This study evaluates the effectiveness of marine reserves as an approach to coral reef management in Southeast Asia and isolates the most effective management techniques. Seven reserve areas in the Philippines are compared with two similar management areas in Indonesia and two in Malaysia. Two control areas in the Philippines are also considered.
This article examines groundfish management philosophies and practices of the United States and Canada in the Gulf of Maine-Georges Bank region. The authors conclude that significant differences in the legal, administrative, and philosophical framework of the two countries' fisheries regimes must be recognized and accommodated before effective management of transboundary stocks can occur.
Coal pyrolysis is the initial reaction of vast utilization technologies, and the quantitative description of pyrolysis characteristics and accurate kinetic parameters under the wide range of heating rates are of significant challenges. The effect of heating rate from 5 ℃/min to 1000 ℃/min on coal pyrolysis in a novel concentrating photothermal thermogravimetric analyzer was systematically investigated. A new temperature control scheme especially for the ultra-fast heating process was proposed, guaranteeing the absolute temperature control error was less than 4 ℃ throughout the whole heating process. As the heating rate increased from 5 ℃/min to 1000 ℃/min, the absolute value of maximum mass loss rate increased linearly from 4.18 wt%/min to 66.06 wt%/min, and the specific reaction rate for coal conversion at 20% and 50% also increased linearly by 15.4 times and 16.4 times, respectively. The mean activation energies exhibited the exponential decrease tendency from 235.41 kJ/mol to 28.37 kJ/mol. The transformation rates for functional groups of chars were accelerated with the heating rate, and the char with same conversion rate would be more condensed. The activation energy of coal during pyrolysis under heating rate of 1000 ℃/min was binomially correlated with the ratio of small aromatic rings to large ones in char.
The depth capabilities of offshore oil technologies have increased substantially over the last four decades. Recently exploratory drilling operations have been conducted in water as deep as 2119 m and oil and gas production facilities have been installed in 311 m of water. The maximum potential impact of the technology is computed yearly using annual depth records which are converted into area of seafloor. In one region, the Western Gulf of Mexico, deep water production capability had exceeded the bathymetric limits and hence area of the geologic shelf by 1975. On a global scale if depth is the sole constraining factor, up to 53 million km2 or 15% of ocean-area is now open to exploratory drilling. This is equivalent to 37% of all land area above sealevel. Using the same bathymetric constraint up to 23 million km2 worldide became available for production by 1978. These subsea areas will influence global supply during times of high demand for oil and gas.
This paper reports a numerical study on the aeroacoustic response of a rectangular T-junction with merging mean flows. The primary motivation of the work is to explain the high sound amplification, recently seen experimentally, when introducing a small merging bias flow. The acoustic results are found solving the compressible Linearized Navier–Stokes Equations (LNSEs) in the frequency domain, where the base flow is first obtained using RANS with a k–ε turbulence model. The model predicts the measured scattering data well, including the amplitude and Strouhal number for the peak amplification, if the effect of eddy viscosity damping is included. It is found that the base flow changes significantly with the presence of a small bias flow. Compared to pure grazing flow a strong unstable shear layer is created in the downstream main duct starting from the T-junction trailing edge. This means that the main region of vortex–sound interaction is moved away from the junction to a downstream region much larger than the junction width. To analyze the sound amplification in this region Howe׳s energy corollary and the growth of acoustic density are used.
