Determining operating variables that impact internal fiber bonding using Wedge statistical analysis methods

In this study, Wedge statistical analysis tools were used to collect, collate, clean up, plot, and analyze several years of operational data from a commercial paper machine. The z-direction tensile (ZDT) and Scott Bond tests were chosen as representative of fiber bond strength. After analyzing thousands of operational parameters, the ones with the most significant impact upon ZDT involved starch application method, starch penetration, and the amount of starch applied. Scott bond was found to be significantly impacted by formation and refining. Final calendering of the paper web has also shown an impact on internal fiber bonding.

Cash Holdings, Commercial Paper and Liquidity

Managing Liquidity has seldom been being as vital as it has during the Covid-19 era. The financial impact of Covid-19 has left many firms on the brink of liquidation. This paper explores the effect cash holdings has had on Profitability of the firm and how it compares with commercial paper between the pre-Covid-19 era and the Covid-19 era. This paper employs and compares the ordinary least square regression between these eras. I find that firms are less liquid during the Covid-19 period compared to the pre-covid period. More importantly, I find that Liquidity has been more critical to a firm's Profitability during Covid-19 era compared to pre-covid 19 periods. Furthermore, Cash holdings represent a significant chunk of Liquidity. However, these Cash holdings dropped by a little in the covid-19 era. Finally, I find that both commercial paper and cash holdings are used as complements. However, this result is weakly supported during the pre-covid period.

A guide to eliminating baggy webs

Slack or baggy webs can cause misregistration, wrinkles, and breaks in printing and converting operations. Bagginess appears as non-uniform tautness in the cross direction (CD) of a paper web. The underlying cause is uneven CD tension profiles, for which there are few remedies once the paper is made. Precision measurements of CD tension profiles combined with trials on commercial paper machines have shown that uniform CD distribution of moisture, basis weight, and caliper profiles at the reel are key to avoiding bagginess. However, the most important but infrequently measured factor is the CD moisture profile entering the dryer section. Wetter areas entering the dryers are permanently elongated more than dry areas, leading to greater slackness in the finished paper. In storage, wound-in tension can amplify baggy streaks in paper near the surface of a roll and adjacent to the core. Unwrapped or poorly wrapped rolls exposed to low humidity environments may have baggy centers caused by moisture loss from the roll edges. All of the factors that impact bagginess have been incorporated in a mathematical model that was used to interpret the observations from commercial trials and can be used as a guide to solve future problems.

Characterization and usage of tule (Typha domingensis Pers) to obtain cellulose pulp in a biorefinery framework

It was proposed that pre-hydrolysing tule (Typha domingensis Pers) would make it possible to produce handsheets with strength-related properties similar to those of conventional commercial paper, in addition to valorizable hemicelluloses. The hypothesis was tested with a biorefining scheme involving autohydrolysis. Conditions were optimized to maximize the extraction of hemicelluloses while preserving glucan integrity. The autohydrolysis at a liquid to solid ratio of 13 at 141 °C for 45 min (optimized conditions) provided a commercially useful liquor containing primarily tule hemicelluloses. The autohydrolysis of tule before alkaline extraction made it possible to obtain a valuable liquid phase comprising between 23.3% and 71.6% of all hemicelluloses in the raw material. The gross heating value for the hydrolyzed tule was increased (1.6% to 7.9 %) with respect the raw material. The solid phase was subjected to soda–anthraquinone pulping. The yield, ethanol extractives, kappa number, viscosity, glucan, xylan, Klason lignin, soluble lignins, as well as the tensile index were evaluated. Tule was found to be amenable to industrial processing for the production of quality cellulose derivatives. Autohydrolysis provided valorizable liquor in addition to solid that yielded soda–anthraquinone pulp having properties similar to those obtained in its absence, but using milder operating conditions.

The Wisselbank and Amsterdam Price Volatility: A fractal test of the Austrian fractional-reserve banking hypothesis

Using 1708-1788 historical data, we test the Austrian hypothesis that fractional-reserve banking destabilizes commodity prices, complicating eco­ nomic calculation and entrepreneurial planning, and contributes to boom-bust cycles. The Bank of Amsterdam («Wisselbank», 1609-1819) maintained high reserve requirements until the Fourth Anglo-Dutch War (1780-1784), when its reserve ratio plummeted from nearly 100% in 1778 to around 20% by 1788. We compare price volatilities for 1722-1779 and 1780-1788 using fractal Hurst exponents. For all commodity prices tested, fractal volatility was higher during the lower fractional reserve period, except for rye, wheat, and Hamburg Bills of Exchange. Bill of Exchange stability was likely attributable to Hamburg transport ships’ ability to evade British incursion and to the Wisselbank’s legal monopsony in the secondary commercial paper market. However, rye and wheat prices — directly indicative of bread prices — generally (and contrary to Austrian theory) stabilized even though British blockades significantly re­ duced Dutch bread grain imports. We attribute this unexpected result primarily to emergency wartime provision by the Amsterdam municipal granary. The Wisselbank experience may confirm, or at least does not clearly falsify, the economic relevance of the Austrian Fractional-Reserve Banking Hypothesis. Keywords: Fractional reserve banking, monetary expansion, price stability, equilibrium. JEL Codes: E42, E44, N13, N23, N83. Resumen: Analizando los datos históricos correspondientes al Banco de Áms­ terdam de 1708 a 1788 concluimos que la evidencia empírica confirma (o al menos no refuta) la hipótesis austriaca sobre los negativos efectos de la banca con reserve fraccionaria. Palabras clave: Banca con reserva fraccionaria, expansión monetaria, estabili­ dad de precios, equilibrio. Clasificación JEL: E42, E44, N13, N23, N83.

The effect of microfibrillated cellulose on the wet-web strength of paper

The wet-web strength of paper immediately after the press section of a paper machine is a critical factor in determining machine runnability. However, it is difficult to determine at commercial scale, because the web has to be broken and production interrupted in order to obtain a sample for measurement. The use of microfibrillated cellulose (MFC) is believed to increase wet-web strength, as it has allowed filler level increases of 10% or more on many commercial paper machines. In this paper, we describe a laboratory method for estimating the effect of MFC on wet sheet strength after pressing, as well as actual measurements of wet-web strength from a pilot paper machine trial. These experiments have demonstrated the positive effect of MFC. At solids contents in the range typically observed after pressing, sheets with MFC at fixed filler content are significantly stronger, but also wetter, than those without it. When the use of MFC is combined with a typical increase in filler content, the wet web remains slightly stronger, but also becomes drier than the reference condition. These results are compatible with the theory put forward by van de Ven that wet-web strength is mainly a result of friction between entangled fibers, and they also suggest that the presence of MFC increases this friction.

From Colour Catcher® to colorimetric sensors: disposable and cheap devices for inorganic ions determination

We describe disposable and cheap colorimetric devices obtained by fixing classical dyes on the commercial paper sheet known as "Colour Catcher®" (here named under the acronym CC), the product used to prevent color runs in washing machines cycles. These devices can be used as colorimetric sensors for different analytes of environmental and biological interest since the indicator dye, fixed on the solid material, changes its spectral properties (color and hence UV-vis spectrum) upon contact with the analyte. The relationship between the analyte content and the UV-vis spectrum (or RGB values) change of each sensor is provided using a chemometric tool: the Partial Least Squares regression (PLS). Promising results were obtained when applying these sensors to actual samples, so because of their simple preparation with low-cost reagents, they can be effective for application in environmental and food analysis.