Year:2003 | Volume:9 | Issue:1|Papers Count:10

During deep fat frying significant quantities of oil is heated for a long period. Some factors namely moisture, heat and oxygen cause different physical and chemical changes such as hydrolysis, oxidation and polymerization that consequently decrease the quality of the oil and the finished product. In this research project frying oils from two potato chips factories were sampled from the first day of production (fresh oil) until the total exchange of the oil and physical and chemical tests were carried out on the collected samples. The results indicated increases in the free fatty acid content, peroxide value, polar compounds, viscosity, color and decreases in the iodine value, induction period and unsaturated fatty acids showing a decline in the quality of the oil, particularly formation of some trans isomers as the results of deep frying.

The main Purpose of this research was to: assess the extensional needs of program - leaders of the rangeland projects in Damavand. This was a descriptive ex-post factors study. A questionnaire was used to collect the data. The target population for this study include 600 program leaders of the rangeland projects who have participated in this program, which 122 of them were selected through random sampling method. The following independent variables in this study was shown to have a positive relationship with the dependent variable: a) income of the program leaders, b) number of livestock, c) the experiences in rangeland activities, d) area of rangeland owned by the program leaders, and e) accessing of program leaders to the cities. This study had two main findings. First, it was found out that extension classes can be an appropriate tool to help program leaders to improve and conserve the rangelands in city of Damavand. Second, results of this study also examine that extension has not been effective in promoting better use of rangelands and therefore, there should be an evaluation of extension classes.

Regarding to importance of road network in Forest Management and wood transportation, this investigation was carried out in four series of "Vaz Research Forest". The study area was 4081 hectares. This forest network planning was based on essential factors such as length of roads, length density of roads, wood transport distance in forest, network percentage, slope, soil mechanics, soil stability, volume of wood production and climatic factors. To conduct the study, two stages were considered to achieve these goals: In first stage, existing roads were evaluated and recorded. The result was as follow: Length of roads: 21770 m Length density of roads: 7.8 m/ha Network percentage: 37% In second stage, because the network of existing roads was unacceptable, forest network planning (Major roads and Minor roads) was performed based on some factors such as length road density, wood transport distance, network percentage, slope, soil mechanics, forest production volume and climatic condition was performed to obtain optimal road coverage and to reduce forest damages. The new road network characteristics were as follow: Length of roads: 52459 m Length density of roads: 14.1 m/ha Percentage of network: 61% The result showed that although road length density was increased, the percentage of network was not expanded because steep areas of the forest. Slope was an important factor in major and minor road planning. Only 43% of the road was located on the best class of slope (0-30%). The logging roads were located on 62% of the forest ground with moderate mechanical class of soil. Soil stability and climatic factors had important role in logging road planning. In series 2, the slope is suitable but the soil stability is a limiting factor in logging road construction all over its area. As a result, cable crane system should be applied to transport logs outside the forest.

In this study, to increase the efficiency of Bacillus thuringiensis against Spodoptera exigua as an important polyphagus pest, the synergistic effect of carbrandom and the mixture of it and henna powder with B.t. was investigated seperately on 3 rd instar larvae in a randomized block design. Results revealed an increasing effect of mortality with those mixtures so that the larval mortality for mixture of carbrandom with B.t. and henna powder and carbrandom with B.t. was 82.5% and 90%% respectively in the least period of time, however it was 18% for B.t. alone. In addition to this, the incubation period in the case of using of those mixtures decreased to less than 3 days and it was more sensitive about the mixture of carbrandom and henna powder with B.t. . Therefore it is possible to decrease the amount of B.t and carbrandom which are expensive, by increasing of henna powder.

Due to cultural, social and economic growth of the country during the development programs, demand for paper products has substantially increased. Studies on different agri-industry projects by Sugar cane and Byproducts Company in the south indicate that bagasse can be one of the most appropriate non-wood raw materials for the new pulp and printing & writing paper factories. In order to undergo the related feasibility study (the capacity of each factory was considered as 88500 tons per year), operational and investment expenditures were defined through the study of proposals and some similar projects as well as gathering information from the investment organizations. Thereafter, financial analysis of the projects was done through the standard method of UNIDO. Thus the total capital investment was estimated as more than RIs. 1713.7 billion. Financial indices including internal rate of return (IRR), payback period, break-even point analysis, currency savings and net domestic value-added show that it would he a great financial advantage to establish the mentioned factory. Moreover, the impacts of the fluctuation of some major parameters on the IRR were also analyzed.

Convenient price - policy can increase the production of given agricultural products. Since the policy of Iranian government is to promote the revenue of non - oil exports, So raising the production and export of some products such as tomato which our country has comparative advantage in its production, would lead to gain more foreign exchanges incomes. Iran has a small share in world tomato paste market. Some exporters in Iran believe that due to low production cost of tomatoes in Iran, by removing the main constrain in tomato production and trade would increase the share of Iran in international markets significantly. Khorasan province, by having a great potentiality in production and processing of tomato, can have a significant role in increasing the production and export of this product. The main objective of this paper is to examine the effects of price on supply of tomatoes in Khorasan province. In order to achieve the study objectives a time series data for years 1360 -78 were used. The results of the study indicate that the price of tomato and the price of substitute product (i.e: Sugar beet) have a significant effect on cultivated area and production of tomato. Thus implementing a convenient price policy could increase the supply of tomato and its products significantly.

Drying is one of the important steps in pistachio processing. During this step kernel moisture content is decreased from 50 to 4-6 percentage (d. b.) for suitable storage. Changes in temperature air velocity and pistachio layer thickness plays important role in pistachio drying process. In this research, pistachio was dried at three temperature levels (60,75, 90 °C), three drying air velocities (1.5, 2, 2.5 m/s) and two thickness levels (5, 10 cm). Changes of drying time and drying rate were investigated for Kalehghouchi variety of pistachio. The experiment results indicated that, Increasing the temperature to 90°C resulted reduce the drying time by more than 50 percent, increased the drying rate and resulted a better roasted flavor in pistachio. Drying temperature does not have any effect on appearance of dried pistachios. Increasing the air velocity at high temperatures can reduce the drying time by about 25 percent. Increasing layer thickness of product caused resulted in drying time, but amount of dried product increased considerably.

An experiment was conducted in 1999 in Mashhad Agricultural Research Station. To evaluate the growth response of sugarbeet, var IC__1 (multigerm) under different planting dates and patterns. A split split-plot layout within a randomized complete block design with four replications was used. Mainplots were planting dates (May, 5th and June, 10th), subplots were row spaces (50 and 60 cm) and sub-sub plots were plants densities (8, 10 and 12 plant m^-2). Delayed planting date, increased row spacing and decreased planting density, resulted in lower leaf area index (JAI), total dry matter (TDM) and crop growth rate (CGR). Net assimilation rate (NAR) reduced as planting was delayed, but was not considerably affected by row spacing or planting density. The least LAI, TDM and CGR were produced by eight plant m^-2 density in both planting dates and row spaces. However, due to higher light use efficiency of lower LAI, eight plant m^-2 density had higher NAR. The results indicates that 10 plant m^-2 density in 50 cm row spacing may be suitable for both normal and delayed plantings, under conditions similar to this experiment.

In agricultural higher education system, educators play significant role on influencing other sectors and the total function of the system. Surveying of the main problems and difficulties on agricultural education system of the country indicates that, most of the educators are not professional and their professional competencies are incompatible with their careers. These are considered as the problems of agricultural education system. Analysis of the problems show that these are due to not having clear strategies to obtain professional competencies and to investigate professional and education needs of educators in agricultural higher education institutes. In This regard, the present research was conducted along with objectives on determining the strategies to obtain professional competencies and to investigate professional and educational needs of educators in agricultural higher education institutes. Theoretical framework of this research is based on designed research and a pilot study. In this research, the method of research was surveying. By the use of questionnaire, the ideas of 191 agricultural educators were studied. The individuals were selected by the census system from all agricultural applied-scientific higher educational institutes. The opinions studied and evaluated were surveyed on the degree of effectiveness and the amount of attention in respect to each of the mentioned strategies. The instrument for the research was questionnaire, and its validity had been approved by R educational specialists and its reliability was determined by Cronbach"s Alpha Coefficient. The research findings indicated that the most effective strategies to obtain professional competencies and to investigate professional educational needs of educators in the institutes, are continuous use of most new scientific books (related to agricultural proficiency), recognizing how to use internet to obtain agricultural research findings, and how to use internet to obtain agricultural education research findings. But with regard to the degree of attention on strategies to obtain professional competencies by planners and managers at the end of research, the importance of enhancing scientific - tour study for trainers in educational centers were studied. Also Internet application to obtain agricultural education and research findings, and economic services to agricultural educators was also considered as focal point.