نتایج جستجو برای: sand

تعداد نتایج: 28228  

2014
Guo Shuai Li Jian Jun Qu Xu Zhi Li Wan Fu Wang

Gravel beds can prevent sand-dust emission and weaken sand-dust flux. We used wind-tunnel experiments and field observations on artificial gravel beds above the Mogao Grottoes to quantify their impact. In the report, we identified a significant correlation between gravel roughness and its ability to trap wind-transported sand. The optimal combinations of gravel diameter and coverage were determ...

Journal: :Optics express 2007
Bradley W Kimmel Gladimir V G Baranoski

In this paper, we present a new spectral light transport model for sand. The model employs a novel approach to simulate light interaction with particulate materials which yields both the spectral and spatial (bi-directional reflectance distribution function, or BRDF) responses of sand. Furthermore, the parameters specifying the model are based on the physical and mineralogical properties of san...

Journal: :The Journal of the Acoustical Society of America 2006
Edwin R Lewis Peter M Narins Jennifer U M Jarvis Gary Bronner Matthew J Mason

Insect prey of the Namib golden mole congregate beneath clumps of grass scattered among the sand dunes of the Namib Desert. In the presence of the light winds that typically blow over the Namib Desert, these grass clumps emit low-amplitude vibrations that are transmitted through the sand. While foraging in the sand-swimming mode (a few centimeters below the surface of the sand), some moles appa...

2012
D. Gerard

63 Three soils (a silt loam, loamy sand, sandy loam) found in Mississippi and pure silica sand were treated with fipronil and bioassayed using eastern subterranean termites, Reticulitermes jlavipes. Soils were treated with aqueous solutions ofTermidor (fipronil) at concentrations of 0, 0.12, 0.25,2.5, 5.0 and 20.0 ppm (wt AI: wt soil) that brought the soils to 15% moisture. Estimated lethal con...

Journal: :Journal of epidemiology and community health 2000
S Laforest Y Robitaille D Dorval D Lesage B Pless

Playground injuries are a major public health problem. Laboratory studies have recommended sand, pearock, synthetic materials, or wood chips as protective surfaces beneath equipment, and epidemiological studies have confirmed that hard surfaces are dangerous. However, some questions remain about grass. To compare the protection oVered by grass and sand, public and residential playgrounds need t...

2014
Meera Joseph Zen Faulkes

We examined sand crabs (Lepidopa benedicti) for endoparasites, and found the only parasite consistently infecting the studied population were small nematodes. Because many nematodes have complex life cycles involving multiple hosts, often strongly manipulating their hosts, we hypothesized that nematodes alter the behavior of their sand crab hosts. We predicted that more heavily infected crabs w...

Journal: Desert 2007
G. Feghhi H. Ahmadi M. Ekhtesasi N. Mashhadi, S. Feiznia

Wind regime and sand grain size are two of the factors that determine the morphology and dynamics of sand dunes in desert areas. Regarding the importance of wind effects on sand dunes especially in Iran, in this study, Khartooran Erg was analyzed to determine wind direction and to detect sand source sites. Khartooran Erg is located on eastern north of Iran and lies in Khorasan Razavi and Semnan...

2016
Ismail Lafri Lionel Almeras Idir Bitam Aurelia Caputo Amina Yssouf Claire-Lise Forestier Arezki Izri Didier Raoult Philippe Parola Alvaro Acosta-Serrano

BACKGROUND Phlebotomine sand flies are known to transmit Leishmania parasites, bacteria and viruses that affect humans and animals in many countries worldwide. Precise sand fly identification is essential to prevent phlebotomine-borne diseases. Over the past two decades, progress in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as an acc...

2012
Mohammad Akhoundi Rounak Bakhtiari Thomas Guillard Ahmad Baghaei Reza Tolouei Denis Sereno Dominique Toubas Jérôme Depaquit Mehdi Razzaghi Abyaneh

BACKGROUND Phlebotomine sand flies are the vectors of the leishmaniases, parasitic diseases caused by Leishmania spp. Little is known about the prevalence and diversity of sand fly microflora colonizing the midgut or the cuticle. Particularly, there is little information on the fungal diversity. This information is important for development of vector control strategies. METHODOLOGY/PRINCIPAL ...

Journal: :Environmental monitoring and assessment 2013
Rui Liu Julie Gress Jie Gao Lena Q Ma

This study investigated the impacts of two best management practices (BMPs) recommended by US Environmental Protection Agency on Pb weathering and leachability in shooting range soils. The two BMPs included replacing soil berm with sand berm and periodically removing bullets or shot from a berm. A column experiment corresponding to the first BMP was conducted by mixing the bullets with sand/soi...

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