نتایج جستجو برای: erosion
تعداد نتایج: 30410 فیلتر نتایج به سال:
This in vitro study investigated the erosion-inhibiting properties of dental rinses during erosion in the presence of the salivary pellicle. The erosion inhibition by a Sn/F containing dental rinse (800 ppm Sn2+, 500 ppm F –, pH = 4.5) was compared with a fluoridated solution (500 ppm F –, pH = 4.5) and water(control). Calcium release and enamel softening were significantly reduced among enamel...
We have developed a mass balance analysis of organic carbon (OC) across the five major river subsystems of the Mississippi (MS) Basin (an area of 3.2 3 106 km2). This largely agricultural landscape undergoes a bulk soil erosion rate of ;480 t·km22·yr21 (;1500 3 106 t/yr, across the MS Basin), and a soil organic carbon (SOC) erosion rate of ;7 t·km22·yr21 (;22 3 106 t/yr). Erosion translocates u...
Suffusion is the process whereby fine particles are moved locally an transported through a coarse layer. This is a bulk erosion, which corresponds to a source term in the mass balance equations. This bulk erosion is counter intuitive, as erosion is basicaly an interfacial process. We suggest a framework within suffusion in a clayey sand can be viewed as a clay/water interface erosion at the mic...
Early recognition of dental erosion is important to prevent serious irreversible damage to the dentition. This requires awareness of the clinical appearance of erosion compared to other forms of tooth wear. An understanding of the etiologies and risk factors for erosion is also important. These form the basis of a diagnostic protocol and management strategy that addresses the multifactorial nat...
This study presents modern erosion rate measurements based upon vertical aerial photography captured in 1955, 1979, and 2002 for a 100 km segment of the Beaufort Sea coastline. Annual erosion rates from 1955 to 2002 averaged 5.6 m a. However, mean erosion rates increased from 5.0 m a in 1955 –79 to 6.2 m a in 1979 –2002. Furthermore, from the first period to the second, erosion rates increased ...
The design of erodible biomaterials relies on the ability to program the in vivo retention time, which necessitates real-time monitoring of erosion. However, in vivo performance cannot always be predicted by traditional determination of in vitro erosion, and standard methods sacrifice samples or animals, preventing sequential measures of the same specimen. We harnessed non-invasive fluorescence...
INTRODUCTION The aim of this study was to evaluate the condition of the ossicular chain in patients requiring surgery for cholesteatoma. MATERIALS AND METHODS In a retrospective analysis, the destruction of the individual and combined bony structures of the ear was described in 166 patients with cholesteatoma who went through surgery in our Otology Center between 2003 and 2009. RESULTS Tota...
Results of an experimental investigation are reported, conducted to study the stress-strain behavior of a soil having undergone different amounts of internal erosion. The soil used is gap-graded and cohesionless comprising silt, sand and gravel. Internal erosion tests and subsequent triaxial tests are performed in a specially designed apparatus having modified perforated end platens and a drain...
Soil erosion is the most widespread form of soil degradation. Land area globally affected by erosion is 1094 million ha (Mha) by water erosion, of which 751 Mha is severely affected, and 549 Mha by wind erosion, of which 296 Mha is severely affected. Whereas the effects of erosion on productivity and non-point source pollution are widely recognized, those on the C dynamics and attendant emissio...
Wind erosion not only affects agricultural productivity but also soil, air, and water quality. Dust and specifically particulate matter ≤10 μm (PM-10) has adverse effects on respiratory health and also reduces visibility along roadways, resulting in auto accidents. The Wind Erosion Prediction System (WEPS) was developed by the USDA-Agricultural Research Service to simulate wind erosion and prov...
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