Study on the Erodibility and Mechanical Resistance of Mulches Prepared from Micro Silica–Cement Mixtures     

Naghizade Asl  Fateme  Asgari  Hamid Reza  Emami  Hojat  Jafari  Mohammad 《Geotechnical and Geological Engineering》2021,39(5):3347-3360

Geotechnical and Geological Engineering - Mulching is fastest strategy to control sand dune movement in arid and semiarid areas. In the present study the effect of micro silica- cement mixture was...  相似文献   

Landslide hazard and risk assessment and their application in risk management and landuse planning in eastern flank of Menoreh Mountains,Yogyakarta Province,Indonesia     

Danang Sri Hadmoko  Franck Lavigne  Junun Sartohadi  Pramono Hadi  Winaryo 《Natural Hazards》2010,54(3):623-642

The Menoreh Mountains in Yogyakarta are severely affected by landslides. Due to the high population densities, mass movements are generally damaging and fatal. More than other Javanese mountains, the Menoreh Mountains cumulate several factors causing landslides. Therefore, it is necessary to evaluate the ways to map landslide risk in order to improve the risk mitigation. The objectives of this paper are to provide landslide hazard and risk assessment that will be useful for risk prevention and landuse planning in the Menoreh Mountains. So far, risk management has been developed by the Research Centre for Disasters Gadjah Mada University in collaboration with the Regional Development Planner (BAPPEDA), which carries out fundamental and applied researches. The results of the studies have been integrated in the risk prevention and landuse planning in order to improve the integrated landslide mitigation programme.  相似文献   

Reduction of environmental pollution through optimization of energy use in cement industries   总被引：1，自引：1，他引：0  

A. R. Karbassi Ph.D.  H. R. Jafari Ph.D.  A. R. Yavari Ph.D.  H. Hoveidi  H. Sid Kalal Ph.D. 《International Journal of Environmental Science and Technology》2010,7(1):127-134

Industrial development has lead to higher energy consumption, emission of greenhouse gases, as well as air pollutants. Cement factories play an important role in over all greenhouse emissions. This study aims to investigate the role of Iranian cement industries and their contribution of greenhouse gases contribution. The measured emission factors for oil and fuel gas shows that carbon dioxide contribution from fuel oil based cement industries is almost 2.7 times higher than gas based cement factories. The strength, weakness, opportunity and threat technique analysis showed that the best strategy to combat greenhouse gases from Iranian cement factory is to implement energy efficiency measures. Further, strategic position and action evaluation matrix analysis indicates that Iranian cement industries fall within invasive category. Therefore, exploitation of opportunities must carefully be used. One of these opportunities is the utilization of financial assistance provided by clean development mechanism. The results show that replacement of ball mills with vertical roller mill can reduce the electricity consumption from 44.6 to 28 kWh/ton. As a result of such substitution about 720 million kWh/y of electricity would be saved (almost a power plant of 125 MW capacities). Though implementation of new mills may not be economic for the cement industries’ owner, but the overall gain for the government of Iran will be about US$ 304 million. If the duration of such efficiency measure is considered as about 12 y, then the overall CO₂ reduction/phase-out would be around 4.3 million tons.  相似文献   

Land Subsidence of Jakarta (Indonesia) and its Geodetic Monitoring System   总被引：6，自引：2，他引：6  

Abidin  Hasanuddin Z.  Djaja  Rochman  Darmawan  Dudy  Hadi  Samsul  Akbar  Arifin  Rajiyowiryono  H.  Sudibyo  Y.  Meilano  I.  Kasuma  M. A.  Kahar  J.  Subarya  Cecep 《Natural Hazards》2001,23(2-3):365-387

Jakarta is the capital city of Indonesia with a population of about 10 million people, inhabiting an area of about 25 × 25 km. It has been reported for sometime that locations in Jakarta are subsiding at different rates. Up to the present, there has been no comprehensive information about the characteristics and pattern of land subsidence in the Jakarta area. Usually land subsidence in Jakarta is measured using extensometers and ground water level observations, or estimated using geological and hydrological parameters. To give a better picture about land subsidence, geodetic-based monitoring systems utilizing leveling and GPS surveys have also been implemented.The land subsidence characteristics of Jakarta and its surrounding area areinvestigated using data from three repeated leveling surveys performed in1982, 1991, and 1997, and two repeated GPS surveys conducted in 1997and 1999. Leveling surveys detected subsidence up to about 80 cm duringthe period of 1982–1991, and up to about 160 cm during the 1991–1997period; while GPS surveys observed subsidence up to about 20 cm duringthe period of 1997–1999. Comparison with the hydrological data shows thatland subsidence in Jakarta is strongly related to excessive groundwater extraction.  相似文献   

Zinc extraction from Iranian low-grade complex zinc–lead ore by two native microorganisms: Acidithiobacillus ferrooxidans and Sulfobacillus   总被引：2，自引：0，他引：2  

S.M. Mousavi  S. Yaghmaei  M. Vossoughi  A. Jafari  R. Roostaazad 《International Journal of Mineral Processing》2006,80(2-4):238-243

A mesophilic iron oxidizing bacterium, Acidithiobacillus ferrooxidans, has been isolated (33 °C) from a typical, chalcopyrite concentrate of the Sarcheshmeh copper mine in the region of Kerman located in the south of Iran. In addition, a thermophilic iron oxidizing bacterium, Sulfobacillus, has been isolated (60 °C) from the sphalerite concentrate of Kooshk lead and zinc mine near the city of Yazd in the center point of Iran. Variation of pH, ferrous and ferric concentration on time and effects of some factors such as temperature, cell growth, initial ferrous concentration and pH on bioleaching of low-grade complex zinc–lead ore were investigated. The results obtained from bioleaching experiments indicate that the efficiency of zinc extraction is dependent on all of the mentioned variables; especially the temperature and initial Fe(II) concentration have more effect than other factors for these microorganisms. In addition, results show that the maximum zinc recovery was achieved using a thermophilic culture. Zinc dissolution reached 58% with Sulfobacillus while it was 51% with A. ferrooxidans at pH = 1.5, initial Fe(II) concentration = 7 and 9 g/L for A. ferrooxidans and Sulfobacillus, respectively, after 30 days.  相似文献   

Experimental Study of Mechanical Behaviour of Rock Joints Under Cyclic Loading   总被引：3，自引：5，他引：3  

M. K. Jafari  F. Pellet  M. Boulon  K. Amini Hosseini 《Rock Mechanics and Rock Engineering》2004,37(1):3-23

Summary Evaluation of the effects of small repetitive earthquakes on the strength parameters of rock joints in active seismic zones is of interest of the designers of underground constructions. In order to evaluate these effects, it is necessary to study the behaviour of rock joints under dynamic and cyclic loadings. This paper presents the results of a systematic study on the behaviour of artificial rock joints subjected to cyclic shearing. More than 30 identical replicas have been tested using triaxial compression devices under different conditions of monotonic and cyclic loading. At the first stage a few samples have been tested in monotonic loading modes under various confining pressures and rate of displacement. In the second series of tests, small cyclic loads were applied on the samples for increasing number of cycles, frequency levels and stress amplitudes. These were then followed by monotonic loading again. The variations of maximum and residual shear strengths for each test have been studied. The results show increase of shear strength as a result of the increase in confining pressure and they display decrease of shear strength due to the increase of rate of loading, number of cycles, frequency levels and stress amplitudes.  相似文献   

Dinoflagellate and foraminiferal biostratigraphy of the Gurpi Formation (upper Santonian–upper Maastrichtian), Zagros Mountains, Iran     

Ebrahim Ghasemi-Nejad  Mohammad Hadi Hobbi  Poul Schiler 《Cretaceous Research》2006,27(6):828-835

A rich dinoflagellate cyst assemblage has been recovered from an outcrop of the Gurpi Formation, the hydrocarbon source rock in the South Iranian Basin. Key dinoflagellates recorded in the section studied provide a means of correlation with zonation schemes for Australasia and north-west Europe. These include Eucladinium kaikourense, Nelsoniella aceras, Odontochitina spp., Cannosphaeropsis utinensis, Palaeocystodinium denticulatum and Dinogymnium spp. The assemblage points to a late Santonian–late Maastrichtian age for the Gurpi Formation. Dinoflagellate and planktonic foraminiferal evidence indicates the presence of a hiatus spanning the uppermost Maastrichtian to at least the lowermost Danian at the base of a glaucony-rich layer separating the Gurpi Formation from the overlying Pabdeh Formation. Palynofacies and lithofacies profiles suggest that the sediments were deposited in an open, relatively deep marine outer ramp environment belonging to ramp facies 8 and 9.  相似文献   

Un exemple de volcanisme calco-alcalin de type orogénique mis en place en contexte de rifting (Cambrien de l'oued Rhebar,Meseta occidentale,Maroc)     

Hassan El Hadi  Abdelfatah Tahiri  Fernando Simancas Cabrera  Francisco González Lodeiro  Antonio Azor Pérez  David Jesús Martínez Poyatos 《Comptes Rendus Geoscience》2006,338(4):229-236

The Middle Cambrian calc-alkaline Oued Rhebar volcanic complex (western Meseta, Morocco) compares with rocks originated in orogenic contexts. The La/Nb ratios are relatively high (5.2), suggesting a lithospheric mantle origin. The La/Ta ratios, higher than 26, and the negative Nb anomaly indicate a lithospheric source contaminated by the continental crust. These rocks were generated in the Mesetian Mid-Cambrian rift and would have inherited their orogenic signature from the partial melting of a previously metasomatized mantle. To cite this article: H. El Hadi et al., C. R. Geoscience 338 (2006).  相似文献   

Influence of Chemical Stabilisation on Permeability of Municipal Solid Wastes     

Behnam Fatahi  Hadi Khabbaz 《Geotechnical and Geological Engineering》2015,33(3):455-466

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Post-Cyclic Undrained Behavior of Compacted Composite Clay Subjected to Various Cyclic Loading Paths     

H. R. Tavakoli  A. Shafiee  M. K. Jafari 《Geotechnical and Geological Engineering》2011,29(6):1085-1097

Using a sequential procedure of undrained cyclic and post cyclic tests, the strength and stiffness degradation characteristics of compacted composite clays are studied immediately after various cyclic loading paths by triaxial and hollow cylinder tests. The effects of cyclic loading paths, sand contents, cyclic loading amplitude and confining pressure on the post-cyclic mechanical behavior of the composite clays are evaluated. The results point out different peculiarities which can be of interest in assessing the mechanical behavior of the composite clays under post seismic shaking. The results show that effect of cyclic loading on post cyclic pore water pressure build-up is significant when pore water pressure build-up is considerably lower than the associated value in monotonic loading. The effect of sand content and cyclic loading path on degradation of stiffness is more remarkable than shear strength. Test results also reveal that the effect of sand content on the post cyclic pore water pressure build-up is minor. However, when the aggregate content increases the shear strength increases.  相似文献