Characterization of a Sedimentary Soft Rock by a Small In-Situ Triaxial Test     

Abbas Taheri  Kazuo Tani 《Geotechnical and Geological Engineering》2010,28(3):241-249

To measure the shear strength and deformability of a sedimentary soft rock, a small down-hole in-situ triaxial testing method is developed. The apparatus consists of a triaxial cell and an axial loading device which enables testing at any depth. In this method, a columnar specimen of diameter 90 mm and 285 mm height can be sheared at the bottom of a drill hole. A series of tests were conducted at a 50 m deep experimental cavern. The test gallery is contained in mudstone with some inter-bedded thin sand layers. The tests were done in three different depths in a borehole by a multiple-step loading method. The new testing method was successful to measure stress–strain relation of rock mass. The test results demonstrated that the multiple-step loading method is acceptable in mudstone formation, if an appropriate criterion for load reversal is selected to recognize the instant of failure by stress–strain relation during loading. In addition, different results for mechanical properties of mudstone rock mass were observed in the specimens contained sand layers. It is also concluded that, the same loading method is not successful if a sand layer is located in the middle of the specimen due to large damage induced in early stages of loading.  相似文献   

Far infrared remote sounding of stratospheric temperature and trace gas distributions     

Mian M. Abbas  Jing Guo  Ira G. Nolt  Bruno Carli 《Journal of Atmospheric Chemistry》1984,2(2):145-161

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Cloudiness and estimation of incoming solar radiation in Iraq     

M. A. Abbas  M. K. Elnesr 《Pure and Applied Geophysics》1974,112(1):234-239

Summary Monthly and seasonal variations of cloudiness have been studied for different zones of Iraq. It was found to be very low over the entire country and descends as we proceed southwards, except in summer, when it was found to be higher in the south than in the north. From the daily records of the Campbell-Stokes sunshine recorders at Mosul, Baghdad and Basrah, during a period of 10 years from 1961 to 1970, the actual hours and the percentage of possible hours of sunshine duration have been studied in detail and the results obtained are presented in a practical form. It has also been found that the pyrheliometric conditions for Baghdad could be considered representative of the entire country.Taking the incoming solar radiation for clear days during different months of the year, and radiation received on a horizontal surface at Baghdad into consideration, and applying Ångström empirical formulae, it was possible to estimate graphically the amount of solar radiation received at any location in Iraq at any time of the year when the cloudiness or the percentage of possible hours of sunshine is known.  相似文献   

An ontological structure for semantic interoperability of GIS and environmental modeling     

Gholam Reza Fallahi  Andrew U. Frank  Mohammad Saadi Mesgari  Abbas Rajabifard 《International Journal of Applied Earth Observation and Geoinformation》2008

Service-oriented architecture in a distributed computing environment, with loosely coupled geo-services is a new approach for using GIS services in environmental modeling. The messages exchanged must follow a set of standard protocols which support syntactic interoperability, but do not address application semantics.  相似文献   

A critical evaluation of 3D spatial information models for managing legal arrangements of multi-owned developments in Victoria,Australia     

Abbas Rajabifard  Behnam Atazadeh  Mohsen Kalantari 《International journal of geographical information science》2018,32(10):2098-2122

Three-dimensional (3D) spatial information models are increasingly being adopted to help communicate the spatial dimensions of complex built environments. Land administration practices in multi-owned developments include the subdivision, registration and management of legal interests associated with private, communal and public properties, which are often located along the vertical dimension. The spatial structure of each legal interest is normally composed of invisible spaces, defined as the inside and outside of multi-owned developments, as well as physically built structures. Additionally, a wide variety of legal boundary types mark out the spatial limits of the individual parts of each legal interest. These legal boundaries are typically delineated by either relying on fixed surveying measurements or referencing physically existent objects. This article provides a critical assessment of 3D spatial information models in terms of their capabilities for modelling legal interests and legal boundaries defined in the Victorian jurisdiction. We classify these models into three categories: purely legal, purely physical and integrated. This assessment provides the basis for developing a new 3D spatial information model, which would subsequently support a pathway towards realising the Victorian land administration system in a 3D digital environment.  相似文献   

Volcanogenic dark matter and mass extinctions     

Samar Abbas  Afsar Abbas 《Astroparticle Physics》1998,8(4):317-320

The passage of the Earth through dense clumps of dark matter, the presence of which is predicted by certain cosmologies, would produce large quantities of heat in the interior of this planet through the capture and subsequent annihilation of dark matter particles. This heat would lead to large-scale volcanism which could in turn have caused mass extinctions. The periodicity of such volcanic outbursts agrees with the frequency of paleontological mass extinctions as well as the observed periodicity in the occurrence of the largest flood basalt provinces on the globe.  相似文献   

Marine administration and spatial data infrastructure     

Lisa Strain  Abbas Rajabifard  Ian Williamson 《Marine Policy》2006

This paper reviews the emergence of the spatial dimension of marine and coastal zone administration, and examines several initiatives around the world that contribute to this idea. Spatial data have been recognised as an important resource to improve decision-making and resource management in both the land and marine environments in terms of sustainable development. Many countries are developing Spatial Data Infrastructures (SDIs) to improve access and sharing of spatial data, however, most of these initiatives stop at the coastline. Recently, global and regional activities such as the 3rd United Nations Convention on the Law of the Sea (UNCLOS) and the Sustainable Development Strategy for the Seas of East Asia (SDS-SEA) have brought to international attention the importance of effective administration of the marine and coastal environments.  相似文献   

Residual impact of biochar on cadmium uptake by rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) grown in Cd-contaminated soil     

Muhammad Rizwan  Shafaqat Ali  Tahir Abbas  Muhammad Zia ur Rehman  Mohammad I. Al-Wabel 《Arabian Journal of Geosciences》2018,11(20):630

Cadmium (Cd) is the family member of toxic heavy metals, and its accumulation in food crops has become a global environmental constraint. Biochar potentially minimizes the metal contents in plants, but limited work has been reported on its residual effect on subsequent crops. The residual effect of various biochar levels (0, 1.5, 3.0, and 5.0% w/w) on Cd accumulation in rice has been investigated in this study. Biochar treatments enhanced the rice growth, photosynthesis, and antioxidant enzymes, whereas diminished the Cd contents and oxidative stress in rice. Cadmium concentration in shoots decreased by 24.4, 36.6, and 57.5% in 1.5, 3.0, and 5.0% biochar treatments over the control. Biochar supply enhanced the soil pH and electrical conductivity, whereas diminished the soil bioavailable Cd. Overall, the results depicted a significant residual impact of rice straw biochar on rice growth attributes and Cd uptake. However, studies are still needed to explore the long-term sustainability of biochars prepared from different feedstocks on bioavailability of toxic metals in soils and uptake by food crops under field conditions.  相似文献   

Initial assessment of recharge areas for large karst springs: a case study from the central Zagros Mountains,Iran     

Hossein?Karimi VardanjaniEmail author  Manouchehr?Chitsazan  Derek?Ford  Haji?Karimi  Abbas?Charchi 《Hydrogeology Journal》2018,26(1):57-70

Sousan Spring emerges from the Keyno Anticline, Zagros Mountains (Iran), and the mean annual discharge is ~24 m³/s. Geological and hydrochemical evaluations suggest that the spring recharge is from the limestone Ilam-Sarvak Formation (Cretaceous) but the Mafaroon Fault, a major thrust feature, influences the regional groundwater flow path by juxtaposing other strata. Geological, geochemical, stable isotope and water balance studies were employed to interpret this behavior. Using the isotope data, the sources and elevations of the recharge area were found. Temporal variations of the isotopic data were compared with variations of electrical conductivity (EC). Unexpectedly, high EC was associated with a relative increase of discharge and depletion of δ¹⁸O. Several hypotheses were investigated and approximate water balance studies employed for validation. It was found that an elongated catchment on the Keyno Anticline plus a lesser catchment on a pair of parallel anticlines recharge the aquifer. While the long groundwater flow path along the Keyno Anticline plus guidance by Mafaroon Fault and the adjacent Garou shaly strata lead to increased EC in the Sousan Spring at the end of the dry season, a flow pulse from two adjoining anticlines (Mahalbakh and Shirgoon) arrives at the same time to increase the discharge and deplete the δ¹⁸O signal. Apparently the spring did not experience true base flow conditions during the recorded hydrological year. Although the spring response to specific precipitation events was similar to typical karst aquifers, standard interpretation of recession curves and related coefficients will not be practical at Sousan.  相似文献   

Long-term impacts of dust storms on transport systems in south-eastern Iran     

Miri  Abbas  Middleton  Nick 《Natural Hazards》2022,114(1):291-312

Natural Hazards - Dust storms are frequent in the Sistan region of south-eastern Iran and cause a wide range of problems, but few studies have assessed their negative impacts. This paper makes an...  相似文献