dumpsites can produce serious pollution problems in soil, water and air, and are the most frequent method of solid waste disposal in many developing countries. one of the pollution concerns at dumpsites is the emission of methane, which has been identified as a green house gas. in order to determine the surface emission of methane at an informal settlement built on a former dumpsite, six sampli...

a hydrothermal method for preparation of nano-size zirconia has been studied to optimize the effective parameters (precursor concentration, temperature and time) using response surface methodology (rsm). the synthesized zirconia samples were characterized through x-ray diffraction (xrd), scanning electron microscope (sem) and transmission electron microscopy (tem) analyses to identify mean nano...

the aisi 316 l stainless steel (ss) specimens were exposed to passivation surface through two different processes including; holding in 40-vol% hno3 at temperature of 60 ºc for 30 min and 15-vol%h2so4 at ambient temperature for 1 hour. the corrosion behavior of specimens was evaluated in physiological solutions by electrochemical in vitro tests through linear and tafel polarization tests. cycli...

the silica aerogel was prepared by the acid–base sol–gel polymerization of tetraethylorthosilicate precursor followed by ambient pressure drying. the prepared silica aerogels were characterized by fourier transform infrared )ft-ir(, thermo-gravimetric and differential thermal analysis )tg/dta(, x-ray diffractometer )xrd(, energy dispersive x-ray microanalysis )edx(, brunauer–emmitt–teller (bet)...

in this paper, surface and piezoelectric effects on the vibration behavior of nanowires (nws) are investigated by using a timoshenko beam model. the electric field equations and the governing equations of motion for the piezoelectric nws are derived with the consideration of surface effects. by the exact solution of the governing equations, an expression for the natural frequencies of nws with ...

although, most of the abnormal structures of human brain do not alter the shape of outer envelope of brain (surface), some abnormalities can deform the surface extensively. however, this may be a major problem in a surface-based registration technique, since two nearly identical surfaces are required for surface fitting process. a type of verification known as the circularity check for the shap...

congestive heart failure (chf) remains to be one of the major cardiovascular disorders in the world. due to the prevalence of chf related issues, it is prudent to seek out new prognostic predictors that would facilitate the prevention, monitoring, and treatment of the disease on a daily basis. a detection approach using entropy measures extracted from surface electrocardiograms (ecgs) and class...

sclerotinia stem rot (ssr), caused by sclerotinia sclerotiorum, is one of the most important diseases of canola (brassica napus) in golestan province, the leading canola producer in iran. in order to assess the yield loss of canola caused by ssr, 80 fields were surveyed in four different regions of the province (gorgan, ali abad, kalaleh and gonbad) during 2006-2007, and ssr intensity was recor...

in this paper, buckling of simply supported column with an edge crack is investigated numerically and analytically. four different scenarios of damage severities are applied to a column, open crack assumption and the effect of closing crack in stability of the column which depends on position and size of cracks, are numerically compared. crack surfaces contact is modeled with gap element using ...