Treesearch

A useful genetic system has been developed for the transformation of Pichia stipitis. This includes two selectable markers (URA3 and LEU2), integrating and autonomous replication vectors, a pop-out cassette that enables multiple targeted disruptions, and a genomic X-library for rapid cloning. Using this system we have cloned two genes for alcohol dehydrogenase (PsADH1 and PsADH2). two genes for pyruvate decarboxylase (PsPDC1 and PsPDC2). and cytochrome c (PsCYC1). Disruption of PsADH1, but not PsADH2, resulted in increased xylitol production. Disruption of PsCYC1 resulted in lower growth...

Exterior house paint has undergone some changes in recent years. Designers now have their own brands. And on a technical front, water-based paint now outstrips oil-based paint in quality and durability. You have six decisions to make1 stain versus paint...oil versus latex... type of latex...type of finish...quality level...and brand-name versus generic.

Researchers at the USDA Forest Products Laboratory have developed a new three-dimensional structural panel, called FPL Spaceboard. This panel is formed using a U.S. patented three-dimensional mold capable of using a variety of fibrous materials with either the wet- or dry-forming process. Structurally, the panel departs from the traditional two-dimensional panel by integrally forming vertical ribs and face in one structure. In the literature, significant work has been conducted to model drying of two-dimensional panels, but no known work has been done on such a three-dimensional integral...

This research study proposed to include the glue material in a finite element model that represents the actual geometry and material properties of a corrugated fiberboard. The model is a detailed representation of the different components of the structure (adhesive, linerboard, medium) to perform buckling analysis of corrugated structures under compressive loads. The objective of this analysis was to quantify the influence of the adhesive on the structural performance of corrugated fiberboard. Adhesive parameters are identified in terms of adhesive stiffness and material properties. The...

The plans for crashworthy bridge railings for low-volume roads were developed through a cooperative research program involving the USDA Forest Service, Forest Products Laboratory (FPL); the Midwest Roadside Safety Facility, University of Nebraska-Lincoln (MwRSF); and the Forest Service, National Forest System, Engineering. Three railings were developed and successfully tested in accordance with National Cooperative Highway Research Program (NCHRP) Report 350 Test Level-1 requirements. The fourth system was developed for a lower test level based on criteria developed by the Forest Service...

Biopulping is the treatment of wood chips and other lignocellulosic materials with lignin-degrading fungi prior to pulping. Ten years of industry-sponsored research has demonstrated the technical feasibility of the technology for mechanical pulping at a laboratory scale. Two 50-ton outdoor chip pile trials recently conducted at the USDA Forest Service, Forest Products Laboratory (FPL) in Madison, Wisconsin have established the engineering and economical feasibility of the technology. After refining the control and the fungus-treated chips through a thermomechanical pulp (TMP) mill, the...

Stickies continue to represent the most challenging contaminant to remove from recycled secondary fiber. Current projections suggest that pressure sensitive adhesive (PSA) markets will continue to grow rapidly, increasing the concentration of these contaminants in common office-pack wastepaper. PSAas reformulated to exhibit higher removal efficiencies within standard secondary fiber processing equipment are expected to prove effective in alleviating cleanliness demands for the recycling industry. The US Postal Service, in their program to develop postage stamp adhesives that do not...

SouthPro is a Microsoft Excel add-in program that simulates the management, growth, and yield of uneven-aged loblolly pine stands in the Southern United States. The built-in growth model of this program was calibrated from 991 uneven-aged plots in seven states, covering most growing conditions and sites. Stands are described by the number of trees in 13 size classes for softwood, soft hardwood, and hard hardwood species. SouthPro allows managers to predict stand development, by year and for many decades, from a specific initial diameter distribution. Cutting regimes are specified by the...

This review summarizes patents in the area of paper recycling that appeared during the first half of 1998 in either of two on-line data bases: Derwent World Patent Index or Claims/U.S.Patents Abstracts. The information in these data bases is intended to keep readers informed about the latest equipment, chemicals, and technology in this field. The abstracts provide only a brief summary of the inventions. Readers will need to access the full texts of specific patents for complete information. The patents summarized in this review cover a broad spectrum of recycling processes, equipment, and...

The glucose analog 2-deoxyglucose (2-DOG) has been used to obtain mutants derepressed for pentose metabolism. Some researchers have used 2-DOG alone whereas others have used it in the presence of a glucoserepressible carbon source. We examined both methods and screened mutant strains for improved use of xylose in the presence of glucose. Pichia stipitis mutants selected for growth on D-xylose in the presence of 2-DOG used xylose from a 1:1 glucose: xylose mixture more rapidly than did their parents. One of these mutants, FPL-DX26, completely consumed xylose in the presence of glucose and...