Treesearch

Nature uses a wide variety of chemicals for providing adhesion internally (e.g., cell to cell) and externally (e.g., mussels to ships and piers). This adhesive bonding is chemically and mechanically complex, involving a variety of proteins, carbohydrates, and other compounds.Consequently,the effect of protein structures on adhesive properties is only partially understood and creates an inherent difficulty in understanding protein structure-property relationships. This complexity has limited researchers in the past to mainly depend on empirical studies for insight, with a few exceptions....

A tornado safe room is a shelter designed to provide protection during a tornado and is specifically engineered to resist the high wind pressures and debris impact generated by these high wind events. The required performance criteria of these shelters has been established and is found in the International Code Council Standard for the Design and Construction of Storm Shelters. A tornado safe room has been developed from commodity wood products and is described in “A Residential Tornado Safe Room from Commodity Wood Products: Design and Development”. In designing this structure, several...

In the United States, tornadoes cause significant damage and result in many injuries and deaths. Although the development and use of tornado safe rooms have helped decrease the human toll associated with these events, the cost of these structures is often too high for many that could benefit from their use. The development of a nonproprietary residential tornado safe room constructed from commodity wood building products, buildable by a local contractor or do-it-yourselfer, and adaptable to existing homes, could lower the cost of these structures and result in more widespread use. This...

The purpose of this study was to develop test data needed to characterize lateral load performance of structural insulated panel (SIP) walls with full bearing (restrained). The research program involved structural testing of 29 full-size SIP walls (8 ft tall by 8 ft long) of various configurations that bracket a range of SIP wall configurations commonly used in the field. Results indicated that the cyclic performance parameters for all walls tested in this study met the over-strength and ductility capacities of ICC-ES AC04, although some walls had drift capacities slightly lower than the...

An extended plate and beam (EP&B) design was developed at Home Innovation Research Labs (Upper Marlboro, Maryland) in an effort to provide traditional light-frame wall construction details that are compatible with continuous insulating sheathing. This would encourage wide-spread adoption of high-R walls and promote greater energy efficiency in new houses. The new wall design provides significant increases in insulation and ensures moisture management while relying on common methods and materials for framing, insulation, and siding attachment. It incorporates the use of foam sheathing...

The bright spot in September was new single-family sales, but housing starts appear to have stalled on a monthly basis. Regionally, data were mixed across all sectors. New construction spending’s contribution to U.S. gross domestic product decreased on a quarterly basis.

The bright spot in September was new single-family sales, but housing starts appear to have stalled on a monthly basis. Regionally, data were mixed across all sectors. New construction spending’s contribution to U.S. gross domestic product decreased on a quarterly basis.

These guidelines are designed for decision makers (selectmen, county commissioners, city planners, preservation officers, etc.) that have responsibility for repairing and maintaining existing covered bridges to help them understand what goes into making effective decisions about how, and when, to repair a covered bridge. The purpose of these guidelines is to present the steps necessary for decision makers to identify effective rehabilitation techniques for restoring the structural integrity of covered bridge members. The intent is to retain the maximum amount of historic fabric while...

Background and Aims Wood is a major innovation of land plants, and is usually a central component of the body plan for two major plant habits: shrubs and trees. Wood anatomical syndromes vary between shrubs and trees, but no prior work has explicitly evaluated the contingent evolution of wood anatomical diversity in the context of these plant habits. Methods Phylogenetic comparative methods were used to test for contingent evolution of habit, habitat and wood anatomy in the mega-diverse genus Croton (Euphorbiaceae), across the largest and most complete molecular phylogeny of the genus to...

The 20th International Nondestructive Testing and Evaluation of Wood Symposium was hosted by the USDA Forest Service Forest Products Laboratory in Madison, Wisconsin, USA, on September 12–15, 2017. This Symposium was a forum for those involved in nondestructive testing and evaluation (NDT/NDE) of wood and brought together many NDT/NDE users, suppliers, international researchers, representatives from various government agencies, and other groups to share research results, products, and technology for evaluating a wide range of wood products, including standing trees, logs, lumber, and wood...