Refining Energy Reduction and Pulp Characteristic Modification of Alkaline Peroxide Mechanical Pulp (APMP) Through Enzyme Application

TAPPI Journal ◽  
2009 ◽  
Vol 8 (5) ◽  
pp. 19-25 ◽  
Author(s):  
PETER W. HART ◽  
DARRELL M. WAITE ◽  
LUC THIBAULT, ◽  
JOHN TOMASHEK ◽  
MARIE-EVE ROUSSEAU ◽  
...  
Keyword(s):  
Wood Chip ◽  
The United States ◽  
Enzyme Treatment ◽  
Chemical Application ◽  
Alkaline Peroxide ◽  
Eucalyptus Wood ◽  
Pulp Properties ◽  
Pulp Processing ◽  
Two Stages ◽  
Enzyme Application

Eucalyptus wood chips were subjected to impregnation with various blends of novel fiber modify-ing enzymes before chemical pretreatment and two stages of refining using the preconditioning refiner chemical–alkaline peroxide mechanical pulping (PRC-APMP) process. Wood chip impregnation and pulp processing was con-ducted at a pilot plant in the United States. When compared under constant chemical application and at a constant 350 mL CSF, enzyme treatment reduced specific refining energy by at least 24%. The effect of one versus two stages of impregnation and of enzyme action upon several physical pulp properties was determined.

Selective enzyme impregnation of chips to reduce specific refining energy in alkaline peroxide mechanical pulping

Holzforschung ◽  
2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Peter W. Hart ◽  
Darrell M. Waite ◽  
Luc Thibault ◽  
John Tomashek ◽  
Marie-Eve Rousseau ◽  
...  
Keyword(s):  
High Spatial Resolution ◽  
Enzyme Hydrolysis ◽  
Chemical Pretreatment ◽  
Alkaline Peroxide ◽  
Fiber Wall ◽  
Transmission Electron ◽  
Eucalyptus Wood ◽  
Pulp Processing ◽  
Two Stages ◽  
S2 Layer

Abstract Eucalyptus wood chips were impregnated with various blends of fiber modifying enzymes prior to preconditioning refiner chemical-alkaline peroxide mechanical pulp processing. The process includes chemical pretreatment and two stages of refining. The energy consumption was compared at the same Canadian standard freeness level of 350 ml. Some enzyme treatments were found to reduce specific refining energy (SRE) by at least 24%. The enzyme hydrolysis within the cell wall was observed by transmission electron microscopy of impregnated chips with high spatial resolution. The enzyme blends that successfully reduced SRE requirements were found to selectively loosen the bonds between the S1 and S2 layers of the fiber wall. Enzymes which selectively attached the S2 layer did not impart any SRE reduction. All experiments for impregnation and pulp processing were conducted at the Andritz Pilot Plant in Springfield, OH.

Chemical characterization and biotreatability of effluents from an integrated alkaline-peroxide mechanical pulping/machine finish coated (APMP/MFC) paper mill

1997 ◽  
Vol 35 (2-3) ◽  
pp. 7-14 ◽  
Author(s):  
A. Schnell ◽  
M. J. Sabourin ◽  
S. Skog ◽  
M. Garvie
Keyword(s):  
Activated Sludge ◽  
Aquatic Toxicity ◽  
Wood Chip ◽  
Chemical Characterization ◽  
Toxicity Testing ◽  
Sampling Period ◽  
Paper Mill ◽  
Alkaline Peroxide ◽  
Conventional Activated Sludge ◽  
Treated Effluent

As part of an extensive audit of the Alkaline-Peroxide Mechanical Pulping (APMPTM) plant at the Malette Quebec Inc. mill in St. Raymond, Que., effluents were sampled from various stages of the process for comprehensive chemical characterizations, aquatic toxicity testing and anaerobic biotreatability assessments. In addition, untreated and secondary treated combined effluent from the integrated paper mill were sampled to determine the effectiveness of a conventional activated sludge process at the mill site. During the one-day sampling period, the APMP plant processed a mixed wood furnish consisting of 50% spruce/balsam fir and 50% aspen, with a chemical charge of 3.5% sodium hydroxide and 3.8% hydrogen peroxide on oven-dry fibre, while the Machine Finish Coated (MFC) paper production rate was 100 odt/d (oven dry metric tonnes per day). Measured production-specific contaminant discharge loadings from the novel APMP process were 56 kg BOD5/odt and 155 kg COD/odt in a combined effluent flow of 28 m3/odt. Sources of process effluent were chip washing, three stages of wood chip pretreatment and chemical impregnation (i.e., Impressafiner stages), interstate washing and pulp cleaning. The three Impressafiner pressates were found to be the most concentrated (i.e., 12-26 g COD/L) and toxic streams. Microtox testing of the pressates revealed EC50 concentrations of 0.07-0.34% v/v. The warm and concentrated effluents generated by the non-sulphur APMP process were found to be highly amenable to anaerobic degradation as determined by batch bioassay testing. Filterable BOD5 and COD(f) of the process effluents were reduced by 87-95% and 70-77%, respectively, with corresponding theoretical methane yields being attained. Acid-soluble dissolved lignin compounds exhibited biorecalcitrance, as revealed by limited removals of 34-55%, and were the main constituents contributing to residual COD(f), while resin and fatty acids (RFA) were reduced by 80-94%. The conservatively operated full scale activated sludge treatment process achieved a similar high 74% COD(f) removal from the whole mill effluent, while BOD5 and RFA reductions were virtually complete and the treated effluent was non-toxic, as measured by Microtox.

scholarly journals Cleaning and disinfecting protocols for hospital environmental surfaces: A systematic review of the literature

2019 ◽  
Vol 8 (6) ◽  
pp. 27
Author(s):  
Keyanna P. Taylor ◽  
Debra D Harris
Keyword(s):  
Systematic Review ◽  
Research Question ◽  
The United States ◽  
Mechanical Action ◽  
Chemical Application ◽  
Environmental Surfaces ◽  
Study Results ◽  
Cleaning Methods ◽  
Reported Data ◽  
Hospital Acquired

Background: Healthcare associated infections are a leading cause of illness and death in the United States and across the world. Environmental surfaces are considered non-critical, although recent evidence suggests that the built environment may contribute to the transmission of pathogens. Ineffective cleaning and disinfecting of environmental non-critical surfaces may increase risk of transmitting nosocomial pathogens leading to hospital acquired infections among hospital patients.Objective: This systematic review identifies elements of cleaning and disinfecting protocols, synthesizing the evidence to evaluate cleaning protocols that effectively reduce surface contamination and minimize risk of hospital acquired illness.Methods: A systematic literature review was conducted with a clearly formulated research question and systematic approach to identify publications, select relevant studies, critically appraise the research through analysis of reported data, and reported the results according to the Cochrane methodology.Results: In total, 245 studies were initially identified with 19 studies meeting inclusion criteria. Emerging categories include chemical application methods, chemical application time, cleaning type and frequency, and interventions for training and monitoring.Conclusions: Establishing adequate cleaning protocols for hospital environments is a complex process which requires consideration of multiple components including mechanical action, chemical application materials, types of cleaning, chemical contact times, education and training of EVS staff, cleaning monitoring and feedback, no-contact cleaning methods, and self-disinfecting surfaces. Recommendations for protocol development based on the study results are provided.

The “Sanctions” of the International Monetary Fund

1972 ◽  
Vol 66 (4) ◽  
pp. 737-762 ◽  
Author(s):  
Joseph Gold
Keyword(s):  
International Monetary Fund ◽  
International Monetary System ◽  
The United States ◽  
Legal Structure ◽  
Monetary System ◽  
Special Drawing ◽  
Third Stage ◽  
Special Drawing Rights ◽  
Two Stages ◽  
The International Monetary Fund

Recent events in the international monetary system culminating in the decision of the United States, announced on August 15, 1971, to suspend the convertibility of the dollar induce the international lawyer to ask once again what contribution sanctions can make to respect for international law and the effectiveness of multilateral treaties. This question has been a practical problem at two stages in the development of the International Monetary Fund. It arose first during the negotiation and drafting of the original Articles of Agreement which were adopted at the Bretton Woods Conference in July 1944. The second stage was the negotiation and drafting of the amendment of July 28, 1969, which dealt mainly with the legal structure of special drawing rights as a supplement to existing reserve assets. It is now apparent that there will be a third stage, in which a reform of the international monetary system, perhaps in some of its most fundamental aspects, will lead to a further amendment of the Fund's charter.

scholarly journals Factors Hindering the Adoption of Business-to-Consumer (B2C) in Developing Countries: A Case Study of Sudan

2017 ◽  
Vol 9 (4) ◽  
pp. 28-33
Author(s):  
Abdelaziz Musbah ◽  
Mira Kartiwi
Keyword(s):  
Credit Card ◽  
The United States ◽  
Internet Banking ◽  
Internet Security ◽  
Structured Interviews ◽  
Major Barrier ◽  
Adoption Decision ◽  
Business To Consumer ◽  
Two Stages

It has been commonly reported that e-commerce (electronic commerce) offers viable solutions to businesses in meeting the challenges of an environment that is undergoing changes. This study seeks to explore the factors that influence the adoption decision of Business-to-Consumer (B2C) e-commerce, using Sudan as a case study. The mixed method design was adopted in two stages in which both exploratory and descriptive research approaches were undertaken. Data was collected from enterprises by questionnaire and through the analysis of research and semi-structured interviews. The findings revealed that most enterprises in the country are still in the initial stages of adoption of B2C e-commerce despite the wide growth of Internet use among enterprises in Sudan. Many factors could be responsible for the low usage of e-commerce among the enterprises in Sudan. Technical barrier is seen as the major barrier that affects the adoption of B2C e-commerce. However, this is accompanied by regulatory and legal barriers. One of the factors that inhibit e-commerce adoption in SMEs in Sudan is the lack of Internet security. Other factors include limited use of web portals and Internet banking by enterprises. The use of credit card and visa card is prohibited in Sudan due to the sanction from the United States of America. However, these issues resulted in all type of transactions that involves carrying cash. This makes it risky for customer who carry huge sum of money. In order to improve B2C e-commerce adoption technologies, this study plays a significant role to organizations and supporting organizations, especially those operating in countries with a unique situation like Sudan.

The First Revolution

2000 ◽  
pp. 27-50
Author(s):  
Frank Broeze
Keyword(s):  
United States ◽  
North Atlantic ◽  
The United States ◽  
Liner Shipping ◽  
Container Terminals ◽  
Trade Routes ◽  
Two Factors ◽  
Two Stages ◽  
The Impact ◽  
Eventual Dominance

This chapter analyses the first two stages of the process of containerisation. The first is the early impact of the industry on the domestic trades of the United States and of Australia. The second is the impact containerisation had on liner shipping and its expansion into North Atlantic, Transpacific (United States-Japan), and Australian trade routes. The chapter argues that these two factors, occuring during the 1950s and 1960s, provided a framework for the eventual dominance of containerisation on global shipping that occured during the 1970s. The chapter ends by detailing the readying of container terminals in all major ports, and the first Japan-Europe container voyage, the 1971 embarkment of the Kamakura Maru.

Patient Selection Criteria for Deep Brain Stimulation for Essential Tremor

2020 ◽  
pp. 11-16
Author(s):  
Laura S. Surillo Dahdah ◽  
Umar Yazdani ◽  
Richard B. Dewey ◽  
Padraig O’Suilleabhain ◽  
Shilpa Chitnis
Keyword(s):  
Deep Brain Stimulation ◽  
Essential Tremor ◽  
Brain Stimulation ◽  
Involuntary Movement ◽  
The United States ◽  
Repeat Surgery ◽  
Patient Selection Criteria ◽  
Second Procedure ◽  
Two Stages ◽  
Deep Brain

Tremor is an involuntary movement characterized by a rhythmic oscillation around a fixed point or trajectory. It can be classified based on its clinical features or underlying cause. Tremor was the first approved indication for deep brain stimulation (DBS) in the United States. Essential tremor (ET) is the most common movement disorder. These patients typically suffer from tremor of the hands and arms, and about 40% suffer from head tremor and 20% from voice tremor. Most candidates for functional neurosurgery have severe action or postural tremor that impairs function and quality of life to the extent that the risks, costs, and inconvenience of DBS treatment are justified. Unilateral procedures are commonly performed, although bilateral procedures should be considered when limb tremor is severe bilaterally or when head, voice, or trunk tremor causes significant disability. One reason for initially pursuing unilateral DBS for control of tremor in the dominant hand is that many patients will not require repeat surgery for the nondominant side despite residual tremor on that side. Many centers have developed a staged approach to DBS for ET that allows time to pass between the two stages; this can facilitate recovery and potentially diminish the negative consequences associated with a second procedure.

Extracting value from Eucalyptus wood before kraft pulping: Effects of hemicelluloses solubilization on pulp properties

2011 ◽  
Vol 102 (8) ◽  
pp. 5251-5254 ◽  
Author(s):  
C. Vila ◽  
J. Romero ◽  
J.L. Francisco ◽  
G. Garrote ◽  
J.C. Parajó
Keyword(s):  
Kraft Pulping ◽  
Eucalyptus Wood ◽  
Pulp Properties

scholarly journals AMERICAN-MEXICAN BORDER CONFLICTS IN THE 1870–1910S

2021 ◽  
Vol 03 (07) ◽  
pp. 139-147
Author(s):  
V.V. Prilutskiy ◽  
Keyword(s):  
United States ◽  
International Relations ◽  
The United States ◽  
Northern Region ◽  
Western Hemisphere ◽  
Spanish Colonization ◽  
Xixth Century ◽  
Border Conflicts ◽  
Territorial Claims ◽  
Two Stages

The article analyzes the border conflicts between Mexico and the United States at the turn of the XIXth and XXth centuries. American-Mexican relations were an important factor in the development of the regional subsystem of international relations in the Western Hemisphere. Historically, Mexico and the United States have had a complicated relationship. Mexico in the late XIXth – early XXth centuries was a secondary peripheral state, which was mainly agrarian in nature. There were both phases of acute confrontation (almost the entire XIXth century and the beginning of the XXth century), as well as periods of good neighborliness, relatively good, friendly, stable relationships and constructive cooperation. In relations with the United States at that time, it remained rather not a subject, but an object of influence. The extreme American expansionists proposed in the middle of the XIXth century to capture all of Mexico. In response to the aggressive aspirations of America, the Mexican radicals put forward their territorial claims to the neighboring country. They hoped to regain the vast northern region, that was lost during the wars of 1835-1848, which included Upper California, New Mexico, Utah, Arizona and Texas (which was called the "New Philippines" during the era of Spanish colonization). There are two stages of confrontation between the two countries: the 1870s – 1890s and the 1910s – 1920s. The most serious exacerbations on the border occurred in 1876, 1877, 1891-1893, 1896, 1906 and 1910-1919. Both government troops and irregular (militias, partisans, rebels) formations took part in the regional armed conflict. As a result, the situation stabilized for almost a century.

Mortality Variation in U.S. Cities in 1900: A Two-Level Explanation by Cause of Death and Underlying Factors

1983 ◽  
Vol 7 (1) ◽  
pp. 31-59 ◽  
Author(s):  
Eileen M. Crimmins ◽  
Gretchen A. Condran
Keyword(s):  
United States ◽  
Urban Areas ◽  
Causes Of Death ◽  
The United States ◽  
Mortality Rates ◽  
Contaminated Water ◽  
Death Registration ◽  
Factors Affecting ◽  
Registration Data ◽  
Two Stages

Health conditions in United States cities at the turn of the twentieth century were very poor. Bleak pictures of crowded dwellings, contaminated water supplies, and filthy streets have been painted by numerous observers of urban areas at the time (Smith, 1964). While the effects of these conditions on mortality levels have not been precisely measured, urban mortality rates were consistently higher than rural mortality rates in 1900 in the United States (Condran and Crimmins, 1980). Nevertheless, considerable variation in the mortality levels of different cities also existed. Our goal in this article is to explain the variation in the mortality conditions in U.S. cities for which death registration data were collected in 1900. The analysis is done in two stages. First, the causes of death which accounted for the different mortality levels are isolated. Second, a multivariate analysis of the factors affecting the rates of occurrence of these causes of death is performed.

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