abstract: in this paper, the results of experimental and numerical simulation of low velocity impact process have been carried out to investigate energy absorption of composite sandwich panels with 3d woven fabrics of glass fibers and epoxy resin. for this purpose, diagrams of force-displacement of the quasi-static and quasi-dynamic impact tests were studied. for the finite element simulation, ...

in order to investigated the effect of flooding, different nutrition levels an anti-oxidant characteristics, chlorophyll fluorescence, amount of chlorophyll (a, b) and carotenoids leaves soybean (glycine max (l.) merr), cultivar dpx research at the university of agricultural sciences and natural resources, gorgan, in a completely randomized design to factorial arrangement with three replication...

introduction noise pollution is one of the environmental pollution that threats public health to the survival of organisms. urban traffic causes noise pollution as a major factor of air pollution. this is one of the problems of urban citizens. this is also a growing problem that has a potential impact on public health, which is mainly resulted from transport vehicles in the cities and the resid...

drain envelopes play significant roles in the performance of drainage systems due to theirreduction in letting sediments into the drainpipes and also because of an increase in thehydraulic conductivity of soil around the drainpipes. throughout the present research, theeffect of a one 1000 hour flow on dual envelopes consisting of geotextile as a means ofimproving the hydraulic gradient and rice...

drought is the most common environmental stresses that affects plant growth. to study the combined effects of arbuscular mycorrhizal fungi (glomus intratadices) and jasmonic acid on growth and ecophysiologycal characteristics of pistachio seedlings cv. qazvini under drought stress, a greenhouse experiment was conducted in a completely randomized design with three replications. experimental fact...

because of the passing of the air systems, temperature changes are often very sudden and plants cannot adapt themselves to these fluctuations and get damage. because low temperatures have harmful effects on the agricultural productions, so, the investigation of these temperatures are very useful for predicting and preventing probable damages. in this study, for determining the time of the freez...

in order to evaluate efficiency of nitrogen fertilizers consumption in a sugar beet monogerm hybrid variety of zarghan, a field experiment was conducted in a loamy soil during 2007 in the research farm of sugar beet seed institute located in karaj. five levels of nitrogen fertilizers including 0 (check), 120, 160, 200 and 240 kg/ha of net nitrogen from urea fertilizer (46 percent of pure nitrog...

the petrochemical industry is the most important and most widely active industries in the country. due to the variety and complexity of industrial products, it also produces a wild range of pollutants. mercury waste disposal from chlor-alkali units is one of the fundamental problems of this industry. various studies have shown that phytoremediation system for removal of mercury from aqueous sol...

abstract introduction: scientific development is essential for each type of development. the first step for planning is to know present situation. for planning to improve student role in research, we must know how much do they know about research methodology and what kind of attitude they have about it. the aim of this study was to determine isfahan dental students' knowledge and attitude about...

nitrogen (n) affects adversely the tobacco yield quantity and quality as it increases yield, chlorine and nicotine contents, but decrease potassium content. this experiment was aimed at optimization of (the balance between) n concentration in leaf, stem and root to increase both yield quantity and quality (high potassium, low chlorine and medium nicotine contents) using artificial neural networ...