for any reduced commutative $f$-ring with identity and bounded inversion, we show that a condition which is obviously necessary for the socle of the ring to coincide with the socle of its bounded part, is actually also sufficient. the condition is that every minimal ideal of the ring consist entirely of bounded elements. it is not too stringent, and is satisfied, for instance, by rings of conti...

For the eigenvalue function on symmetric matrices, we have gathered a number of it’s properties.We show that this map has the properties of continuity, strict continuity, directional differentiability, Frechet differentiability, continuous  differentiability. Eigenvalue function will be extended to a larger set of matrices and then the listed properties will prove again.

high groundwater salinity, a high water table and secondary soil salinization are dominant conditions in eastern isfahan province, iran. this region has a low annual rainfall, high annual evaporation demand, saline soils and limited fresh water supplies. to investigate the effects of irrigation deficit and salinity on cantaloupe (cucumis melo l. var. cantalupensis) production, a field experimen...

chronic otitis media is a common disease which can lead to serious complications or even death. betterment of eustachian tube function is effective on results of operations. the main goal of this study was to determine the effect of eustachian tube function on outcome of graft in tympanoplasty or tympanomastoidectomy for chronic otitis media. we prospectively studied 126 patients who underwent ...

background: foundry workers are occupationally exposed to hazardous substances such as silica dusts and toxic gases. the aim of this study was to examine the effects of simultaneous exposure to complex mixtures of silica dust, formaldehyde, and triethylamine on lung function parameters. study design: a cross-sectional study. methods: this study was conducted on 55 male workers of core making un...

background: in this study we evaluated the incidence of hypothyroidism in patients who received external beam radiation due to cancer, when radiation portals included thyroid gland. methods: this prospective study was conducted from april 2004 to december 2005 among patients with head and neck or breast malignancies who referred to radiation oncology department of cancer institute, imam khomein...

melatonin has both pro-inflammatory and anti-inflammatory properties depending on the stage of inflammation. despite its therapeutic effect in alleviation of some symptoms of multiple sclerosis; the precise role of melatonin in ms pathogenesis remains a topic of debate. the aim of this study was to measure the urine level of one of melatonin products which is an index of serum melatonin level, ...

in this paper. (1) we determine the complex-valued solutions of the following variant of van vleck's functional equation $$int_{s}f(sigma(y)xt)dmu(t)-int_{s}f(xyt)dmu(t) = 2f(x)f(y), ;x,yin s,$$ where $s$ is a semigroup, $sigma$ is an involutive morphism of $s$, and $mu$ is a complex measure that is linear combinations of dirac measures $(delta_{z_{i}})_{iin i}$, such that for all $iin i$,...