Life Sciences Commons^™

The Use Of Dimethyldioxirane In Refiner Bleaching Of High-Yield Pulps, Michael J. Harmes

Paper Engineering Senior Theses

In the attempt to find improved bleaching chemicals for the bleaching of high-yield pulps, dioxiranes may prove to be the solution. Unlike hydrogen peroxide, which has been introduced to a refiner environment in the past, dimethyldioxirane (DMD) does not require the use of sodium silicates. This is very beneficial due to the fact that silicates have a highly undesirable side effect of causing excessive refiner plate wear.

The experimentation was constructed to determine the exact feasibility of the use of dimethyldioxirane as a refiner bleaching agent. This was completed through the comparison of the pulp strength and brightness values of …

Thermomechanical Pulp Bleaching Optimization Via Dimethyldioxirane, Roger Allen Rouleau

Paper Engineering Senior Theses

In recent years, the paper industry has received increased pressure from environmental groups to reduce both air-borne & water-borne discharges. During element-chlorine bleaching processes, absorbable organic halides are formed , some of which are considered harmful to aquatic life. To reduce absorbable organic halides, many mills are moving towards chlorine-free bleaching stages. A potential chlorine-free bleaching agent is dimethyldioxirane. Dimethyldioxirane is an intermediate produced in-situ from acetone and peroxymonosulfate. Due to the bond strain of the oxygen-oxygen bond in this cyclic peroxide, it behaves as a strong oxidizing agent.

The goal of this thesis was to determine the optimum levels …

The Effect Of Washing Between Stages On Brightness Reversion For Sodium Hydrosulfite On Unbleached High Yield Pulps, Greg Semashko

Paper Engineering Senior Theses

The objective of the project is to determine the effect of bleaching with washing between stages on high yield unbleached pulp. The bleaching chemical used for this experiment is sodium hydrosulfite. Sodium hydrosulfite is a lignin preserving bleaching agent, which is necessary due to the high yield pulp. The lignin concentration in high yield pulp is extremely high compared to the normal amount found in other papers. The experiment will be done using a two stage bleaching sequence. The control sequence will consist of a direct charge of sodium hydrosulfite and the other two sequences will be done with washing …

Bod And Cod Loading Effects Of Repeatedly Recycled Paper Fibers, Ken Stager

Paper Engineering Senior Theses

BOD and COD are two very important and highly regulated aspects of the paper industry. The first is the biochemical oxygen demand, BOD, and it is simply the amount of oxygen that bacteria need to digest the nutrients in a wastestream. The second is the chemical oxygen demand, COD, and is the amount of oxygen required to fully oxidize all the material present in an effluent sample using hot concentrated chemicals.

One aspect of recycling that has not been discerned is the effect of repeatedly recycling paper fibers on the BOD and COD of the effluent. This is important because …

Feasibility Of Anionic Waxy Maze Starch As A Coating Cobinder, Peter D. Yake

Paper Engineering Senior Theses

This project will demonstrate the potential of incorporating a 100% waxy maze, anionic starch into a paper coating. This has been done in the past using oxidized starches as a primary binder, and has been met with a great deal of success with respect to rheological improvements as well as improved runnability in coating operations. The primary drawback to the use of oxidized starches in coatings was the negative impact that they had when introduced to the wet end of the paper machine as broke. The anionic properties of the starch decreased retention of fines and fillers on the fourdrinier …

Magnesium Oxide Use As A Pigment In Coating Formulations, Stephen O'Driscoll

Paper Engineering Senior Theses

The objective of this project was to evaluate the performance of magnesium oxide as a possible pigment for use in paper coatings. The use of magnesium oxide as a pigment in coatings is not currently nor has it ever been practiced in a mill situation. The principle goal of using magnesium oxide was to increase brightness and opacity in coatings at the level of performance found with titanium dioxide at a far lower cost. The evaluation was done of the basis of rheological performance as well as optical testing. Coatings of various levels of magnesium oxide and titanium dioxide were …

Environmental Comparison Of Soy To Petroleum Ink With Respect To Degradation Of Effluent Aerobically And Anaerobically, Monique Musgrave

Paper Engineering Senior Theses

This project compares a soy ink formulation to a petroleum ink formulation for their advantages and disadvantages. This was accomplished by evaluating the rejected samples from the flotation cell deinker. These samples were degraded aerobically and anaerobically to determine the rate at which degradation takes place and the ultimate degradation over a specific time interval. This was done by finding the biochemical oxygen demand (BOD). The data from these tests was put into a spreadsheet and data processing program to find the rate of degradation and ultimate degradation. From this, the two methods of degradation were compared along with the …

The Use Of Demolition Wood In Papermaking, Todd W. Anderson

Paper Engineering Senior Theses

The reason for this study came from three factors affecting the paper industry as well as society as a whole. These factors are decreasing landfill space, increasing tipping fees, and increasing demands for alternative fiber sources. In the United States, approximately 9.8 million tons of demolition wood waste is landfilled per year. Increasing governmental regulations which require greater amounts of secondary fiber to be used in papermaking are forcing the industry to consider alternative fiber options. The seven steps in the procedure include: rough wood, wood chips, kraft pulping, fiber refining, screening, handsheets, and testing. The four types of wood …

The Effect Of Manganese Peroxidase On Peroxide Bleaching Of High Yield Pulps, Cyril Vusani Simelane

Masters Theses

The main objective of this study was to investigate the effect of adding a pretreatment stage in conventional hydrogen peroxide bleaching of high yield pulps. To achieve this, three main variables considered crucial in the effectiveness of manganese peroxidase on the oxidation of lignin substructures, were chosen to evaluate the effect of this enzyme on high yield pulps. The responses to evaluate this effect were brightness, brightness reversion, pulp viscosity, and yield. Other properties included opacity, scattering and absorption coefficients, and the Hunter Lab values.

The pulps were bleached using two sequences Q(MnP), and Q(MnP)QP, to assess the effect of …

Effects Of Insulin And Insulin-Mimetics On Mrna Levels Of C-Fos And C-Jun In Primary Rat Hepatocytes In Culture, Guangmin Li

Masters Theses

Insulin is capable of regulating cellular and metabolic processes as well as gene expression. Selenate and vanadate are two compounds that have been found to mimic the action of insulin in several tissue and cell types. cFos and cJun are the products of immediate early responsive genes c-fos and c-jun. They are members of the family of the AP-1 (Activator Protein-1) transcription factors. AP-1 transcription factors bind as cJun.cJun homodimer or cJun.cFos heterodimer to the TRE found in the promoter regions of several genes. AP-1 is characterized by its ability to alter gene expression in response to various peptide …

The Effect Of Age And Recycling On Paper Quality, Zhuang Wu

Masters Theses

The effects of recycling paper that has undergone aging for different periods on paper and fiber properties like strength, weighted average fiber length, and water retention value were investigated in this study. Old Newspapers (ONP) with different periods of natural aging (between 1 to 10 months) were recycled repeatedly for up to six times. Another goal was the study of aging effects on paper properties using accelerated aging at high temperatures (105±2) °C. Four different aging times (24, 48, 72, and 144 hours) were employed.

The results showed that naturally aged ONP loses little in strength properties up to 7 …

The Role Of Nitric Oxide In The Modulation Of The Leukocyte-Endothelial Cell Interactions During Ischemia And Reperfusion, Fernando López-Neblina

Masters Theses

Nitric oxide (NO) is involved in several metabolic pathways and physiological phenomena. The role of NO in inflammation after ischemia and reperfusion (I/R) is controversial. The early phases of inflammation include the leukocyte-endothelial (L/EC) cell interactions which have been divided in rolling, activation, adhesion and migration.

The first experiment was to demonstrate the role of NO in a model of renal I/R. We demonstrated that exogenous NO improves survival and renal function tests after renal I/R, while endogenous NO does not appear to be an important contributor to renal I/R. We also demonstrated that NO modulate the infiltration of neutrophils …

The Use Of Speciality K-Flute As A Substitute For Common Grades Of Single Wall And Double Wall, Ron Pristash

Paper Engineering Senior Theses

This study examines a new corrugated flute profile known as "K" flute. The purpose of the study was to show that K flute can maintain the same structural integrity and use significantly less paper. The main tests performed were tests for compression strength. Studying the results of compression testing, allows the designer to engineer the corrugated container to meet the performance level required. The study consists of two parts. The first part of the study examines the effect of an increase in caliper has on Edgwise Compression Testing (ECT). It was found that K flute tested 5% stronger than A …