Conclusions: Neither process is completely sufficient for establishing relative scientific soundness. However, changes occurring both in peer-review processes and in regulatory guidance resulting in clearer, more transparent communication of scientific information point to an emerging convergence in ensuring information quality. The solution to determining relative merit lies in developing a well-documented, generally accepted weight-of-evidence scheme to evaluate both peer-reviewed and GLP information used in regulatory decision making where both merit and specific relevance inform the process.
At we laser personalize direct mail campaigns. Our client may buy 1 million forms that arrive on rolls of approximately 30,000 forms per roll. They use the forms up over the course of several months to mail several different projects of varying quantities. We needed a formula in order to do inventory on the partial rolls that are kept for future mailings. There is waste involved each time we start and stop so it is difficult to track usage just by subtracting mail quantities from received quantities. We considered doing it by weight but a scale is expensive. We are currently testing the formula to tweak the paper thickness and expect it to work well.
Another reason to understand M weights is because often times paper basis weights are the same. An 80# text sheet is much lighter and thinner than an 80# cover sheet. By comparing M weights and also by feeling the paper you will notice a substantial difference.
One of the most confusing aspects of paper weights is called the Basis, Substance (Sub.) or the pound (#) specification. In dealing with paper, these terms mean basically the same thing. Paper manufacturers name the weights a little different sometimes. Most likely you have heard of the term “20 lb copy paper”. The 20lb copy paper is the most widely used paper for copiers, fax machines and where printing needs a minimal quality paper for printing. It is also low in cost and performs well when printing on one side only. On the label previously shown you will notice Basis Weight. Many sheets will be what are called comparative weight papers and so the previous label could also have read “20/50 lb”. Why would that be? It is because a 20 lb Bond sheet is the same weight and thickness as a 50 lb. Text / Offset sheet. The basis weights specified are based on the parent size sheet they were converted from.
Knowing M weights can be very helpful when comparing different grades of paper. The paper with the greater M weight is heavier and most likely thicker. For example, compare 8.5 x 11 90 lb. 21.62M Index to 8.5 x 11 80# 28.77M Cover. The M weight of the 80# is greater so it is most likely the thicker of the sheets.
Example: Let Outer Diameter of Roll (Do) is 40", Outer Diameter of Core (Di) is 6.5", thickness is 8 Pt., Width of roll is 40" and Basis weight is 100 g/m2
In addition to the various weights of paper, you can use watercolor board, which is paper adhered to illustration board. It doesn’t buckle when wet and is available in 20-x-30-inch pieces or by the case.
Given an appropriate selection of gel % (see table below) and a protein which displays near-ideal behavior, molecular weights can be determined to within 5 - 10%. Molecular weights of non-ideal proteins can be determined by the use of , a technique which employs .
If you know the outer diameter of the roll and the core on which paper is wound and the thickness of the paper and basis weight, you can calculate the weight of paper on roll using following equations.
Example: Let Outer Diameter of Roll (Do) is 100 cm, Outer Diameter of Core (Di) is 16 cm, Width of roll is 100 cm, basis weight is 100 g/m2 and thickness is 200 micrometer.
If a , larger ranges of proteins may be analyzed on the same gels, with greater resolution. The complexity of the relationship between migration and molecular weight is dependant upon the shape of the gradient. The overall equation is of the form log(MW) α log(P), where P is the concentration of acrylamide at the band position. A graph of log(MW) vs log(P) is linear, and allows the determination of MW's from a set of standard protein positions. For linear gradient gels, the percentage of acrylamide is proportional to the position in the gel, so log(MW) will be proportional to log(band position). Therefore, a graph of log(MW) vs log(Rf) for a set of standards will be linear, and Rf values for unknowns can then be converted to MW values. On a 3 - 30% gradient gel, a range of proteins which differ in MW by up to 100 fold can be resolved and MW's determined.
Basis weight: Basis weight is a common paper industry term for unit weight, or weight per unit area. Units are lb/ream. "Ten pounds of poly" means 10 lb/ream, which equals 43,200 in/lb (because a ream equals 432,000 in) or .70 mils of LDPE (at a specific gravity of .92).
The mobility (Rf) of a molecule in gel electrophoresis is determined by its free solution mobility, Y0 (= mobility in a gel of zero %) and the sieving action of the gel matrix. In , the addition of to the electrophoresis buffer uniformly coats the proteins with negative charges, equalizing the charge to mass ratio for all proteins, thus making Y0 he same for all species. In this case, relative mobilities are determined solely by the sieving action of the gel. This sieving action is proportional to the molecular weight (MW) of the particular protein. Theoretical treatments suggest that the logarithm of Rf should vary with MW, but most users use an empirical plot of the logarithm of MW vs Rf for several standards of known molecular weights to determine the molecular weights of unknowns.
There are many types of paper and mills are constantly working to improve them. This publication will provide you with a better understanding of the physical make-up of today’s paper. Explaining sizes, weights, finishes and more. Our PDF will make you a quick expert regarding paper. (PLEASE NOTE: All of the sizes listed in this publication are in inches.)