Showing 10 results for لب
Volume 9, Issue 3 (10-2010)
Abstract
A study of flora and population changes in a sample paddy field in Kalat (Mashhad) were done from May to September 2007 in four stages. Physical and chemical factors such as EC, pH and temperature were measured. Totally, 23 species, 8 genera and 5 families were identified. The identified species were: Chroococcaceae: Chroococcus, Gloeothece, Aphanothece Oscillatoriaceae: Oscillatoria Rivulariaceae: Calothrix Nostocaceae: Cylindrospermum, Nostoc, Anabaena Scytonemataceae: Scytonema. Regarding the heterocystous species, the most abundant cyanobacteria belong to genus Nostoc. pH in 4 collection were alkaline and did not show significant difference. Colony number did not indicate direct relation with pH despite of EC. Maximum colony number was seen in minimum temperature.
Salman Ahmady-Asbchin, Naser Jafari,
Volume 15, Issue 1 (4-2015)
Abstract
Abstract
Methods of physical and chemical adsorption of heavy metals, has some disadvantages such as high cost and are ineffective at low concentrations. Methods for biological uptake of heavy metals in recent decades were considered. Among the biological adsorbent include: bacteria, fungi and alga, algae have the highest efficiency of metal uptake. This study determined that the main role in the uptake of metals, nickel (II) and cadmium (II) Alginic acid is responsible. Focus serratus brown alga, as adsorbent in this study used a cost-effective biological and biological uptake of cadmium and nickel ions simultaneously in a batch reactor has been studied. Surface structure of algae has been studied. Adsorption kinetics have been studied, the equilibrium time is about 300 minutes, the Langmuir adsorption isotherm using the equation can be interpreted as the maximum adsorption of about 0/85and 0/95mmol/g are, respectively, for cadmium(II) and nickel(II).
M Mirabedini, M Aghatabay,
Volume 16, Issue 42 (5-2015)
Abstract
Baladeh-Kojour earthquake of May 28th, 2004 is one of the largest earthquakes in vicinity of Tehran, occurred in the northern part of the Alborz range. In this research, spatial variation of fractal parameters has been studied to estimate the seismic pattern of the study area. In order to draw the spatial variation maps, b-value, correlation dimension of epicentral and temporal distribution of earthquakes, De and Dt have been calculated for the data sets of before and after the mainshock, separately. The results show that before the earthquake, these parameters have low values in the eastern side of the mainshock epicenter. It seems that these low values before the earthquake may arise due to clusters of events with larger magnitude and small events after it. Seismic rate has decreased in the surroundings of the mainshock (seismic quiescence). After the mainshock, the lowest values of b-value and Dt is seen in the epicentral and western part of the mainshock. These low values are due to aftershock clustering and stress release, took placed just after the mainshock and during the aftershock sequence. Intensity increasing is observed in the shake map of earthquake. The De parameter is low after the mainshock occurrence. Low b-value and high De indicate high level of seismic activity in the region. The obtained results show the fractal parameters sensitivity to spatial and temporal clustering of earthquakes. Therefore, these parameters can be used as an indicator for seismic precursory patterns of major earthquakes.
Volume 18, Issue 44 (10-2009)
Abstract
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.
Volume 18, Issue 48 (2-2007)
Abstract
A major part of structural studies is the analysis of elements of fold style. In this paper, the elements of main folds style in the Alborz – Central, Iran border zone, were investigated. In this respect, cylindricity, symmetry, style of a folded surface, style of a folded layer and style of a folded multilayer were evaluated. Finally, fold style characteristics and young history of folding in the studied area were indentified. In addition, two main mechanisms (Buckle and Detachment Folding) were distinguished.
Volume 18, Issue 48 (2-2007)
Abstract
Shekarnab intrusion is a part of an extensive magmatism in the Central Alborz Tectonic Zone of Iran. This intrusive body, which is mostly composed of monzonitic, gabbroic and syenitic lithologies, was intruded within green tuffs of the Karaj formation. These plutonic rocks show geochemical alkaline-potassic affinity and in the case of aluminum saturation index, they could be classified as meta-aluminous rocks. These rocks show Nb negative anomaly, enrichment of LILE and are depleted in HFSE. The spider and discrimination diagrams demonstrate that the parent magma of the plutonic intrusion could be related to a subduction zone and have emplaced in an active continental margin. Based on geochemical analysis of trace and major elements, as well as field and petrographical studies, it could be suggested that crystal differentiation has played an important role in lithological diversity of this intrusive body.
Volume 18, Issue 50 (10-2005)
Abstract
Southern flank of the East– Central Alborz Mountain is consisting of several tectonic elements, which were introduced and analyzed, in this paper. This region is including a complex thrust system at north and a widespread foreland basin at south of Alborz– Central Iran border zone. Two significance curvatures at Alborz Mountain belt that have introduced here such as Neyshabur– Esfarayen– Shahrud Syntaxis and Damghan– Semnan– Qazvin Salient, had been created by change in trend of Alborz from NW– SE to NE–SW. According to this research, creative and activities of the fault systems in a sinistral displacement shear zone that had been elongated from south Semnan to north Gonbad–e Kavus was suggested as a cause to forming of above curvatures and thinning of Alborz width at north Bastam. Therefore, deformation in this region is a combination of compressional and left–lateral strike slip components that (Transpression) demonstrated by field evidences and focal mechanism solutions.
Volume 18, Issue 51 (5-2005)
Abstract
In this paper, we purpose a new algorithm for shape-based image indexing and retrieval. This new scheme efficiently extracts the image feature vector without any need to segmentation algorithms and high computation. The feature considers correlation between adjacent edges. Thus it includes information of continuous edges and lines of images and estimates shape of objects in images. With implementation of algorithms on a prototype system and using some evaluation metrics, we show the indexes are invariant relative to translation, image size, color, illumination, and small viewing positions. Experimental results show that averages of precision and recall rates of this new indexing scheme compared to other similar methods are 1.02 to 6.9 and 1.22 to 10.59 times greater respectively.
Volume 18, Issue 53 (7-2003)
Abstract
A part of Alburz Mountains which is located between Damghan plain (in the south) and Gorgan plain (in the north) structurally is a S-SE vengeance thin-skinned flodthrust belt. Sequential thrusting and related folding during Cimmerian and Alpine orogeny have been the most deformation style since late Triassic. Tectonostratigraphy of Alburz Based on foreland stratigraphical evolution models reveals that structural evolution of Alburz had taken place at three stages: 1) Late Triassic– Early Jurassic duo to Cimmerides 2) Late Cretaceous – Early Paleocene duo to Middle Alpine compress ional movements 3) Neogene duo to Late Alpine compress ional movements. Southward migration of Alburz in each stage accompanied by generation of new thrust faults , uplift and unroofing in fold- thrust belt and caused southward marine transgress-sion and synorogenic classic sedimentation in Foreland basin. Each stage of structural evolution followed by a relaxation period that is characterized by isostasic rebound, reducing of erosion and shallow marine sedimentation in foreland basin duo to north war marine regression.
Volume 18, Issue 54 (8-2001)
Abstract
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