this study has been conducted in order to investigate the effect of using onp recycled fibers on the mechanical and optical properties of local mixed hardwoods kraft pulp at iran wood and paper industry (chooka). onp and virgin kraft pulp have been prepared from chooka’s waste paper storage and pulping digester, respectively. onp has been repulped in the common method as used by paper recycling...

A brightness of 76% (initially 57%) was reached with a charge of 4.5% hydrogen peroxide based on thermomechanical pulp in 10 min with microwave heating, compared to 45 min with water-bath heating. The maximum brightness attained with water-bath heating (78%) was nearly one point higher than that obtained with microwave heating, albeit after twice the time (120 min vs. 60 min). Under similar con...

We present measurements of focal spot size and brightness in a focused ion beam system utilizing a laser-cooled atomic beam source of Cs ions. Spot sizes as small as (2.1 ± 0.2) nm (one standard deviation) and reduced brightness values as high as (2.4 ± 0.1) × 107 A m-2 Sr-1 eV-1 are observed with a 10 keV beam. This measured brightness is over 24 times higher than the highest brightness observ...

during the last three decades publication of papers in different fields of agronomic sciences have been increased drastically in iran. however, there is growing warnings about research misconducts. to get a quantitative insight into the commitment to the research ethics, 1269 papers published during the last 3 decades in the refereed domestic journals were surveyed using human tools. the freque...

BACKGROUND AND AIM: Perception of the need for oral healthcare plays a key role in creating motivation and demand for utilization of oral healthcare services. Furthermore, while the lack of resources, people with perceived needs to oral healthcare, due to the higher profit potential of services, will be on higher priority for services. The aim of this study was to undertake a systematic review ...

Surface brightness data can distinguish between a Friedman-Robertson-Walker expanding universe and a nonexpanding universe. For surface brightness measured in AB magnitudes per angular area, all FRW models, regardless of cosmological parameters, predict that surface brightness declines with redshift as (z+1), while any non-expanding model predicts that surface brightness is constant with distan...

A series of experiments was performed to evaluate the effect of substituting sodium carbonate for the sodium hydroxide used in peroxide bleaching of spruce CTMP. Three peroxide levels were tested: I , 2, and 4% HzOz, and two levels of causticsubstitution; SO% and 80%. At both the 2% and 4% peroxide levels, substituting 50% of the caustic charge with sodium carbonate decreased the initial bright...