نتایج جستجو برای: gpr
تعداد نتایج: 2556 فیلتر نتایج به سال:
روش رادار نفوذی به زمین (gpr) به منزلة یک روش غیرتخریبی به منظور آشکارسازی اهداف زیرسطحی واقع در عمق کم، براساس ارسال امواج الکترومغناطیسی به درون زمین و ثبت بازتاب های دریافت شده از امواج ارسالی، مورد استفاده قرار می گیرد. دانه بندی ذرات و وجود رُس مواد زیرسطحی به دلیل تغییراتی که در میزان رسانندگی و گذردهی الکتریکی ایجاد می کنند و در نتیجه، ایجاد تغییر نسبی در عمق نفوذ امواج gpr قابل تشخیص و ب...
Introduction: The thickness of the lunar regolith and potential for frozen water are important considerations for future lunar outposts. However, the thickness of the regolith is largely unknown and the presence of water ice has yet to be directly detected at or beneath the surface. A rapid and economical geophysical method to determine both the thickness of the lunar regolith and possibly iden...
to date, a number of numerical methods, including the popular finite-difference time domain (fdtd) technique, have been proposed to simulate ground-penetrating radar (gpr) responses. despite having a number of advantages, the finite-difference method also has pitfalls such as being very time consuming in simulating the most common case of media with high dielectric permittivity, causing the for...
The landmines presence causes serious safety hazards, which demand the clean up of contaminated land. Ground Penetrating Radar (GPR) is considered as a powerful nondestructive testing tool for high-resolution imaging of the shallow subsurface and its ability to detect both metallic and non-metallic landmines. The contrast in the dielectric constant between a landmine and the surrounding soil is...
The gastropyloric receptor (GPR) neurons of the stomatogastric nervous system of the crab Cancer borealis are muscle stretch receptors that can fire in either a spiking or a bursting mode of operation. Our goal is to understand what features of muscle stretch are encoded by these two modes of activity. To this end, we characterized the responses of the GPR neurons in both states to sustained an...
Effect of elevated CO2 on coarse-root biomass in Florida scrub detected by ground-penetrating radar.
Growth and distribution of coarse roots in time and space represent a gap in our understanding of belowground ecology. Large roots may play a critical role in carbon sequestration belowground. Using ground-penetrating radar (GPR), we quantified coarse-root biomass from an open-top chamber experiment in a scrub-oak ecosystem at Kennedy Space Center, Florida, USA. GPR propagates electromagnetic w...
در مطالعه حاضر از روش رادار نفوذی به زمین (GPR) جهت تعیین مشخصات هندسی و فیزیکی اهداف استوانهای مدفون نظیر انواع ساختارهای تونلی استفاده شده است. برای این منظور از روش تطبیق الگو بهکمک روابط ریاضی موجود بین مشخصات هندسی هدف استوانهای شامل شعاع، عمق دفن و موقعیت افقی، با پارامترهای هذلولی پاسخ، استفاده شد. روش تطبیق الگو از طریق بکارگیری دو روش تعیین ...
GPR senses electrical inhomogeneities, with these manifested, for example, by the electrical contrast of a metal mine in the presence of a far-less-conducting soil background. Of much more difficulty, GPR senses the electrical inhomogeneity caused by a dielectric (plastic) landmine in the presence of soil. Often this contrast is very weak, implying that the landmine GPR signal is very small. Th...
We investigated the eff ects of urantide, a receptor antagonist of urotensin II (U-II), on the expression of U-II and its receptor GPR in rat vascular smooth muscle cells. Vascular smooth muscle cells from rat thoracic aorta were cultured by explant method. Subjects in this experiment were divided into eight groups: normal control group (group C), U-II group (group M), positive control group ...
In this paper, results of GPR experiments carried out in Nalaih, Mongolia and Yakutsk, Russia will be shown. In the measurements, target is ground water and permafrost. Especially in these regions, there are special kind of permafrost structure, which are important in the study of permafrost. In Nalaih, there is “pingo”, which is composed of several layers including permafrost in the subsurface...
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