Dispersion of Flue Gases from Power Plants in Brunei Darussalam     

P.N. Tandon  P. Ramalingam  A.Q. Malik 《Pure and Applied Geophysics》2003,160(1-2):405-418

— A series of mathematical and computer models describing alternative methods for the disposal of flue gases emitted from coal and gas fired power plants is discussed. Brunei Darussalam has three gas-fired power plants using approximately 3.106 m³/day gas and emitting substantial flue gases into the atmosphere. After desulphurisation with sea water, carbon-dioxide, the gas primarily associated with global warming and the main constituent of flue gas, can be dissolved under pressure in seawater and injected into the sea at suitable depth. The injected solution constitutes a negatively buoyant plume in the sea, carried by currents to deeper regions. It has been noted that the solution mixes and reacts with other oceanic components and converts to carbonates and sulphates that can remain near the bottom for several hundreds of years. Until a better alternative is developed, this may be an immediate solution to the problem of dealing with flue gases. The feasibility and economics of this alternative have been discussed in the literature. For optimal design criteria for such disposal, numerous parameters (such as location, pipe diameter, type of diffuser, angles of discharge, etc.) are involved in the mathematical analysis. Many alternative sets of these parameters must be used as input parameters to arrive at final design parameters for optimal results.  相似文献   

Evidence of paleoearthquakes from trench investigations across Pinjore Garden fault in Pinjore Dun, NW Himalaya   总被引：2，自引：0，他引：2  

Javed N. Malik  George Mathew 《Journal of Earth System Science》2005,114(4):387-400

The Pinjore Garden Fault (PGF) striking NNW-SSE is now considered one of the active faults displacing the younger Quaternary surfaces in the piggyback basin of Pinjore Dun. This has displaced the older Kalka and Pinjore surfaces, along with the other younger surfaces giving rise to WSW and SW-facing fault scarps with heights ranging from 2 to 16 m. The PGF represents a younger branch of the Main Boundary Thrust (MBT) system. An ~ 4m wide trench excavated across the PGF has revealed displacement of younger Quaternary deposits along a low angle thrust fault. Either side of the trench-walls reveals contrasting slip-related deformation of lithounits. The northern wall shows displacement of lithounits along a low-angle thrust fault, while the southern wall shows well-developed fault-related folding of thick sand unit. The sudden change in the deformational features on the southern wall is an evidence of the changing fault geometry within a short distance. Out of five prominent lithounits identified in the trench, the lower four units show displacement along a single fault. The basal unit ‘A’ shows maximum displacement of aboutT _o = 2.85 m, unit B = 1.8 m and unit C = 1.45 m. The displacement measured between the sedimentary units and retro-deformation of trench log suggests that at least two earthquake events have occurred along the PGF. The units A and D mark the event horizons. Considering the average amount of displacement during one single event (2 m) and the minimum length of the fault trace (~ 45 km), the behaviour of PGF seems similar to that of the Himalayan Frontal Fault (HFF) and appears capable of producing large magnitude earthquakes.  相似文献   

Nonlinear disturbances in self-gravitating media     

S. K. Malik  M. Singh 《Astrophysics and Space Science》1979,66(1):133-141

Using a multiple time-scale method, the weakly nonlinear waves on a self-gravitating incompressible fluid column are investigated. The analysis reveals that near the wavenumberk=k _c , the amplitude modulation of a standing wave can be described by the nonlinear Schrödinger equation with the roles of time and space variables interchanged. The nonlinear cutoff wavenumber, which depends sensitively on initial conditions, can then be derived from the nonlinear Schrödinger equation so obtained. The finite amplitude standing wave is stable against modulation.  相似文献   

Credibility of design rainfall estimates for drainage infrastructures: extent of disregard in Nigeria and proposed framework for practice     

Aiyelokun  Oluwatobi  Pham  Quoc Bao  Aiyelokun  Oluwafunbi  Malik  Anurag  Adarsh  S.  Mohammadi  Babak  Linh  Nguyen Thi Thuy  Zakwan  Mohammad 《Natural Hazards》2021,109(2):1557-1588

Natural Hazards - Rainfall intensity or depth estimates are vital input for hydrologic and hydraulic models used in designing drainage infrastructures. Unfortunately, these estimates are...  相似文献   

Upper-Level Winds over Southern Ontario: O-QNet Wind Profiler and NARR Comparisons     

Peter A. Taylor  Wensong Weng  Zheng Qi Wang  Mathew Corkum  Khalid Malik  Shama Sharma 《大气与海洋》2017,55(1):1-11

Upper-level winds are primarily measured by tracking the position of radiosonde balloons as they rise through the atmosphere. Radiosondes are released from a global network at 0000 utc and 1200 utc each day, and data are quickly available to the world's weather services, as well as to the public. The network is relatively coarse spatially, and there are normally only two soundings per day. In an endeavour to provide better spatial and temporal upper-level regional wind measurements, the O-QNet (a demonstration very high frequency wind profiler network for Ontario and Quebec) was installed and has been operated by York, Western, and McGill Universities with support from Mardoc Inc., The Weather Network, and Environment and Climate Change Canada. Initial funding was provided by the Canada Foundation for Innovation, the Ontario Innovation Trust, and Mardoc Inc. The present paper reports primarily on comparisons between winds measured by the O-QNet profilers and the winds reported in the North American Regional Reanalysis (NARR). There is good agreement between the two, which provides support for the use of NARR data to investigate longer term variations in upper-level winds associated with climate change for this region.  相似文献   

Load Settlement Behaviour of Fly ash Mixed with Waste Sludge and Cement     

Malik Shoeb Ahmad  S. S. Shah 《Geotechnical and Geological Engineering》2016,34(1):37-58

One of the effective utilization strategies for fly ash and waste sludge is to use it as a fill material to raise low lying areas. Bearing capacity and settlement are the required input for the design of foundations on such fills. To determine the bearing capacity, plate load tests were carried out on the compacted beds of fly ash, fly ash-waste sludge and fly ash-waste sludge–cement. The tests were conducted by keeping 90, 95 and 100 % relative compaction, fresh and fresh submerged conditions, aged (28 days) and aged (28 days) submerged conditions as variables of the tests. The load-settlement curves were plotted for fly ash and mix blends. The minimum load was obtained for fly ash under submerged condition, further the test results show that the fly ash becomes flowable on submergence. On the other hand when the fly ash was mixed with waste sludge and cement, the load carrying capacity was found to improve to a greater extent. Test beds prepared with fly ash–cement-waste sludge under as compacted condition (fresh) show very high load carrying capacity (1600–2180 kN/m²). An analytical method has also been validated for fly ash–cement-waste sludge mix which was developed to estimate the settlement of footing resting on fly ash taking into account the pre-consolidation stresses. The non linearity of load-settlement behavior was appropriately modeled, on the basis of available plate load test data incorporated in the method. The method requires as input, the pre-consolidation stress and Young’s modulus of compacted mix of fly ash-waste sludge–cement. A comparison of load-settlement values observed in plate load tests and predicted values for the mix 47 %FA + 45 %S + 8 %C, using the proposed method shows good agreement. Hence, this relationship may also be useful to the field engineers to check the reported load-settlement values for such types of mixes in the field.  相似文献   

Radiative transfer code: Application to the calculation of PAR     

Devred Emmanuel  Dubuisson Phillipe  Chami Malik 《Journal of Earth System Science》2000,109(4):407-413

The production of carbon in the ocean, the so-called primary production, depends on various physicobiological parameters: the biomass and nutrient amounts in oceans, the salinity and temperature of the water and the light available in the water column. We focus on the visible spectrum of the solar radiation defined as the Photosynthetically Active Radiation (PAR). We developed a model (Chamiet al. 1997) to simulate the behavior of the solar beam in the atmosphere and the ocean. We first describe the theoretical basis of the code and the method we used to solve the radiative transfer equation (RTE): the successive orders of scattering (SO). The second part deals with a sensitivity study of the PAR just above and below the sea surface for various atmospheric conditions. In a cloudy sky, we computed a ratio between vector fluxes just above the sea surface and spherical fluxes just beneath the sea surface. When the optical thickness of the cloud increases this ratio remains constant and around 1.29. This parameter is convenient to convert vector flux at the sea surface as retrieved from satellite to PAR. Subsequently, we show how solar radiation as vector flux rather than P A R leads to an underestimate of the primary production up to 40% for extreme cases.  相似文献   

Mineralogy,chemistry, and composition of organic compounds in the fresh carbonaceous chondrite Mukundpura: CM1 or CM2?     

S. Potin  P. Beck  L. Bonal  B. Schmitt  A. Garenne  F. Moynier  A. Agranier  P. Schmitt‐Kopplin  A. K. Malik  E. Quirico 《Meteoritics & planetary science》2020,55(7):1681-1696

We present here several laboratory analyses performed on the freshly fallen Mukundpura CM chondrite. Results of infrared transmission spectroscopy, thermogravimetry analysis, and reflectance spectroscopy show that Mukundpura is mainly composed of phyllosilicates. The rare earth trace elements composition and ultrahigh‐resolution mass spectrometry of the soluble organic matter give results consistent with CM chondrites. Finally, Raman spectroscopy shows no signs of thermal alteration of the meteorite. All the results agree that Mukundpura has been strongly altered by water on its parent body. Comparison of the results obtained on the meteorite with those of other chondrites of known petrologic types leads to the conclusion that Mukundpura is similar to CM1 chondrites, which differ from its original classification as a CM2.  相似文献   

The December 24, 2006 eruption of Bezymyannyi Volcano,Kamchatka     

N. A. Malik 《Journal of Volcanology and Seismology》2011,5(4):268-277

An explosive eruption occurred on Bezymyannyi Volcano December 24, 2006. The distribution of ashfall deposits over the peninsula was studied. The tephra was investigated for its chemical, mineral, and grain-size composition, its water-soluble complex was studied. About 30 000 tons of water-soluble substances along with 7 million tons of ash entered the environment over an area of over 8000 km². Information is supplied for this eruption from various sources and its geological impact has been estimated. The total volume of erupted pyroclastics was 0.01–0.014 km³, of which 0.004 km³ consisted of ash and 0.006–0.01 km³ were pyroclastic flow deposits.  相似文献   

Adaptive state estimation of groundwater contaminant boundary input flux in a 2-dimensional aquifer     

Muhammad Nauman Malik  Mehdi Murtuza  Iqbal Asif  Bakar Muhammad Saifullah Abu  Brahim Aissa  Dk Nur Afiqah Jalwati Puteri  Amer Farhan Rafique 《地下水科学与工程》2014,7(4):373-382

In many circumstances involving heat and mass transfer issues, it is considered impractical to measure the input flux and the resulting state distribution in the domain. Therefore, the need to develop techniques to provide solutions for such problems and estimate the inverse mass flux becomes imperative. Adaptive state estimator (ASE) is increasingly becoming a popular inverse estimation technique which resolves inverse problems by incorporating the semi-Markovian concept into a Bayesian estimation technique, thereby developing an inverse input and state estimator consisting of a bank of parallel adaptively weighted Kalman filters. The ASE is particularly designed for a system that encompasses independent unknowns and /or random switching of input and measurement biases. The present study describes the scheme to estimate the groundwater input contaminant flux and its transient distribution in a conjectural two-dimensional aquifer by means of ASE, which in particular is because of its unique ability to efficiently handle the process noise giving an estimation of keeping the relative error range within 10% in 2-dimensional problems. Numerical simulation results show that the proposed estimator presents decent estimation performance for both smoothly and abruptly varying input flux scenarios. Results also show that ASE enjoys a better estimation performance than its competitor, Recursive Least Square Estimator (RLSE) due to its larger error tolerance in greater process noise regimes. ASE’s inherent deficiency of being slower than the RLSE, resulting from the complexity of algorithm, was also noticed. The chosen input scenarios are tested to calculate the effect of input area and both estimators show improved results with an increase in input flux area especially as sensors are moved closer to the assumed input location.  相似文献