James Kudjo Govina | University of Sopron (original) (raw)

Papers by James Kudjo Govina

Wood research, Jun 13, 2024

Bulletin of the Transilvania University of Braşov, Dec 20, 2023

Acta Silvatica & Lignaria Hungarica, Dec 31, 2022

E3S web of conferences, 2024

Wood Research

To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Gha... more To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Ghana was the objective of this research. The samples for the experiment were prepared and tested according to GS EN 326-1, GS EN 310, GS EN 314-1, and GS EN 314 -2. The data obtained were analysed using the factorial ANOVA analysis. The mean results obtained for the various treatments were MOE (6520 – 7638 N/mm2), MOR (53.29 – 60.56 N/mm2, shear strength (2.47 – 5.51 N/mm2), failure (72 -90%) and density (725 – 748 kg/m3). The orientation of the surface veneer caused variations among treatments whiles the adhesives PF and MUF largely did not cause any variations among treatments. This study has proven that it is possible to produce sufficiently strong and resistant plywood from the juvenile wood of eucalyptus.

Wood Research

To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Gha... more To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Ghana was the objective of this research. The samples for the experiment were prepared and tested according to GS EN 326-1, GS EN 310, GS EN 314-1, and GS EN 314 -2. The data obtained were analysed using the factorial ANOVA analysis. The mean results obtained for the various treatments were MOE (6520 – 7638 N/mm2), MOR (53.29 – 60.56 N/mm2, shear strength (2.47 – 5.51 N/mm2), failure (72 -90%) and density (725 – 748 kg/m3). The orientation of the surface veneer caused variations among treatments whiles the adhesives PF and MUF largely did not cause any variations among treatments. This study has proven that it is possible to produce sufficiently strong and resistant plywood from the juvenile wood of eucalyptus.

Matéria (Rio de Janeiro)

The aim to evaluate the raw material (agroforestry residues) for particleboard manufacture from t... more The aim to evaluate the raw material (agroforestry residues) for particleboard manufacture from the: pseudostem of Musa paradisiaca; the stem and pods of Theobroma cacao; and the sawdust of Ceiba pentandra. The particleboards produced from these cellulosic residues are mixed with cassava starch's natural adhesive and urea formaldehyde's synthetic adhesive. The results indicate that lignin, α-cellulose, hemicellulose, and extractives ranged from 6.2-19.0%, 41.4-50.2%, 24.4-31.5%, and 6.8-18.8% respectively and they were significantly different from each other. Additionally, tannins, alkaloids, saponins, flavonoids, phenols, glycosides, and sterols were the phytochemicals present in biomass materials in different quantities. Also, carbon, oxygen, nitrogen, and boron were the elementals significantly present in the manufactured particleboards in the range of 35.3-52.8, 30.2-43.0, 4.2-24.0, and 3.2-9.9 percentage concentration respectively. As for the mechanical properties, it was verified that the cellulose content influenced 96.5% of the variability of the modulus of rupture (MOR) values. Understanding the distribution, functional properties, and impact of biomass organic, phytochemicals and elemental constitutions is an impetus to the improvement of processes with higher retention of these constitutions in the utilization of agroforest residues in the particleboard industry. These chemical compositions of the residues under study contributed largely to the characteristics of the manufactured particleboards.

This paper studied the basic density and mechanical properties differences of wood among and with... more This paper studied the basic density and mechanical properties differences of wood among and within Sclerocarya birrea and Anogeissus leiocarpus. Three trees from each species were selected from the Lagawa Natural Forest Reserve in Western Kordofan State, Sudan. Test specimens were selected from three vertical positions (10, 50, and 90% along the bole length) of the trees. Specimens were also collected from three horizontal positions (innerwood, middlewood, and outerwood) within each of the three vertical positions. Tests for basic density of wood (BD), modulus of rupture (MOR), modulus of elasticity (MOE), compressive (CS), and shear strength (SS) parallel to the grain were performed. An analysis of variance shows that only the horizontal positions were a significant source of variation for both species studied. The correlation coefficient of BD was significant, weak, and positive for the mechanical properties of A. leiocarpus. A similar observation was found for BD correlated with CS and SS for S. birrea.

Acta Silvatica et Lignaria Hungarica

This paper studied the basic density and mechanical properties differences of wood among and with... more This paper studied the basic density and mechanical properties differences of wood among and within Sclerocarya birrea and Anogeissus leiocarpus. Three trees from each species were selected from the Lagawa Natural Forest Reserve in Western Kordofan State, Sudan. Test specimens were selected from three vertical positions (10, 50, and 90% along the bole length) of the trees. Specimens were also collected from three horizontal positions (innerwood, middlewood, and outerwood) within each of the three vertical positions. Tests for basic density of wood (BD), modulus of rupture (MOR), modulus of elasticity (MOE), compressive (CS), and shear strength (SS) parallel to the grain were performed. An analysis of variance shows that only the horizontal positions were a significant source of variation for both species studied. The correlation coefficient of BD was significant, weak, and positive for the mechanical properties of A. leiocarpus. A similar observation was found for BD correlated with...

Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land.... more Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land. In Ghana, the role of bamboo for land restoration has not been fully assessed. The main objectives of this study were to explore the potentials of bamboo to reclaim degraded mined land and to identify 2 suitable bamboo species. Plots measuring 825 m demarcated on un-mined, reclaimed mined and unreclaimed mined sites located in the moist semi-deciduous forest in Ghana. Seedlings of seven bamboo species were planted at 2m x 2 m matrix in blocks on each plot and the seedlings were assessed for survival rate, shoot production rate, height growth and qualitative phenotypic characteristics. The results indicated 97% survival of seedlings of all the species on all the plots and 70% of seedlings developed new shoots on the un-mined and reclaimed sites one month after planting while the un-reclaimed site recorded 50%. Also, the mean shoot production for reclaimed-, un-mined-, and un-reclaimed mi...

Journal of the Indian Academy of Wood Science

.................................................................................................... more .................................................................................................................................... V 1. General Introduction ........................................................................................................... 1 1.

Acta Silvatica et Lignaria Hungarica, 2021

This study sought to determine selected anatomical properties of young Eucalyptus hybrid species ... more This study sought to determine selected anatomical properties of young Eucalyptus hybrid species (E. grandis x E. urophylla) grown in Ghana. Images of fibres from macerated wood, and micro–sections produced with microtome were analysed using a compound digital microscope associated with Motic Image Plus Software (MIPS), version 2.0, installed on a computer. Images were initially processed using ImageJ software. Study data were analysed using an R statistical package. The overall mean value for fibre length was 907.67 µm, whereas double fibre wall thickness was 7.76 µm. Both variables had higher mean values in sapwood than in heartwood. Nevertheless, the found values decreased from the butt to the top portion. Statistically, axial and radial positions had no influence on fibre characteristics. In a 1 mm2 of the cross-section, the proportion of fibres was 38%, vessels were 19%, axial parenchyma were 22%, and radial parenchyma were 21% on average. Again, the radial and axial positions ...

Conference Proceedings, page 38 - 46, 2021

The High Forest Zone and the Savanna Woodland of Ghana is composed of a variety of hardwood speci... more The High Forest Zone and the Savanna Woodland of Ghana is composed of a variety of hardwood species.
Over the years, the natural forest cover has been phenomenally lost through over-exploitation of timber,
illegal logging, wildfire, illegal mining, agricultural expansion, weak implementation of forest management
policies etc. The challenges associated with the forests destruction in Ghana includes the shortage of raw
materials for the wood industry which was once a pillar to the Ghanaian economy. Presently plantation
forestry runs parallel to natural forest management as the guarantee for future wood supply. Considering
other benefits derived from forests, Ghana developed its National Climate Change Policy which recognizes
forest plantations development as one of the tools to combat climate change challenges. Reports from the
National Forest Plantation Development Programme and the Ghana Forest Plantation Strategy suggests that
close to 300, 000 hectares of forest plantation cover has been established between the year 2002 and 2019.
Tree species used in forest plantations across the country are hardwoods, but predominantly (about 90%)
Tectona grandis (Teak) which is an exotic species. The other species, covering the about 10% of
plantations, include Cedrela odorata (Red Cedar), various Eucalyptus species, and Gmelina arborea. Some
indigenous species successful in plantation establishment include, Terminalia superba and T. ivorensis,
Ceiba pentandra, Triplochiton scleroxylon, Khaya species, and Milicia excelsa.
Keywords: Ghana, plantation, forestry, hardwood, properties.

Journal of Bamboo and Rattan, 2014

Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land.... more Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land. In Ghana, the role of bamboo for land restoration has not been fully assessed. The main objectives of this study were to explore the potentials of bamboo to reclaim degraded mined land and to identify 2

New Forests, 2020

Resin canal features are associated with signifcant economic losses to appearance grade Pinus rad... more Resin canal features are associated with signifcant economic losses to appearance grade
Pinus radiata timber. This study investigated the variation in resin canal features in young,
2-year-old, P. radiata. Axial resin canal size, density and relative cross-sectional area were
determined in twenty families and ten clones from images of microtomed sections, scanned
with polarised light to highlight resin canals. Axial resin canal size was generally homogenous with a mean value estimate of 0.02 mm2
, and a coefcient of variation of ~10%. Estimated mean values for axial resin canal density and relative area were more variable (coeffcients of variation ~30%) and lower for clones (0.69 canals/mm2
and 1.13%, respectively)
than for families (0.90 canals/mm2
and 1.53%, respectively). Narrow-sense heritability
(h2
) estimates of the studied axial resin canal features in radiata pine at age 2-years-old
were ~0.30. Modulus of elasticity and longitudinal shrinkage were moderately correlated
with axial resin canal density and relative area, while basic density and volumetric shrinkage were independent of axial resin canal features. The study indicated that there could be
potential for breeding P. radiata for resin canal features, with the aim to improve the grade
yields of appearance grade products.
Keywords Appearance grade · Heritability · Radiata pine · Stifness · Wood defect

Teaching Documents by James Kudjo Govina

INBAR Working Paper, 2020

The International Bamboo and Rattan Organisation, INBAR, is an intergovernmental organisation ded... more The International Bamboo and Rattan Organisation, INBAR, is an intergovernmental organisation dedicated to the promotion of bamboo and rattan for sustainable development. For more information, please visit www.inbar.int.

Wood research, Jun 13, 2024

Bulletin of the Transilvania University of Braşov, Dec 20, 2023

Acta Silvatica & Lignaria Hungarica, Dec 31, 2022

E3S web of conferences, 2024

Wood Research

To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Gha... more To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Ghana was the objective of this research. The samples for the experiment were prepared and tested according to GS EN 326-1, GS EN 310, GS EN 314-1, and GS EN 314 -2. The data obtained were analysed using the factorial ANOVA analysis. The mean results obtained for the various treatments were MOE (6520 – 7638 N/mm2), MOR (53.29 – 60.56 N/mm2, shear strength (2.47 – 5.51 N/mm2), failure (72 -90%) and density (725 – 748 kg/m3). The orientation of the surface veneer caused variations among treatments whiles the adhesives PF and MUF largely did not cause any variations among treatments. This study has proven that it is possible to produce sufficiently strong and resistant plywood from the juvenile wood of eucalyptus.

Wood Research

To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Gha... more To obtain the mechanical properties of plywood produced from six yearold hybrid Eucalyptus in Ghana was the objective of this research. The samples for the experiment were prepared and tested according to GS EN 326-1, GS EN 310, GS EN 314-1, and GS EN 314 -2. The data obtained were analysed using the factorial ANOVA analysis. The mean results obtained for the various treatments were MOE (6520 – 7638 N/mm2), MOR (53.29 – 60.56 N/mm2, shear strength (2.47 – 5.51 N/mm2), failure (72 -90%) and density (725 – 748 kg/m3). The orientation of the surface veneer caused variations among treatments whiles the adhesives PF and MUF largely did not cause any variations among treatments. This study has proven that it is possible to produce sufficiently strong and resistant plywood from the juvenile wood of eucalyptus.

Matéria (Rio de Janeiro)

The aim to evaluate the raw material (agroforestry residues) for particleboard manufacture from t... more The aim to evaluate the raw material (agroforestry residues) for particleboard manufacture from the: pseudostem of Musa paradisiaca; the stem and pods of Theobroma cacao; and the sawdust of Ceiba pentandra. The particleboards produced from these cellulosic residues are mixed with cassava starch's natural adhesive and urea formaldehyde's synthetic adhesive. The results indicate that lignin, α-cellulose, hemicellulose, and extractives ranged from 6.2-19.0%, 41.4-50.2%, 24.4-31.5%, and 6.8-18.8% respectively and they were significantly different from each other. Additionally, tannins, alkaloids, saponins, flavonoids, phenols, glycosides, and sterols were the phytochemicals present in biomass materials in different quantities. Also, carbon, oxygen, nitrogen, and boron were the elementals significantly present in the manufactured particleboards in the range of 35.3-52.8, 30.2-43.0, 4.2-24.0, and 3.2-9.9 percentage concentration respectively. As for the mechanical properties, it was verified that the cellulose content influenced 96.5% of the variability of the modulus of rupture (MOR) values. Understanding the distribution, functional properties, and impact of biomass organic, phytochemicals and elemental constitutions is an impetus to the improvement of processes with higher retention of these constitutions in the utilization of agroforest residues in the particleboard industry. These chemical compositions of the residues under study contributed largely to the characteristics of the manufactured particleboards.

This paper studied the basic density and mechanical properties differences of wood among and with... more This paper studied the basic density and mechanical properties differences of wood among and within Sclerocarya birrea and Anogeissus leiocarpus. Three trees from each species were selected from the Lagawa Natural Forest Reserve in Western Kordofan State, Sudan. Test specimens were selected from three vertical positions (10, 50, and 90% along the bole length) of the trees. Specimens were also collected from three horizontal positions (innerwood, middlewood, and outerwood) within each of the three vertical positions. Tests for basic density of wood (BD), modulus of rupture (MOR), modulus of elasticity (MOE), compressive (CS), and shear strength (SS) parallel to the grain were performed. An analysis of variance shows that only the horizontal positions were a significant source of variation for both species studied. The correlation coefficient of BD was significant, weak, and positive for the mechanical properties of A. leiocarpus. A similar observation was found for BD correlated with CS and SS for S. birrea.

Acta Silvatica et Lignaria Hungarica

This paper studied the basic density and mechanical properties differences of wood among and with... more This paper studied the basic density and mechanical properties differences of wood among and within Sclerocarya birrea and Anogeissus leiocarpus. Three trees from each species were selected from the Lagawa Natural Forest Reserve in Western Kordofan State, Sudan. Test specimens were selected from three vertical positions (10, 50, and 90% along the bole length) of the trees. Specimens were also collected from three horizontal positions (innerwood, middlewood, and outerwood) within each of the three vertical positions. Tests for basic density of wood (BD), modulus of rupture (MOR), modulus of elasticity (MOE), compressive (CS), and shear strength (SS) parallel to the grain were performed. An analysis of variance shows that only the horizontal positions were a significant source of variation for both species studied. The correlation coefficient of BD was significant, weak, and positive for the mechanical properties of A. leiocarpus. A similar observation was found for BD correlated with...

Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land.... more Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land. In Ghana, the role of bamboo for land restoration has not been fully assessed. The main objectives of this study were to explore the potentials of bamboo to reclaim degraded mined land and to identify 2 suitable bamboo species. Plots measuring 825 m demarcated on un-mined, reclaimed mined and unreclaimed mined sites located in the moist semi-deciduous forest in Ghana. Seedlings of seven bamboo species were planted at 2m x 2 m matrix in blocks on each plot and the seedlings were assessed for survival rate, shoot production rate, height growth and qualitative phenotypic characteristics. The results indicated 97% survival of seedlings of all the species on all the plots and 70% of seedlings developed new shoots on the un-mined and reclaimed sites one month after planting while the un-reclaimed site recorded 50%. Also, the mean shoot production for reclaimed-, un-mined-, and un-reclaimed mi...

Journal of the Indian Academy of Wood Science

.................................................................................................... more .................................................................................................................................... V 1. General Introduction ........................................................................................................... 1 1.

Acta Silvatica et Lignaria Hungarica, 2021

This study sought to determine selected anatomical properties of young Eucalyptus hybrid species ... more This study sought to determine selected anatomical properties of young Eucalyptus hybrid species (E. grandis x E. urophylla) grown in Ghana. Images of fibres from macerated wood, and micro–sections produced with microtome were analysed using a compound digital microscope associated with Motic Image Plus Software (MIPS), version 2.0, installed on a computer. Images were initially processed using ImageJ software. Study data were analysed using an R statistical package. The overall mean value for fibre length was 907.67 µm, whereas double fibre wall thickness was 7.76 µm. Both variables had higher mean values in sapwood than in heartwood. Nevertheless, the found values decreased from the butt to the top portion. Statistically, axial and radial positions had no influence on fibre characteristics. In a 1 mm2 of the cross-section, the proportion of fibres was 38%, vessels were 19%, axial parenchyma were 22%, and radial parenchyma were 21% on average. Again, the radial and axial positions ...

Conference Proceedings, page 38 - 46, 2021

The High Forest Zone and the Savanna Woodland of Ghana is composed of a variety of hardwood speci... more The High Forest Zone and the Savanna Woodland of Ghana is composed of a variety of hardwood species.
Over the years, the natural forest cover has been phenomenally lost through over-exploitation of timber,
illegal logging, wildfire, illegal mining, agricultural expansion, weak implementation of forest management
policies etc. The challenges associated with the forests destruction in Ghana includes the shortage of raw
materials for the wood industry which was once a pillar to the Ghanaian economy. Presently plantation
forestry runs parallel to natural forest management as the guarantee for future wood supply. Considering
other benefits derived from forests, Ghana developed its National Climate Change Policy which recognizes
forest plantations development as one of the tools to combat climate change challenges. Reports from the
National Forest Plantation Development Programme and the Ghana Forest Plantation Strategy suggests that
close to 300, 000 hectares of forest plantation cover has been established between the year 2002 and 2019.
Tree species used in forest plantations across the country are hardwoods, but predominantly (about 90%)
Tectona grandis (Teak) which is an exotic species. The other species, covering the about 10% of
plantations, include Cedrela odorata (Red Cedar), various Eucalyptus species, and Gmelina arborea. Some
indigenous species successful in plantation establishment include, Terminalia superba and T. ivorensis,
Ceiba pentandra, Triplochiton scleroxylon, Khaya species, and Milicia excelsa.
Keywords: Ghana, plantation, forestry, hardwood, properties.

Journal of Bamboo and Rattan, 2014

Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land.... more Bamboo is useful for soil erosion control, carbon sequestration and restoration of degraded land. In Ghana, the role of bamboo for land restoration has not been fully assessed. The main objectives of this study were to explore the potentials of bamboo to reclaim degraded mined land and to identify 2

New Forests, 2020

Resin canal features are associated with signifcant economic losses to appearance grade Pinus rad... more Resin canal features are associated with signifcant economic losses to appearance grade
Pinus radiata timber. This study investigated the variation in resin canal features in young,
2-year-old, P. radiata. Axial resin canal size, density and relative cross-sectional area were
determined in twenty families and ten clones from images of microtomed sections, scanned
with polarised light to highlight resin canals. Axial resin canal size was generally homogenous with a mean value estimate of 0.02 mm2
, and a coefcient of variation of ~10%. Estimated mean values for axial resin canal density and relative area were more variable (coeffcients of variation ~30%) and lower for clones (0.69 canals/mm2
and 1.13%, respectively)
than for families (0.90 canals/mm2
and 1.53%, respectively). Narrow-sense heritability
(h2
) estimates of the studied axial resin canal features in radiata pine at age 2-years-old
were ~0.30. Modulus of elasticity and longitudinal shrinkage were moderately correlated
with axial resin canal density and relative area, while basic density and volumetric shrinkage were independent of axial resin canal features. The study indicated that there could be
potential for breeding P. radiata for resin canal features, with the aim to improve the grade
yields of appearance grade products.
Keywords Appearance grade · Heritability · Radiata pine · Stifness · Wood defect

INBAR Working Paper, 2020

The International Bamboo and Rattan Organisation, INBAR, is an intergovernmental organisation ded... more The International Bamboo and Rattan Organisation, INBAR, is an intergovernmental organisation dedicated to the promotion of bamboo and rattan for sustainable development. For more information, please visit www.inbar.int.