نتایج جستجو برای: determining boundaries snow the

تعداد نتایج: 16072425  

2013
T. Bartels - Rausch S. N. Wren S. Schreiber F. Riche M. Schneebeli M. Ammann

Release of trace gases from surface snow on earth drives atmospheric chemistry, especially in the polar regions. The gas-phase diffusion of methanol and of acetone through the interstitial air of snow was investigated in a wellcontrolled laboratory study in the temperature range of 223 to 263 K. The aim of this study was to evaluate how the structure of the snowpack, the interaction of the trac...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده ادبیات 1389

the present study reports an analysis of response articles in four different disciplines in the social sciences, i.e., linguistics, english for specific purposes (esp), accounting, and psychology. the study has three phases: micro analysis, macro analysis, and e-mail interview. the results of the micro analysis indicate that a three-level linguistic pattern is used by the writers in order to cr...

Journal: :Natural Hazards and Earth System Sciences 2018

2017
N. Rutter R. Essery

Microwave radar amplitude within a snowpack can be strongly influenced by spatial variability of internal layer boundaries. We quantify the impact of spatial averaging of snow stratigraphy and physical snowpack properties on surface scattering from near-nadir frequency-modulated continuous-wave radar at 12–18 GHz. Relative permittivity, density, grain size and stratigraphic boundaries were meas...

2015
Gregor von Laszewski Fugang Wang Geoffrey C. Fox Jilu Li John Paden

Without doubt the analysis of data from Polar Regions is an important aspect of identifying environmental impact by humans. The calculation of automatic techniques for determining ice and snow layer boundaries in radar echograms remains a hard problem because of two reasons. First, the data volume and the associated calculations to retrieve results are large requiring considerable supercomputin...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

seismic retrofit strategies have been developed in the past few decades following the introduction of new seismic provisions and the availability of advanced materials and methods. it can be observed that new approaches to deal with more lateral forces are more innovative and more energy absorbent. in line with this, there is a growing trend toward the use of steel shear walls as a system with ...

ژورنال: کواترنری ایران 2019
, , Maghsoudi, Mehran,

Introduction Site selection of human habitats in pre-historic times, unlike the current periods, has been strongly influenced by natural factors. Studies may be focused on three areas including paleoclimate, paleogeomorphology and archeology in order to identify environmental factors affecting primary habitats. Based on studies, most of the ancient lakes in central Iran were formed during the Q...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم انسانی 1390

supervisors play an undeniable role in training teachers, before starting their professional experience by preparing them, at the initial years of their teaching by checking their work within the proper framework, and later on during their teaching by assessing their progress. but surprisingly, exploring their attributes, professional demands, and qualifications has remained a neglected theme i...

 In this study in order to monitor snow cover, the Moderate Resolution Imaging Spectroradiometer (MODIS) optical images were used, while for detection of snow covered areas, the  snow index-NDSI, was applied. The results showed - according to the climatic conditions of the region- during the following months: December, January, February and March, most of the area is covered by snow and the max...

Journal: :IEEE Trans. Geoscience and Remote Sensing 2001
Son V. Nghiem Wu-Yang Tsai

This paper presents a study to demonstrate the potential of a spaceborne u-band scatterometer to monitor global snow cover. Global u-band data were acquired by the National Aeronautics and Space Administration (NASA) Scatterometer (NSCAT) operated on the Advanced Earth Observing Satellite (ADEOS) from September 1996 to June 1997. NSCAT backscatter patterns over the northern hemisphere reveals b...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید