modern research physics

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Genus Cerastium belongs to the subfamily Alsinoideae. This genus is represented with about 30 species in two subgenera (subgenus Dichodon and subgenus Cerastium) and three sections (sect. Strephodon, sect. Orthodon and sect. Schizodon) in flora Iranica area, of which 19 species were reported from Iran. The materials in the TARI herbarium were studied. The vegetative and reproductive characteristics of specimens were checked by stereomicroscope. In family Caryophyllaceae, the seeds bear numerous characters which can be used for taxonomic purposes. The ornamentation features of the seed surface and its relief are different from one species to another. The seeds were carefully taken from mature and dehiscent capsules. Pollen grains obtained from flowers bearing mature anthers. In this paper, Cerastium pentandrum (Caryophyllaceae) is reported as a new record from northwest Iran and Iranian plateau. It belongs to the subg. Cerastium sect. Orthodon. In this section teeth of the capsule are elongated, straight or reflexed, with flat or recurved margins. Morphological characteristics of the new record are provided. This taxon is compared with its closest relative C. balearicum. The ultrastructure of seed and pollen is examined by SEM.

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The most prevalent and important mechanism of bacterial resistance to &beta-lactam antibiotics, is the production of &beta-lactamase enzymes which inactivate these drugs by the hydrolytic cleavage of the four-membered &beta-lactam ring during two steps which is including the nucleophilic attack of the bridging hydroxide ion on the substrate and eventual protonation of the leaving amine group. During this reaction, metal ions play an important role in the catalytic process. Despite the availability of &beta-lactamase crystallographic structures, their mechanism of action is still unclear and no clinically useful inhibitors of these enzymes have been reported. Density functional theory (DFT) using B3LYP and 6-31G, 6-31G* and 6-311G** basis sets have been employed to calculate the details of electronic structure and electronic energy of catalytic reaction of CcrA enzyme active center from metallo-&beta-lactamase enzymes (M&betaLs), penicillin from &beta-lactam antibiotics, and the formed complexes including ES, ETS₁, EI₁, EI₂, ETS₂ and EP respectively, has been used. Also all the thermodynamic functions including ∆Hº, ∆Sº and ∆Gº to form two transition states, ETS₁ and ETS₂, and for the total reaction are evaluated at 25 °C, 31 °C, 37 °C and 40 °C and 1 atmosphere pressure. In all calculations solvent effects have been considered by using PCM method for water, ethanol, protein environment, nitro methane and carbon tetrachloride. Finally this reaction proceeds during an exothermic and spontaneous process, and the first step, the nucleophilic attack of the bridging hydroxide ion on the substrate, is the rate-limiting step

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Formation of feather and hair follicles during embryonic stage is nearly similar but whether they possess a similar structure and organization in mature stage as well? The aim of the present research is to study similarities and differences of these two follicles in adult rats and pigeons. To fulfill this task, after removing follicles from the skin, the follicles processed for light and transmission electron microscopy. The results provided here demonstrated that these two follicle types are similar in having the dermal papilla, epidermal matrix and epidermal stem cells. Moreover, the production of hair and feather fibers in them is almost the same. One of differences seen between these follicle is that, unlike the hair follicle in the feather follicle a distinct compartment, called the pulp, is observed at the top of the dermal papilla. At the center of this pulp as well as the dermal papilla a blood vessel exists, a character which never seen in the hair follicle. Another difference observed is related to the thickness of the basement membrane exists at the interface between the papilla and epidermal matrix. This membrane in feather follicle is much thicker than its hair counterpart. In addition, at the basal region of the feather follicle there is a distinct population of stem-like cells which could not be distinguished in the hair follicle. Based on results provided here it seems that the feather in birds and the hair in mammals have been adapted for different biological tasks.

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Saponins are secondary metabolites that are found in many plants and some animals. These compounds are high molecular weight glycosides, consisting of a sugar moiety linked to a triterpene or steroid aglycone. Many saponins have detergency properties and give stable foam in water. The genus Silene L. with more than 700 species is one of the largest genera of the family Caryophyllaceae mainly distributed in north hemisphere. Saponins are one of important secondary metabolites in members of the genus. Quantitative and qualitative study of the saponins in the aerial parts and roots of three Silene species, namely S. ginodioca, S. spergulifolia and S. swertiifolia were carried out by spectrophotometry and TLC methods. In this study, 5 fractions were obtained from each plant part and in both parts of three species, fraction 1 contain the highest amounts of saponins. On the other hands, root extracts have a high amount of saponins. In addition, thin layer chromatography (TLC) of the extracts evaluated some saponins spots with different Rf.

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The Almabulage complex is located in the Sanandaj-Sirjan structural zone, NW of Hamadan. This complex consists of low-grade metamorphic rocks, and two intrusions of felsic and mafic rocks. In this research, we have studied the mafic intrusion. The intrusion has ophitic, subophitic and inter-granular textures and is mainly composed of plagioclase, clinopyroxene, amphibole and minor amounts of K-feldspar, quartz and opaque minerals. Secondary minerals include epidote, chlorite and amphiboles formed in the rim of clinopyroxene. Clinopyroxene is of augite type, amphibole is tschermakite, plagioclase is in the range of andesine-labradorite, k-feldspar is anorthoclase and the opaque mineral is ilmenite. According to the bulk rock geochemistry and mineral chemistry of clinopyroxene, the mafic intrusion of the Almabulage complex has been crystallized from a calc-alkaline magma and is related to subduction area. The element Nb displays distinctive negative anomalies compared to the primitive mantle, which can suggest subduction-related magmatism. Emplacement temperatures and pressure of mafic rocks shown by pyroxene-amphibole thermometer and amphibole barometer indicate temperature and pressure ranges of 750 to 900 °C and 6 to 7 kbar, respectively.
Based on Sm/Yb and La/Sm rations, the parental melt of the mafic rocks of the Almabulage complex, derived from partial melting of garnet–spinel lherzolite. According to the bulk rock geochemistry and mineral chemistry of mafic rocks, the rocks formed in a subduction area during Late Jurassic-Early Cretaceous before the Neo-Tethys closure in Sanandaj- Sirjan zone.

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Fractional derivatives and integrals are new concepts of derivatives and integrals of arbitrary order. Partial differential equations whose derivatives can be of fractional order, are called fractional partial differential equations (FPDEs). Recently, these equations have been under special attentions due to their most practical usages. In this paper, we survey a rather general case of FPDE, to obtain a numerical scheme, the fractional derivatives in the equation are replaced by common definitions such as Grundwald-Letnikov, Riemann-Liouville and Caputo, to improve the numerical solution, partial derivatives inside the equation are discrete using non-standard finite difference scheme. Then, we survey the stability of numerical scheme and prove that the proposed method is unconditionally stable. Eventually, in order to approve the theoretical results, we use presented technique to solve wave equation with fractional-order that is very practical and widely used in physics and its branches. Numerical results confirm the findings of the theory and show that this technique is effective.

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In order to increase public health many study have been performed with adding probiotic bacteria in dairy products. In this filed on of the most critical problem is unfavorable taste and aroma produced by probiotic bacteria. So isolation probiotic bacteria from traditional dairy product could solve this problem. A rapid screening method is used to isolate acid tolerant bacteria from 30 different fermented dairy products After enrichment samples in MRS broth followed acid stressing (pH=2.5) different colony were selected on MRS agar, avoiding preliminary time consuming isolation steps. All the isolates were examined by microscopy, gram staining and catalase reaction. Fifty-eight isolates were selected and defined as lactobacillus SPP. The screening at low pH bile salt led to the selection of 19 resistant isolates. Cholesterol assimilation determined by difference in cholesterol content in the medium before and after the incubation period, showed that all lactobacilli strains were able to assimilate cholesterol at varying levels ranging from 54 to 266 μg/ml .Most cholesterol assimilation were seen in L.farieminis ,L. planetarium ,L.alimentarium ,L.casei, L. acidophilus isolated from yogurt and cheese of lighvan region. These data showed yogurt and cheese of lighvan region have probiotic potential.

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Malachite green is a carcinogen and mutagen material that is not permitted by FDA as a fungicide for edible fishes. Alvita(sodium di acetate), is a fungicide and bactericide material which is admitted by FDA.The research has been done by two methods: invivo and invitro. In invitro, at first the eggs that fungi attached them, cultured on SDA, then fungi colonies pured. At last, Mucor and Rhizopus were known by Slide culture and morphological analysed. In the second phase, Alvita was added to SDA in 1,5,10,15 and 20 g/lit concentration. Then pured colonies, cultured on SDA with 1,5,10,15 and 20 g/lit concentration of Alvita. After 48 hours and one week, samples were examined. In blank(without Alvita), the fungi colonies grew, but no colonies grew on other samples with 1,5,10,15 and 20 concentration of Alvita, then 1 g/lit was recognized as a minimal concentration that any colonies didn't grow on it. In invivo method(which has been done in Niyak farm), there were 5 traphs for trout culture, that one of them was blank, three of them contained Alvita, with 1 g/lit for 30 minutes, 1g/lit for 1 hour, 2 g/lit for 30 minutes and one of them contained malachite green with 2 mg/lit concentration for one hour. All of examinations were done in triplicate. The results of study analyzed by ANOVA, with 95% confidence limit and(P=0.265), to show, concentration of Alvita(1 g/lit), is the best alternative of malachite green, between examined concentration.

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In the larviculture the use of high quality dietary components is critical for rearing fish. Artemia nauplii and decapsulated cyst have very wide usage on aquaculture industry. In most of fish species, especially in fresh water fish’s larvae stage, Artemia nauplii and decapsulated cyst have very important effects on growth rate and survival. In this study, effect or different initial feeding upon the second growth rate of trout larvae stage was studied. To this end, the new absorbed yolk sack trout larvae were used. All larvae in five feeding treatments(artemia nauplii, decapsulated cyst, commer-cial diet mixed with decapsulated cyst, commercial diet mixed with nauplii, commercial diet) for 20 day with intensity 6 larvae per litter at tanks 35-liter were reared. Then experiment extended in these treatments with the commercial diet (only) for 20 days more. Larvae fed with the artemia nauplii in the first experiment had the highest growth and the difference was significant compared with the other treatments (p<0.05). In the second experiment, after 20 day in the all treatments, the growth rate, survival, SGR, FCR, condition factor, feed intake rate, Gross efficiency were measured. Results showed that in the second 20-day period, the larvae fed with commercial diet mixed with decapsulated cyst treatment in first experiment, had a significant difference with the other treatments (p<0.05).The fish that were fed with decapsulated cyst mixed with commercial diet had the highest growth rate rather than the other treatments.

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A proton NMR method for the study of the solvation of alkaline earth cations with methanol (MeOH), ethanol (EtOH) and propanol (PrOH) in nitromethane (NM) as diluent is described. The method is based on monitoring the resonance frequency of alchohols protons as a function of solvent to metal ion mole ratio at constant metal ion concentration. The average solvation number of cation, , at any alchohol/methal ion mole ratio was calculated from the NMR chemical shift-mole ratio data and was plotted against the mole ratio values. The solvation numbers of alkaline earth cations were obtained from the limiting values of the corresponding vs. mole ratio plots. With regard to the results presented, there are increases in the solvation number from Mg2+ to Sr2+ about every alcohols, but decreases in solvation number from methanol to propanol as concerns every metal ion.

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Cyanobacteria is a big group of monera kingdom, that high potential for product some natural product, such as nutritional, pharmacologic material and etc. Oscillatoria is a kind of filamentous cyanobacteria. This microorganism observed in Tyab – bay in all of seasons. Seawater medium (SWM) is the best media for isolation of Oscillatoria from natural environment. Enriched SWM with B12 and semi-solid Z8 medium (0/7% agarose) is too suitable for purification of condense culture. Maximum coefficient (µ) was in valance medium. Purification of Oscillatoria has down at during nine mounths. Oscillatoria was exposed to five treatments of light /dark periods and six different temperatures. Results obtained revealed that among the employed 30°С treatment has had the best effect on increase maximum coefficient (µ=0.602) and also another treatment among the employed 14/10 (light / dark) hours (µ =0.506). In this treatment temperature was 25 °С.

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Efron's bootstrap method can only be used to estimate the precision measures of estimators when observations are independent. For spatial data that are spatially correlated, the moving block bootstrap method is usually used. But, in this method, the boundary observations have less chance of presence in blocks resampling than the other observations. In this paper, the new separate block bootstrap method is introduced and an algorithm is given for estimating the precision measures of estimators. A simulation study is carried out to compare the efficiency of the separate block bootstrap method with moving block bootstrap. It is shown that, with their method we can estimate the bias of sample mean with no error, and the estimator for variance of sample mean is consistent.

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Qopi bauxitic horizon is located west of Miandoab, in West-Azarbaidjan, NW of Iran. This stratiform horizon lies along the boundary of Permian carbonates and triassic shales and limestones. The upper Permian uplift exposed the pre-Permian rocks to weathering and bauxitization. Based upon field evidence and petrographic studies, five bauxitic facies are recognized within this horizon. Normative values of constituent minerals and chemical processes characterize the mode of development of bauxitic minerals in this horizon. Chemical data and correlation coefficient show that Al, Ti, Zr, and Nb acted as immobile elements during bauxitization processes. Mass change calculations of elements in the bauxitic units at Qopi indicate that considerable amounts of Si, Ca, Mg, Na, P, and K were leached out from the system. Based upon ratios of immobile elements, the diabasic rocks in the area are the principal source for Qopi bauxitic horizon and at least 17 meters of it was consumed during weathering and bauxitization processes

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Sometimes observations in statistical analysis are not independent and typically are correlated with their spatial locations. In spatial statistics there are some methods to interpolate this kind of data. In this paper some of interpolators for spatial data will be studied. Then they will be evaluated and compared by means of mean square errors criteria. Finally it will be shown that kriging acts better than other methods such as spline, inverse distance, for interpolation of spatial data.

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Karkheh River is the third largest river in the west part of Iran, regarding its high flow. During raining seasons the overflow of Karkheh river destroys villages, bridges, pumping stations and farms in Khozestan plain. In this research by taking samples from water and river banks and beds, and performing different test such as conducting sediment logical and geotechnical test, the capability of marginal erosion and its causes were taken into consideration. Investigations show that the river progresses few meters per year toward the outer – bank. The reasons for this process are as follows. a. Low-grade compaction of the bank sediments. b. Differences between the compaction of the marginal layers. c. Low cohesive of sedimentary layers, which are exposed. d. The presence of disperses minerals in some layers. e. Disregarding the control factors for preventing the marginal erosion. In order to prevent marginal erosion of the river the use of plant cover, construction structures such as retaining wall, rock mesh structure or the construction of artificial cut-off are proposed.

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الت

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لاتع

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Non-catalytic conversion of methane to ethylene and ethane was studied using non-equilibrium positive corona discharge at atmospheric pressure.The total selectivity for C2 hydrocarbons was more than 87% with a yield of 4.8% ethylene. The effect of voltage, temperature, and the ratio of methane to oxygen on methane conversion and selectivity of products at different levels are investigated. The experimental results indicate that the methane conversion increases with increasing the voltage applied to the electrodes. The methane conversion up to 300oC increases but above this temperature depend on feed ratio, it may increase or decrease. The highest methane conversion and C2 yield occures at CH4/O2 = 4/1.In a few experimets smale amounts of COX also was produced.

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Flooding ranks very high among the natural disasters in Iran which causes human misery and economic hardship in different part of the country. Floodwater spreading can be considered as a cost-effective method for optimal utilization of floodwater for artificial recharge, vegetation recovery, and reduction of flood damages. In this research selection of proper areas for floodwater spreading in Meimeh basin were concerned. For this purpose different thematic maps including slope, infiltration rate, transitivity, sediment thickness, and water quality were produced based on satellite images, aerial photos, and field survey. The thematic layers were input in a geographic information system (GIS). All layers were classified to several classes based on existing criteria. The classes in the thematic layers were analyzed and integrated using a decision support system (DSS). The generated criterion through the model was verified with applying the model for a number of successful floodwater spreading stations in Iran, to ascertain the validity of the model. The verification of the model indicated in general, satisfactory results for all the stations. The result indicates that in Meimeh basin, about 10 percent of the study area is considered suitable and 70 percent moderately suitable for artificial recharge with floodwater spreading.

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The most prevalent and important mechanism of bacterial resistance to &beta-lactam antibiotics, is the production of &beta-lactamase enzymes which inactivate these drugs by the hydrolytic cleavage of the four-membered &beta-lactam ring during two steps which is including the nucleophilic attack of the bridging hydroxide ion on the substrate and eventual protonation of the leaving amine group. During this reaction, metal ions play an important role in the catalytic process. Despite the availability of &beta-lactamase crystallographic structures, their mechanism of action is still unclear and no clinically useful inhibitors of these enzymes have been reported. Density functional theory (DFT) using B3LYP and 6-31G, 6-31G* and 6-311G** basis sets have been employed to calculate the details of electronic structure and electronic energy of catalytic reaction of CcrA enzyme active center from metallo-&beta-lactamase enzymes (M&betaLs), penicillin from &beta-lactam antibiotics, and the formed complexes including ES, ETS₁, EI₁, EI₂, ETS₂ and EP respectively, has been used. Also all the thermodynamic functions including ∆Hº, ∆Sº and ∆Gº to form two transition states, ETS₁ and ETS₂, and for the total reaction are evaluated at 25 °C, 31 °C, 37 °C and 40 °C and 1 atmosphere pressure. In all calculations solvent effects have been considered by using PCM method for water, ethanol, protein environment, nitro methane and carbon tetrachloride. Finally this reaction proceeds during an exothermic and spontaneous process, and the first step, the nucleophilic attack of the bridging hydroxide ion on the substrate, is the rate-limiting step