presentation of Ingrowth models and determination of biotic and abiotic factors affecting regeneration in the Hyrcanian forests
Mahmood
Bayat
هیات علمی
author
Manychehr
Namiratiyan
استاد دانشگاه تهران
author
Farokh
Pourshakouri
کارشناس پژوهشی، سازمان فضایی ایران
author
text
article
2017
per
Background and objectives: Hyrcanian is a productive region near the southern coast of Caspian Sea. Her forests are mostly uneven-aged beach-dominated hardwood mixtures. There is increasing willingness to treat these forests without clear-felling, following the ideas of continuous cover management. This paper examines the possible ecological controls on ingrowth in a high-elevation forest in northern Iran. Natural regeneration is one of the most important affecting factors in survival and stability of natural forests. Understanding the factors that affecting the forest species regeneration can be helpful to understand the ecosystem succession stages. Recently, due to complexity of factors that affecting natural regeneration, using the growing models in order to determine affecting factors is very common. Materials and methods: The Kheyrud forest covers 80 km2 near the port city of Nowshahr. The elevation of the Kheyrud forest varies from 10 m to 2200 m above sea level Ingrowth model was used to estimate the diameter increment in oriental beech at fixed sample plots level over a period of 9 years (2003-2012) In this study the impact of biotic and abiotic variables like competition, energy of sunlight in the growing season, topographic wetness index, highest point to nearest of drainage area, wind speed from ground-complex process models and other variables which are considered to be achieved for the first time on natural regeneration were investigated using fixed plots in Hyrcanian forests. Results: Results showed that the mean number of regeneration in the unit area (hectares) are very low and equal to approximately 15 trees per hectare (up to a diameter of 7 cm) in a period of 9 years. The simplest way to predict and simulate ingrowth is to use the mean values for all stands. However, this is not biologically justified since ingrowth should eventually start decreasing with increasing stand basal area. The beech trees are of the most number of regeneration per hectare which represents the suitability of environmental and biological conditions for these valuable trees in the Hyrcanian forests. Basel area per hectare was the main affecting factor on regeneration in study area which defines about 40 percent of regeneration. Conclusion: Humidity and temperature and the amount of solar radiation were the most important variables in the number of regeneration in Hyrcanian Forests. Consequently methods that used in this study are new and also can be used in other forested area in Iran. Finally, this research is trying to explain changes of ingrowth and abiotic and biotic variables in the fixed sample plots.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
1
16
https://jwfst.gau.ac.ir/article_3656_59bd2fdd12424d8620f5b8076dc51022.pdf
dx.doi.org/10.22069/jwfst.2017.11364.1598
Efficiency of nearest neighbor indices to assessment structure of Fageto-Carpinetum in Growth area hyrcanian (Case Study: Nave Asalem-Gilan forests -Iran)
Peyman
farhadi
دانشجوی دکتری جنگلداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه لرستان
author
Javad
Soosani
استادیار گروه جنگلداری، دانشکده کشاورزی و منابع طبیعی، دانشگاه لرستان.
author
Syed Yousef
Erfanifard
دانشیار، بخش منابع طبیعی و محیط زیست، دانشکده کشاورزی، دانشگاه شیراز.
author
text
article
2017
per
Background and objectives: Maintaining the structure and biodiversity of ecosystems is considered to be one of the most important goals of modern forestry. For this purpose, the tools are needed for forest management, to have the lowest cost and time to check the current status, as well as the changes caused by development of forest management activities. Indicators of nearest neighbor have advantages that their application gives priority to direct measurements of biological diversity. Because in addition to the study of species diversity, it investigates the locations of trees. Also nearest neighbor indices provide valuable information about ecological interactions of trees in forests. Therefore, this study was aimed to introduce and apply important indices based on nearest neighbor analysis to study ecological relationships of trees in beech-hornbeam stands in Nave Asalem- Gilan forests. Materials and methods: In order to do this research, seven 1-ha plots with homogeneous environmental conditions were inventoried in a Fageto-Carpinetum association in Nave Asalem- Gilan. In each plot, distance and azimuth of all trees on the plot with more than 7.5 cm diameter at breast height from the center of sampling area and species, and diameter at breast height were recorded. The spatial pattern and species diversity were then investigated using the uniform angle, mean directional, species mingling and segregation indices. The amounts of each of the mentioned indices were calculated for each sample individually. The average of the values obtained for each sample were calculated for the Fageto-Carpinetum. Results: The results showed in seven 1-ha plots of Fageto-Carpinetum, Fagus orientalis, Carpinus betulus, Acer cappadocicum, Acer velutinum and Alnus subcordata had the maximum density per hectare. The values of uniform angle and mean directional indices were 0.53 and 2.02, respectively, showing a spatial distribution between random and clustered. In terms of species diversity, the Fageto-Carpinetum association with an average of 0.47 and 0.25 for species mingling and segregation indices, respectively, presenting a medium level of species mixing. The amount of species mingling indices indicated low level of mixing of beech species and high level of mixing of other species. The segregation index showed a pair of trees or nearest neighbor reference trees belonged to different species. Conclusion: In general, the results of this study indicated the efficiency of nearest neighbor indices to study the structure of Fageto-Carpinetum associations and the results can be used for planning to revitalize the structure and status of biodiversity in degraded Fageto-Carpinetum associations.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
17
32
https://jwfst.gau.ac.ir/article_3657_a0bc5988e530c7f4f98ff69410464092.pdf
dx.doi.org/10.22069/jwfst.2017.11197.1587
Factors affecting people’s participation in forest protection plans in Gilan-e Gharb
Ahmad
Yaghoubi Farani
عضو هیأت علمی دانشگاه بوعلی سینا- همدان
author
Saeid
Karimi
عضو هیأت علمی دانشگاه بوعلی سینا- همدان
author
Farshad
Permozeh
کارشناس ارشد ترویج و آموزش کشاورزی
author
text
article
2017
per
Abstract Background and objectives: In Iran, zagros forests are important in terms of size, plant diversity and their impacts on the lives of local people and economic security. Thus, the preservation of these forests is imperative and governmental natural resource organization implements some different plans with local people cooperation. The purpose of this study was to explore the factors affecting the level of local people’s participation in forest protection plans in Gilan e Gharb County. Materials and Methods: This study was a descriptive- correlational research which was done through a surveying methodology in Gilan e Gharb (Kermanshah province). The statistical population of this descriptive-correlational study included 550 local people in Gilan-e Gharb County. According to Morgan’s table, a sample of 220 local people was chosen through random sampling method. Data were collected using a questionnaire as a main research tool. The validity of the questionnaire was confirmed by a panel of experts and its reliability was determined using Cronbach's Alpha test (0.75). Pearson correlation formula and multiple regression analysis were run to analyze the data. SPSSwin20 was used to do statistical analysis. Results: Results showed that the level of people’s participation and cooperation in different actions of forest protection plans were low. There was also a significant and positive relationship between some independent variables like age, education level, and occupation, number of livestock, cultural and social characteristics of the population, economic dependence on woods and forest, organizational communications and knowledge about forest with participation in conservation forest projects as dependent variable. The result of multiple regressions indicated that organizational communications and knowledge and information had significant effects on people’s participation in the forestry projects. Totally, 29% of people’s participation was explained by organizational communications and knowledge and information. Conclusions: In total, the research results showed that the level of local people’s participation in the forest protection plans was low. This means that protection plans should focus on new motivations to improve people’s participation. In addition, findings showed that socio-cultural characteristics, knowledge and information are two important factors affecting the level of participation in forest protection plans. Therefore, to improve people’s participation, it is necessary to focus on improving the level of knowledge and information of local people, explaining the role of people in forest protection plans and using the capacity of local institutions. Another way to foster people’s participation is to increase local people’s interaction with relevant organizations and institutions.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
33
46
https://jwfst.gau.ac.ir/article_3658_02fa3d0627c7370a7055a8ae07327b3c.pdf
dx.doi.org/10.22069/jwfst.2017.11058.1577
Evaluation of homogeneity of tree spatial distribution in a mixed mesquite (Prosopis cineraria) stand in Barchah protected area, Hormozgan province
Elaheh
Khosravi
دانشگاه شیراز
author
Yousef
Erfanifard
Shiraz University
author
text
article
2017
per
Background and objectives: Spatial pattern of trees in a stand is the outcome of different processes such as their interactions, seed dispersal, and environmental heterogeneity. In consequence, knowledge of spatial pattern of plant species is important for deeper understanding of different hypotheses in ecology. Considering the importance, unbiased recognition of spatial pattern of plant species using reliable techniques is essential in ecology. Summary statistics used in point pattern analysis to explore spatial pattern of plants are based on the null model of homogeneous Poisson process (Complete spatial randomness: CSR). So it seems necessary to investigate homogeneity of tree spatial distribution before analyzing their spatial pattern. Considering this issue, this study was aimed to evaluate the homogeneity of tree spatial distribution in a mixed mesquite stand in Khalij-Omanian vegetation zone using two methods. Moreover, it was also aimed to investigate the impact of ignoring the CSR null model on spatial pattern analysis of trees in the plot. Materials and methods: A 49-ha study plot (700 m × 700 m) was selected in a mixed mesquite stand in Barchah protected area in Hormozgand province. The spatial location of all tree and shrubs with height > 0.5 m was registered and their height and crown area were measured. Furthermore, another plot with similar number of plants and environmental conditions was simulated with homogeneous spatial distribution and clustered spatial pattern of plants. Two methods of Chi-squared test based on quadrat accompanied with Pearson residuals and Kolmogorov-Smirnov test were applied to explore homogeneity of tree spatial distribution. Moreover, homogeneous and inhomogeneous pair correlation functions were used to analyze spatial patterns in two plots. Results: The study plot was covered by 498 trees and shrubs including 149 mesquites, 248 umbrella thorns (Acacia tortilis), and 101 desert thorns (Lycium shawii). The results showed that Chi-squared test only with 4 × 4 quadrats could recognize homogeneity of the simulated plot. Mean of Pearson residuals also did not characterize the homogeneity difference of two plots. While Kolmogorov-Smirnov test explored the difference between tree spatial distribution of the real plot (p-value Conclusion: In general, it was concluded that Kolmogorov-Smirnov test is a reliable method to assess homogeneity of plant spatial distribution in the study area. Moreover, it was revealed that efficiency of g(r) in spatial pattern recognition of plants was influenced by homogeneity of their spatial distribution and application of inappropriate form of g(r) resulted in biased spatial pattern analysis in the study site.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
47
58
https://jwfst.gau.ac.ir/article_3659_e8b20074ebc48ebd8aad0eaa0ccfa2d6.pdf
dx.doi.org/10.22069/jwfst.2017.12497.1652
Investigation of rooting ability of poplar interspecific hybrids (Populus alba x P. euphratica) through apical meristem culture
Hossein
Mirzaie-Nodoushan
موسسه تحقیقات جنگلها و مراتع کشور
author
Sadaf
Khosravan
دانشجو
author
Abbas
Ghamari Zare
عضو هیات علمی
author
Mohammadali
Ebrahimi
عضو هیا علیم دانشگاه پیام نور
author
text
article
2017
per
Background and objectives: Much attention being paid on silviculture of different Populus species and their inter-specific hybrids have increased hopes for wood yield increments in Iran. For the mentioned reason much efforts have been done on hybridization between various Populus species in order to broaden their genetic basis, as well as utilizing their entire potentials and extending their ecologic zones. However, experiences of researchers have shown that produced hybrids have increased new genetic variability, as well as differences with their parental species, by which new high yielding cultivars were introduced. This research was performed in order to quantify possible differences between new inter-specific hybrids between Populus alba as female parent and P. euphratica as male parent based on their rooting capability to be introduced as a criteria for selecting new high yielding poplar genotypes. Materials and methods: Producing a number of inter-specific hybrids between two poplar species, Populus euphratica and P. alba, vegetative propagation of three of the best hybrids through apical meristem culture was performed. First active vegetative buds were harvested and surface sterilized by dipping in 20% sodium hypochlorite for five minutes. Then one to two mm of the apical tips were inoculated on half-MS medium containing IBA and BA of 0.01 and 0.5 mg/l respectively. The explants were maintained in growth chamber at 24 ±1°C and 16/8 hr photoperiod for 60 days. DKW with 0.5 mg/l of BAP, 0.5 mg/l of 2iP and 0.5 mg/l IBA were used as proliferation medium. Propagated shoots were inoculated on two rooting media, DKW and ACM. Data were recorded on characteristics such as freshness, number and length of shoots and roots on rooted plantlets and analyzed based on a factorial experimental model. Results: The studied hybrids were significantly different based on freshness, stem length and rooting ability, in such a way that one of the hybrids even highly rooted at proliferation stage. The hybrid was strongly different with the others studied hybrids at rooting stage by producing much more roots than others as well as producing longer shoots. Conclusion: The studied hybrids differentiated significantly by meristem culture based on vegetative characteristics such as rooting ability and shoot length. Superior hybrids with specific rooting ability may be selected based on the observed differences between the studied genotypes. Conclusion: The studied hybrids differentiated significantly by meristem culture based on vegetative characteristics such as rooting ability and shoot length. Superior hybrids with specific rooting ability may be selected based on the observed differences between the studied genotypes.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
49
58
https://jwfst.gau.ac.ir/article_3660_e2f17cc0ffd8760d81260d970a976506.pdf
dx.doi.org/10.22069/jwfst.2017.11589.1609
Evaluation of soil erosion using imagery SPOT5 satellite in Chehel chi catchment of Golestan Province
Seyed hashem
Mousavi nezhad
اداره کل منابع طبیعی و آبخیزداری استان گلستان- دبیر کمیته فنی
author
Hashem
Habashi
Gorgan university of agricaltural sciences and natural resources- college of Forest sciences
author
Farshad
Kiani
Gorgan university of agricultural sciences and natural resources- college of water and soil sciences
author
Shaban
shataei
Gorgan university of agricultural sciences and natural resources- college of Forest sciences
author
Omid
Abdi
Gorgan university of agricultural sciences and natural resources- college of Forest sciences
author
text
article
2017
per
Background and objectives: Soil erosion is a natural processing that occurs on the earth continues and it is considered as one of the most important environment problems in world. It has been presented different methods to estimate erosion rate including simple until complex methods. Revised Universal Soil Loss Equation (RUSLE) is an experimental relation and it has a strong physical base compared the rest of experimental methods. This model that is revised of the USLE equation, include different erosion forms and some parameters such land cover and rainfall in the daily and monthly scale effect on the erosion. Materials and methods: Current research was done of forest cover and soil erosion relation between density and canopy of forest cover and soil erosion using RUSLE and SPOT5 imagery satellite at the Chelchai watershed in Minoodasht city. For this purpose, provided NDVI map from SPOT5 imagery satellite, after determination of erosion in the place of samples and finding relation between cover and erosion with SPSS software. Then soil erosion estimated with NDVI map in GIS environment. Soil erosion estimation was classified in 5 class including very low, low, moderate, high and sever.Materials and methods: Current research was done of forest cover and soil erosion relation between density and canopy of forest cover and soil erosion using RUSLE and SPOT5 imagery satellite at the Chelchai watershed in Minoodasht city. For this purpose, provided NDVI map from SPOT5 imagery satellite, after determination of erosion in the place of samples and finding relation between cover and erosion with SPSS software. Then soil erosion estimated with NDVI map in GIS environment. Soil erosion estimation was classified in 5 class including very low, low, moderate, high and sever.Materials and methods: Current research was done of forest cover and soil erosion relation between density and canopy of forest cover and soil erosion using RUSLE and SPOT5 imagery satellite at the Chelchai watershed in Minoodasht city. For this purpose, provided NDVI map from SPOT5 imagery satellite, after determination of erosion in the place of samples and finding relation between cover and erosion with SPSS software. Then soil erosion estimated with NDVI map in GIS environment. Soil erosion estimation was classified in 5 class including very low, low, moderate, high and sever. Results: Results indicated that dangerous condition of erosion moderate to severe in the low plant cover(less 5%), is average from 14.11 to 34.683 ton/ha/year. Meanwhile agricultural areas with 28.33 percentage of total area, include more than 64.99 percentage of erosion, need to necessary designs. Conclusion: According to results, the dense and semidence forest area, comprise very low erosion about 0.66 to 1.91 ton/ha/year, and showed that dense land cover is very efficient in soil conservation.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
73
86
https://jwfst.gau.ac.ir/article_3661_53ab7551b3bf127f656d3db0f91eeb2c.pdf
dx.doi.org/10.22069/jwfst.2017.1446.1
Study of physical, optical and biological properties of antibacterial bank-note paper including Nano-silver
Omid
Yazdani aghmashhadi
کارمند بانک مرکزی ایران
author
Ghasem
Asadpour
استاد یار دانشگاه ساری
author
Esmaeil
Rasouli Garmaroudi
استاد یار دانشگاه شهید بهشتی
author
Reza
Emani
دانش آموخته مقطع دکتری دانشگاه آزاد اسلامی واحد علوم تحقیقات تهران، ایران،
author
text
article
2017
per
Background and objectives: The purpose of this research is production of antibacterial banknote paper using silver nanoparticles. Bank-notes have been a part of commercial exchanges from the past. There are about 8 billion Bank-note leaves in Iran that have been in circulation in a 5-year period. This amount of Bank-notes and the frequency with which they are touched can promote transmission of many pathogenic factors, especially bacteria. Based on scientific research results, Bank-notes are seriously contaminated and must be considered a potential danger to society. In the field of antibacterial paper, an investigation was performed on two materials, chitosan and Nanosilver particles to produce filter paper and Nanosilver and chitosan particles were applied as negatively and positively charged layers over the fibers (LBL), respectively. It was found that with increasing numbers of the layers, there were increases antibacterial properties. Materials and methods:In this study, Laboratory pulp made from Iranian cotton fiber, were used to produce antibacterial bank-note paper. To prepare above mentioned pulp, its freeness was received to 12 oSR by laboratory Defibrator. Then, obtained pulp was bleached by H2O2 in 120 oC, pH=11, 120min. and after refining to 34 oSR, were adjusted 3.1% consistency and neutral pH to adding additives. Antibacterial Nano-silver with amounts of 25, 50, 75 and 100 ppm as antibacterial material and 0.3% Cationic-Polyacrylamid (C-PAM) as retention aids were used as additives. Then, standard handsheets 90 g/m2 were made from above pulps and compared to reference handsheets in pHysical and optical properties. For biological test of papers, bacterial inhibition measurment of S.Aureus and E.Coli as to indicator bacteria in biological tests was used. Results: Results showed that increasing in nano-silver consumption was led to increasing in ash content, smoothness and opacity of paper; lacking in brightness and had no effect in wax test and bulk of paper. Biological test results showed that by increasing in nano-silver consumption, antibacterial properties of paper and consequently bacterial inhibition area were increased . Conclusion: According to all results, 25 ppm of nano-silver consumption was determined as optimized treatment. In this consumption level of nanosilver, pHysical and optical properties of paper are very similar to control samples with accepted antibacterial properties. By adding of low levels of Nanosilver in pulp suspension and then applying supplemental refining of the fiber furnish, both antibacterial and mechanical properties of Bank-note paper likely will be increased Keywords: nano silver, anti-bacterial paper, cationic polyacrylamide, bank-note paper, inhibition zone
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
87
102
https://jwfst.gau.ac.ir/article_3662_838feb05c18a09fabe19fbbddb5ebf59.pdf
dx.doi.org/10.22069/jwfst.2017.10217.1535
Investigation of using old corrugated container in the production of three- layer particleboard
vahid
vaziri
دانشگاه گنبد کاووس- استادیار گروه صنایع چوب و کاغذ
author
Majid
Salari
فارغ التحصیل کارشناسی ارشد فرآورده های چند سازه چوبی دانشگاه گنبد کاووس
author
text
article
2017
per
Background and objective: The demand for composite wood products, such as plywood, oriented strand board (OSB), hardboard, particleboard, medium density fiberboard, and veneer board products has recently increased substantially throughout the world. Particleboard represents 57% of total consumption of wood based panels and its demand is continuously growing with 2-5% annually. The demand for particleboards in the sectors of housing construction, furniture manufacturing, and interior decoration has continued to increase. The demand for wood in the forest product industry has been growing, but the production of industrial wood from natural forests continues to decline. There is still an ongoing research interest to find alternative sources of raw materials for composite manufacturing. OCC (Old Corrugated Container) could be a good alternative raw material because, 1) this material is a recycled fiber resource available almost anywhere in the country; 2) it is relatively low- priced compared to office waste paper; 3) it is a relatively clean source of fiber without significant fillers or plastic contaminants. In this research, the use of OCC in surface and middle layers on the mechanical and physical properties of three layer particleboard has been investigated. Materials and methods: OCC used for packaging various low-weight materials (furniture, equipment, instruments and especially grocery items etc.) which mainly consisted of 3 or 5 paper sheets, were included in this study. OCC with various ratios (15:85, 30:70, 45:55 and 60:40) in surface and middle layers of three layer particleboard were separately used. Coarse and fine wood chips from senate choube shomal company used. Urea formaldehyde resin used at 10% content on dry weight basis of the wood particles and OCC and ammonium chloride was used as a catalyst to 2% of the dry weight of adhesive. After the mixing process of wood particle/OCC with adhesive and hardener, mat at temperature of 170°c for 5 minutes under hot press was. After making particleboard, physical and mechanical properties of panels using variance analysis in statistical confidence level of 95% will be analyzed. Results: The results showed that the bending strength and modulus of elasticity of boards had the best resistant at the level of 30% and 15% in surface and middle layers respectively. Internal bond decreased with increasing of old corrugated container content and control sample had the maximum strength. Water absorption and thickness swelling increased with increasing of OCC content. Conclusion: On the basis of results of this study, it can be concluded that particleboard containing OCC in the surface layers up to the level of 30% and in the middle layer up to the level of 15% % can be used for general purpose boards for use in dry conditions.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
103
114
https://jwfst.gau.ac.ir/article_3663_f75b7678c253febad63e0b0362aedd5e.pdf
dx.doi.org/10.22069/jwfst.2017.11110.1581
Improve the surface quality of particleboard for finishing
Seyedeh zahra
Hosseini
forest technical university
author
Ali Akbar
Enayati
Professorof Tehran University
author
Victor Vladimirovich
Vasilyev
Professor of Saint Petersburg state forest technical university
author
text
article
2017
per
Background and objectives: The purpose of this research is to reduce amount and speed of absorption of the liquids coating substances of the particleboard surface (lacquer, paint and enamel in the lacquer painting process and glue in the lamination method). In this context, the researchers found that the increasing of the average density of particleboard increases the minimum and maximum density of its surface layers. According to the researches, increasing the surface layers density of particleboard decreases their liquid finishing materials absorption. Since at the present the main solvent of liquid finishing materials for finishing the surface of wooden boards is on the water-based, researchers have invented a method of surface absorption test of wooden boards by water instead of toluene. After several studies, they performed water absorption test by the surface layer of wooden boards during the test period of 60-minute. Materials and methods: In this study, the large particles with 1% moisture in the middle layer and industrial fine particles in the surface layers were used for production three layers particleboard. Knowing that by increasing the wood moisture to fiber saturation point (30%), perpendicular compressive strength to the wood fibers significantly is reduced, in this study, the moisture of the surface layer particles was increased to 5% and 10 % with water spray method. The wood particles of surface and middle layers were mixed with resin separately. For wood particles of surface layers was used UF with concentration of 55 % and commercial resin UF with concentration of 68.8 % (with purpose of control the surface layers moisture of three layers mats in the desired limit). Commercial resin UF was heated to temperature of 60 °C with the purpose of reducing its viscosity. Then, three layers particleboard with medium density of 650 kg/m3 were obtained by 2.7 MPa specific press pressure and at temperature by 220 °C. The analyses of mechanical strengths, water and toluene absorption were performed to evaluation the properties of the particleboards surface layer. Results: According to the results of the density gradient graph in the thickness of the samples, increasing wood particle moisture of the surface layer increases the density of samples surface layer. The results of the mechanical strengths and liquid absorption analysis showed that, by increasing wood particle moisture of the surface layer increases flexural strength and surface soundness of samples and decreases absorption and absorption speed of the samples surface layer. Conclusion: Increasing wood particle moisture of the surface layers increases the quality of particleboard surface layer for finishing. The moisture optimal amount of the surface layer wood particle is 5% in treatment 7 (made by commercial urea-formaldehyde resin).
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
115
128
https://jwfst.gau.ac.ir/article_3664_f433b5caa6104b47e0612ae9e3a4ad98.pdf
dx.doi.org/10.22069/jwfst.2017.11901.1631
Production and evaluation of nanopaper from cotton linter by partial dissolution method
Seyed Ali
Nasehi
کارشناس ارشد، دانشگاه علوم کشاورزی و منابع طبیعی ساری
author
Seyed Majid
Zabihzadeh
عضو هیات علمی
author
Hossein
Yousefi
عضو هیئت علمی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان
author
Hossein
Kermaniyan
عضو هیئت علمی، دانشگاه شهید بهشتی
author
text
article
2017
per
Background and objectives: The use of cellulose at nanoscale has been greatly studied in the production of biological compounds due to its high strength, low weight and biodegradability. Nanostructures are synthesized through two mechanisms including top-down and bottom-up approaches. In this study, top-down partial dissolution was used as a simple and fast technique to produce nano cellulose. By controlling dissolution parameters such as time, the solvent interrupts the adjacent nanofibrils linking which is supplied through hydrogen bonds, and solves partially outer chains of nanofibril. During solvent rinsing, the partially dissolved chains re-solidified and welded each other, making consolidated structure in which the main components are undissolved native nanofibrils surrounded by cellulose type II and non-crystalline cellulose. Because of this, the final film was named nanopaper. This study considers the characteristics of fully biocompatible nanopaper directly produced from cotton linter fibers by partial dissolution method. Materials and Methods: Refining the cotton linter fibers were done in three steps; pneumatic, washing with hot water followed by treating with sodium hydroxide. The handsheets were made by TAPPI standard method. The partial dissolution of papers with high content of alpha cellulose were done in the solvent N,N-dimethylacetamide/ 9% lithium chloride (DMAc/LiCL) and translucent cellulose nanopaper was obtained through pressing and drying the resulting gel. To evaluate the properties of the nanopaper, field emission scanning electron microscopy, X-ray diffraction, mechanical properties and thermal gravimetric analysis were used. Results: The diameter of undissolved nanofibrils in nanopaper fell between 60 and 66 nm. . Electron micrographs showed that nanopaper had more uniformity than paper. Visual transparency (back view) of nanopaper was significant due to the liberalization of cellulose nanostructures, the increase of uniformity and density, the loss of surface roughness and the increase of light transmission. The results of tensile properties showed that the nanopaper tensile stress was higher than that of paper. Paper and nanopaper tensile stress were 8.02 and 27.28 MPa, respectively and tensile modulus elasticity were 0.483 and 0.649 GPa, respectively. X-ray diffraction (XRD) of paper matched cellulose type I. During partial dissolution/re-solidification cellulose type II was appeared and non-crystalline phase increased judging from XRD data. The crystallinity degree of paper and nanopaper were measured 84.9 and 54.89%, respectively. The crystallite size of paper and nanopaper obtained 6.44 and 2.55 nm, respectively. The thermal stability of nanopaper was less than that of paper. Conclusions: In nanopaper structure, undesolved cellulose type Iβ (undesolved nanofibrils) played reinforcing phase role, and cellulose type (II) and the amorphous cellulose formed the matrix phase. Partial dissolution destroyed part of the crystals and after solvent rinsing and re-solidification, some parts of the amorphous chains were rearranged to form crystals of cellulose type II. Finally, a tough translucent nanopaper was produced by creating consolidated nano structures. The reduction of cellulose crystallinity in nanopaper resulted in the loss of thermal stability in nanopaper.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
129
142
https://jwfst.gau.ac.ir/article_3665_0cc0190f91d724a98789d0ad874bb181.pdf
dx.doi.org/10.22069/jwfst.2017.11400.1602
The effect of synthesis zeolite as pigment on paper physical properties
Seyed Mohammad
Hosseini
Teacher
author
Ahmad
Saraeiyan
عضو هیأت علمی- دانشگاه گرگان
author
Ali
Ghasemian
استاد دانشگااه
author
Mohammadreza
Dehghani
استاد دانشگااه
author
text
article
2017
per
Abstract Background and objective: Utilizing coated papers depends on the selection and proper usage of the paper ultimate coverage structure. Since pigment forms 80 to 95 percent of the weight of the cover, it is clear that the type and characteristics of the ingredients, play an important role in the cover structure, light characteristics and the quality of printing. Zeolite is one of the substances that have recently entered the field of research in connection with coating. The aim of this study was to investigate the effects of 4A synthetic zeolite as pigment, on the physical characteristics of the coated papers with synthetic zeolite pigments in pure form and in combination with precipitated calcium carbonate and kaolinite. Material and Methods: Requirements for this study 75 grams printing paper produced by mill Kayvta Finland, 14 and 30 grams of coating weight were considered on one side of the paper, and different calendaring conditions (70 and 90 centigrade temperature) were also considered for the samples. Some of the physical characteristics of the coated papers were considered like thickness, surface roughness, gloss, gloss variation, opacity, brightness, light scattering coefficient, whiteness and yellowness. Results: One of the very important factors, for the consumers of coated papers is the low level of yellowish. Using zeolite makes this factor to decrease dramatically and also coated papers with zeolite benefit a high whiteness as the white papers coated with calcium carbonate. Brightness of the paper coated with zeolite is higher than the papers coated with calcium carbonate and calendaring caused a little reduction of the brightness. Before calendaring, papers coated with calcium carbonate has the highest scattering coefficient and also after calendaring, has the highest amount of light scattering coefficient despite large reduction in the amount of light scattering coefficient. And as a result of this, they have a high opacity. The results also showed that adding a small amount of calcium carbonate and kaolinite to zeolites improves light scattering coefficient and opacity of the papers. The results showed that paper coated with zeolite has a small amount of gloss. Calendaring increase the gloss of all the treatments and this increase is more evident in calcium carbonate and kaolinite. Adding calcium carbonate and kaolinite to zeolites improves the gloss of the papers coated with them and it seems that because of hardness of zeolites comparing to other pigments it is better to apply more pressure for calendaring than the pressure that was used in this research. Conclusion: In summery it can be said that 4A zeolite can be a good alternative for precipitated calcium carbonate and kaolinite, because of its unique physical characteristics. And the most ideal condition for using synthetized zeolite and reducing the amount of its deficits is to combine it with calcium carbonate and kaolinite. Keyword: Coating, Physical properties of paper, synthesis zeolite, precipitated calcium carbonate, kaolinite
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
143
156
https://jwfst.gau.ac.ir/article_3666_b2a0b9c193982388b879f32c9c6c5e74.pdf
dx.doi.org/10.22069/jwfst.2017.10975.1574
Investigation of dielectric properties of bacterial cellulose -thermoset resin nanobiocomposite
Somayeh
Sheykhnazari
دانشجو دکتری فراورده های چند سازه چوب دانشکده چوب و کاغذ دانشگاه علوم کشاورزی و منابع طبیعی گرگان
author
Taghi
Tabarsa
هیات علمی دانشکده چوب و کاغذ دانشگاه علوم کشاورزی و منایع طبیعی گرگان
author
Mahdi
Mashkour
هیات علمی دانشکده چوب و کاغذ دانشگاه علوم کشاورزی و منابع طبیعی گرگان
author
Abolghasem
Khazaeian
هیات علمی دانشکده چوب و کاغذ دانشگاه علوم کشاورزی و منابع طبیعی گرگان
author
text
article
2017
per
Abstract Background and objective: Cellulose is the most abundant polymer on earth and has enormous industrial importance.one of the common applications for native cellulose is using as electrical insulator. The main hurdle of cellulose as application in electrical insulators is porosity and hygroscopicity of paper. Thus to remove humidiy from pores, paper is impregnated by oil or resins. The aim of this research is using of bacteria to produce cellulose and preparation insulator composite and paper from bacterial cellulose. The other purpose is comparison physical properties them with composite and paper produced from kraft pulp. Material and Methods :The organism used was Gluconacetobacter xylinus (BPR 2004) which was purchased from IROST, Iran. Kraft pulp was prepared from factory of Mazandaran wood and paper. G.xylinus was incubated in a static Hestrin-Schramm culture at 28°c For 30 days. The obtained BC pellicles had 10mm thick.Then, BC pellicles purified and washed by deionized water .The pellicles were cut into small pieces and disintegrated by blender and standard pulp-disintegrator in lab. Aqueous suspension of kraft pulp was prepared. The content of bacterial cellulose that was added to suspension, was as follows: %5, 10 % and 15%. To prepare hand sheets of kraft pulp and kraft pulp- BC was used from hand sheet maker. BC sheets prepared from disintegrated BC by vacuum method. The handsheets were dried in oven then conditioned. Basis weight of hand sheets was considered 60g/m2. Dried handsheets were immersed in phenolic resin (PF). To obtain composites, 5 immersed handsheets from every treatment lay up and hot pressed at 150 °c and 100Mpa for 10min. Then obtained samples conditioned. Findings:To investigate of physical properties of samples was used from Dp, XRD ,FTIR,FE-SEM tests and also insulation tests composed of Loss tangent,capacitance,dielectric constant and break down voltage was used.The result showed degree of polymerization (Dp) bacterial cellulose was upper than kraft pulp.The result of X-ray diffraction indicated, crystallinity and crystalline size of bacterial cellulose was upper that kraft pulp. Air penetration test in hand sheets demonstrate with increasing bacterial cellulose decrease porosity and the air couldn’t penetrate in handsheet. Kraft paper showed most air penetration and also most porosity. FE-SEM images showed morphology and structure of samples. Findings of FTIR demonstrate interaction between reinforcement and matrix in composites. Dielectric properties was measured as loss tangent, capacitance, dielectric constant and breakdown voltage. The results showed BC and kraft paper had minimum and maximum loss tangent in order and this is conversely in its composite. With increasing of bacterial cellulose from 5-15%, loss tangent increased in hand sheets and its composites. Capacitance and dielectric constant showed similar trend to loss tangent. The breakdown voltage of hand sheets and composites increased with enhancement of bacterial cellulose. Conclusion:The results showed ,crystallinity, crystal size and degree of polymerization of bacterial cellulose was upper than kraft pulp. Also hand sheets of bacterial cellulose had lower dielectric loss factor, dielectric constant, capacitance.But dielectric break down voltage ofbacterial cellulose handsheets was upper.
Journal of Wood and Forest Science and Technology
Gorgan University Of Agricultural Sciences and Natural Resources
2322-2077
24
v.
2
no.
2017
157
170
https://jwfst.gau.ac.ir/article_3667_890ec386b50dbec0a0ffd74751da8c4f.pdf
dx.doi.org/10.22069/jwfst.2017.12328.1643