introduction: according  to  the  latest  statistical  and  epidemiological  studies,  copd  will  become  the  fourth  leading  cause  of  death  in  2030  worldwide.  scientists  are  studying  on  methods  to  diagnose  copd  in  the  patients  in  early  stages,  because  it  is  a  curable  and  preventable  disease  in  early  stages.  in  this  study,  evidences  of  hyperinflation  on  ...

today, due to qualitative growth and scientific advances, energy, especially electricity is increasingly needed by human society. one of the almost endless and pure energy which have been paid attention over the years is the solar energy. solar cells directly convert solar energy into electrical energy and are one of the main blocks of photovoltaic systems. significant improvement has been made...

Check dams are one of the structures used to control debris flows. In this study, in order to evaluate the effect of hydraulic parameters on debris sediment trapping rate by the slit trapezoidal check dams with different angles, and to develop an empirical relation for determination of trapping coefficient of the dam reservoirs, three physical models of the check dams were used. The tests were ...

The auto-oxidation of trans-1,2-disiloxybenzocyclobutene was found to be very efficient, giving endo-peroxide in quantitative yield. Each step of the mechanism of spin-forbidden addition of triplet oxygen O2((3)Σg) was studied by both EPR/spin trapping and theoretical studies.

The spin-trapping method is introduced and discussed. Some chemistry of nitroxides and nitrones is reviewed. Pattern recognition of ESR spectra of nitroxides is outlined. Factors controlling the magnitude of hyperfine splitting constants are mentioned. Methods of assigning spin adducts are listed. Review articles in the literature are referenced. Results in the electrochemical reduction of halo...

Through direct transmetalation reaction of Z-vinylic tellurides with nBuLi was observed the unexpected isomerization of double bonds leading to potassium E-vinyltrifluoroborates salts in low to moderate yields. Using EPR spin trapping experiments the radical species that promoted the stereoinversion of Z-vinylic organometallic species during the preparation of potassium vinyltrifluoroborate sal...

This study explored the effect of porosity and installation angle, thickness (dimension) and second layer of permeable obstacles on density current control and trapping in the laboratory. For this purpose, an insoluble suspended polymer and two types of groove and cavity obstacles made from plexiglass sheets were selected. The experiments were conducted with two different concentrations, five d...

intractable asthma is a challenging clinical problem. this study was conducted to determine whether a subset of patients with intractable asthma may be misdiagnosed and have a form of bronchiolitis instead and also to determine the effectiveness of macrolide therapy in these patients. seventy six patients with intractable asthma were re-treated with recommended maximal doses of oral prednisolon...

The superoxide radical spin adduct of the spin trap 5,5-dimethyl-lmine-l-oxide was found to be relatively unstable in aqueous solution. The half-life of the electron spin resonance signal is approximately 80 set at pH 6 and only about 35 set at pH 8. These observations as well as the possible reaction products of 0' that may develop in the time course of an experiment, must be considered whe a ...