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Journal articles
Magazine articles
Open Access
Evaluation of rice straw for purification of lovastatin, TAPPI Journal November 2021

ABSTRACT: Cholesterol synthesis in the human body can be catalyzed by the coenzyme HMG-CoA reductase, and lovastatin, a key enzyme inhibitor, can reduce hypercholesterolemia. Lovastatin can be obtained as a secondary metabolite of Aspergillus terreus ATCC 20542. In this study, rice straw of lignocellulose was used in aeration and agitation bath fermentation in a 1-L flask, and a maximal crude extraction rate of 473 mg/L lovastatin was obtained. The crude extract was treated with silica gel (230•400 mesh) column chromatography. Ethyl acetate/ethanol (95%) was used as the mobile phase, and isolation was performed through elution with various ethyl acetate/ethanol ratios. The highest production rate of 153 mg/L was achieved with ethyl acetate/ethanol in a ratio of 8:2. The lovastatin gained from the crude extract was added to 12 fractions treated with 0.001 N alkali, and acetone was then added. After 24 h of recrystallization at 4°C, the extract underwent high-performance liquid chromatography. The purity had increased from 25% to 84.6%, and the recovery rate was 65.2%.

Journal articles
Magazine articles
Open Access
Rethinking the paper cup — beginning with extrusion process optimization for compostability and recyclability, TAPPI Journal June 2021

ABSTRACT: More than 50 billion disposable paper cups used for cold and hot beverages are sold within the United States each year. Most of the cups are coated with a thin layer of plastic — low density polyethylene (LDPE) — to prevent leaking and staining. While the paper in these cups is both recyclable and compostable, the LDPE coat-ing is neither. In recycling a paper cup, the paper is separated from the plastic lining. The paper is sent to be recycled and the plastic lining is typically sent to landfill. In an industrial composting environment, the paper and lining can be composted together if the lining is made from compostable materials. Coating paper cups with a compostable performance material uniquely allows for used cups to be processed by either recycling or composting, thus creating multiple pathways for these products to flow through a circular economy.A segment of the paper converting industry frequently uses an extrusion grade of polylactic acid (PLA) for zero-waste venues and for municipalities with ordinances for local composting and food service items. The results among these early adopters reveal process inefficiencies that elevate manufacturing costs while increasing scrap and generally lowering output when using PLA for extrusion coating. NatureWorks and Sung An Machinery (SAM) North America researched the extrusion coating process utilizing the incumbent polymer (LDPE) and PLA. The trademarked Ingeo 1102 is a new, compostable, and bio-based PLA grade that is specifically designed for the extrusion coating process. The research team identified the optimum process parameters for new, dedicated PLA extrusion coating lines. The team also identified changes to existing LDPE extrusion lines that processors can make today to improve output.The key finding is that LDPE and PLA are significantly different polymers and that processing them on the same equipment without modification of systems and/or setpoints can be the root cause of inefficiencies. These polymers each have unique processing requirements with inverse responses. Fine tuning existing systems may improve over-all output for the biopolymer without capital investment, and this study showed an increase in line speed of 130% by making these adjustments. However, the researchers found that highest productivity can be achieved by specifying new systems for PLA. A line speed increase to more than 180% and a reduction in coat weight to 8.6 µm (10.6 g/m2 or 6.5 lb/3000 ft2) was achieved in this study. These results show that Ingeo 1102 could be used as a paper coating beyond cups.

Journal articles
Magazine articles
Open Access
Probing the molecular weights of sweetgum and pine kraft lignin fractions, TAPPI Journal June 2021

ABSTRACT: The present investigation undertook a systematic investigation of the molecular weight (MW) of kraft lignins throughout the pulping process to establish a correlation between MW and lignin recovery at different extents of the kraft pulping process. The evaluation of MW is crucial for lignin characterization and utilization, since it is known to influence the kinetics of lignin reactivity and its resultant physico-chemical properties. Sweetgum and pine lignins precipitated from black liquor at different pHs (9.5 and 2.5) and different extents of kraft pulping (30•150 min) were the subject of this effort. Gel permeation chromatography (GPC) was used to determine the number average molecular weight (Mn), mass average molecular weight (Mw), and polydispersity of the lignin samples. It was shown that the MW of lignins from both feedstocks follow gel degradation theory; that is, at the onset of the kraft pulping process low molecular weight-lignins were obtained, and as pulping progressed, the molecular weight peaked and subsequently decreased. An important finding was that acetobromination was shown to be a more effective derivatization technique for carbohydrates containing lignins than acetylation, the technique typically used for derivatization of lignin.

Magazine articles
Open Access
Views from the top: ceos offer global perspectives on the pulp and paper industries, TAPPI JOURNAL, August 1999, Vol. 82(8)

Views from the top: ceos offer global perspectives on the pulp and paper industries, TAPPI JOURNAL, August 1999, Vol. 82(8)

Journal articles
Open Access
Modeling studies of a composite tube floor in black liquor recovery boilers, TAPPI JOURNAL, December 1999, Vol. 82(12)

Modeling studies of a composite tube floor in black liquor recovery boilers, TAPPI JOURNAL, December 1999, Vol. 82(12)

Journal articles
Open Access
Techniques for expanding the sphere of statistical process control, TAPPI JOURNAL July 1988

Techniques for expanding the sphere of statistical process control, TAPPI JOURNAL July 1988

Journal articles
Open Access
Birch thermomechanical pulp for newsprint via the Opco treatment, TAPPI JOURNAL July 1988

Birch thermomechanical pulp for newsprint via the Opco treatment, TAPPI JOURNAL July 1988

Journal articles
Open Access
Formulating to enhance the radiation cross linking of thermoplastic rubber for the hot-melt pressure-senstivie adhesives, June 1988, TAPPI Journal 88JUN155

Formulating to enhance the radiation crosslinking of thermoplastic rubber for hot-melt pressure-sensitive adhesives, TAPPI JOURNAL June 1988

Journal articles
Open Access
Ethylene-carbon monoxide extrudable adhesive copolymers for polyvinylidene chloride, June 1988, TAPPI Journal 88JUN140

Ethylene-carbon monoxide extrudable adhesive copolymers for polyvinylidene chloride, TAPPI JOURNAL June 1988

Journal articles
Open Access
Improved control of drum level for boilers with "shrink" and "swell" problems, June 1988, TAPPI Journal 88JUN65

Improved control of drum level for boilers with "shrink" and "swell" problems, TAPPI JOURNAL June 1988