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41.
ABSTRACT: Recent assessments have emphasized the lack of a field and laboratory component in hydrologic education at the university level. Consequences of this lack include: (1) an unwarranted faith in published data; (2) lack of appreciation for the spatial and temporal variability of most hydrologic processes; (3) lack of appreciation for the difficulty of collecting good quality field data; (4) an inability to design and execute projects to collect field data; (5) a lack of field experience which can be applied when confronted with different problems or new environments; (6) an inability to evaluate published materials or models against “field reality;” (7) an excessive reliance on, and trust in, theoretical or conceptual models; and (8) reduced potential for lifelong learning through observation and analysis. Field courses need not be costly or difficult, but the instructor must be willing to adapt to the uncertainty and problems associated with field measurements. A recently updated course on watershed measurements at Colorado State University illustrates the type of field courses which can be developed if there is the necessary commitment and flexibility. The lack of a current text can be overcome by assembling selected portions of existing government documents, and a sample bibliography is included.  相似文献   
42.
ABSTRACT: The town of Jamestown, Rhode Island, located on Conanicut Island in Narragansett Bay, is constructing a secondary treatment plant in order to comply with NPDES regulations. Twelve candidate sites for the plant and marine outfall were initially proposed, and ability to meet State water quality standards at these sites was evaluated using an EPA buoyant plume model. A final outfall site, Taylor Point, was selected by the Town from among the sites considered acceptable. Taylor Point was then subjected to field hydrographic studies including drogue tracking, current recordings, and tracer dye surveys. Results of the measurement program served as input to a two-dimensional effluent dispersion model which predicted excess BOD, coliform, and suspended solids resulting from effluent discharge off Taylor Point. The model predictions demonstrated that State water quality standards can be maintained outside the initial discharge plume.  相似文献   
43.
This paper begins with a brief review of radiation theory as applied to water temperature determinations. Errors introduced in “radiant” temperature measurements due to nonblackness of the water surface and the effects of the atmosphere are included in this discussion. The airborne scanner system is described. Analysis and display of scanner data using the Laboratory for Applications of Remote Sensing (LARS) display system are discussed. Thermal maps of four sections of the Wabash River are included and points of interest of each map are discussed in the text.  相似文献   
44.
When designing energy efficient buildings it is useful to study existing climate—responsive building typologies. The wind towers or wind-catchers of Yazd city in Iran are typical examples of such a typology. Although many previous studies have investigated the performance of various types of wind catcher systems, studies based on a long-term real-life measurement can be rarely found. In this study a long-term whole year monitoring campaign on an existing full scale four sided wind catcher in Yazd was carried out in 2014–2015. Three prevailing wind directions were identified and the measured on-site wind speeds were used to estimate the wind induced natural ventilation potential of the tower. A shaft/tower airflow performance index was developed. The monitoring results were compared to the ASHRAE Standard 62:2001 ventilation rate requirement. Results show that the total ventilation rate of the wind tower surpasses the ASHRAE Standard requirements. Furthermore it shows that the shafts are exposed to the prevailing wind directions perform better. For more effective natural ventilation a wind tower with adaptable openings/shafts are proposed.  相似文献   
45.
Managers need measurements and resource managers need the length/width of a variety of items including that of animals, logs, streams, plant canopies, man-made objects, riparian habitat, vegetation patches and other things important in resource monitoring and land inspection. These types of measurements can now be easily and accurately obtained from very large scale aerial (VLSA) imagery having spatial resolutions as fine as 1 millimeter per pixel by using the three new software programs described here. VLSA images have small fields of view and are used for intermittent sampling across extensive landscapes. Pixel-coverage among images is influenced by small changes in airplane altitude above ground level (AGL) and orientation relative to the ground, as well as by changes in topography. These factors affect the object-to-camera distance used for image-resolution calculations. ‘ImageMeasurement’ offers a user-friendly interface for accounting for pixel-coverage variation among images by utilizing a database. ‘LaserLOG’ records and displays airplane altitude AGL measured from a high frequency laser rangefinder, and displays the vertical velocity. ‘Merge’ sorts through large amounts of data generated by LaserLOG and matches precise airplane altitudes with camera trigger times for input to the ImageMeasurement database. We discuss application of these tools, including error estimates. We found measurements from aerial images (collection resolution: 5–26 mm/pixel as projected on the ground) using ImageMeasurement, LaserLOG, and Merge, were accurate to centimeters with an error less than 10%. We recommend these software packages as a means for expanding the utility of aerial image data.  相似文献   
46.
Five monolithic catalysts with low noble metal content were prepared by irnmerge method (Pt/γ=Al2O3, Pt/La-Al2O3, Pt/YSZ-AI203, Pt+Pd/La-Al2O3 and Pd/La-Al2O3) and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. The Pt/La-Al2O3 catalyst has the highest activity and can be applied in wide range of gas hourly space velocity (GHSV). Some characterizations (XRD, TPR) were carried out with the objective to explain differences in catalytic behaviors. The prepared catalyst showed a great potential for application.  相似文献   
47.
Water quality at Omerli Dam, which is a vital potable water resource of Istanbul City, Turkey was assessed using the first four bands of Landsat 7-ETM satellite data, acquired in May 2001 and water quality parameters, such as chlorophyll-a, suspended solid matter, secchi disk and total phosphate measured at several measurement stations at Omerli Dam during satellite image acquisition time and archived at the Marine Pollution and Ecotoxicology laboratory of the Marmara Research Center, where this study was carried out. Establishing a relationship between this data, and the pixel reflectance values in the satellite image, chlorophyll-a, suspended solid matter, secchi disk and total phosphate maps were produced for the Omerli Dam.  相似文献   
48.
49.
利用2013年8月,以Y-12飞机为空中观测平台,搭载PCASP、SMPS、AMS、CCN200、TSI-3563型积分浊度仪和美国MAAP-5012型多角度吸收光度计等多种气溶胶观测仪器,首次对黄土高原大气气溶胶特性开展联合观测的资料,对大气气溶胶粒度,散射和颗粒吸收特性进行了分析,研究了区域气溶胶的空间分布及理化特征.结果表明黄土高原特殊地形区域气溶胶的微物理特性较稳定,但随探测时气象条件的变化,散射系数仍然出现波动;区域气溶胶中以细粒子为主;三个波长散射系数变化趋势非常一致,可以认为探测过程中气溶胶的微物理特性基本不变,而仅仅是浓度在改变;散射系数的变化趋势与体积浓度的变化趋势基本一致;其高值区与大气高湿区的正相关性比较明显;四次探测过程中小尺度粒径的气溶胶粒子为优势粒子;后向轨迹分析可知研究区域大部分气溶胶粒子都来源于高空,由蒙古、内蒙、甘肃、陕西等地远距离输送而来.  相似文献   
50.
Medical isotope production facilities (MIPF) have recently been identified to emit the major part of the environmental radioxenon measured at many globally distributed monitoring sites deployed to strengthen the radionuclide component of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime. Efforts to raise a global radioxenon emission inventory revealed that the yearly global total emission from MIPF’s is around 15 times higher than the total radioxenon emission from nuclear power plants (NPP's).Given that situation, from mid 2008 until early 2009 two out of the ordinary hemisphere-specific events occured:1) In the Northern hemisphere, a joint temporary suspension of operations of the three largest MIPF's made it possible to quantify the effects of the emissions related to NPP’s. The average activity concentrations of 133Xe measured at a monitoring station close to Freiburg, Germany, went down significantly from 4.5 ± 0.5 mBq/m3 to 1.1 ± 0.1 mBq/m3 and in Stockholm, Sweden, from 2.0 ± 0.4 mBq/m3 to 1.05 ± 0.15 mBq/m3.2) In the Southern hemisphere the only radioxenon-emitting MIPF in Australia started up test production in late November 2008. During eight test runs, up to 6.2 ± 0.2 mBq/m3 of 133Xe was measured at the station in Melbourne, 700 km south-west from the facility, where no radioxenon had been observed before, originating from the isotopic production process.This paper clearly confirms the hypothesis that medical isotope production facility are at present the major emitters of radioxenon to the atmosphere. Suspension of operations of these facilities indicates the scale of their normal contribution to the European radioxenon background, which decreased two to four fold. This also gives a unique opportunity to detect and investigate the influence of other local and long distance sources on the radioxenon background. Finally the opposing effect was studied: the contribution of the start-up of a renewed radiopharmaceutical facility to the build up of a radioxenon background across Australia and the Southern hemisphere.  相似文献   
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