This research with purpose to distinguish properties of Pulping and Paper making from stem of colza (Brassica napus) and capability of Semi-chemical Pulping was performed. The exception was Type selection of used tests was Ocapie that was prepared from center of modification of seeds, karaj county and transferred to the Mazandaran Pulp and Paper mill. In Conditions of Cooking process, were two different chemicals consumption (chemical charge) 10% and 20 % on the (basis of dry) colza weight and periods of digestion were 30 and 40 minutes and the condition of pulping was 170 degree of centigrade temperature. Using PFImill,four kinds of pulps with four different freeness were made up to 410±25 CSF by PFI mill refiner. Then seven hand sheet 127gr/m² were made measured. For study the resistant properties of hand sheet papers, used the TAPPI standard, study on mechanical strength of handsheets showed that when the yield decreased, the resistance index of paper like that: Tensile Strength, Ring crush Test ((RCT)), Burst Strength, Burst Strength, Stiffness, Strage, Breaking Length Corrugated Medium Test was increased.

The samples of Sunflower stalks were collected from Behshar and Neka. The average fiber length, cell wall diameter and thickness measured were 0.9581lm, 23.605 and 5.927µm respectively. The components of chemical and depithed stalk including: cellulose, lignin, ash and extractives content using Alchol-Aceton and NaOH 1% were measured as 39.93, 22.24, 12.49,4.92,36.10% and 47.37, 21.20, 7.50, 3.61, 34.00%, respectively. The following optimum conditions were selected regarding of pulp yield 43.80% and kappa number 82.55: with cooked chemical substances: 20% Na2o applied, on the basis of dry sunflower stalk, pulping temperature: 170°C and residence time at maximum temperature: l80min. Pulp refining carried out with PFI revolutions 150 and 500 RPM up to freeness 372 and 328ml CSF, respectively. Statistical analysis showed that physical and mechanical, properties of hand sheets with basis weight 127gr/m2 NSSC pulp made from Sunflower stalk with freeness 328ml CSF are better than mixed hardwood NSSC pulp (except burst index) and NSSC pulp of Sunflower stalk with freeness 372ml CSF. Furthermore, no significant difference was observed between mixed hardwood NSSC pulp and NSSC pulp of Sunflower stalk with freeness 372ml CSF.

Stickies are one of the main challenges in the papermaking industry, especially in recycling process of old corrugated containers (OCC). Application of a fixing cationic polymer is one of the main approaches to control these harmful substances. However, it is obvious that these agents besides fixing characters could also influence the final product properties. Therefore, in this study, the effect of using an industrial cationic polymer i. e. GL (Trade name), as a stickies control agent on mechanical properties of hand-sheets made of OCC fibers, was assessed at three levels of 0. 4, 0. 8 and 1. 2% (based on pulp dry weight) and at two pH ranges of 4 and 7. The characterization of the GL by FT-IR spectroscopy demonstrated that it was synthesized based on poly (diallyldimethylammoniumchloride). The results showed that use of the cationic polymer enhanced the strength properties of the hand-sheets by influencing formation and inter-fiber bonding through fixing and flocculating the stickies and fines into the fibers network. These respective enhancements were measured at pH ranges of 4 and 7 as follows: Tensile strength of 35 and 30%, burst strength of 12 and 10%, ring crush test ((RCT)) of 29 and 21%, Concora medium test ((CMT)) of 19 and 32% and tear strength of 10 and 13%. It can be concluded that 0. 4 % GL cationic fixing agent could be proposed as optimum value at pH =7 for industrial applications.

In this research, effect of freeness on mechanical properties of papers made from colza with three different freeness was performed. Type selection of used was prepared from center of modification of seeds, karaj county and transferred to the Mazandaran Pulp and Paper mill. Best choice of condition of pulping was 170 degree of centigrade temperature and 20% chemical consumption and period of digestion was 40 minutes. And than by using PFI mill, three kind of pulps with three different freeness were produced from the proper pulp and then, 127gr/m2 hand sheet papers produced from different samples of pulps and their strength properties were measured study of mechanical strength of hand sheets showed that the beating has effect on tear strength and reduces this strength with more beating when the refining increased, the resistance indexes of paper such as ring corrugated medium test ((CMT)), ring crush test ((RCT)), stiffness; and other strength was increased the only exception was tear strength that decreased. With regard to reduces of tear strength that no important for linear boeard and increases ring crush test ((RCT)) and curugated medium test ((CMT)) and stiffness and other strength resulted pulps with 300±25 (CSF)is recommended.

By carrying various cooking from sunflower stack chips using NSSC pulping process, optimum cooking at pulp yield of 43.8 % and kappa number of 82.6 was selected under cooking condition of 20 % chemical charge based on sodium oxide, cooking time of 180 min, and maximum temperature of 170 degree Celsius. The pulps were refined to obtain freeness levels of 328 ad 372 ml, CSF, by PFI mill revolutions of 150 and 500, respectively. Standard hand sheets with grammage of 127 g/m2 were made from both sunflower NSSC pulps, at three levels of 10, 20 and 30 % in admixture with hardwood NSSC pulp from Mazandaran Wood and Paper Industries (MWPI), and their physical and strength properties were measured. Statistical analysis showed that, up to 30 % of sunflower NSSC pulp with freeness of 328 ml, CSF can be blended with hardwood NSSC pulp from MWPI, to make fluting paper. It has been also shown that, up to 30 % of hardwood NSSC pulp from MWPI can be substituted by sunflower NSSC pulp at freeness level of 372 ml, CSF, if 5 % unbleached softwood kraft pulp can be used in the furnish.

In this study, the critical state shear strength of a type of sand with different silt percentages in saturated and unsaturated states has been investigated. For this purpose, a number of undrained consolidated (CU) and drained consolidated (CD) triaxial tests were performed on saturated and unsaturated samples, respectively. The samples were sheared under confining pressures of 50, 100 and 150 kPa and suction levels of 50, 100, 150 and 250 kPa for unsaturated samples. In the saturated state, the results showed that if samples are remolded with the same eeq, for the different percentages of fines the critical state lines are converged. In the unsaturated state and net stress state, the critical state line is not only dependent on suction, but also changes with changes in the percentage of fines. However, in the effective stress state, by applying the appropriate effective stress relations and the concept of equivalent intergranular skeleton void ratio, these lines can be converged independently of suction and fine content and reach a single critical state line in the stresses space.

This research down with aim of study of substitution possibility of bagasse neutral Sulfite semi chemical (NSSC) instead of division of wood pulp for production of floating paper in Mazandaran wood and paper complex. In this study use of depithing bagasse in wet process from pars paper factory that located in Khuzestan province. Cooking of pulp is in (NSSC) process with use of chemicals of Mazandran wood and paper factory equal to 20 percent (in dry material basis) in 30 minutes time and 170°c heat. After that bagasse pulp refine with (PFI Mill) refining to 400±25 CSF Freeness and mixture with NSSC pulp of Mazandaran and paper factory. From elective bagasse pulp in 10%, 20% and 30% ratio of pure bagasse, produce of mixtures with NSSC pulp of Mazandaran wood and paper factory with 400±25 CSF Freeness. In addition to: unbleached importer long fiber pulp with 510±25 Freeness in 5% area mixture with NSSC pulp of factory. (The above pulp was the witness pulp for produce the paper) and produce from one sample of 127 gr/m2 hand sheet paper. At last studied the resistances of hand sheet papers. For study of resistance properties of hand sheet papers, used from TAPPI standard, Studies show that, with increase of using of bagasse pulp, the resistance indicators like that Ring crush Test ((RCT)), Stiffness, Tensile Strength, Burst Strength, tear Strength, and Breaking make increased.

Concrete structures undergo a reduction in strength and ultimately premature deterioration during their life due to environmental factors. Corrosion of reinforcement is known as one of the most important factors in reducing the performance of concrete structures. Assessing the current condition as well as predicting the remaining useful life of structures is very important for providing maintenance plans. In this research, considering the limit-state function of the shear strength of reinforced concrete beams, the life model is calculated under different scenarios of chloride ion penetration. Reduction of the cross-section of longitudinal and transverse rebars, reduction of the cross-section of the concrete beam, and reduction of mechanical properties of concrete and rebar, which are known as side effects of rebar corrosion, have been considered in evaluating the life model. Stochastic properties of effective parameters in shear strength, as well as chloride ions, are also considered for the probabilistic evaluation of the life model. The Monte Carlo sampling method was used to generate the input values of the models. The results show that considering the effect of concrete scaling causes a large difference in the predicted values for the shear strength of concrete beams, so in the critical case, considering the effects of concrete scaling reduces the shear strength by 20% and a more realistic estimate of the remaining life of the structure will be obtained.