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Gonbad-e Qābūs, Iran

Farasati M.,Razi University | Seyedian M.,Gonbad Kavoos University | Boroomandnasab S.,Shahid Chamran University | Jaafarzadeh N.,Iran University of Science and Technology | And 2 more authors.
Desalination and Water Treatment | Year: 2013

The effects of Phragmites australis anion exchanger (PHA-AE) with micrometer and nanometer scales as adsorbents for nitrate removal were investigated. Also, the effects of operating conditions including pH, contact time, adsorbent loading, initial anion concentrations, and desorption experiments were examined. The results showed that the optimum pH was equal to 6 as the equilibrium time were 3 and 2 h for micrometer and nanometer PHA-AE, respectively. With the increased nitrate concentrations (5, 15, 50, 80, and 120 mg/L) for micrometer and nanometer PHA-AE, q e (adsorption capacity) increased from 0.4 to 6.97 mg/g and 0.45 to 7.7 mg/g. With increase of adsorbents dose from 0.1 to 0.3 g, the percentage of nitrate removal increased from 47 to 56% and 54 to 68% for microstructure and nanostructure adsorbent, respectively; however, the percentage of removal remained almost constant with the adsorbent dosage ranging from 0.3 to 1 g. The adsorption of nitrate ions onto PHA-AE was described successfully by pseudo-second-order adsorption kinetic and Langmuir-Freundlich adsorption isotherm. The results of the present study indicated that PHA-AE may be used to remove nitrate ions from water treatment process. PHA-AE nanometer showed greater capability of nitrate adsorption, too, as compared to PHA-AE micrometer adsorbent. © 2013 Copyright Balaban Desalination Publications. Source

Zarafshar M.,University of Mazandaran | Akbarinia M.,University of Mazandaran | Bruschi P.,University of Florence | Hosseiny S.M.,University of Mazandaran | And 3 more authors.
Folia Oecologica | Year: 2010

Sweet chestnut (Castanea sativa Mill.) is marginally distributed - as a rare species, in Hyrcanian forest, located in the north of Iran. In Iran, this species is economically important for timber and nut production, therefore its conservation is very necessary. However, no information exists on its variability in the Iranian chestnut populations. The aim of this study is to survey the variability in leaf morphology of three chestnut natural populations. Twenty trees per a population and forty leaves per a tree were sampled, data of nine characteristics (lamina length, lamina width, petiole length, distance from leaf base to the leaf maximum width, tooth width, tooth length, tooth distance, vein (count variable), teeth (counted variable) and four characteristic ratios (leaf length/leaf width, leaf length/petiole length, leaf length/distance from leaf base to the widest point, distance from leaf base to the leaf widest point/petiole length), were recorded. Principal components analysis (PCA) was used to separate inter-relationships into statistically independent basic components. Most of the variation (85%) was explained by the first four components, and leaf size emerged as the most important variable in the corresponding eigenvectors. We used one-way ANOVA on the scores of the factors extracted in the PCA. These analyses revealed significant between-population differences with regard to most of factors. The results of discriminant analysis showed a high percentage of correctly classified cases in all actual populations (in total 93%). The patterns of leaf plasticity exhibited low values for all parameters. We concluded that leaf parameters are suitable variables for detecting levels of phenotypic variability among chestnut natural populations. The high diversity observed in the populations is very important for the conservation of the species genetic resources. Source

Parad G.A.,Tarbiat Modares University | Zarafshar M.,Tarbiat Modares University | Striker G.G.,University of Buenos Aires | Sattarian A.,Gonbad Kavoos University
Trees - Structure and Function | Year: 2013

European pear is a flooding-sensitive species, and for its cultivation in lowland areas, it is necessary to carry out the grafting of scions of commercial pear varieties into rootstocks belonging to flooding-tolerant wild pear species. Flooding tolerance of Pyrus boissieriana-a type of wild pear-was studied as a promissory rootstock for commercial pear. For this purpose, 3-month-old plants of P. boissieriana were subjected for 30 days to control (C), well-irrigated treatment, short-term (15 days) flooding plus 15 days recovery (F + R) and long-term (30 days) continuous flooding (F). Physiological performance, plant morphological changes and biomass accumulation were assessed. Results showed that, although stomatal conductance, transpiration and photosynthesis were progressively decreased by flooding, when flooding was short term (i.e., 2 weeks, F + R treatment) plants were able to adequately recover their physiological activity (50-74 % with respect to controls). In contrast, when plants continued to be flooded (F treatment), the physiological activity became null and the plants died quickly after the water subsided. Adventitious rooting was the most conspicuous registered morphological response to flooding, despite that flooded plants had shorter shoots and roots than control plants. Leaf and root biomass were 63 and 89 % higher under short-term flooding (F + R) than under continuous flooding (F), condition in which plants did not survive. In conclusion, P. boissieriana appears to be a promising species for its use as rootstock of commercial pear in lowland areas prone to flooding of up to 2 weeks. However, if the flooding period is extended, plants of this species are at risk of perishing. © 2013 Springer-Verlag Berlin Heidelberg. Source

Mehdipoor M.,Gonbad Kavoos University | Neirameh A.,Islamic Azad University
Astrophysics and Space Science | Year: 2012

The nonlinear propagation of ion acoustic waves in an ideal plasmas containing degenerate electrons is investigated. The Korteweg-de-Vries (K-dV) equation is derived for ion acoustic waves by using reductive perturbation method. The analytical traveling wave solutions of the K-dV equation investigated, through the (G′/G)-expansion method. These traveling wave solutions are expressed by hyperbolic function, trigonometric functions are rational functions. When the parameters are taken special values, the solitary waves are derived from the traveling waves. Also, numerically the effect different parameters on these solitary waves investigated and it is seen that exist only the compressive solitary waves in Thomas-Fermi plasmas. © 2011 Springer Science+Business Media B.V. Source

Daneshvar A.,Swedish University of Agricultural Sciences | Daneshvar A.,Gonbad Kavoos University | Tigabu M.,Swedish University of Agricultural Sciences | Oden P.C.,Swedish University of Agricultural Sciences
New Forests | Year: 2016

Dormancy in Juniperus polycarpos (K. Koch) seeds is a major hurdle for production of the desired quantity of seedlings in nurseries for restoration purpose. Thus, the aim of this study was to develop an optimal dormancy breaking treatment and subsequent stimulation of germination. The treatments applied were cold stratification at 1 °C for 4, 8, 12, and 16 weeks; warm stratification at 20 °C for 4, 8, 12, and 16 weeks followed by 12 weeks of cold stratification; exogenous application of 250, 500, and 1000 ppm gibberellic acid (GA3) and 6-Benzylamino purine (BAP); and a combination of 500 ppm hormones and cold stratification. The results show significant differences in germination between cold and warm-cold stratification, length of stratification and their interaction (p < 0.01). Warm stratification for 16 weeks followed by 12 weeks of cold stratification induced 72 % of the seeds to germination in 12 days compared with 16-week cold-stratification alone (42 %) and the control (8 %). Exogenous application of GA3 and BAP alone or in combination with cold stratification resulted in less than 50 % germination though significantly (p < 0.01) higher than the control. Apparently, the hormone treatments alone or in combination with cold stratification are not effective in completely breaking dormancy and stimulation of germination. The findings suggest that J. polycarpos seeds may possess intermediate simple morpho-physiological dormancy, which could be an adaptive mechanism for relatively warmer autumn temperature during seed maturation and the subsequent cold winter temperature under natural conditions. © 2016 Springer Science+Business Media Dordrecht Source

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