Year:2004 | Volume:9 | Issue:4|Papers Count:11

The recognition of physiological relations is important for the analysis of factors which affect yield and its components of safflower. Yield components are affected by the management, genotype and the environment. They help researchers to recognize the reasons for the increase or decrease of yield too. Five safflower genotypes, including two chosen lines from Esfahan safflower landrace and cultivars Arak 2811, Gilla and Kooseh, were compared at two seeding dates (April 4 and July 6) and three planting densities (40,20 and 13 plants per square meter). The planting date had significant effects on the yield, yield components and other physiological characters, except the oil percentage. Head per plant, seed weight, seeds per plant and plot and plant yield in spring planting were higher than summer planting. Plant and plot yield, yield components, seed per plant and seed pith percentage were affected by the planting density. The mean comparison of this characters showed a decrease in planting density due to increased heads per plant, seed weight, seeds per plant, pith percentage and plant grain yield, but decreased seeds per head and plot grain yield significantly. Genotypes were showed to have significant differences in physiologic characters and yield components. Heads and seeds per plant, pith and oil percentage, harvest index and plot and plant grain yield in line 1 were clearly higher than other genotypes. The result of stepwise regression for the grain yield estimation shows that heads per plant described 73% of variation in seed yield. Seed number per head, total grains of plant number of days from planting to physiologic ripening and harvest index explained 8.7, 5.4, 5.0 and 1.5 percentage of seed yield variation, respectively.

According to the economic development and other related disciplines increase in production seems to be a necessary challenge of any economy. There are two different ways to achieve this goal. One is taking more inputs during the production when constraints in natural resources would be a barrier. The other way is to increase the inputs productivity which is used during production process. In the present study input productivities have been examined using average and mariginal productivity concepts for the production of cotton in Garmsar region. Results indicate that totally farmers who have been grouped according to their land size use most of the inputs in the third region of production. Also farmers with larger farms behave totally more logically in comparison to the medium and small farmers. TFP indexices calculation for each group, confirm these results.

Drag force is one of the aerodynamic properties of Chickpea that is used extensively in the pneumatic separation and conveying systems in agricultural machinery and process engineering. Based on dimension eight samples of Chickpea were chosen. In order to hold Chickpeas in the wind tunnel 450 mm length comb was used. There are needles on the comb with 30 mm intervals.The experiment was done at three different moisture levels (42%, 46%, 52% wet basis) and at three different air velocities (10m/s, 12m/s, 15m/s) for eight dimension and at eight replications. Factorial experiment based on completely randomized design was used to analyze data.Effect of dimension moisture content and air velocity on the drag force at α=1% were more significant and their interactions did too. The mean of drag force was 7.923× 10-3 N the highest and the lowest were 18.8× 10-3 N, and 3.91 ×10-3 N, respectively. Drag force increases with increasing dimension moisture content and air velocity.Finally the results are shown based on the regression analysis with the related equations and tables.

The precise prediction of advance phase is crucial for surface irrigation design, evaluation and management. Several models are now available to predict the advance phase. Among those, the so-called "volume balance model" is widely used because of its simplicity and applicability. Different methods are employed to solve the volume balance model, in which the advance phase is predicted with different precision. The objective of this study was to evaluate the existing methods and to select the best approach for designing different surface irrigation systems. Consequently, "the Hall", "the corrected Hall", "the varied surface shape factor", "the varied sub-surface shape factor", and "the ultimate explicit" methods were selected to solve the volume balance equation. A computer program was written in Quick Basic for each of these methods, The data collected by Roth et al. (1974) and Walker et al. (1983) were used to verify and compare the models for border and furrow irrigation, respectively. The collected data were also used as input parameters in the computer programs. The outputs were the rates of the advance time in different lengths of furrow or border (advance phase curve). The results indicated that "the corrected Hall" and"the varied sub-surface shape factor" methods provides the best performance to predict the advance time for border irrigation. The "varied surface shape factor" method, however, provided the best estimation of advance time in the furrow irrigation.

Lignin of poplar wood was investigated using chemical methods and nuclear magnetic resonance (1H NMR) spectroscopy. Klason lignin and acid soluble lignin of this species was determined to be 19% and 3.1% respectively. Carbon, oxygen and hydrogen of purified lignin sample was found to be 63.1%, 31.6% and 5.3%. Methoxyl groups and phenolic and aliphatic hydroxyl groups of lignin was found to be 1.29, 0.45 and 0.92 respectively using 1H NMR spectroscopy. By chemical methods of analysis, these data was found to be 1.25 for methoxyl groups and 1.32 for hydroxyl groups for each phenyl propane unit. The degree of substitution of aromatic hydrogens by C-C and R-5 linkages was determined to be 25%. Therefore, using 1H NMR spectroscopy, the structure of lignin was determined as following:C9Ha1 3.o8Hph 2.02O 1.21 (OH) ph 0.45 (OH) al 0.92 (OCH3) 1.29

Fishery reserves is an integral part of national wealth and should be preserved for future generation. Caspian sea due to variety of Fish such as Caviar has an important place in the country and policymakers and authorities in Fishery organization have been trying to preserve fish reserves in that sea. In this regard, this research was done to find ways to protect the fish reserves and to identify the factors that affect the participation of members of fishery cooperatives. Independent variables in this study are as following: age, educational level, experience, knowledge about conservation rules and regulations, access to educational facilities, loan, income, studying extension publications, knowledge about benefits of role and regulation, perception of cooperative members about their role in implementing the regulation, perception of members about board of cooperatives, attending the extension classes and etc. The dependent variable was participation members in preserving the fish reserves. The population for this study was all members of fishery cooperatives in City of Sari. One hundred thirty members was selected randomly. The result of study indicate that there was relationship between age, educational level, experience, income, knowledge, accessibility to educational facilities, loan, extension printing materials, opinion of members about their role in implementing the laws, using the educational programs in TV and Radio, extension visits, number of occupations, marital status and contact with extension agents as independent variables and participation of members as dependent variables.

In this research work, the experiment was performed with laboratory spray dryer on orange juice for achieving primary design data. Results indicate that for drying of orange juice the optimum feeding temperature is 20-35 °C, outlet air temperature is 70 °C, maximum inlet air temperature is 170 °C and powder sticky point temperature for moisture content of 2%, is 44°C. Also the main cause of dryer walls deposit is the walls high temperature. With these results, a spray dryer of two-layer chamber with capacity of 15 kg/h powder for fruit juice was designed constructed and evaluated.The constructed dryer is able to control of wall temperature, inlet and outlet air temperature and atomizer speed. Evaluation of dryer indicated that yield of dryer is 65 to 90% and wall deposit is less of 15%, in the variation of inlet air temperature. In the all of experiment, the temperature of walls chamber was less of powder sticky point temperature, and walls deposit very decreased in comprise with laboratory spray dryer. The results of statistical analysis of data show that the parameters of inlet air temperature and feed flow rate have significant effect on the dryer yield and wall deposit individually and jointly. In constant of inlet air temperature, with increasing of feed flow rate, the dryer yield is decreased and wall deposit is increased.

River flow forecasting is one of the important applications in hydrology. Several methods have been developed for this purpose and one of the most famous methods is Auto Regressive Moving Average (ARMA). In this method, the hydrological parameters of time series are estimated given a set of observations. After calibration, the model can be used to forecast the stream flow. In estimating the parameters, it is tried to minimize the error between the observed and calculated data for the whole series. In this research, the goal was to minimize the error for a specific season of the year as well as the whole series. Goal programming (GP) was used to estimate the ARMA model parameters. Shaloo Bridge station on Karun River with 68 years observed stream flow data was selected to evaluate the performance of proposed method. It was compared with the usual method, maximum likelihood estimation, and results were in favor of new proposed algorithm.