Propagation of solitary waves in non uniform dusty plasmas

Interaction of dust acoustic solitary waves in plasmas consisting of medium disorders is investigated. Disorders and inhomogeneities of the medium are added to the equation of motion as perturbative terms through the medium parameters. The effects of these perturbations on the behaviour of solitary waves are studied with numerical simulations and the results are compared with theoretical predictions in a uniform media.     

Groundwater pesticides residue in the southwest of Iran-Shushtar plain

Study area with an area of about 415 km² is located from 31°40′ to 32°05′ northern latitudes and 48°45′ to 49°00′ eastern longitudes 85 km to the north-east of Ahwaz city, in the north of Khuzestan province, and south west of Iran. The purpose of this study is: (1) the determination of the pesticides concentration in the groundwater of the Shushtar plain (Mian-Ab) and (2) the assessment of geology, hydrogeology and anthropogenic activities impacts the groundwater quality. Thirty-seven groundwater samples were taken from product wells based on the standard methods. A simple and efficient automated method for extraction and preconcentration was used. In this method, a pyrrole-based polymer was synthesized and applied as an efficient sorbent for micro-solid-phase extraction. After extraction, analytes were desorbed in ethyl acetate and analyzed using gas chromatography–flame. The study area is surrounded by Aghajari Formation dominated by silt and clay sediments and the Bakhtiari Formation dominated by sand and gravel. Existence of these formations affects the aquifer sediments and the hydrogeological properties. In the study area, the sediments grade from gravel and sand in the north and east into silt and clay to the south and west, respectively. The topsoil in the south of the study area contains more clay sediments. In this study, the concentration of two common herbicides, i.e., 2,4-D and clodinafop propargyl and two pesticides, i.e., permethrin and diazinon, in the groundwater of Mian-Ab aquifer was assessed. Chemical analysis results showed that the 2,4-D residue in the groundwater has the highest concentration (15 ppm). About 50% of the samples have concentration values more than the maximum contamination level based on EPA drinking standard. The pesticides concentrations decrease from the north to the south of the study area. Pesticides influx to the groundwater in the south of the area is prevented or diminished due to the specific geological situation and soil type. Distribution pattern of population centers, which increase to the north of the study area, and the role of groundwater as the main source of drinking water are two important issues that must be considered in management of pesticides use in the area.     

Hazards of mechanized tunnel excavation in H<Subscript>2</Subscript>S bearing ground in Aspar tunnel,Iran

Occurrence of hydrogen sulfide gas (H₂S) is one of the most important engineering geological hazards during tunneling. Its hazards and consequent challenges are very difficult and costly to solve. During site investigation, one of the tasks for engineering geologists is prediction and evaluation of the risk of H₂S gas in the underground spaces. In this study, water conveyance tunnel of Aspar, which was excavated in H₂S-bearing environments, is discussed. The tunnel is excavated in the hydrocarbon formations. Applied experiments suggest that geological formations pertaining to hydrocarbon resources are crucial in formation and reservation of H₂S gas. This paper briefly discusses hazards and geological sources of H₂S, as well as remedial measures for decreasing the risks and problems in excavation of the tunnel. To predict the risk of H₂S gas in the underground spaces, it is possible to use some precursors such as: sulfur springs, organic traces, organic argillaceous rocks, exposure of H₂S odor from fresh surface of rock and smell of H₂S during boreholes drilling. Controlling the inflow of groundwater into the excavation, diluting the concentration of H₂S, training the personnel and utilization of some proper safety equipment have been used to mitigate risks and problems in tunnel excavation.     

Basin analysis study of block 10 in the Say'un-Masilah Basin, Yemen, using a 1D backstripping method

Geohistory analysis was carried out on block 10 in the Say??un-Masilah Basin. The present study is based on the analysis of the well logs of six exploration wells. In the Middle Jurassic to the Middle Eocene, Say??un-Masilah Basin exhibited a complex subsidence history over a period of about 155?Ma. Backstripped subsidence curves are constructed by removing the effects of decompaction to the water column and sediment loads. In the Middle Jurassic, slow subsidence was driven under the effect of sediment load as Kuhlan and Shuqra Formations were deposited as pre-rift deposits. The average total subsidence value of the basement during the deposition of Shuqra Formation was 276?m. The highest subsidence rates during this time are observed northeast of the study area. Rapid subsidence initiated in the Upper Jurassic driven by mechanical extension of the rift, resulting in the deposition of Madbi and Safer Formations, or the so-called Syn-rift deposits. The average tectonic subsidence value of the basements during the deposition of Madbi Formation was 368?m. The highest subsidence rates during this time are observed southwest of the study area. Mechanical extension ceased at about 145?Ma, being replaced by a phase of post-rift subsidence, resulting in more widespread uniform sedimentation, with reduced tectonic subsidence rates forming post-rift deposits represented by Nayfa Formation, Sa??ar Formation, Biyad Formation, and Mahra Group. The total subsidence value of the basement during the deposition of the post-rift sediments increases gradually due to the increase of the sediment load as the rate of deposition was high especially northeast of the area.     

Age and tectonic setting of the Bavanat Cu–Zn–Ag Besshi-type volcanogenic massive sulfide deposit, southern Iran

The Bavanat Cu–Zn–Ag Besshi-type volcanogenic massive sulfide (VMS) deposit occurs within the Surian volcano-sedimentary complex in the Sanandaj–Sirjan zone (SSZ) of southern Iran. The Surian complex is comprised of pelite, sandstone, calcareous shale, basalt, gabbro sills, and thin-bedded limestone. Mineralization occurs as stratiform sheet-like and tabular orebodies hosted mainly by greenschist metamorphosed feldspathic and quartz feldspathic sandstone, basalt, and pelites. The basalts of the Surian complex show predominantly tholeiitic to transitional affinities, with a few samples that are alkalic in composition. Primitive mantle-normalized trace and rare earth element (REE) patterns of the Surian basalts display depletions in light REE, negative anomalies of Nb, Ta, and Ti, and positive anomalies of P. Positive P anomalies are indicative of minor crustal contamination. Furthermore, Th enrichments in the mid-ocean ridge basalt-normalized patterns of the Surian basalts are characteristic of rifted arc basalts emplaced in continental margin subduction zones. The high MgO content (>6?wt.%) of most Surian basalts and low TiO₂ content of two samples (0.53 and 0.62?wt.%) are characteristic of boninites. The aforementioned features of the basalts indicate arc tholeiites emplaced in intra-arc rift environments and continental margin subduction zones. U–Pb dating by laser ablation- inductively coupled plasma mass spectrometry of detrital zircons extracted from the host feldspathic and quartz feldspathic sandstone yields various ages that are predominantly Permian and Triassic; however, the youngest zircons give a mean Early Jurassic concordant U–Pb age of 191?±?12?Ma. This age, together with geological and petrochemical data, indicate that VMS mineralization formed in the Early Jurassic in pull-apart basins within the SSZ. These basins and the VMS mineralization may be temporally related to an intra-arc volcano–plutonic event associated with Neo-Tethyan oblique subduction.     

Characteristics of meteorological drought in Bangladesh

Meteorological drought events occur in Bangladesh are diagnosed using monthly rainfall and mean air temperature from the surface observations and Regional Climate Model (RegCM) by calculating Standardized Precipitation Index (SPI) and Palmer Drought Severity Index (PDSI) for the period 1961?C1990. The historical records of drought event obtained from the Bangladesh Bureau of Statistics and International Disaster Database are used to verify the SPI and PDSI detected events. The SPI and monthly PDSI are obtained for 27 station data across Bangladesh as well as for two subregions over the country. Result based on the observed data shows that regional information is better in drought diagnosis compared to the point information. The regional analysis is able to detect about 80?% of the drought events occurred during the study period. Frequency of moderate drought is higher for all over the country. The SPI calculated from RegCM rainfall shows that the detection of moderate drought events is 10, 7, and 21?% overestimated for 1-, 3-, and 6-month length, respectively, compared to using of observed data. For extreme drought cases, detection is overestimated (underestimated) by 25?% (79?%) for 1-month (6-month) length. The PDSI results for model and observed data are nearly same to SPI calculations. Model monthly PDSI result is overestimated (underestimated) by 29?% (50?%) for moderate (severe) drought events with reference to the observed PDSI. Hence, RegCM output may be useful to detect 3?C6-month (monthly to seasonal) length moderate drought events over a heavy rainfall region likely Bangladesh.     

A survey of challenges in reducing the impact of geological hazards associated with earthquakes in Iran

Most of the recent earthquakes in Iran were associated with some types of geological hazards that were the cause of additional damage and casualties in the earthquake-affected areas. In order to reduce the impacts of geo-hazards, several policies and plans were prepared, approved, and implemented by the Iranian government during the last two decades. However, such activities have not yet resulted in risk reduction to an acceptable level; since they are not formulated based on local conditions and are not linked to location-specific comprehensive plans. In this paper, after introducing some of the impacts of geo-hazards associated with recent earthquakes in Iran, the country trends in development of relevant risk reduction plans and policies are introduced, evaluated, and compared with some other countries having similar challenges. Strategies toward risk mitigation in the country are addressed, and a number of indices for the assessment of the geo-hazard risk reduction plans and activities are introduced. Finally, a conceptual model for the evaluation of the preparedness level against geo-hazards is proposed and discussed.     

Plain move predicate and its consistency concerning the moving agents in a network

Advances in GIS and databases for dealing with spatiotemporal frameworks are leading to efficient querying, analyzing, and reasoning about moving objects/agents. However, contemporary frameworks on spatiotemporal logics are usually limited to qualitative approaches, such as the numerous studies on spatiotemporal databases that focus on observations, ignoring the intended movements of the agents. Moving object databases, on the other hand, can handle queries about the location, velocity, and time by assuming some agents to be targets. However, reasoning about the plan of moving agents, especially on the network and the achievability of such a plan, still remains a challenge. Studies on vehicle routing are often about the centralized planning of moving agents from scratch and do not deal with intended plans. Based on a plain move predicate, this paper presents a generic framework that can be used for representing and reasoning about plans of moving agents. Concepts from motion, network structure, graph theory, predicate logic, and constraint satisfaction are used to create the framework. We have also provided efficient algorithms for checking the consistency of the movement and extracting compatible plans along with some discussions on computational analysis, logical deduction, and flexibility. Finally, we have demonstrated the application of the methodology by developing NETwork-based Move Atoms Planning System (NETMAPS). The experiments show how NETMAPS can overcome an inconsistent movement plan and deliver advantageous suggestions to an executive agent.     

Experimental investigation of density current patterns using dynamic fractal analysis

Density currents are caused by a difference in density,though low,of an entering fluid with the ambient fluid.This type of current is two-phased and found on riverbeds or in reservoirs behind dams,and is nonlinear in nature,complex,and sensitive to initial conditions.Fractal geometry is used as a powerful tool for studying complex natural phenomena.Using experimental studies and changes in inlet current conditions,the fractal and multi-fractal analyses of the interface between the density current and the ambient fluid were done.In addition,a search was made to find a possible connection between the nonlinear patterns.According to the results,with an increase in the inlet discharge and inlet density of the current the fractal dimension decreased.Further,the smaller the range of the singularity spectrum diagram was,i.e.,the more it was less than 0.34,the lower the system's tendency was to be multi-fractal,and the system sensitive to large local changes.In the interface between the density current and the ambient fluid,using the fractal dimension-based Richardson number could improve experimental data by 12.4%.Moreover,with an increase in the Richardson number,the Reynolds number of the current decreased.Further,upon considering the fractal dimension,the Reynolds number improved by 23%and a good correlation with a coefficient of determination of 0.76.     

A new well behaved class of charge analogue of Adler’s relativistic exact solution

The paper presents a new class of parametric interior solutions of Einstein–Maxwell field equations in general relativity for a static spherically symmetric distribution of a charged perfect fluid with a particular form of electric field intensity. This solution gives us wide range of parameter, K (0.69≤K≤7.1), for which the solution is well behaved hence, suitable for modeling of superdense star. For this solution the gravitational mass of a superdense object is maximized with all degree of suitability by assuming the surface density of the star equal to the normal nuclear density ρ _nm=2.5×10¹⁷kg?m^?3. By this model we obtain the mass of the Crab pulsar M _Crab=1.401M _⊙ and the radius, R _Crab=12.98 km constraining the moment of inertia I _NS,38>1.61 for the conservative estimate of Crab nebula mass 2M _⊙ and M _Crab=2.0156M _⊙ with radius, R _Crab=14.07 km constraining the moment of inertia I _NS,38>3.04 for the newest estimate of Crab nebula mass 4.6M _⊙ which are quite well in agreement with the possible values of mass and radius of Crab pulsar. Besides this, our model yields the moments of inertia for PSR J0737-3039A and PSR J0737-3039B are I _A,38=1.4624 and I _B,38=1.2689 respectively. It has been observed that under well behaved conditions this class of parametric solution gives us the maximum gravitational mass of causal superdense object 2.8020M _⊙ with radius 14.49 km, surface redshift z _R =0.4319, charge Q=4.67×10²⁰ C, and central density ρ _c =2.68ρ _nm.