This study aimed to apply the Taguchi optimization technique to determine the process conditions for producing synthetic lightweight aggregate (LWA) by incorporating tile grinding sludge powder with reservoir sediments. An orthogonal array L16(4⁵) was adopted, which consisted of five controllable four-level factors (i.e., sludge content, preheat temperature, preheat time, sintering temperature,...

Chemical-flooding schemes for recovering residual oil have been in general less than satisfactory due to loss of chemicals by adsorption on reservoir rocks, precipitation, and resultant changes in rock wettability. Adsorption and wettability changes are determined mainly by the chemical structure and mix of the surfactants, surface properties of the rock, composition of the oil and reservoir fl...

The Olfus-Bakki geothermal area (OBGA) in SW Iceland is located in the S and SE margins of the high-enthalpy systems of Hveragerdi and Hengill, respectively. This geothermal area contains a productive region, denominated the Bakki field, which produces fluid at temperatures in the range of 100-130 °C. Since 1979, the geothermal resource has supplied thermal energy to the town of Thorlakshofn, m...

The concept of Carnot efficiency is a cornerstone of thermodynamics. It states that the efficiency of a cyclic (“Carnot”) thermal engine that transforms an amount Qr of energy extracted from a heat reservoir at temperature Tr into an amount of work W is at most η = W/Qr ≤ ηc = 1−Tl/Tr, where Tl is the temperature of a second, colder reservoir. The theoretical implications of this result are mom...

Two reservoirs in Taiwan were modeled to simulate the hydrodynamics and water quality in the water column. The modelling effort was supported with data collected in the field for a 2-year period for both reservoirs. Spatial and temporal distributions of temperature in the water column of the two reservoirs were well reproduced by the hydrodynamic model. Model calculated concentrations of key wa...

BACKGROUND Operation of the Three Gorges Reservoir (TGR, China) imposes a new water fluctuation regime, including a prolonged winter submergence in contrast to the natural short summer flooding of the rivers. The contrasting water temperature regimes may remarkably affect the survival of submerged plants in the TGR. Plant survival in such prolonged flooding might depend on the carbohydrate stat...

A predictive framework is developed and applied to evaluate benefits of multilevel intake configurations in managing temperature TW and turbidity CT,W in water withdrawn from a water supply reservoir, Schoharie Reservoir, New York, that presently, has a single level intake. High values of TW occur in late summer for the reservoir in major drawdown years, and high CT,W levels occur irregularly f...

Our understanding of the processes underlying the formation of heavy oil has been transformed in the last decade. The process was once thought to be driven by oxygen delivered to deep petroleum reservoirs by meteoric water. This paradigm has been replaced by a view that the process is anaerobic and frequently associated with methanogenic hydrocarbon degradation. The thermal history of a reservo...

[1] Buffett and Archer (2004) showed a model of the steady state global ocean clathrate reservoir that reproduces drill data and predicts a global methane inventory of about 5000 Gton C. The model inventory is very sensitive to ocean temperature, with factor-of-two changes in methane inventory in response to temperature changes of 1.5 C. Here we explore the potential time-dependent behavior of ...

Understanding nanodiamond functionalisation is of great importance for biological and medical applications. Here we examine the stabilities of oxygen, hydroxyl, and water functionalisation of the nanodiamonds using the self-consistent charge density functional tight-binding simulations. We find that the oxygen and hydroxyl termination are thermodynamically favourable and form strong C–O covalen...