Evaluation of Negative Economic-Environmental Externalities of Overextraction of Groundwater     

Mostafa Baniasadi  Mohammad Reza Zare' Mehrjordi  Hossein Mehrabi Boshrabadi  Hamid Reza Mirzaei Khalilabad  Abbas Rezaei Estakhrooye 《Ground water》2020,58(4):560-570

In recent decades, increased extraction of groundwater for human and agriculture consumption has led to a substantial drop in groundwater level in large areas of across the world. Declining groundwater levels is a serious problem in itself and has multiple economic, social, cultural, political, security-related, and environmental externalities. The negative economic-environmental externalities of overextraction of groundwater in the Orzouiyeh plain in the Kerman Province, Iran, were evaluated using methods such as replacement cost, production function, market prices, shadow price, and the value of the input marginal product. After evaluating externalities, the Positive Mathematical Programming method was used to evaluate different water policies to reduce the consumption of groundwater. The total economic losses due to the externalities were calculated to equal 2.8 U.S. million dollars. The damages caused by environmental externalities were calculated to equal 436.1 U.S. million dollars. The results related to the positive planning model show that the best policy among different options, such as deficit irrigation policy or combined policies, involves implementation of pressurized irrigation systems.  相似文献   

Thermal evaluation of shear-free charged compact object     

S. M. Shah  G. Abbas 《Astrophysics and Space Science》2018,363(8):176

This paper is devoted to the thermal evolution of shear-free charged gravitating compact objects which undergoes exhausted its inner heat during gravitational collapse. The evaluation equations have been formulated by applying the perturbation of first order to Einstein–Maxwell equations and Catteno-type heat transportation equation. We show that the temperature gradient (induced in the system owing to external effects), sufficiently depends upon multiple of relaxation time and total time during which the gravitating system oscillates. By taking some particular examples of nuclear matter, it has been noted that at a particular value of luminosity, the change in existing thermal profile is greater corresponding to higher values of times during which a system comes to rest position.  相似文献   

A Study of Largest Active Region AR12192 of 24th Solar Cycle Using Fractal Dimensions and Mathematical Morphology     

Asma Zaffar  Abbas  Shaheen  Ansari  Muhammad Rashid Kamal 《Solar System Research》2020,54(4):353-359

Solar System Research - An active region (AR) of the sun is an area of strong magnetic field. Sunspots are frequently formed in an AR. Solar activity exhibits in the form of solar flares and...  相似文献   

Mélange development in the Neyriz region of Zagros Orogen,Iran: Record of convergence and collision in the Neotethyan Realm     

Parisa Gholami Zadeh  Mohammad Hossein Adabi  Mohammad Reza Ghassemi  Abbas Sadeghi  Safar Ali Eshraghi 《Basin Research》2020,32(6):1626-1652

Mélanges are formed by sedimentary, tectonic and diapiric processes and are generally found in collisional belts. The Zagros Orogeny provides an intriguing geological laboratory for the study of mélange-forming processes during the progressive tectonic evolution of the Neotethys Ocean. Different types of tectonic and sedimentary mélanges occur in specific structural positions within the Zagros orogenic belt in the Neyriz Region (Iran). Based on their block-in-matrix fabrics, and tectonostratigraphic positions, we differentiated 14 different mélange types, which mark different episodes of the tectonic evolution of the Neyriz Region from the Cretaceous subduction to the Miocene collision. The Cretaceous subduction stage is recorded by volcanic-sedimentary mélanges (Mv). Sedimentary mélanges characterized by megabreccia from the Cretaceous limestone (Ms1) and Eocene polymictic megabreccia (Ms2) represent epi-nappe mélanges formed during the Palaeocene–Eocene in wedge-top basins. The ophiolite emplacement in the Oligocene resulted in local extensional tectonics in the upper part of the ophiolitic nappe, and deposition of a polymictic megabreccia (Ms3, Ms4). As the final production of the Neotethys Ocean closure and the Eurasian-Arabian collision, the sedimentary mélanges characterized by different types of chaotic rock units (Ms5, Ms6, Ms7 and Ms8 facies) were developed in front of the Cretaceous–Eocene nappes due to growth of the orogenic wedge in the Miocene. Our findings indicate that the recognition and distinction of different types of mélange may provide additional constraints for a better understanding of the tectono-sedimentary evolution of the Neotethyan region.  相似文献   

Monitoring hawksbill turtle nesting sites in some protected areas from the Persian Gulf     

Hesni Majid Askari  Rezaie-Atagholipour Mohsen  Zangiabadi Somaye  Tollab Mohammad Amin  Moazeni Mostaf  Jafari Hosein  Matin Mohammad Talebi  Zafarani Ghasem Ghorbanzadeh  Shojaei Maht  Motlaghnejad Abbas 《海洋学报(英文版)》2019,38(12):43-51

Iranian nesting populations of the critically endangered hawksbill turtle(Eretmochelys imbricate) are some of the most important in the Indian Ocean. In this study, four of the most important hawksbill nesting grounds in the Persian Gulf, situated within three Iranian marine protected areas, were surveyed during nesting season,including Nakhiloo, Ommolgorm and Kharko Islands and the mainland beaches of the Naiband Marine-Coastal National Park(NMCNP). We present GIS maps of these key nesting grounds and describe sand texture of key nesting zones, along with conservation recommendations. About 9.2(28.3%) out of 32.5 km of all shores surveyed in this study were used by nesting hawksbill turtles follows: Nakhiloo: 1.4 km(52% of potential nesting area);Ommolgorm: 1.94 km(40%); Kharko: 3.4 km(28%), and NMCNP: 2.46 km(18.9%). The average nesting density was calculated as 131 nests/km at Nakhiloo, 76 nests/km at Ommolgorm, 7 nests/km at Kharko, and 15 nests per km at NMCNP. Highest nesting density was observed in Nakhiloo and Ommolgorm. It is thought that high hawksbill nesting density in these islands seems likely a result of limiting adequate nesting shores rather than the size of population, and also low density in Kharko and NMCNP more related to past and current pressures and low population density. With the exception of Ommolgorm Island, sands at the nesting grounds were well sorted.Grain size indicated that female hawksbill turtles in the Iranian Persian Gulf nest in sands that are generally mixed, with mean grain size ranging from coarse sands(0.4Φ;～0.5–1 mm) to fine sands(2Φ;～0.25 mm). We provide and discuss conservation recommendations and suggestions for future.  相似文献   

Experimental Investigation of Rheological Behavior and Wax Deposition of Waxy Oil–Disulfide Oil Systems     

Mansourpoor  Mojtaba  Azin  Reza  Osfouri  Shahriar  Izadpanah  Amir Abbas  Saboori  Rahmatallah 《Natural Resources Research》2019,28(4):1609-1617

Natural Resources Research - In this work, we studied the feasibility of using disulfide oil (DSO) as a solvent for wax prevention in pipelines. Several tests were carried out to determine the...  相似文献   

Gravitational charged perfect fluid collapse in Friedmann universe models     

M. Sharif  G. Abbas 《Astrophysics and Space Science》2010,327(2):285-291

This paper is devoted to the study of gravitational charged perfect fluid collapse in Friedmann universe models with cosmological constant. For this purpose, we assume that the electromagnetic field is so weak that it does not introduce any distortion into the geometry of the spacetime. The results obtained from the junction conditions between the Friedmann and the Reissner–Nordström de Sitter spacetimes are used to solve the field equations. Further, the singularity structure and mass effects of the collapsing system on the time difference between the formation of apparent horizons and singularity have been studied. This analysis provides the validity of the Cosmic Censorship Hypothesis. It is found that the electromagnetic field affects the area of apparent horizons and their time of formation.  相似文献   

Occurrence and biomarker potential of 23-methyl steroids in diatoms and sediments     

Sebastiaan W. Rampen  Stefan Schouten  Ellen C. Hopmans  Ben Abbas  Anna A.M. Noordeloos  Jan A.J. Geenevasen  J. Michael Moldowan  Peter Denisevich  Jaap S. Sinninghe Damsté 《Organic Geochemistry》2009,40(2):219-228

23-Methyl sterols have been reported to be synthesized by a few marine algae, but unambiguous identification of 23-methyl steroids in sediments and petroleum is lacking. We report the presence of 23-methylcholesta-5,22E-dien-3β-ol in 14 out of 106 diatom cultures, thereby showing that diatoms, together with dinoflagellates, may be an important environmental source for such steroids. Synthesis of authentic 23-methylcholestanes showed that their mass spectra are identical to those of 24-methylcholestanes, but that they elute earlier on apolar stationary phases during gas chromatography (GC) analysis. Co-injection of the authentic standards with sediment extracts revealed the presence of these compounds in the Skole unit of the Oligocene Menelite Formation, the Miocene Monterey Formation and the Messinian Vena del Gesso Formation. In addition, we tentatively identified 23,24-dimethyl-27-norcholestanes in some of these sediments. Molecular clock calculations suggest that diatoms are a possible source for 23-methyl steroids in sediments and petroleum from the late Jurassic onwards.  相似文献   

Stability Analysis and the Stabilisation of Flexural Toppling Failure   总被引：1，自引：0，他引：1  

Mehdi Amini  Abbas Majdi  Ömer Aydan 《Rock Mechanics and Rock Engineering》2009,42(5):751-782

Flexural toppling is a mode of failure that may occur in a wide range of layered rock strata in both rock slopes and large underground excavations. Whenever rock mass is composed of a set of parallel discontinuities dipping steeply against the excavated face plane, the rock mass will have the potential of flexural toppling failure as well. In such cases, the rock mass behaves like inclined superimposed cantilever beams that bend under their own weight while transferring the load to the underlying strata. If the bending stress exceeds the rock column’s tensile strength, flexural toppling failure will be initiated. Since the rock columns are “statically indeterminate,” thus, their factors of safety may not be determined solely by equations of equilibrium. The paper describes an analytical model with a sequence of inclined superimposed cantilever rock columns with a potential of flexural topping failure. The model is based on the principle of compatibility equations and leads to a new method by which the magnitudes and points of application of intercolumn forces are determined. On the basis of the proposed model, a safety factor for each rock column can be computed independently. Hence, every rock column will have a unique factor of safety. The least factor of safety that exists in any rock column is selected as the rock mass representative safety factor based on which simple equations are proposed for a conservative rock mass stability analysis and design. As a result, some new relations are established in order to design the length, cross-sectional area and pattern of fully grouted rock bolts for the stabilisation of such rock mass. Finally, the newly proposed equations are compared with the results of existing experimental flexural toppling failure models (base friction and centrifuge tests) for further verification.  相似文献   

Spring rainfall prediction based on remote linkage controlling using adaptive neuro-fuzzy inference system (ANFIS)     

Gholam Abbas Fallah-Ghalhary  Majid Habibi-Nokhandan  Mohammad Mousavi-Baygi  Javad Khoshhal  Akbar Shaemi Barzoki 《Theoretical and Applied Climatology》2010,101(1-2):217-233

This paper aims to study the relationship between large-scale synoptic patterns and rainfall in Khorasan Razavi Province. The adaptive neuro-fuzzy inference system (ANFIS) was used in this study to predict rainfall in the period between April and June in Khorasan Razavi Province. We first analyzed the relationship between average regional rainfall and the changes in synoptic patterns including sea-level pressure, sea-level pressure difference, sea-level temperature, temperature difference between sea level and the 1,000-hPa level, the temperature of the 700-hPa level, the thickness between the 500- and 1,000-hPa levels, the relative humidity at the 300-hPa level, and precipitable water content. We have examined the effect of synoptic patterns in these regions on the rainfall in the northeast region of Iran. Then, the ANFIS in the period 1970–1997 has been taught. Finally, we forecast the rainfall for the period 1998–2007. The results show that the ANFIS can predict the rainfall with reasonable accuracy.  相似文献