sizing of paperboard has a distinctive position in packaging grade paperboard material. optimization of sizing by alum-rosin at neutral ph in 4 layered paperboard (330 g/m2) wereevaluated in this study to find the optimum ratio of alum- rosin loading in the process. fixed amount of 1% cationic dispersed rosin together with alum as a fixing agent at 5 different levels of 1, 1.5, 2, 3, and 4% (ba...

introduction earth has ever been exposed to environmental hazards. the hazards are continually occurring in the world in the recent years. among them, atmospheric elements have created many human and financial losses in different regions. one of the hazards is dust events and in its severe case is dust storm. it happens more frequently in arid and semiarid regions in deserts and their surroundi...

among the six classes of pro-2-groups of finite and fixed co-classes and trivial schur multiplicator which studied by abdolzadeh and eick in 2009, there are two classes $$s_5=langle a,bmid [b,a^2]=1, a^2=[b,a]^2, (b^2)^{[b,a]}b^2=1rangle$$ and $$s_6=langle a,t,bmid a^2=b^2,[b,a]^2=1, t^a=t^{-1}[b,a], b^t=abarangle$$that have been conjectured to have deficiency zero presentations. in this paper ...

a field experiment was conducted in research farm of isfahan university of technology, isfahan, iran in 2011 . various weeding periods were investigated on growth and yield of potato under drip tape and furrow irrigation systems. a split plot arrangement was used in a randomized complete block design with three replications. irrigation treatments were included in main plots and periods of weed ...

lead is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-br-padap)-ammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the ph range 4.0-6.0 from a large volume of aqueous solutions of various samples with preconcentration factor of 60. after filtration, the solid mass consisting of the lead complex and naphthalene was dissolved with 5...

willows due to the rapid growth rate, low nutrient requirements, resistance to many pollutants, and environmental stresses are ideal candidates for developing the landscapes and reducing the environmental degradation. the purpose of this study was to determine the response of salix alba seedling to water deficit conditions. this experiment was set up as complete randomized design with five irri...

cellulose was applied as a reusable and green catalyst for the facile four-component synthesis of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile derivatives using hydrazine monohydrate, ethyl acetoacetate, malononitrile and aryl aldehydes, under solvent-free and thermal conditions. the use of non-toxic and inexpensive catalyst, short reaction time, clean work-up and goo...

background: iodine-123 (123i) is regarded as one of the best radionuclides for in vivo medical studies using single-photon emission computed tomography (spect) due to its suitable physical property. materials and methods: to design a new system in order to replace cryogenically solidified xenon target by the gas one, some necessary calculations are needed to be done such as finding the excitati...