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1.
Risk-based decision-making for drilling waste discharges using a fuzzy synthetic evaluation technique 总被引：5，自引：0，他引：5
Offshore petroleum drilling wastes contain toxic substances that are potentially harmful to the marine ecosystem. Despite environmentally benign characteristics, wastes associated with synthetic-based fluids still contain a certain amount of pollutants due to contamination with formation oil and the presence of trace heavy metals in barite, which may pose risk when discharged into the marine environment. A framework is presented here for a decision support system for the selection of the best drilling waste discharge option. Uncertainties in the quantification of risk, cost and technical feasibility are expressed by fuzzy numbers. An analytical hierarchy process with a technique called fuzzy synthetic evaluation is employed to determine the best management alternative (discharge scenario). 相似文献
2.
Akhtar Husain Siddiqi 《GeoJournal》1992,26(3):395-411
This study assesses the condition of the fishing industry in Pakistan. It briefly reviews the ecological environment of Pakistan's
fisheries and describes recent developments in technology and their impact on the catch. The factors contributing to growth
include government efforts, fleet expansion and development of export markets. This study also points out the difficulties
in arriving at a satisfactory management policy for the regulation of the industry. Development strategies seek rational,
efficient exploitation of marine resources for the broad goals of national development. Consequently, policy makers' fisheries
management concepts and techniques are generally less effective in addressing the need of the coastal communities. The conclusion
is that fisheries development effort need balanced resource management, serving as an instrument for regional development
while taking into account the traditional resource use rights of small-scale fishermen. 相似文献
3.
Kak Choon Loy Prakash Chandra Sinha Juneng Liew Fredolin Tangang Mohd Lokman Husain 《Natural Hazards》2014,70(1):23-37
Super typhoon Durian struck the central Philippines on November 30, 2006 and southern coast of Vietnam on December 5, 2006. The reported maximum wind exceeded 250 km/h, and the central pressure was 904 hPa during the peak of the system. The typhoon brought colossal damage, both in terms of lives and in terms of properties to the Philippines and Vietnam while Thailand and Malaysia were slightly affected. The energy from the high-velocity wind and central pressure drop resulted in the generation of storm surges along the coastal region of the Philippines including its surrounding islands as well as parts of southern Vietnam. In this paper, a numerical 2D model is used to study the oceanic response to the atmospheric forcing by 2006 super typhoon Durian in the coastal regions of the Philippines and Vietnam. The initial study of this model aims to provide some useful insights before it could be used as a coastal disaster prediction system in the region of South China Sea (SCS). The atmospheric forcing for the 2D model, which includes the pressure gradient and the wind field, is generated by an empirical asymmetrical storm model. The simulated results of storm surges due to typhoon Durian at two locations lie in the range of observed data/estimates published by the Joint Typhoon Warning Centre (JTWC). 相似文献
4.
Ismail Husain Fathi Kaoru Miyashita Jun Kawahara 《Arabian Journal of Geosciences》2013,6(8):3111-3118
We adopted the seismic tomography technique to refine the three-dimensional velocity structure model of the western part of Hokkaido, Japan. Using the P-wave first arrival data listed by Japan Meteorological Agency from 2002 to 2005, we could estimate a 3-D inhomogeneous velocity structure model with a low velocity at a depth of 14 km beneath Asahikawa. The crustal structure near Sapporo was characterized by lateral velocity change toward the southern seaside. The low-velocity zone near Urakawa, proposed by previous research, was also clarified. In general, the present model showed lower-velocity values for most of the crustal layers in the area concerned. The results of this study were affected by less number of higher magnitude events (M?≥?0.5) in the central part of the area of interest. However, the perturbation results for comparatively shallow layers (6–50 km) were good in resolution. It was found that the source region of the Rumoi–Nanbu earthquake of December 14, 2004 was characterized by a low-velocity zone, located between high velocity zones. Such an inhomogeneous crustal structure might play an important role in the relatively high seismic activity in the Rumoi–Nanbu earthquake source region. 相似文献
5.
M. Ahadi M. Saber Tehrani P. Aberoomand Azar S. Waqif Husain 《International Journal of Environmental Science and Technology》2016,13(12):2797-2804
Sensitized ZnS nanoparticles were synthesized by chemical precipitation method using anthocyanin as the capping agent and sensitizer. X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscopy, UV visible spectrophotometer, Fourier transform infrared spectroscopy and photoluminescence spectrometry methods were used for the characterization of nanoparticles. The electron microscopy studies of nanoparticles showed that the size of crystallites is in the range of 35–80 nm and optical studies showed a blue shift in the absorption edge by adding capping agent. The effective band gap energy was increased with decrease in the particle size. Photocatalytic activities of sensitized ZnS and pure ZnS were evaluated by degradation of tetracycline in aqueous solution under visible light irradiation, and progress of the reaction was monitored spectrophotometrically. The different parameters affecting degradation such as the pH of solution, amount of semiconductor and reusability of catalyst for three cycles and the photocatalytic degradation kinetics of tetracycline were studied. More than 80% degradation was achieved within 5 h under visible light. 相似文献
6.
Many studies have been carried out in the past to provide solutions to the threat of chemicals to the ecosystem. However, the basic scientific capability to predict the risk of adverse effects on the ecological system has not kept pace with society's increasing demand for uses of chemicals. As a scientific methodology for quantifying the risk to the environment associated with exposure to chemicals, ecological risk assessment is increasingly important in environmental problem solving. The purpose of this paper is to present a methodology for conducting ecological risk assessment using deterministic and probabilistic approaches. A systematic discussion on elements of ecological risk assessment is presented. A framework of ecological risk assessment is explained with the help of the Persian Gulf environmental problem as a case study. The study was based on the output of a long-range transport model of soot deposition in the Gulf. Results of the assessment using the deterministic and probabilistic approaches are discussed. 相似文献
7.
Akhtar Husain Siddiqi 《GeoJournal》1995,37(1):9-15
The Arabs acquired Greek geographical and astronomical knowledge in the eighth century, when the works of Ptolemy and other Greek philosophers were translated into Arabic. Muslim scholars learned Greek scientific thought and accepted these views as working theories necessary for further scientific inquiry. Muslim scholars were impressed by the Greek point of view, but they added to scientific knowledge in each succeeding generation. In the spirit of objective research, the scientific work of the Muslim scholars was progressive. They were ready to receive the truth from any source, even if that source be foreign. As Western thought became dominant in the Islamic areas in the thirteenth century, Muslim scholars' interest in geography and other natural sciences declined. 相似文献
8.
The crystallization ages of a suite of Apollo 17 basalts from four different stations have been measured using the39Ar-40Ar stepwise heating technique. The rocks analyzed include all principal petrographic types found at Apollo 17 landing site. A correlation between the ages and the petrographic type exists; plagioclase-poikilitic ilmenite basalts are youngest and olivine porphyritic ilmenite basalts are the oldest. The duration of volcanism in Mare Serenitatis is about 200 m.y., the same as observed for Mare Imbrium, and less than observed for Mare Tranquillitatis, 400 m.y. A relationship between duration of volcanism and gravity anomalies is noted. The cosmic ray exposure ages (in m.y.) for various locations range as: station 4, 58–315; station 5, 85–440; station 6, 110; station 8, 90–160. 相似文献
9.
Analyses of 40Ar-39Ar have been made on a whole rock sample and a maskelynite (feldspar) separate of the shocked Shergotty achondrite. The maskelynite gave a plateau age of 254 ± 10 Myr. The whole rock sample gave a complex release with apparent ages between 240 and 640 Myr. The slightly younger Rb-Sr isochron age of 165 Myr for Shergotty (Nyquistet al., 1978) suggests that the maskelynite as well as the whole rock was incompletely degassed. Reasonable Ar diffusion characteristics for Shergotty for shock heating temperatures of <400°C indicate D/a2 of 10?11?10?13 sec?1. The time required to lose 95% of the 40Ar from the plagioclase would be ~103–104 yr. When this gas diffusion time is introduced into a thermal model of a cooling ejecta blanket of variable thickness, a post-shock cooling time of ? 103 yr and a burial depth of ? 300 m are indicated for Shergotty. These conclusions are not seriously affected by uncertainties in the thermal model. Most likely the shock event occurred ~ 165 Myr ago, but no earlier than 250 Myr ago, when the Shergotty parent object experienced a collision in the asteroid belt. As a result of that collision, feldspar was converted to maskelynite, the K-Ar and Rb-Sr ages were completely or nearly completely reset, and the Shergotty meteorite was heated to <400°C and left to cool slowly inside the parent body. 相似文献
10.
Applying the iterative shooting/bisection technique for rapid forward modeling to the seismic explosion data, we could refine the crustal velocity structure model of the western part of the Hidaka collision zone, Hokkaido, Japan. We used only the precise P-wave first arrival data obtained by the Research Group for Explosion Seismology, which set up a 113.4-km-long profile in August 2000 along with 327 observation points and four shot points with TNT charges from 100 to 300 kg. We could estimate a two-dimensional inhomogeneous crustal velocity structure model with a velocity decrease in the eastern direction at a depth of 15.7 km, several portions of velocity reversals with depth and a low velocity anomaly proposed in previous studies. The root-mean-square of travel-time residuals was improved from 0.398 s for the previous structure model to 0.176 s for the present model with a reduction of 55.8%. 相似文献