The present study described the possibility of using wood-treated oil-fungicide of lemon-scented ... more The present study described the possibility of using wood-treated oil-fungicide of lemon-scented gum (Corymbia citriodora) from newly emerged leaves and unripened fruits against the infestation of Fusarium culmorum, Rhizoctonia solani and Penicillium chrysogenum. Air-dried wood samples of Melia azedarach were treated with the extracted oils from leaves and unripened fruits from C. citriodora. The main chemical constituents identified in the essential oil (EO) from leaves were citronellal (55.31%), citronellol (21.03%) and isopulegol (10.79%), while in unripened fruits were α-pinene (17.86%), eudesmol (13.9%), limonene (9.19%), γ-terpinen (8.21%), and guaiol (7.88%). For recovered oils (ROs), the major components from leaves were D-limonene (70.23%), γ-terpinene (13.58%), β-pinene (2.40%) and isopregol (2.23%), while, 4-terpineol (21.35%), cis-β-terpineol, (19.33%), D-limonene (14.75%), and γ-terpinene (7.42%) represented the main components in fruits. EOs from leaves and fruits at the amounts of 100, 50 and 25 µL showed the highest inhibition percentage (IP) of 100% against F. culmorum and P. chrysogenum compared to control treatment, while at the amounts of 100, and 50 µL showed 100% IP of R. solani. Wood treated with ROs from leaves and fruits showed IPs of 96.66% and 93.33%, respectively, against the growth of R. solani. The mass spectra of the main components of C. citriodora leaves and fruits' EOs have been recorded in electron ionization mode at 70 eV and fragmentation has been reported and discussed. On the other hand, different quantum parameters such as the heat of formation, ionization energy total energy, binding energy, electronic energy and dipole moment using the modified neglect of diatomic overlap (MNDO) semi-empirical method have been calculated.
The present study evaluated for the first time, some strength properties and the chemical composi... more The present study evaluated for the first time, some strength properties and the chemical compositions of seven hardwood species grown in Northeast Egypt, namely, Acacia saligna, Delonix regia, Erythrina humeana, Ficus elastica, Leucaena leucocephala, Melia azedarach, and Meryta sinclairii. The analysis of variance (ANOVA) results indicated that the effect of wood species on the mechanical properties and chemical compositions was significant (P M. sinclairii > L. leucocephala > D. regia > F. elastica > A. saligna > E. humeana.
Effects of aqueous extraction on the performance and properties of polypropylene/wood composites ... more Effects of aqueous extraction on the performance and properties of polypropylene/wood composites from Phoenix dactylifera and Acacia tortilis wood
This study was carried out in 2010 to investigate the suitability of date palm midribs (Phoenix d... more This study was carried out in 2010 to investigate the suitability of date palm midribs (Phoenix dactelifera L.) as a lignocellulosic material for the production of wood-cement composite panels, in addition to enhancement their compatibility with cement using various pretreatments and chemical additives. Materials used for this study were midribs of fronds of different date palm varieties available in Saudi Arabia and Portland cement (Type I) manufactured by Yammama Cement Company. To achieve this aim, hydration tests of net cement and date palm-cement mixture were carried out using a 2-litter Dewar flask. The suitability of date palm for this industry was made according to inhibitory index (I) and compatibility factor (C) which A were calculated from the hydration data. The results showed that under untreated condition, date palm particles are incompatible with cement and were classified as "unsuitable" for making wood-cement boards. Using of cold or hot water extraction for date palm materials resulted in an enhancement in their compatibility with cement. However, date palm can be reclassified as suitable under limited conditions for making wood-cement boards only by using hot water extraction. Addition of 3% CaCl to untreated date palm particles resulted in 2 reclassified it to suitable under limited conditions (T value was 54.23°C and C value was 75.73%). These max A results suggested that date palm midribs can be used to produce wood-cement panels either after extraction by hot water or addition of 3% CaCl as an accelerator to date palm-cement mixture.
The present study was carried out in central region of Saudi Arabia. The objective of the study w... more The present study was carried out in central region of Saudi Arabia. The objective of the study was to evaluate the diversity, stocking and regeneration capacity of the natural growing Acacia gerrardii (Benth) in 5 sites selected from three governments namely; Huraymila', Dhurmah and Dawadmi. The sampling of Acacia species was conducted within circular sample plots. Inside each site, three sample plots were selected to determine the regeneration capacity, tree stocking and productivity. The results indicated that the growth diversity and stand structure of naturally growing Acacia gerrardii in Riyadh region varied with location. Most of the trees in locations occurred as woodlots. Dawadmi recorded the maximum tree stocking and productivity. The regeneration capacity in Huraymila' was higher whereas the least total seedling ha-1 was record at Dawadmi location. Removing trees for various purposes reduced heavily the stocking density of the trees, regeneration capacity and the chlorophyll contents in locations. The stocking density and regeneration in locations were low cause of indiscriminate cutting of trees and intensive grazing. Tree heights were below the average as a result to low stocking density and increased natural spacing between trees. Acacia gerrardii woodlots in this area require immediate intervention and protection to attain sustainability.
Journal of environmental biology / Academy of Environmental Biology, India, 2014
This study investigated the possibility of using the prunings of six locally grown tree species i... more This study investigated the possibility of using the prunings of six locally grown tree species in Saudi Arabia for cement-bonded particleboard (CBP) production. Panels were made using four different wood particle sizes and a constant wood/cement ratio (1/3 by weight) and target density (1200 kg/m3). The mechanical properties and dimensional stability of the produced panels were determined. The interfacial area and distribution of the wood particles in cement matrix were also investigated by scanning electron microscopy. The results revealed that the panels produced from these pruning materials at a target density of 1200 kg m(-3) meet the strength and dimensional stability requirements of the commercial CBP panels. The mean moduli of rupture and elasticity (MOR and MOE) ranged from 9.68 to 11.78 N mm2 and from 3952 to 5667 N mm2, respectively. The mean percent water absorption for twenty four hours (WA24) ranged from 12.93% to 23.39%. Thickness swelling values ranged from 0.62% to ...
The aim of the current investigation was to study the suitability of pruning of vine (Vitis vinif... more The aim of the current investigation was to study the suitability of pruning of vine (Vitis vinifera L.) as a lignocellulosic material for the production of wood-cement composite panels, enhance their compatibility with cement using various pretreatments and chemical additives. Hydration tests of net cement and vine-cement mixture were carried out using a 2-litre Dewar flask. Suitability was determined by inhibitory index (I) and compatibility factor (C), which were calculated from the hydration data. Under untreated condition, vine A pruning particles were incompatible with cement and were classified as "unsuitable" for making wood-cement boards. Using of cold or hot water extraction for those materials enhanced their compatibility with cement. However, it can be reclassified as 'suitable under limited conditions' for making wood-cement boards only by using hot water extraction. Addition of 3% CaCl to untreated vine particles resulted in its reclassification as 2 'suitable under limited conditions' (T value was 39.27°C and C value was 69.37%). These results suggested max A that vine grape prunings can be used to produce wood-cement panels after extraction by hot water or addition of 3% CaCl as an accelerator.
... impact. This affirms that removal of high extractives contents of Ceteris paribus had a signi... more ... impact. This affirms that removal of high extractives contents of Ceteris paribus had a significant consequence on Cmax and МОЕ. On the other hand our findings contradictBadran and El-Osta [29] and Al-Mefarrej [30]. The former ...
The objective of this study is to measure and evaluate the suitability of two types of reed, name... more The objective of this study is to measure and evaluate the suitability of two types of reed, namely giant reed (Arundo donax) and common reed (Phragmites australis) as non-woody raw materials using soda-anthraquinone (AQ) pulping process for pulp and paper industry. Two fractions of reed were used to produce experimental papersheets. The two fractions are woody stem and whole plant including woody stem, leaves, and sheathes. The biometric characteristics, such as extractive solvents, chemical, morphological properties, and physical properties in addition to some strength properties of the papersheets made from these resources were measured. The results indicated that P. australis had the highest contents of cellulose, hemicellulose and ash were 53.5%, 33.9% and 3.9%, respectively while the lowest lignin content value was 13.6%. Fiber length of both types of fiber length were also determined as 1800μm and 1400μm. The derived Runkel ratio and flexibility coefficient for P. australis were also determined as 1.25, 61.4, respectively. Overall strength properties of pulp and papersheets made from the two reed types were significantly different from each other. Based on the results of this study, it appears that both types of reed, giant reed and common reed could have a potential to be used as an alternative raw material for pulp and paper production with accepted properties.
This study investigated the effect of some treatments on the compatibility of three lignocellulos... more This study investigated the effect of some treatments on the compatibility of three lignocellulosic materials with cement. The lignocellulosic materials used were sunt (Acacia nilotica) sawdust, bagasse and cotton stalks collected from Es-Suki Sawmill, EL Gunied Sugar Factory and the fields of EL Kamlin governarate, respectively. The treatments were control, addition of 3% CaCl2, hot water extraction, hot water extraction 3%CaCl2, 1%NaOH extraction, and 1%NaOH extraction+3%CaCl2. Two Dewar flasks and a digital thermocouple were used. Hydration characteristics (maximum hydration temperature, time to reach maximum temperature and rise in temperature above ambient) of the lignocellulosic materials with cement were determined for each lignocellulosic material. The most suitable treatment common to all materials was the 1%NaOH extraction +3%CaCl2. The average maximum hydration temperatures attained by this treatment were 63.87 °C for bagasse, 67.87 °C for cotton stalks and 67.9 °C for su...
This study investigated the effects of nine different mixtures of three lignocellulosic materials... more This study investigated the effects of nine different mixtures of three lignocellulosic materials and four ratios of cement to lignocellulosic materials (LCM) (2.5:1, 3:1, 3.5:1 and 4:1) on the properties of cement bonded particleboard. The materials were (sunt) Acacia nilotica saw dust, bagasse and cotton stalks. They were collected from different locations in Sudan. Reasonable panel properties were obtained from the three lignocellulosic materials either pure or mixed using different cement/lignocellulosic materials (C/LCM) ratios (3:1, 3.5:1 and 4: 1). The mean values of water absorption percent (WA %) and the thickness swelling percent (TS %) for both the two hours and 24-hours soaking tests, conform favorably to figures reported in previous studies.The highest bending strength (MOR) and modulus of elasticity (MOE) were attained by100% sunt particles with all cement/lignocellulosic materials ratios.
The accelerated ageing of wood in terms of heating or iron rusting has a potential effect on the ... more The accelerated ageing of wood in terms of heating or iron rusting has a potential effect on the physio-mechanical, chemical and biological properties of wood. The effects of accelerated ageing on the mechanical, physical and fungal activity properties of some wood materials (Schinus terebinthifolius, Erythrina humeana, Tectona grandis, Pinus rigida and Juglans nigra) were studied after several cycles of heating and iron rusting. The fungal activity was assayed against the growth of Aspergillus terreus, Aspergillus niger, Fusarium culmorum and Stemphylium solani. In addition, the mechanical and optical properties of paper sheets produced from those wood pulps by means of Kraft cooking were evaluated. The mechanical and chemical properties of the studied wood species were affected significantly (p < 0.05) by the accelerated ageing, compared to control woods. With Fourier transform infrared (FTIR) spectroscopy, we detected an increase in the intensity of the spectra of the function...
In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus au... more In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus aurantium (green leaves/twigs, small branches, wooden branches, and branch bark) were studied through gas chromatography coupled with mass spectrometry (GC/MS). Furthermore, the EOs in the amounts of 5, 10, 15, 20, and 25 µL were studied for their antibacterial activity against three pathogenic bacteria, Agrobacterium tumefaciens, Dickeya solani, and Erwinia amylovora. The main EO compounds in the leaves/twigs were 4-terpineol (22.59%), D-limonene (16.67%), 4-carvomenthenol (12.84%), and linalool (7.82%). In small green branches, they were D-limonene (71.57%), dodecane (4.80%), oleic acid (2.72%), and trans-palmitoleic acid (2.62%), while in branch bark were D-limonene (54.61%), γ-terpinene (6.68%), dodecane (5.73%), and dimethyl anthranilate (3.13%), and in branch wood were D-limonene (38.13%), dimethyl anthranilate (8.13%), (-)-β-fenchol (6.83%), and dodecane (5.31%). At 25 µL, the EO fr...
This study measures the formaldehyde content (FC) of different types of oriented strand board (OS... more This study measures the formaldehyde content (FC) of different types of oriented strand board (OSB) panels. Panels with different thicknesses were produced on the OSB production line of a prominent manufacturer of board composite materials in the Czech Republic. The resins used were polyurethane (PU1, PU2) and melamine-urea-formaldehyde (MUF). The corrected FC from 3-layer OSB/3 panels (MUF/surface, PU2/core) ranged from 5.95 ± 0.42 to 7.24 ± 0.67 mg formaldehyde/100 g of dry board. The corrected FC of the 3-layer OSB panels bonded with PU2 resin ranged between 0.48±0.04 and 0.57±0.11 mg formaldehyde/100 g dry board. Additionally, the corrected FC of 3-layer OSB/3 panels bonded with PU1 resin ranged from 0.09±0.22 to 0.46±0.40 mg formaldehyde/100 g dry board. Furthermore, the corrected FC of 3-layer OSB/4 panels bonded with PU1 resin ranged from 0.178±0.309 to 0.473±0.027 mg formaldehyde/100 g dry board. These results showed that the FC was limited to the natural content of formaldehyde in solid wood, where the values are extremely low, and which resulted in the production of green product. Additionally, the FC of OSB panels bonded with PU1 was lower than that of panels glued with PU2.
Non-woody biomass species have high-energy potentials, which could be used for bioenergy producti... more Non-woody biomass species have high-energy potentials, which could be used for bioenergy production. Invasive species are species spreading into areas, where they are not native, consequently causing environmental and economic problems. Therefore, the present study evaluated the proximate, ultimate, chemical, and fuel characteristics of wood and charcoal of three invasive nonforest tree species in Saudi Arabia: Calotropis procera, Rhazya stricta, and Phragmites australis, which were compared with the wood of Acacia tortilis, a preferable local fuelwood. All these data were discussed to investigate the possibility of using the invasive plants for energy production. The thermal behavior of wood was analyzed using thermo-gravimetric and derivative thermo-gravimetric methods. Overall, compared with the wood of A. tortilis, the woods of R. stricta and P. australis are suitable for energy production. The charcoal produced from P. australis emitted less nitrogen (N) oxide than that of R. stricta.
The effect of particle pretreatments on the biodeterioration of woodplastic composites (WPCs) was... more The effect of particle pretreatments on the biodeterioration of woodplastic composites (WPCs) was investigated. WPCs made from untreated and pretreated frond midrib particles of date palm were used. Before the addition of a coupling agent, the wood particles were pretreated or extracted with either cold or hot water and mixed with polypropylene to produce panels, which were then superficially inoculated with an ascomycete's fungus Trichoderma harzianum T6776. The WPC surfaces were studied using scanning electron microscopy (SEM) and electron dispersive X-ray spectroscopy (EDX) measurements. In comparison with the control, an intensive growth of T. harzianum hyphae was found over the WPC surface manufactured from untreated date palm midrib particles with the colonies clearly visible. The pretreatments of date palm particles reduced the growth of T. harzianum in comparison with the control and untreated particles. The results suggested that particle pretreatments could be a suitable way to limit the growth of molds over WPC surfaces made from date palm midrib.
Mold invasion by Trichoderma harzianum T6776 over the surface of wood-plastic composites (WPCs) m... more Mold invasion by Trichoderma harzianum T6776 over the surface of wood-plastic composites (WPCs) made from Juniperus procera woodbranch and polypropylene with a melt-blending technique was examined using scanning electron microscopy (SEM) and electron dispersive X-ray spectroscopy (EDX). Before the addition of coupling agent, the WPC samples were made from untreated and pretreated wood-branch particles of J. procera with either cold or hot water and then mixed with polypropylene to produce panels. The surfaces of WPC samples were inoculated by a mold suspension of T. harzianum. SEM-EDX measurements of WPCs made from J. procera particles showed little or no growth of T. harzianum, irrespective of treatment with cold or hot water. The results suggest that WPCs made from the particles of J. procera wood-branch pretreated with either cold or hot water could be useable in wet conditions. In addition, using of J. procera as durable wood for manufacturing of WPCs had good effects on the prevention of the mold infestation over the surfaces of the produced panels.
The present study described the possibility of using wood-treated oil-fungicide of lemon-scented ... more The present study described the possibility of using wood-treated oil-fungicide of lemon-scented gum (Corymbia citriodora) from newly emerged leaves and unripened fruits against the infestation of Fusarium culmorum, Rhizoctonia solani and Penicillium chrysogenum. Air-dried wood samples of Melia azedarach were treated with the extracted oils from leaves and unripened fruits from C. citriodora. The main chemical constituents identified in the essential oil (EO) from leaves were citronellal (55.31%), citronellol (21.03%) and isopulegol (10.79%), while in unripened fruits were α-pinene (17.86%), eudesmol (13.9%), limonene (9.19%), γ-terpinen (8.21%), and guaiol (7.88%). For recovered oils (ROs), the major components from leaves were D-limonene (70.23%), γ-terpinene (13.58%), β-pinene (2.40%) and isopregol (2.23%), while, 4-terpineol (21.35%), cis-β-terpineol, (19.33%), D-limonene (14.75%), and γ-terpinene (7.42%) represented the main components in fruits. EOs from leaves and fruits at the amounts of 100, 50 and 25 µL showed the highest inhibition percentage (IP) of 100% against F. culmorum and P. chrysogenum compared to control treatment, while at the amounts of 100, and 50 µL showed 100% IP of R. solani. Wood treated with ROs from leaves and fruits showed IPs of 96.66% and 93.33%, respectively, against the growth of R. solani. The mass spectra of the main components of C. citriodora leaves and fruits' EOs have been recorded in electron ionization mode at 70 eV and fragmentation has been reported and discussed. On the other hand, different quantum parameters such as the heat of formation, ionization energy total energy, binding energy, electronic energy and dipole moment using the modified neglect of diatomic overlap (MNDO) semi-empirical method have been calculated.
The present study evaluated for the first time, some strength properties and the chemical composi... more The present study evaluated for the first time, some strength properties and the chemical compositions of seven hardwood species grown in Northeast Egypt, namely, Acacia saligna, Delonix regia, Erythrina humeana, Ficus elastica, Leucaena leucocephala, Melia azedarach, and Meryta sinclairii. The analysis of variance (ANOVA) results indicated that the effect of wood species on the mechanical properties and chemical compositions was significant (P M. sinclairii > L. leucocephala > D. regia > F. elastica > A. saligna > E. humeana.
Effects of aqueous extraction on the performance and properties of polypropylene/wood composites ... more Effects of aqueous extraction on the performance and properties of polypropylene/wood composites from Phoenix dactylifera and Acacia tortilis wood
This study was carried out in 2010 to investigate the suitability of date palm midribs (Phoenix d... more This study was carried out in 2010 to investigate the suitability of date palm midribs (Phoenix dactelifera L.) as a lignocellulosic material for the production of wood-cement composite panels, in addition to enhancement their compatibility with cement using various pretreatments and chemical additives. Materials used for this study were midribs of fronds of different date palm varieties available in Saudi Arabia and Portland cement (Type I) manufactured by Yammama Cement Company. To achieve this aim, hydration tests of net cement and date palm-cement mixture were carried out using a 2-litter Dewar flask. The suitability of date palm for this industry was made according to inhibitory index (I) and compatibility factor (C) which A were calculated from the hydration data. The results showed that under untreated condition, date palm particles are incompatible with cement and were classified as "unsuitable" for making wood-cement boards. Using of cold or hot water extraction for date palm materials resulted in an enhancement in their compatibility with cement. However, date palm can be reclassified as suitable under limited conditions for making wood-cement boards only by using hot water extraction. Addition of 3% CaCl to untreated date palm particles resulted in 2 reclassified it to suitable under limited conditions (T value was 54.23°C and C value was 75.73%). These max A results suggested that date palm midribs can be used to produce wood-cement panels either after extraction by hot water or addition of 3% CaCl as an accelerator to date palm-cement mixture.
The present study was carried out in central region of Saudi Arabia. The objective of the study w... more The present study was carried out in central region of Saudi Arabia. The objective of the study was to evaluate the diversity, stocking and regeneration capacity of the natural growing Acacia gerrardii (Benth) in 5 sites selected from three governments namely; Huraymila', Dhurmah and Dawadmi. The sampling of Acacia species was conducted within circular sample plots. Inside each site, three sample plots were selected to determine the regeneration capacity, tree stocking and productivity. The results indicated that the growth diversity and stand structure of naturally growing Acacia gerrardii in Riyadh region varied with location. Most of the trees in locations occurred as woodlots. Dawadmi recorded the maximum tree stocking and productivity. The regeneration capacity in Huraymila' was higher whereas the least total seedling ha-1 was record at Dawadmi location. Removing trees for various purposes reduced heavily the stocking density of the trees, regeneration capacity and the chlorophyll contents in locations. The stocking density and regeneration in locations were low cause of indiscriminate cutting of trees and intensive grazing. Tree heights were below the average as a result to low stocking density and increased natural spacing between trees. Acacia gerrardii woodlots in this area require immediate intervention and protection to attain sustainability.
Journal of environmental biology / Academy of Environmental Biology, India, 2014
This study investigated the possibility of using the prunings of six locally grown tree species i... more This study investigated the possibility of using the prunings of six locally grown tree species in Saudi Arabia for cement-bonded particleboard (CBP) production. Panels were made using four different wood particle sizes and a constant wood/cement ratio (1/3 by weight) and target density (1200 kg/m3). The mechanical properties and dimensional stability of the produced panels were determined. The interfacial area and distribution of the wood particles in cement matrix were also investigated by scanning electron microscopy. The results revealed that the panels produced from these pruning materials at a target density of 1200 kg m(-3) meet the strength and dimensional stability requirements of the commercial CBP panels. The mean moduli of rupture and elasticity (MOR and MOE) ranged from 9.68 to 11.78 N mm2 and from 3952 to 5667 N mm2, respectively. The mean percent water absorption for twenty four hours (WA24) ranged from 12.93% to 23.39%. Thickness swelling values ranged from 0.62% to ...
The aim of the current investigation was to study the suitability of pruning of vine (Vitis vinif... more The aim of the current investigation was to study the suitability of pruning of vine (Vitis vinifera L.) as a lignocellulosic material for the production of wood-cement composite panels, enhance their compatibility with cement using various pretreatments and chemical additives. Hydration tests of net cement and vine-cement mixture were carried out using a 2-litre Dewar flask. Suitability was determined by inhibitory index (I) and compatibility factor (C), which were calculated from the hydration data. Under untreated condition, vine A pruning particles were incompatible with cement and were classified as "unsuitable" for making wood-cement boards. Using of cold or hot water extraction for those materials enhanced their compatibility with cement. However, it can be reclassified as 'suitable under limited conditions' for making wood-cement boards only by using hot water extraction. Addition of 3% CaCl to untreated vine particles resulted in its reclassification as 2 'suitable under limited conditions' (T value was 39.27°C and C value was 69.37%). These results suggested max A that vine grape prunings can be used to produce wood-cement panels after extraction by hot water or addition of 3% CaCl as an accelerator.
... impact. This affirms that removal of high extractives contents of Ceteris paribus had a signi... more ... impact. This affirms that removal of high extractives contents of Ceteris paribus had a significant consequence on Cmax and МОЕ. On the other hand our findings contradictBadran and El-Osta [29] and Al-Mefarrej [30]. The former ...
The objective of this study is to measure and evaluate the suitability of two types of reed, name... more The objective of this study is to measure and evaluate the suitability of two types of reed, namely giant reed (Arundo donax) and common reed (Phragmites australis) as non-woody raw materials using soda-anthraquinone (AQ) pulping process for pulp and paper industry. Two fractions of reed were used to produce experimental papersheets. The two fractions are woody stem and whole plant including woody stem, leaves, and sheathes. The biometric characteristics, such as extractive solvents, chemical, morphological properties, and physical properties in addition to some strength properties of the papersheets made from these resources were measured. The results indicated that P. australis had the highest contents of cellulose, hemicellulose and ash were 53.5%, 33.9% and 3.9%, respectively while the lowest lignin content value was 13.6%. Fiber length of both types of fiber length were also determined as 1800μm and 1400μm. The derived Runkel ratio and flexibility coefficient for P. australis were also determined as 1.25, 61.4, respectively. Overall strength properties of pulp and papersheets made from the two reed types were significantly different from each other. Based on the results of this study, it appears that both types of reed, giant reed and common reed could have a potential to be used as an alternative raw material for pulp and paper production with accepted properties.
This study investigated the effect of some treatments on the compatibility of three lignocellulos... more This study investigated the effect of some treatments on the compatibility of three lignocellulosic materials with cement. The lignocellulosic materials used were sunt (Acacia nilotica) sawdust, bagasse and cotton stalks collected from Es-Suki Sawmill, EL Gunied Sugar Factory and the fields of EL Kamlin governarate, respectively. The treatments were control, addition of 3% CaCl2, hot water extraction, hot water extraction 3%CaCl2, 1%NaOH extraction, and 1%NaOH extraction+3%CaCl2. Two Dewar flasks and a digital thermocouple were used. Hydration characteristics (maximum hydration temperature, time to reach maximum temperature and rise in temperature above ambient) of the lignocellulosic materials with cement were determined for each lignocellulosic material. The most suitable treatment common to all materials was the 1%NaOH extraction +3%CaCl2. The average maximum hydration temperatures attained by this treatment were 63.87 °C for bagasse, 67.87 °C for cotton stalks and 67.9 °C for su...
This study investigated the effects of nine different mixtures of three lignocellulosic materials... more This study investigated the effects of nine different mixtures of three lignocellulosic materials and four ratios of cement to lignocellulosic materials (LCM) (2.5:1, 3:1, 3.5:1 and 4:1) on the properties of cement bonded particleboard. The materials were (sunt) Acacia nilotica saw dust, bagasse and cotton stalks. They were collected from different locations in Sudan. Reasonable panel properties were obtained from the three lignocellulosic materials either pure or mixed using different cement/lignocellulosic materials (C/LCM) ratios (3:1, 3.5:1 and 4: 1). The mean values of water absorption percent (WA %) and the thickness swelling percent (TS %) for both the two hours and 24-hours soaking tests, conform favorably to figures reported in previous studies.The highest bending strength (MOR) and modulus of elasticity (MOE) were attained by100% sunt particles with all cement/lignocellulosic materials ratios.
The accelerated ageing of wood in terms of heating or iron rusting has a potential effect on the ... more The accelerated ageing of wood in terms of heating or iron rusting has a potential effect on the physio-mechanical, chemical and biological properties of wood. The effects of accelerated ageing on the mechanical, physical and fungal activity properties of some wood materials (Schinus terebinthifolius, Erythrina humeana, Tectona grandis, Pinus rigida and Juglans nigra) were studied after several cycles of heating and iron rusting. The fungal activity was assayed against the growth of Aspergillus terreus, Aspergillus niger, Fusarium culmorum and Stemphylium solani. In addition, the mechanical and optical properties of paper sheets produced from those wood pulps by means of Kraft cooking were evaluated. The mechanical and chemical properties of the studied wood species were affected significantly (p < 0.05) by the accelerated ageing, compared to control woods. With Fourier transform infrared (FTIR) spectroscopy, we detected an increase in the intensity of the spectra of the function...
In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus au... more In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus aurantium (green leaves/twigs, small branches, wooden branches, and branch bark) were studied through gas chromatography coupled with mass spectrometry (GC/MS). Furthermore, the EOs in the amounts of 5, 10, 15, 20, and 25 µL were studied for their antibacterial activity against three pathogenic bacteria, Agrobacterium tumefaciens, Dickeya solani, and Erwinia amylovora. The main EO compounds in the leaves/twigs were 4-terpineol (22.59%), D-limonene (16.67%), 4-carvomenthenol (12.84%), and linalool (7.82%). In small green branches, they were D-limonene (71.57%), dodecane (4.80%), oleic acid (2.72%), and trans-palmitoleic acid (2.62%), while in branch bark were D-limonene (54.61%), γ-terpinene (6.68%), dodecane (5.73%), and dimethyl anthranilate (3.13%), and in branch wood were D-limonene (38.13%), dimethyl anthranilate (8.13%), (-)-β-fenchol (6.83%), and dodecane (5.31%). At 25 µL, the EO fr...
This study measures the formaldehyde content (FC) of different types of oriented strand board (OS... more This study measures the formaldehyde content (FC) of different types of oriented strand board (OSB) panels. Panels with different thicknesses were produced on the OSB production line of a prominent manufacturer of board composite materials in the Czech Republic. The resins used were polyurethane (PU1, PU2) and melamine-urea-formaldehyde (MUF). The corrected FC from 3-layer OSB/3 panels (MUF/surface, PU2/core) ranged from 5.95 ± 0.42 to 7.24 ± 0.67 mg formaldehyde/100 g of dry board. The corrected FC of the 3-layer OSB panels bonded with PU2 resin ranged between 0.48±0.04 and 0.57±0.11 mg formaldehyde/100 g dry board. Additionally, the corrected FC of 3-layer OSB/3 panels bonded with PU1 resin ranged from 0.09±0.22 to 0.46±0.40 mg formaldehyde/100 g dry board. Furthermore, the corrected FC of 3-layer OSB/4 panels bonded with PU1 resin ranged from 0.178±0.309 to 0.473±0.027 mg formaldehyde/100 g dry board. These results showed that the FC was limited to the natural content of formaldehyde in solid wood, where the values are extremely low, and which resulted in the production of green product. Additionally, the FC of OSB panels bonded with PU1 was lower than that of panels glued with PU2.
Non-woody biomass species have high-energy potentials, which could be used for bioenergy producti... more Non-woody biomass species have high-energy potentials, which could be used for bioenergy production. Invasive species are species spreading into areas, where they are not native, consequently causing environmental and economic problems. Therefore, the present study evaluated the proximate, ultimate, chemical, and fuel characteristics of wood and charcoal of three invasive nonforest tree species in Saudi Arabia: Calotropis procera, Rhazya stricta, and Phragmites australis, which were compared with the wood of Acacia tortilis, a preferable local fuelwood. All these data were discussed to investigate the possibility of using the invasive plants for energy production. The thermal behavior of wood was analyzed using thermo-gravimetric and derivative thermo-gravimetric methods. Overall, compared with the wood of A. tortilis, the woods of R. stricta and P. australis are suitable for energy production. The charcoal produced from P. australis emitted less nitrogen (N) oxide than that of R. stricta.
The effect of particle pretreatments on the biodeterioration of woodplastic composites (WPCs) was... more The effect of particle pretreatments on the biodeterioration of woodplastic composites (WPCs) was investigated. WPCs made from untreated and pretreated frond midrib particles of date palm were used. Before the addition of a coupling agent, the wood particles were pretreated or extracted with either cold or hot water and mixed with polypropylene to produce panels, which were then superficially inoculated with an ascomycete's fungus Trichoderma harzianum T6776. The WPC surfaces were studied using scanning electron microscopy (SEM) and electron dispersive X-ray spectroscopy (EDX) measurements. In comparison with the control, an intensive growth of T. harzianum hyphae was found over the WPC surface manufactured from untreated date palm midrib particles with the colonies clearly visible. The pretreatments of date palm particles reduced the growth of T. harzianum in comparison with the control and untreated particles. The results suggested that particle pretreatments could be a suitable way to limit the growth of molds over WPC surfaces made from date palm midrib.
Mold invasion by Trichoderma harzianum T6776 over the surface of wood-plastic composites (WPCs) m... more Mold invasion by Trichoderma harzianum T6776 over the surface of wood-plastic composites (WPCs) made from Juniperus procera woodbranch and polypropylene with a melt-blending technique was examined using scanning electron microscopy (SEM) and electron dispersive X-ray spectroscopy (EDX). Before the addition of coupling agent, the WPC samples were made from untreated and pretreated wood-branch particles of J. procera with either cold or hot water and then mixed with polypropylene to produce panels. The surfaces of WPC samples were inoculated by a mold suspension of T. harzianum. SEM-EDX measurements of WPCs made from J. procera particles showed little or no growth of T. harzianum, irrespective of treatment with cold or hot water. The results suggest that WPCs made from the particles of J. procera wood-branch pretreated with either cold or hot water could be useable in wet conditions. In addition, using of J. procera as durable wood for manufacturing of WPCs had good effects on the prevention of the mold infestation over the surfaces of the produced panels.
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Papers by Ramadan Nasser