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 ...

the aim of this study was to evaluate the efficacy of a hyaluronic acid containing eye drop in ameliorating ocular surface pathology and discomfort in canine keratoconjunctivitis sicca (kcs). twenty five dogs with kcs treated with a topical carbomer (ca)-based tear replacement gel were moved to treatment with a hyaluronic acid (ha)-containing tear replacement eye drop. dogs were subject to a fu...

this review focuses on the latest developments in applications of carbon nanotubes (cnts) in medicine. a brief history of cnts and a general introduction to the field are presented. then, surface modification of cnts that makes them ideal for use in medical applications is highlighted. examples of common applications, including cell penetration, drug delivery, gene delivery and imaging, are giv...

objective: to determine the diagnostic value of blood cells surface markers in patients with acute appendicitis. methods: in this cross-sectional study, 71 patients who underwent appendectomy following a diagnosis of appendicitis were recruited during a one-year period. the patients were divided into two groups: patients with histopathologically confirmed acute appendicitis and subjects with no...

background the transmission of hepatitis b virus (hbv) is parenteral, sexual and prenatal. prevention of vertical transmission of hbv is extremely important, because hbv infection in early life usually results in a chronic carrier state. there has been so much debate about hepatitis b surface antigen (hbsag) screening in pregnant women. objectives the aim of this study was to determine the prev...