نشریه علوم و فنون منابع طبیعی
سال دهم شماره 4 (زمستان 1394)

This research was conducted to study the effect of mixing different contents of old corrugated container (OCC) pulp on mechanical properties of virgin neutral sulfite semi chemical (NSSC) pulp. The NSSC pulp was procured from Mazandaran Wood and Paper Industries Company. For the OCC pulp,old corrugated containers were collected throughout Sari city after removing printed and gluedparts or unwanted objects. Then, the containers were split by hand into similar small parts in order to prevent cutting of the fibers. Afterwards, the OCC pulp was prepared from them. Handsheet papers of 127 g/m2 base weight were prepared from mixing of the NSSC pulp with the OCC pulp in contents of 60, 70, 80 and 100%. Mechanical properties of the produced papers including tensile strength, burst strength, tearing strength and crushing strength were then compared with each other in corrugated case, while squeezing strength was evaluated in ring case using TAPPI standard. The obtained results indicated that increasing consumption of the OCC up to 30%, improves tensile strength, tear strength and burst strength of the handsheet papers significantly in comparison with the control sample (for 21, 25 and 59%, respectively).However, crushing strength in the corrugated case and squeezing strength in the ring case were degraded about 13 and 9%, respectively. The results of this study revealed that mixing 30% of the OCC with the NSSC could yield papers of higher quality.

The present study investigated physical and biometry properties of Juniperuspolycarpos wood. For this purpose, three normal trees were selected from Chamestan-Nour city of Mazandaran province. Three log-5 cm thicknesses were taken at 1.30, 3 and 6 meter from each tree. Three samples position were prepared along radial position from the pith to the bark. Then physical properties (oven-dried basic density and volumetric shrinkage), biometry properties (fiber length, fiber diameter and cell wall thickness) mechanical properties (MOE and MOR) were determined and then analyzed by SPSS software. Results indicated that the average of density, MOR and MOE were decreased along vertical and radial position. Variations of fiber dimensions were increased along radial direction and were decreased along vertical position from bottom to upward of trees. The average of oven dried density was 0.44 g cm-3, basic density 0.41 g cm-3, the volumetric shrinkage 10.86%, the fiber length was 1.612 mm, the fiber diameter was 30.78μm, the cell wall thickness was 5.53 μm, MOR 41.65 MPa, and MOE 4.58 GPa.

In this study, the anatomical, physical, and chemical properties of Acer velutinum L and Acer cappadocicum Gled from the Aceraceae species were studied. Wooden discs were
prepared of the trunk and root sections. Then by using microtome, microscopic specimens were prepared from which. after being stained with stratblo and saffronin, they were fixed on the glass lam by the Canadian Balsam adhesive. To find out their anatomic specifications, specimens were carefully observed under microscope with a polarizing light, and then were photographed using a Nikon microscope equipped with a camera attached to computer, and then were analyzed according to the microscopic features of the broadleaved, presented by the IAWA committee. Morphological samples were also prepared according to the Franklin method to determine the fiber length, diameter of the cell cavity and subsequently, biometric coefficients. Based on the results prepared, the trunk vegetative circles of Acer velutinum L and Acer cappadocicum Gled were distinguished and clearly visible, so in terms of this characteristic, there is no significant difference between these two species of Acer. The diameter of the vegetative layers is the particular case in Acer velutinum L, which is larger in diameter than Acer cappadocicum Gled. Wooden rays are clearly visible. Given that there are obvious differences in some anatomical characteristics between two types of velutinum L and cappadocicum Gled, it is easy to identify these two species, but distinction between the anatomy and the biometry of the fibers between the two species is very difficult. Regarding the physical properties, velutinum L and cappadocicum Gled are lightwoods and their specific masses were measured 0.59 and 0.63 respectively.

In this research, furniture production in Tehran province was investigated economically.
The annual production of all types of furniture with a capacity of 1,000 wooden table types, 1800 comforters, and 440 square meters of home furnishings per year are considered. The total investment volume is estimated at 51,000 million Rials. The results of the economic appraisal indexes of the project, such as the top spot of production (40.55%), sales at the top spot (20353.1 million rials), the return period (73 months), the internal rate of return (16.4%), The fixed investment per capita (2966.6 million Rials / person), the ratio of working capital to fixed capital (14.6%), and the ratio of profit to capital (18.8%), suggest that the construction of the factory in addition to employment, in part, reduces the need for imports, and prevents foreign currency from leaving the country, and also has a good economic justification.

In this study estimation method of wood in forest management planning (notably the series originated a forestry plan) and its impact on income, fees and royalties basic factor was studied. Piece license issued by the forest Parliament document mark, the renewal volume, and the estimated recoverable wood were extracted and examined and was descriptive and comparative analysis. Implantation, to modify these instructions no action was taken. This is also forestry management plans and obligations in the interests of the parties are at risk.

Soil restoration and establishment of natural regeneration in their skid trails, sustainability plays an important role in forest. This study has been done in piece 308 Shanderman forest, located in the west of Guilan. The parcel, three skid trail slope grade 0-10, 10-20 and 20-30 percent those 10 years since the last ground-based skidding in past, were selected. On each route and adjacent natural forest of 30 pieces selected, Type and number of natural regeneration was one hundred percent in their inventory. And in 20 of them were taken soil samples from a depth of 20 cm, bulk density and soil porosity were determined. The results showed bulk density and porosity of the soil in the skid trails nearby natural forest is significantly different. The average number of maple in skid trails has been significantly higher than natural forests. And the average number of horn beam and milky in natural forests is significantly greater than the skid trail. But in the number of beech and alder there was no significant difference between the two locations. Between classes gradients less than 30% there is no significant difference in this properties, but the porosity of the soil between the skid trail 0-10 & 20-30 percent slope is significantly different. The period of 10 years to recover the physical properties of soil and seedling establishment is not enough time in the skid trails. And the slope of less than 30%, no significant effect on the recovery path.

This study was aimed to investigate the effect of coupling agent and acetylation on the
thermal properties and amount of damaging against brown rot fungus through reducing the weight of the samples and contact angle of acid-base of composites acetylated fibers / polypropylene wood. For this purpose, before the acetylation, fir wood flour extraction material was removed using hot water. By acetylation of weight gain in this study by 0 (control) and 18.8 percent, respectively. Acetylated fibers with coupling agent MAPP (0, 3 and 6%) were mixed in the extruder two screw (Collin) (speed 60 rpm, temperature 160 °C). Wood plastic composite (WPC) was made by hot press (temperature 200 °C, pressure 25 MPa, press time 5 minutes). The samples were treated by brown rot for 8 weeks. Finally enthalpy, the percentage of crystallites and limited oxygen index and contact angle of acid-base and acetylated samples obtained from fungal decay and weight loss also was evaluated. The results showed the effect of increasing the percentage of acetylation agent and enthalpy, the percentage of crystallites and limited oxygen index of 86, 86 and 1.1 percent, weight loss, in all samples, including the rotten and non-decayed decreased but increased contact angle. Acetylation of acids and bases contact angle respectively 4.8 and 10.5 percent. By increasing the contact angle of acid-base coupling, respectively 20.7 and 10.7 percent.