192 research outputs found
A Quantitative Study of the Effect of Cutting & Fibrillation on Certain Paper Properties
Introduction
From the time of the invention of paper about the year 105 by Ts\u27ai Lun, the process of beating the pulp as a preliminary to forming a sheet of paper has been recognized as of prime importance.
Early papermakers did not concern themselves greatly with theories; it was enough to know the process necessary to produce the various combinations of long and short, slow and free stocks according to the paper being made. When chemists began to enter the mills, however, their attention was naturally drawn to this important aspect of beating, and to the relationship between cellulose and water in the beating cycle. This relationship is of such fundamental importance in the practice of papermaking that it has been subject to a myriad of published unanimity amongst the so-called experts concerning this complex cellulose-water relationship in beating.
In order to explain the various known effects of beating, there seem to be two distinctly different schools of thought to consider; those supporting the chemical aspects of beating, and those advocating the physical colloidal aspects of the beating action
Effects of Season, Spacing and Intensity of Seeding on Emergence and Survival of Four Wheatgrass Species in Central Utah
Rehabilitation of deteriorated and abused range lands is being accomplished with greater success each year by the aid of better methods of seeding which include seedbed preparation, intensities of seeding, implements for planting and improvised methods of eliminating competition. Much more information is needed however in order to recommend suitable methods and species for seeding various vegetation types and genes with reasonable reliability. Throughout the arid and semi-arid range lands, moisture is the principal factor limiting satisfactory seedling establishment. Special attention should therefore be given to more efficient utilization of the moisture supply. Closely related species of species with similar growth characteristics are said to compete for more water, for space and for nutrients; therefore, studies dealing with the effect of spacing and intensity of seeding upon seedling establishment are of paramount importance
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