نشریه تحقیقات منابع طبیعی تجدید شونده
سال دوم شماره 1 (پیاپی 3، بهار 1390)

In this research, the recycling of chemical waste paper has been taken into consideretion.To produce printing paper, the effect of various combinations of deinked pulp with CMP pulp has studied. Deinking results showed that, besides of the chemicals effect, temperature and repulping time directly affect the brightness of deinked pulp so that when the temperature or repulping time or both go up, the brightness of deinking pulp goes up too. Test results of deinked pulps mixed with CMP pulp indicated that by adding deinked chemical pulp, with the percentage of 10, 20, and 30 to CMP pulp, optical and physical features and also mechanical strengths of paper improve. From optical and physical features and also mechanical strengths point of view, the best circumstances to combine deinked chemical pulp with CMP pulp and long-fiber pulp included 60% CMP Pulp, 30% Deinked Pulp, 10% Long-fiber Pulp. It can be suggested that %30 deinked pulp can be used to produce printing paper. Also, optimum Deinking variables were %2 NaOH (on the oven dry pulp), repulping time 10 minute and repulping temperature 65°c.

In order to study the nutritional behavior of Saurida tumbil in the Oman Sea (Sistan & Baluchistan province), a total of 116 specimens were seasonally collected, of which 77 specimens were males and 39 specimens were female. The minimum and maximum length of males was respectively 22.8 and 45.5 cm and for females there were 25.5 and 53.4 percent. The results showed that by increasing TL, the weight of stomach will increase too. In this study, the kind of food, some factors such as frequency percentage, Vacuity Index, Gastromatic Index of different food items were calculated. Also, results showed that Saurida tumbil has the Carnivorous diet and feeds on e.g Upeneus sulphureas, Trichiurus lepturus, Nemipterus japonicas, Platycephalus indicus, Leiognathus bindus, Sardinella sp. Tylosurus corcodilu, Sphyraena putnamie, shrimp postlarve, Sepia pharaonis and Uroteuthis duvauceli The measurement of (FP) Index expressed that Upeneus sulphureas and Trichiurus lepturus respectively by (FP) 29.6 and 12.9 percent are the seconds and main foods.Cephalopoda, Crustacea and other species are random hunts. Saurida tumbil doesn’t have any target food and hunts its foods according to the availability of existence nutrition species. Vacuity index was obtained 51.7% and it was recognized by the explanation of (CV) so this aquatic animal has the medium nutrition. The maximum Index of (FI) 93.7 percent occurred in winter and the minimum 36.8% occured in summer.

In this study, distribution and tension concentration are analyzed in dowel joint. In current research, the effect of screw diameter are 4, 5 mm and type of woods are fugues oriental is, Alnus subcordata and white spruce on tension resistance and bending moment were tested. The dimensions for malting T- form joints were 5×5×2/5 wooden dowel used in this research was carpinus betulus which is the common dowel in malted. Also, Poly-vinyl acetate was used in Joints. The combination of above said factors in dowel joint 6 male totally 24 T sample by 4 repetitions and tension resistance and bending moment were measured by mechanical test machine. For exertion strength in order to analyze the aforementioned resistance, loading speed equal to 1.25 mm/min was used. Also, for analyzing the way of distribution and tension concentration in joint and changing process of tension base on changing the variables in this research finite element method and ANSYS Software were used. Based on the findings, the German modeling of joint which endures the maximum tension is equal to the type being used in real joints. Distribution of tension in the middle of the bending moment depths is maximum and tension in screw joints is consent Reid in failure Points.

Enough wood supplying for pulp and paper industry of our country has been encountered with serious difficulties caused by destruction of forest and wood shortage and fiber resources. Thanks to the developments in the widespread plantation of canola in Iran, in this research, we have studied the specific features of CMP pulp prepared from Rapeseed Straw. For this purpose, Rapeseed Straw CMP pulp was prepared at 160°C temperature, 40 minute time, 5 and 10 percent chemicals charge and 7:1 cooking liquor and canola stem ratio. In order to brighten the resulted pulp, hydrogen peroxide (5.5%) was applied. The yield of pulp obtained in 5% and 10% cooking chemicals conditions, were 78.07% and 74.07% respectively. In this content, the Strength Properties of the hand sheets prepared were measured as followings: tensile strength, 19.33 and 20.033 Nm/g; Burst strength, 0.83 and 0.57 Kpa.m2/g; tear strength, 2.57 and 3.25 mN.m2/g and Opacity 95.02% and 96.32%. This study has shown that, considering limitations in wood resources, the Rapeseed Straw, could be successfully substituted impart, in pulp and paper industry of our country, as a cheap and available lignocelluloses material for producing CMP pulp and papers.

This study was conducted to explore the effects of natural fires on vegetation and soil characteristics in Pir Golsorkh rangeland of Behbahan. Samples were collected in two areas which were burned and unburned by random- systematic method. In each plot percentage of total cover, percentage of bare soil, percentage of gravel and rocks, percentage of litter, percentage of vegetation according to their growth, the amount of production were measured and the condition of pasture was determined. Five profiles dug and soil samples were collected from two depths (0-20 and 20-40 centimeters) in each area and analyzed. The amount of nitrogen, potassium, carbon and phosphor were determined. Results show that in the area where fire took place the percentage of vegetation class III more than vegetation of class III of unburned area. While class I vegetation in unburned area was more than vegetation class I in the fire place. The percentage of vegetation in the burned area is qualitatively increased and the amount of grass is decreased. Percentage of vegetation and amount of grass in the burned place has a meaningful increase compare to unburned place. Soil factors analysis show no meaningful differences in nitrogen, carbon, potassium or phosphor between these two areas. Therefore, when there is fire along with drought, this can cause an increase in unpalatable grass and then it will become a suitable place for the upcoming fire.

Due to the process of deforestation and Increasing human population and growing demands for forests, afforestation and the development of forest is and will be of paramount importance. The objective of this research is to identify suitable plant species for afforestation and forest development in Dareh vesieh watershed by using multi criteria evaluation making. Slope, aspect, hypsometry, isometric, isothermal, soil, geology, river and land-use maps were used to produce the homogenous unit by using GIS. After removed Limitations from homogenous unit were determined suitable area for afforestation and studied ecological unit specifications. According to autochthonous species and adaptive exotic species and their ecological demand suggest species for afforestation in 26 ecosystem units that ecological demand of the suggested species is similar to ecology specifications of units that have capability for afforestation. Several species suggest for afforestation in every ecosystem unit such as Juniperus polycarpos, Amygdalus scoparia, Celtis caucasica, Elaeagnus angustifolia, Berberis crataegina, Pinus eldarica, Amygdalus lyciodes and Morus alba. Then, the best species suggests for afforestation in every ecosystem.

In this study, the effect of bovine lactoferrin (Lf) on growth parameters of rainbow trout (Oncorhynchus mykiss) were investigated. Fish with mean body weight of 40±5 g were fed for 30 days on three feeding regimes (1) commercial diet supplemented with 200 mg Lf/kg (2) commercial diet supplemented with 100 mg Lf/kg, (3) commercial diet without Lf. Growth and nutritional parameters were measured at the end of the experiment. Results revealed that the fish in all experimental treatments fed by LF, had significantly higher SGR, weight gain and lower FCR compared to the fish in control group (P <0.05). Fish fed on the diet containing 200 mg LF/kg exhibited higher growth parameters except condition factor, but no significant differences were observed with the group fed on diet supplemented with 100 mg LF/kg (P>0.05). The results indicated that use of 100 mg Lf/kg diet is highly recommended for feeding rainbow trout.

A 36-day rearing trial was conducted to examine the enrichment of Artemia fransiscana nauplii with fatty acid and C (Ascorbyl-6-palmitate) on growth performance, survival and stress resistance of yellowfin seabream, Acanthopagrus latus larvae. Yellowfin seabream larvae at the first exogenous feeding with 53±0.01 mg body weight and 0.84±0.08 mm length were randomly distributed into 5 treatments and three replicate were assigned to each diet. The test treatments were as follows: larvae fed Cod liver oil + 5 %, 10 % and 15 % (w/w) vitamin C enriched Artemia nauplii (C1, C2 and C3 groups, respectively); larvae fed fatty acid without vitamin (HUFA group) and non-enriched Artemia (control). All treatments fed Rotifer for 5 days and then fed non-enriched Artemia for 10 days after first feeding and then fed enriched Artemia and commercial artificial feed for 21 days. At day 36, submersion in salt water (0 ppt for 2 hours) and cold water (15 ºC for 2 hours) was performed to evaluate larvae resistance to salinity and temperature stress. Growth parameters were analyzed at the end of the experiment. The highest growth was found in control group at the end of the experimental trial, but growth factors were not significantly different between groups (P<0.05). Survival was significantly different between control and other group from day 17 that fed enriched Artemia (P<0.05). Stress tolerance was not significantly different at 0 ppt and 15ºC. There was no comparable different in cortisol, total protein and glucose under stress conditions (P<0.05). These results indicated that the enrichment of Artemia with essential fatty acids and vitamins C can affect survival in Yellowfin seabream Acanthopagrus latus larvae.