modern research physics

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Vegetation of Kasf forest with an area of over 12 ha, located in the east-west direction at a distance of 20 kilometers north of the city of Bardaskan, between 57° and 52' and 30" to 58° and 00' and 00" East longitude and 35° and 22' and 30" to 35° and 30' and 00" North latitude, in a mountainous arid region with a minimum and maximum temperature of -10 and +45° C , respectively and average annual precipitation of 155 mm, at an altitude of about 1600 m above sea level with 15% slope was studied using floristic method 2 years after fire and life forms and geographical distribution of plant species were determined. Sixty nine plant species belonging to 29 families (25 Dicots, 3 monocots and one gymnosperm). The largest families were the mint (Lamiaceae) with 11, Compositeae (Asteraceae) with 9 and carnation family (Caryophyllaceae) with 5 species. The life forms included Therophytes with 36% (25 species), Hemicryptophytes 29% (20 species), Chamaephytes 16% (11 species), Phanerophytes 13% (9 species) and cryptophytes with 6% (4 species). The high percentage of Hemicryptophytes indicated dominance of cold mountainous climate and the presence of Asteraceae species such as harmala (Peganum harmala) showed sever disturbance had taken place in the region and thus, the need for administering greater ecological care and employing more extensive environmental supervision and management was identified.

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Effects of decreased ozone and increased UV radiation have been studied by many researchers. The aim of this study was to investigate the effects of UV-B radiation on Melissa officinalis L. and to study the impact of salicylic acid and magnetic fields in reducing the harmful effects of radiation on plants. The Melissa officinalis L. plants were treated with 28_+2 Celsius temperature for about 60 days. The light intensity was 150 µ E mˉ² Sˉ¹ and the lightness-darkness condition was8-16 hours. UV treatment was applied after the six-leaf stage and UV-B radiation was applied for a period of 15 days, the time for each application was 20 minutes. Salicylic acid was sprayed on the plants after the six-leaf stage with a concentration of 1 mmol. Magnetic field treatment was applied for an hour with intensities of 0, 40 and 85 mT. The results indicated that the UV-B radiation led to reduction in dry and fresh weight, root elongation and shoots. The radiations also reduced the photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoid) and sugar rate and soluble proteins amount. The phenylalanine ammonia-lyase compounds rate and UV-absorbing compounds were increased under the effect of UV-B radiation. The results showed that treatment with salicylic acid and magnetic fields caused a reduced damage to the plant which had been created due to UV-B radiation and were able compensate for changed factors that had been changed because of UV radiation.

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The genus Pedicularis with 600-800 species is a semiparasitic plant distributed mostly in cold and mountainous regions of the northern hemisphere . In this study, nine species of this genus in the flora of Iran has been studied by electron microscopy . The surface of stigma of P. pycnantha and P. wilhelmsiana are flat. It is hemispherical in P. cabulica , P. caucasica , P. rechingeri, P. sibthorpii, P. condensate, P. strausii and conical only in P. rhinanthoides . In order to determine relationships between species, numerical analysis was carried out using 44 quantitative and qualitative of morphological, anatomical and palynological traits. The diagrams obtained from UPGMA and PCA methods were used to establish the relationship between the studied specie. Based on the results of the analysis, traits such as fruit pericarp thickness , spongy parenchyma thickness of leaf , stem height , stem thickness , total thickness of the stem and midrib length with high variability can be useful for species determination and evaluation of the similarities between them.

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Free radicals especially various kind of active oxygens, with destruction of biomolecules such as DNA and proteins, are believed to be the cause of many cancers. In search for antioxidative reagents, it seems that use of natural antioxidants especially those from plants, are of special interest. Salvia leriifolia Benth, from Lamiaceae (syn. Labiatae) family, is a native plant of Iran ( North of Khorasan) and Afghanestan with significant applications in medicine, pharmacology, and food industry. The aim of current investigation, was to recognize the composition of essential oil of S. leriifolia and perform a comparative study on the antioxidant properties of the extracted essence from plants grown in two regions of Khorasan (Neyshabour and Bajestan). According to Gas Chromatography – Mass spectrophotometric analysis, 1,8 Cineole, &alpha-Pinene and &beta-Pinene, were main components of the essential oilAntioxidant activity of essential oil were measured by three different methods, TBARS and BCB (two lipid systems) and DPPH (aqueous system). Antioxidative properties of the essence in both former methods were higher than DPPH assay. It was found that the total essential oil and its pure constituents have a significant antioxidant effect when tested by each method, respectively. BCB assay was the most appropriate method for measurement of antioxidant activity. The antioxidant concentrations influenced its antioxidant power, too. The essence of plants collected from Neyshabour showed stronger antioxidative effect compared to those from Bajestan.

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Deltas of the most important morphological units are a tremendous effect on agricultural activities, mining, coastal management and etc. Despite appropriate soil and water resources deltas, are influenced by environmental phenomena such as climate change and sea level changes. The effect of these changes will appear on physico-chemical, mineralogical deposits. This study was conducted to analyze the Karkheh delta depositional environments based on the chemical characteristics of ancient sediments. Depositional environments and locations of core were identified using digital data processing, geomorphology mapping and initial visit of the area. The coring was carried out with rotary drilling machine and continuously to a depth of ten meters in jofeir and Rofayeh. Among The cores, 20 samples were selected for mineralogical and chemical tests. Differences in chemical and mineralogical characteristics revealed at least three major discontinuities exist between sedimentary layers to a depth of 10 m. In addition, thickness and type of the sediment are not same conditions and it changes depending on the stability of depositional environments. Increasing of Mg / Ca, magnesium and salinity, and reducing of clay particles, show Sedimentary environments trend is toward dry conditions and high energy environments at depths from 10 to 5 meters. In contrast, the depth of 5 to 4 and 3 to 0 meter this trend towards more humid climate and low energy environments. Therefore, it is concluded that the depositional environment of the Karkheh River delta at the upper Holocene is not constant, and this has led to changes in the delta.

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In this research, changes in structural geometry of thrusting of the Aghajari anticline on the Marun anticline in Dezful Embayment (SW Iran) have been studied based on seismic reflection data. These two anticlines have a NW –SE trends and thrusting of the Aghajari anticline on the Marun anticline is located in North of the study area. The Marun anticline with visible plunge is forming in the south of study area and 4 and 5 seismic profiles, and most of deformation is concentrated in Aghajari anticline. Also, Marun anticline has formed in the middle of the study area, but thrusts not formed in this part of anticline and maximum thrusting of Aghajari anticline on the Marun anticline is visible. There is a shallow thrust in south limb of two anticlines in northern part and an upper thrust from Gachsaran formation exposed from progressive deformation and finally a shallow thrust propagate to surface in both anticlines in the end of NW parts of study area and back thrusts separate from main shallow thrust in two anticlines. But unlike the Aghajari anticline, an upper thrust from Gachsaran formation propagates to surface with progressive deformation in the Marun anticline showing low depth of the Marun anticline.

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Marziyan granitic pluton is one of the numerous intrusive bodies in Sanandaj-Sirjan structural zone. The pluton is composed of locogranite, granite and granodiorite and its contact metamorphic rocks are consisting of cordierite and andalusite schist. Tourmaline and garnet bearing locogranite, aplite, pegmatite, mylonite and injected migmatite are exposed in the metamorphic halo. The major minerals include quartz, plagioclase, K-feldspar, biotite as well as muscovite, tourmaline and garnet. Structural studies indicate the presence of shear zones, especially in the southeastern parts with NNW-SSE trend. Four types of microstructures are present in the region 1) magmatic microstructures, 2) high temperature solid state microstructure, 3) low temperature solid state microstructure and 4) sub-mylonitic and mylonitic microstructure. All rocks of the region have been subjected to shear deformation which led the formation of S-C foliations and other sense of shear markers. The presence of asymmetric porphyroclasts and porphyroblast, biotite and feldspar kink bands, mica-fish mica and andalusite and domino and boudinaged structures of feldspar and tourmaline are evidences of ductile deformation in a contractional and dextral shear regime. All evidences indicate that high temperature solid state zones in greenschist facies to lower amphibolite conditions (300-500°C) have formed simultaneously with emplacement of granitic bodies. Low temperature solid state, sub-mylonitic and mylonitic zones developed following the emplacement of granitic bodies.

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Baladeh-Kojour earthquake of May 28^th, 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, D_e and D_t 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 D_t 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 D_e parameter is low after the mainshock occurrence. Low b-value and high D_e 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.

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One of the main goals in studying the time series is estimation of prediction interval based on an observed sample path of the process. In recent years, different semiparametric bootstrap methods have been proposed to find the prediction intervals without any assumption of error distribution. In semiparametric bootstrap methods, a linear process is approximated by a autoregressive process. Then the bootstrap samples are generated by resampling from the residuals.

In this paper, at first these sieve bootstrap methods are defined and then, in a simulation study sieve bootstrap prediction intervals are compared with a Standard Gaussian prediction interval. at last these methods are used to find the prediction intervals for weather data of Isfahan.
One of the main goals in studying the time series is estimation of prediction interval based on an observed sample path of the process. In recent years, different semiparametric bootstrap methods have been proposed to find the prediction intervals without any assumption of error distribution. In semiparametric bootstrap methods, a linear process is approximated by a autoregressive process. Then the bootstrap samples are generated by resampling from the residuals.

In this paper, at first these sieve bootstrap methods are defined and then, in a simulation study sieve bootstrap prediction intervals are compared with a Standard Gaussian prediction interval. at last these methods are used to find the prediction intervals for weather data of Isfahan.

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Diffusion Processes such as Brownian motions and Ornstein-Uhlenbeck processes are the classes of stochastic processes that have been under considerations of the researchers in various scientific disciplines including biological sciences. It is usually assumed that the outcomes of these processes
are lied on the Euclidean spaces. However, some data are appeared in physical, chemical and biological phenomena that cannot be considered as the observations in Euclidean spaces due to various features
such as the periodicity of the data. Hence, we cannot analysis them using the common mathematical methods available in Euclidean spaces. In addition, studying and analyzing them using common linear statistics are not possible. One of these typical data is the dihedral angles that are utilized to identifying, modeling and predicting the proteins backbones. Because these angles are representatives of points on the surface of torus, it seems that proper statistical modeling of diffusion processes on the torus could be of a great help for the research activities on dynamic molecular simulations in predicting the proteins backbones. In this article, using the Riemannian distance on the torus, the stochastic differential equations to describe the Brownian motions and Ornstein-Uhlenbeck processes on this geometrical objects will be derived. Then, in order to evaluate the proposed models, the statistical simulations will be performed using the equilibrium distributions of aforementioned stochastic processes. Moreover, the link between the gained results with the available concepts in the non-linear statistics will be highlighted.

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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.