نتایج جستجو برای: soil attenuation

تعداد نتایج: 229138  

2016
Andrea Colombi Philippe Roux Sebastien Guenneau Philippe Gueguen Richard V. Craster

We explore the thesis that resonances in trees result in forests acting as locally resonant metamaterials for Rayleigh surface waves in the geophysics context. A geophysical experiment demonstrates that a Rayleigh wave, propagating in soft sedimentary soil at frequencies lower than 150 Hz, experiences strong attenuation, when interacting with a forest, over two separate large frequency bands. T...

2016
Steven Footitt Simonetta Palleschi Eugenio Fazio Raffaele Palomba William E. Finch‐Savage Leopoldo Silvestroni

Seeds beneath the soil sense the changing environment to time germination and seedling emergence with the optimum time of year for survival. Environmental signals first impact with the seed at the seed coat. To investigate whether seed coats have a role in environmental sensing we investigated their ultraweak photon emission (UPE) under the variable temperature, relative humidity and oxygen con...

Journal: :Physical Communication 2009
Ian F. Akyildiz Zhi Sun Mehmet C. Vuran

Wireless Underground Communication Networks (WUCNs) consist of wireless devices that operate below the ground surface. These devices are either (i) buried completely under dense soil, or (ii) placed within a bounded open underground space, such as underground mines and road/subway tunnels. The main difference between WUCNs and the terrestrial wireless communication networks is the communication...

Journal: :The Analyst 2015
Tobias Jochum Beate Michalzik Anne Bachmann Jürgen Popp Torsten Frosch

Soil and groundwater contamination with benzene can cause serious environmental damage. However, many soil microorganisms are capable to adapt and are known to strongly control the fate of organic contamination. Innovative cavity enhanced Raman multi-gas spectroscopy (CERS) was applied to investigate the short-term response of the soil micro-flora to sudden surface contamination with benzene re...

2008
K. W. Campbell Y. Bozorgnia

We present a new empirical ground motion model for PGA, PGV, PGD and 5% damped linear elastic response spectra for periods ranging from 0.01–10 s. The model was developed as part of the PEER Next Generation Attenuation (NGA) project. We used a subset of the PEER NGA database for which we excluded recordings and earthquakes that were believed to be inappropriate for estimating free-field ground ...

BACKGROUND AND OBJECTIVES: Very low grid power penetration in some urban areas has led to telecoms companies investing massively in the deployment of diesel generators (DGs). These deployments have led to diesel and waste oil spill at base transceiver station (BTS) sites during maintenance cycles, impacting the environment and human activities. The objective of this study is to...

Journal: :محیط شناسی 0
مریم فراهانی گروه محیط زیست، دانشگاه آزاد اسلامی واحد رودهن ، دکتری محیط زیست سید احمد میرباقری استاد گروه عمران محیط زیست، دانشگاه صنعتی خواجه نصیر الدین طوسی

poly aromatic hydrocarbons are hydrophobic organic compound found as major contaminants in soil. soil biological activities are vital for the restoration of soil contaminated with hydrocarbons. successful application of bioremediation technology to contaminated soil requires knowledge of the characteristics of the site and the parameters that affect the microbial biodegradation of pollutants. t...

2013
Xiaoqing Yu Pute Wu Zenglin Zhang Ning Wang Wenting Han

Wireless underground sensor networks (WUSN) consist of wireless devices that operate below the ground surface. These devices are buried completely under dense soil, thus electromagnetic wave transmits only through soil medium. However, the high attenuation that caused by soil is the main challenge for the electromagnetic wave transmission for WUSN. In this study, architecture of wireless underg...

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