In this study, rice straw as an abundant and inexpensive raw material was selected to produce soda - anthraquinone pulp. Nano cellulose fiber from rice straw, cationic starch and cationic ployacrylamide were added to improve the pulp strength. Cationized nano cellulose fibers suspension was mixed with rice straw pulp at three levels (2, 5 and 10 percent) and mixed for five minutes. Starch and polyacrylamide as cationic chemicals were used to stabilize nano fiber cellulose at 1.5% and 0.2% (based on oven dried pulp) respectively. The result showed that there is a linear change between stock drainage time and paper strengths containing nano cellulose fiber. Tensile and burst strength indices were improved at 18.66% and 18.12% respectively by adding 10% of nano cellulose fiber to suspension treated with cationic polyacrylamide. Furthermore, the two indices increased by 19.35% and 19.24% by adding the maximum amount of nano cellulose fiber (10%) to pulp suspension cationized with cationic starch, respectively. The overall results indicated that nano cellulose fiber had a positive significant effect on the refined and unrefined pulp strengths of rice straw.

In order to investigate the effect of processing type (whole straw bale processing or opened straw bale processing with urea) on diet digestibility, economical and productive parameters in feedlot cattle, 18 Holstein bull with average body weight 224.72±20.45 kg were used in a completely randomized design with 3 treatments and 6 replicate. Treatments 1, 2 and 3 contained 40% typical straw, 40% whole straw bale processed with 5% urea (WSBP) and 40% opened straw bale processed with 5% urea (OSBP), respectively. The average in vitro digestibility of DM (32.7, 46.9 and 46.5%, respectively for treatments 1 to 3) and OM (30.5, 47.0 and 45.8%, respectively for treatments 1 to 3) was not significant between WSBP and OSBP, but was significant between treated and typical straw. The average daily gain (698, 881 and 882 g/d, respectively for treatments 1 to 3) and daily DMI (8.8, 10.2 10.0 kg/d, respectively for treatments 1 to 3) were significantly higher for WSBP and OSBP compared to typical straw. The cost price of consumed diet for 1 kilogram weight gain was 910 Rials lower for WSBP than typical straw. Also, the time require to achieve 200 kg weight gain reduced to approximately 2 month. The results of present study showed that processing of WSB can reduce needed time and labour cost, and in comparison with typical straw time required for achieving weight gain reduced.

CEHEP and HEP sequences were used for bleaching of rice straw organosolv pulps and the effects of these sequences were investigated on optical (brightness and opacity) and mechanical (tear index, burst index and breaking length) properties of produced paper sheets. Despite of the significant reduction in mechanical properties, brightness was increased so that it was suitable for writing and printing paper. CEHEP sequence had more increment on brightness and more decrement on mechanical properties than the HEP sequence. The catalytic soda organosolv pulping was used for the pulp production (delignification) from rice straw via batch process at high temperatures and high pressures. The catalytic pulping of rice straw was performed in ethanol-water mixtures (50 and 65% w/w) at various cooking times (150 and 180 min). The ratio of cooking liquor to dry mass of rice straw was 10:1 and the catalyst (soda) was 1(%) dry mass of rice straw.

The aim of conducting this research was determining the digestibility of some feedstuffs (barley straw and wheat straw of Ilam province, barley straw, wheat straw and clover "1st cut" of Kermanshah province) using in vivo method. For determination of digestibility, 4 male castrated adult sheep on the average 3 years old and 62±3.1 kg weight were used. Feeding level was regulated for clover adlibitum and for straws in maintenance (40 g DM/kg w0.75 of 60:40 for straw and cottonseed meal, respectively). Apparent digestibility of DM, OM and GE for Ham barley straw was 50.77±1.88, 54.00±1.87 and 40.73±3.38 percent, for Kermanshah barley straw 44.4±1.03, 48.3±1.33 and 33.8±1.12 percent, Ham wheat straw 45.69±2.96, 49.30±2.93 and 36.10±3.3 percent, Kermanshash wheat straw 44.65±1.32, 50.10±1.07 and 34.03±1.24 percent and clover 67.59±1.60, 71.84±1.72 and 65.13±1.73 percent respectively and digestibility of CP for clover 79.94±2.06 was determined. DMD, OMD and digestibility of GE for barley straw between provinces were significant (P<0.05). Significant difference wasn't observed between provinces for DMD, OMD and digestibility of GE for wheat straw (P>0.05).

In this study, the effect of alkali treatment on the mechanical properties of rice straw flour-polypropylene composite was investigated. Rice straw flour (40 mesh) was treated with hydroxide sodium 5 and 10% in two times, once for 45 and another time for90 min respectively. The composites were made from rice straw flour as filler (30%), polypropylene (65%) as matrix and maleic anhydride (5%) as coupling agent. In order to blend the raw materials of internal mixer a Haake HBI system 90 machines and make standard samples testing an injection molding were applied. The results of this study suggest that treatment of rice straw flour with alkali 5% concentration increases tensile modulus and impact strength which increase with time prolongation. However, treatment of rice straw flour with alkali 10% concentration decreases these properties even with the increasing of time. Furthermore, the increasing of alkali concentration and treatment time resulted in an increase in the tensile strength of composites.

The objective of this study is to develop a new process for the production of pulp using the wheat straw. Environmentally-friendly wheat straw pulp with potassium hydroxide was prepared, and their mechanical and optical properties were studied.Pulping tests were carried out varying active alkali (16, 18 and 20 wt %) and cooking time (60 and 90 min). Liquor-to-solid ratio, time to reach the maximum temperature and the cooking temperature were kept constant. The increase in active alkali significantly reduced the yield and kappa number of the pulp. Chemical pulps of 48.71–53.73% yield produced from the KOH pulping process exhibited acceptable papermaking properties comparable to those of soda pulp. Refining the pulps increased the tensile index, breaking length, and burst index of the handsheets. The tear index and brightness were lower for refined pulp compared with the unrefined one. The black liquor of this process can be utilized as a fertilizer for agricultural production.