1,444 research outputs found
The Role of Subsurface Flow Dynamic on Spatial and Temporal Variation of Water Chemistry in a Headwater Catchment
Variation of water chemistry does not merely occur due to in situ chemical process, but also transport process. The study was carried out to address the role of subsurface flow dynamic on spatial and temporal variation of water chemistry in a headwater catchment. Hydrometric and hydrochemistry measurements were done in transect with nested piezometers, tensiometers, and suction samplers at different depths across hillslope and riparian zone in a 5.2 ha first-order drainage of the Kawakami experimental basin, Nagano, Central Japan from August 2000 to August 2001. Spatial variation of solute concentration was defined by the standard deviation and coefficient of variation of the seasonal observed concentrations. Autocorrelation analysis was performed to define temporal variation of solute concentration. The results showed that spatial variation of water chemistry was mainly influenced by the variation of subsurface flow through the hillslope and riparian zone. Solute concentration in the deep riparian groundwater was almost three times higher than that in the hillslope segment. A prominent downward flow in deep riparian groundwater zone provided transport of solutes to the deeper layer. Time series analysis showed that in the deep riparian groundwater, Ca2+, Mg2+, SO42- and HCO3- concentrations underwent a random process, Na+ concentration of a random process superimposed by a trend process, and SiO2 of a random process superimposed by a periodic process. Near the riparian surface, SO42- concentration was composed of a random process superimposed by a periodic process, whereas other solutes were mainly in a random process. In the hillslope soil water, there was no trend observed for the Na+ concentration, but there were for Ca2+ and Mg2+. The magnitude and direction of subsurface flow across hillslope and riparian zone created transport and deposition processes that changed solute concentration spatially and temporally
Evaluation and correlation of viscosity data : the most probable values of the viscosity of gaseous propane and propylene
The critical evaluation of the viscosity data of gaseous propane and propylene has beed carried out based on the experimental data available in literature. The most probable values of the viscosity of propane are presented in the form of numerical tables covering the range of temperatures from 298.15 to 523.15 K and that of pressures up to 550×10^5 Pa. The estimated uncertainties of the tabulated values are also given. Since there exist only three sets of experimental data available in literature for propylene, the smoothed values are generated on the basis of these data covering the range of temperatures from 300 to 525 K and that of pressures up to 800×10^5 Pa
<Articles><Hydrology>Dynamics of soil carbon dioxide during a storm event Geomorphology
In general, soil carbon dioxide(CO2)is produced by two major processes, the respiration of plant roots and the decomposition of soil organic substances. Because the produced CO2, is essentially biogenic its concentration is ..
On the Emulsification of the Flotation Reagents by Means of Ultrasonic Waves
The method utilizing frothers as a flotation reagent, emulsified in water by means of ultrasonic waves of a suitable frequency and intensity, was investigated. The object is to obtain high selectivity for the differential flotation with the lowest economical comsumption of the flotation reagents. By this process, the ore minerals to be required can be collected with high efficiency which is due to the increase of the floating action, even if the reagents are hardly mixing with water, the emulsion can be readily intermixed into the pulp
Differential diagnosis of chronic lymphocytic leukemia/small lymphocytic lymphoma and other indolent lymphomas, including mantle cell lymphoma
Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) accounts for approximately 1% of all lymphomas in our department. In this article, we describe the differential diagnosis of CLL/SLL from other indolent lymphomas, with special reference to follicular lymphoma, marginal zone B-cell lymphoma, lymphoplasmacytic lymphoma, and mantle cell lymphoma, although the latter is considered to be aggressive. CLL/SLL often exhibits proliferation centers, similar to follicular lymphoma. Immunohistological examination can easily distinguish these two lymphomas. The most important characteristic of CLL/SLL is CD5 and CD23 positivity. Mantle cell lymphoma is also CD5-positive and there are some CD23-positive cases. Such cases should be carefully distinguished from CLL/SLL. Some marginal zone lymphomas are also positive for CD5 and such cases are often disseminated. Lymphoplasmacytic lymphoma should also be a differential diagnosis for CLL/SLL. It frequently demonstrates MYD88 L265P, which is a key differential finding. By immunohistological examination, the expression of lymphoid enhancer-binding factor 1 is specific for CLL/SLL and can be a good marker in the differential diagnosis
Methodology of integrated watershed management for sustainable water resources use
Water resources in the Asia region are very severe and scarce, and a very rapid population increase is apparent in recent years. This rapid population increase causes not only increase of water demand but also affect the land use change, resulting land degradation, soil erosion and change in hydrologic regimes. To overcome those water crises, it is necessary to develop a methodology and analytical methods for the desired watershed management. In the paper, the author proposed an integrated watershed management as one of the desired watershed managements for the next generation and showed a framework and a research flow of the management emphasizing the capacity building and the water governance as well as scientific researches on water resources issues
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