运用爆破震动来识别地下裂隙和软弱夹层

从爆破震动信号主要来源于爆破区邻近范围内地质结构的自振的观点出发，提出了一种探测地下裂隙和软弱夹层的新技术：把震源布置在裂隙和软弱夹层附近进行爆破，由于介质中裂隙和软弱夹层的存在使得局部结构的刚度减小。直接影响到爆破介质振动的速度幅值和频率，因此可以通过地表接收器接收的振动信号(包括振动速度的幅值和频率)识别出裂隙和软弱夹层的大小和形状等特征．通过无网格的数值算例分别从水平裂隙和斜裂隙的情况下总结规律说明了这种方法的可行性．

[C_Cordoba_Teatro] Documentación geométrica de los restos del Teatro Romano de Córdoba

[ES] El proyecto documenta los restos de una parte del antiguo teatro romano de Córdoba que se encuentran bajo la ampliación del museo arqueológico (MAECO) y ocupan una superficie de unos 50 x 20 metros, en el momento de la documentación era un área sobre la que se estaba construyendo el nuevo edificio. Se incluyen también otros posibles restos visibles desde el sótano de una residencia anexa.

Appraisal of water resources in the east central Florida region

The rapidly expanding population and economic growth in the seven counties of the East Central Florida Regional Planning Council as shown in Figure 1, herein called the East Central Florida Region or the Region, has resulted in increasing demands on its water resources. Although there is abundant water in the Region as a whole, the water in some areas of the Region is of unacceptable quality for most uses. As the population increases the demand for water will become much greater and the available supply may be reduced by pollution and increased drainage necessitated by urbanization and other land development- Ground-water supplies can be increased by capturing and storing water underground that now drains to the sea or evaporates from swamp areas. Research is needed, however, to develop artificial-recharge methods that are feasible and which will preserve or improve the quality of water in the aquifer. (PDF contains 57 pages)

Experimental Studies on Model Scramjet in a Mach 6 High Enthalpy Free-Jet Wind Tunnel

A side-wall compression scramjet model with different combustor geometries has been tested in a propulsion tunnel that typically provides the testing flow with Mach number of 5.8, total temperature of 1800K, total pressure of 4.5MPa and mass flow rate of 4kg/s. This kerosene-fueled scramjet model consists of a side-wall compression inlet, a combustor and a thrust nozzle. A strut was used to increase the contraction ratio and to inject fuels, as well as a mixing enhancement device. Several wall cavities were also employed for flame-holding. In order to shorten the ignition delay time of the kerosene fuel, a little amount of hydrogen was used as a pilot flame. The pressure along the combustor has an evident raise after ignition occurred. Consequently thrust was observed during the fuel-on period. However, the thrust was still less than the drag of the scramjet model. For this reason, the drag variation produced by different strut and cavities was tested. Typical results showed that the cavities do not influence the drag so much, but the length of the strut does.

Springs and swallets of the lower Santa Fe River

Many of our surface waters go underground to the aquifer via sinkholes (or swallets) and the water is then called groundwater. Most of us rely on groundwater for our drinking water. Springs are where the groundwater comes to the surface to once again become surface waters. Below is a map of the springs and swallets of the Lower Santa Fe River.

Experimental Studies on Scramjet Tested in a Freejet Facility

Two different type scramjet models with side-wall compression and top-wall compression inlets have been tested in HPTF (Hypersonic Propulsion Test Facility) under the experimental conditions of Mach number 5.8, total temperature 1700K, total pressure 4.5MPa and mass flow rate 3.5kg/s. The liquid kerosene was used as main fuel for the scramjets. In order to get fast ignition in the combustor, a small amount of hydrogen was used as a pilot. A strut with alternative tail was employed for increasing the compression ratio and for mixing enhancement in the side-wall compression case. Recessed cavities were used as a flameholder for combustion stability. The combustion efficiency was estimated by one dimensional theory. The uniformity of the facility nozzle flow was verified by a scanning pitot rake. The experimental results showed that the kerosene fuel was successfully ignited and stable combustion was achieved for both scramjet models. However the thrusts were still less than the model drags due to the low combustion efficiencies.

Interface electronics for an RF resonance-based displacement sensor

6 p. Paper of the 17th Conference on Sensors and Their Applications held in Dubrovnik, Croatia. Sep 16-18, 2013