Journal of Sciences, Islamic Republic of Iran
Year:2001 | Volume:12 | Issue:3|Papers Count:19

Plants of Hashilan, a 260 ha freshwater wetland, located at 35 km northwest of Kermanshah, the provincial capital of Kermanshah Province, western Iran, were studied. Altogether, 116 species of plants (77 terrestrial and 39 aquatic) representing 96 genera and 42 families were identified. Asteraceae with 11 genera and 13 species, Poaceae 9 genera and 10 species, and Cyperaceae with 6 genera and 9 species were the most common plants. Aquatic plants had more biomass and distribution compared to terrestrial plants which were restricted to the islands. Among them Carex spp. were found from the edge of the wetland to areas with 40 cm depth. Distribution of all major plant species were recorded and mapped. Names of aquatic and terrestrial plant species are given in appendices 1 and 2, respectively.

The Mouteh refractory pyrite concentrates at pulp densities of 1.5%, 3%, 4.5% and 6% were treated, using Thiobacillus ferrooxidans DSM 581 and the same bacteria adapted on the Mouteh pyritic concentrate. Compared with a non-adapted culture, use of an adapted inoculum of T. ferrooxidans increased bioleaching rate of iron by a factor of 1.940, 2.011, 1.859 and 1.559 for pulp densities 1.5%, 3%, 4.5% and 6%, respectively. Lag phase time for growth of adapted cells decreased to less than 24 hours. Ore samples were analysed for gold recovery by cyanide extraction before and after biooxidation in 4L and 20L bioreactors. When 55% of the sulphides were oxidised, as a result the gold recovery-upon subsequent cyanide extraction improved more than 95%. Mathematical analysis of bioleaching data showed that the X3 variable equation satisfactorily predicts the gold recovery in relation to the oxidation degree of pyrite concentrate.

A cytogenetical study on 13 alfalfa (Medicago sativa) cultivars available in Iranian Forest and Rangelands Genebank was performed in order to obtain basic information on the variability in chiasma frequency/distribution, chromosome association and segregation. Such cytogenetic information is useful for planning hybridization programs. Cluster analysis of meiotic data and ordination of cultivars based on the first two principal component axes (PCA) grouped the genotypes with similar meiotic characteristics. PCA analysis of meiotic data revealed that the mean total chiasma, mean terminal chiasma, ring and rod bivalents are the most variable meiotic characteristics among the genotypes studied. Pollen fertility was studied in all genotypes that showed a significant positive correlation with the frequency of terminal and total chiasma as well as proper segregation of chromosomes during anaphase and telophase stages. Bchromosomes were observed in some of the cultivars affecting the chiasma frequency/distribution as well as chromosome association.

The deposits of clinoptilolite (CLI) in Iran after activation with sodium chloride or sodium hydroxide solution was subjected to ion exchange with some heavy and toxic cations. The results showed that the absorption for Ca2+ (7.5 ppm), Cu2+ (50 ppm), Zn2+ (40 ppm), Cd2+ (40 ppm), Pb2+ (500 ppm) and Al3+ (5 ppm) were 95.2, 96.70, 93.30,99.12, 99.2 and 90.0 percents, respectively. The noteworth of our method in eliminating of contamination and conversion of waste water to drinking water is discussed in this report.

In an environmentally benign solventless system, aldehydes and ketones were readily converted to their corresponding azines with hydrazine sulfate, sodium hydroxide and alumina in high yield.

Reaction of tryptamine 1 with dimethyl -3-methoxyallylidenemalonate 2 afforded Nβ-[4,4-bis (methoxycarbonyl)-1,3-butadienyl] tryptamine 3 which in combination with acetylchloride and pyridine in dichloromethane gave Nβ, Nβ [acetyl]-[(4,4-dinethoxycarbonyl) 1,3butadienyl] tryptamine 4. Treatment of 3 with sodium hydroxide afforded 2H[N-(3-indolyl) ethyl] 2-oxo-3-methoxycarbonyl- 1-pyridine 5. Cyclization of 2 with trifluoroacetic acid gave methyl-2- (methoxycarbonyl) 4-(2,3,4,9-tetrahydro-1H-pyrido [3,4-b] indole-1-yle) butanoate 6. Heating of the latter in ethylacetate at reflux temperature afforded a new tetracyclic system methyl 4-oxo 1, 4, 6, 7, 12, 12b-hexahydro indolo [2, 3-a] quinolidine 3 carboxylate 7.

Metal markers were installed along three traverses onto two masses of late Eocene – early Oligocene salt extruded along 2 major faults near Garmsar in Central Iran. Each marker consisted of a 30×30×1 cm steel plate with its four corners securely anchored into the salt by steel bars 50 cm long. An accurate survey method measured the horizontal and vertical distances of particular markers relative to fixed baselines at time intervals between 15 to 60 min. during particular days in 1997. Surface shade temperature was measured at the baseline at the same time intervals. The main results are: 1– Markers moved irregularly between a few centimeters and 7 m each day but their return each evening close to where they began each morning indicates that diurnal strains in the salt were essentially elastic. 2– Horizontal and vertical movements of markers were strongly related to each other and to their distances and heights relative to the baseline. 3– Translating markers movements to salt strains found horizontal strains to relate with their distance from the baseline whereas vertical strains are close to constant regardless of the thickness of salt beneath them. 4– Salt movements measured over hours can be modeled as thermal expansions induced by temperature rise close to those measured. Salt movements measured over longer intervals are modeled by thermal expansions due to temperature rises much smaller than measured. 5– On some days when tidal forces opposed temperature changes, irregular marker movements matched smooth changes in tidal forces at least as well as changes in surface temperature. It is therefore suggested that lunar and solar gravitation affects the movements of extruded salt masses.

In this paper we review some recent ideas of synchronization theory. We apply this theory to study the different synchronization aspects of uni-directionally coupled pair of chaotic one-dimensional Gaussian maps.

In the ordinary linear models, regressing the residuals against lagged values has been suggested as an approach to test the hypothesis of zero autocorrelation among residuals. In this paper we extend these results to the both equally and unequally replicated functionally measurement error models. We consider the equally and unequally replicated cases separately, because in the first case the residuals of the means of replicate groups of observations in both X and Y directions are functions of the same residual while in the second case we have no analogous result and so we have to deal with the residuals in each direction. We derive the asymptotic validity of these tests and we carry out a bootstrap simulation study to determine how well the asymptotic theory of the proposed test works for different size of samples.

Different glasses suitable for temperature sensing in the fiber optic sensors were studied in this article. The phase changes for eight different glass materials were calculated and results were compared. Our results showed that extra dense flint glass is the most sensitive one, while pure silica results in the lowest phase change. In another study the effect of wavelength on the phase variation was also investigated and the results were presented. Finally, the effect of glass formation in phase change was considered for different glasses, which were prepared using different techniques. The result showed that the Corning glass #7940 offers the highest sensitivity in comparison with the other three glasses for temperature sensing. Our studies for different silica glasses indicated that glass formation is important in preparing the glass materials required for the fiber sensors.

example of a fully relativistic equation with both negative and positive energy solutions. The effect of the negative energy states was mitigated by maximizing the energy with respect to a relevant parameter while at the same time minimizing it with respect to another parameter in the wave function. The Cornell potential and a power-law scalar and vector potentials were used in our calculations for the quark confinement. Cares were taken to avoid the Klein paradox by the dominance of the scalar component over the vector part.