فهرست مطالب حوریه رضایی

Bridges are the most important river structures and lots of bridges are damaging every years by river floods. One of the reason in bridge damage is local scour in around of bridge abutment. Investigations are reveal that controlling of scour methods are based on mechanism of scour. If the design criteria perfectly do not use, extinctive damages will be occurs in bridges foundation. Proper design and management of spur dike structure can control scour and crate stability for bridge .Effect f scours on flow properties and sediment transport are different and depend on scour design parameters, flow hydrology and amount of sediment. Different factors have effected scour phenomena. For study of these factors different researches are necessary. The aim of this research are study of effective parameters on maximum scour depth in bridges abutment in asymmetric composite sections.
Material and This research has contacted on a rectangular shape flume with dimension of 1 m width,12 m length and 60 cm depth in hydraulic laboratory of Shahrood University. In this research the amount of scour in cape of abutment have been studied with asymmetric T- Shaped spur dike by 4 relative conjunction of 0.2, 0.5, 2 and 5 for length of wing by the 9, 18, 27, 36 and 45 cm distance from abutment. The amount of discharges used in study were 18,20, 22, 24 and 26 litter per second.
Result of study reveal that maximum depth of scour is decreasing with increasing of the upstream length of spur dike to downstream, also it is showing that depth of scour is decreasing with increasing the distance of spur dike from abutment. Decreasing of the scour depth was 100 percent with 18 lit/s discharge and 70 percent with 26 lit/s. Results also showed that dimensions of scour hole is increasing with increasing discharge. In this research assessment of hydraulic and geometric parameters like discharge, average flow velocity, depth of water, length of spur dike, length of spur wing and distance of abutment was done. Analysis of these factors led to obtain a dimensionless equation. Final results of study was a new equation to estimate maximum depth of scour around the abutment.
Main results of this research revealed that with increasing of the distance of spore dike from abutment amount of dike effect to abutment erosion is increasing so that depth of scour in cap of abutment is decreasing.

Abundance of Thrips tabaci Lind., an important pest of vegetables, was investigated on upper and lower leaves of different genotypes of eggplant, including Siah-Mashhad, Borazjan, Black beauty, Siah-Neyshabour, Zabul indigenous, Imami-905, Juybar-Mazandaran, Sarkhoun-Hormozgan and Galami-Varamin, during 2000-2001 in Varamin region. Eggplant seedlings were cultivated in May in a randomized complete block design with three replications. Each replication consisted of four rows of 10 plants. Five leaves were randomly sampled at weekly intervals until October to estimate the incidence and population fluctuation of T. tabaci. The number of thrips was counted on the surface of four square centimeters of leaves using a binocular microscope. All analyses and comparisons were carried out using statistical package SAS. The results showed that there was a significant difference between the number of thrips on upper and lower leaves, so that the number of thrips on lower leaves were several times higher than that of on upper leaves. Borazjan and Juybar-Mazandaran with the mean number of 1.55 and 0.86 had the highest population in 2000 and 2001, respectively. In complex analysis, there was no significant difference between the thrips abundance on lower and upper leaves. Incidence of thrips faced with increase from June, and the maximum number was recorded in early until late July in both years. The results indicated that, a trend of increase initiated from late June in Varamin. Borazjan had more thrips than other genotypes and the thrips abundance in the first year was two times of the second year.

With expanding greenhouse crop production and improper pesticides management, spider mite damages and resistance to acaricides increased rapidly. Alternative application of recommended acaricides is the solution to protect mite resistance and implement mite pest managements in the greenhouses. An investigation about four doses Kingbo 6% SL (0.4, 0.5, 0.6, 0.75), NeemaAzal-T/S (0.5, 0.75), Hexythiazox EC 10% (0.5), Abamectin EC 1.8 (0.75), along with water application treatments done in rose greenhouse hydroponics cultivation which by two spotted spider mite (Tetranychus urticae.) during 2007 in Varamin region. Complete block randomized designed in three replications and each replicate consisted 10 meters cultivated rose were used for evaluation treatments. Infested rose treated when observed 3 or more active mite stages under side rose leave with 10% rose leaves infestation. Sampling of 20 leaves from different parts of rose plants in each treatment done randomly and number active mite stages counted at interval of one day before and 1, 3, 7, and 10 days after treatments respectively. Collected data through Abbott formula converted into mortality% and analysis of variance on mean collected data carried out with SAS method. Grouping of the treatments done with DMRT method. Results of finding showed that, max. active mite and egg stages before treatments observed 12.28, and 8.02 in lateral side of greenhouses for Kingbo 0.4 dose and min 2.24 active stages, 2.8 eggs recorded for NeemAzal (0.75) and Abamection in middle part of greenhouse respectively. Lower (30%) and higher (48%) rose leaves infested by mites observed for Abamectin and Hexythiazox whereas rose leaves infested by mite eggs was found varied between 32 up to 56% for those treatments. NeemAzal (0.5), Abamection (0.75), Kingbo (0.4, 0.7), and water spray treatments caused higher mite mortalities of 67.11, 67.18, 69.36, 71.18 and 56.94 respectively. The maximum control% among sampling intervals recorded 67.03% three days after treatments. Application of Kingbo and NeemAzal as new acaricides did not produced any rose leaf burning effects. Therefore these treatments along with water spray application can recommend in integration mite management programme against rose spider mite in the greenhouse.