-1, and that 33-44% of the production are concentrated in the leaves. At three years, the SRWC presented 50% mortality, with a diameter of 4.8 cm at 30 cm-height from the ground, with total tree heights ranging from 5.17 to 6.98 meters. The evaluation of the biomass showed a calorific value between 18.9 and 19.4 MJ/kg, less than 1.81% of ash content and 86% of volatile content. As for the effect of the spacing, the green density of the wood and the moisture content increased with increasing spacing, while spacings of 1.0x1.0 m and 1.0x0.5 m showed the best behaviour regarding annual biomass production. RESUMO A pesquisa e a implementação de plantios energéticos usando espécies lenhosas de rotação curta (SRWC) estão aumentando na América Latina, especialmente para a produção de biomassa e uso na bioenergia. Para esse fim, um dos principais fatores a considerar é a avaliação de espécies. O objetivo do presente estudo foi avaliar as características de crescimento da árvore, a produção e distribuição de biomassa e as propriedades químicas, físicas e energéticas da biomassa de um plantio energético de Dipteryx panamensis de três anos de idade em SRWC em três diferentes espaçamentos (1,0x2,0 m, 1,0x0,5 m e 1,0x1,0 m) e, assim estabelecer a melhor condição de espaçamento para esta espécie tropical. Os resultados mostraram que a produção de biomassa varia entre 1,1 e 42,36 t.ha-1 e que 33-44% dessa produção está concentrada nas folhas. Aos três anos, o SRWC apresentou 50% de mortalidade com um diâmetro de 4,8 cm a 30 cm de altura do solo e com alturas totais de árvores de 5,17 a 6,98 metros. A avaliação da biomassa mostrou um valor calorífico foi de 18,9 a 19,4 MJ/kg, 1,81% de cinzas e 86% de conteúdo volátil. A densidade verde da madeira e o teor de umidade aumentaram com o aumento do espaçamento. Os espaçamentos 1,0x1,0 m e 1,0x0,5 m apresentaram o melhor comportamento em relação à produção anual de biomassa.
- Published
- 2020
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