Autonomous Crack Monitoring (ACM) and Autonomous Crack Propagation Sensing (ACPS) are two types of structural health monitoring in which characteristics of cracks are recorded over long periods of time. ACM seeks to correlate changes in widths of cosmetic cracks in structures to nearby blasting or construction vibration activity for the...
The finite element method is used to investigate failure mechanisms in pin-hanger connection in aging highway bridges. Bridge pins and hangers are typically considered as critical elements whose failure may result in partial or entire collapse of the structure. The primary function of a pin-hanger connection is to allow for...
This report includes the findings of acoustic emission (AE) tests on the Fremont tied arch bridge in Portland Oregon conducted by research engineers from the Infrastructure Technology Institute of Northwestern University on March 24th, 1997.
The underutilized tropical fruit tree, “cempedak” (Artocarpus integer (Thunb.) Merr. , Moraceae), is a major crop in Malaysia but the distribution of genetic diversity in the crop and its putative wild progenitor, “bangkong” (Artocarpus integer var. silvestris Corner), have not been studied. To investigate the diversity and origins of cempedak,...
The tallgrass prairie once dominated much of the mid-western United States. Today, this highly productive system has been severely reduced, contributing to an array of environmental problems. The recent renaissance in natural area restoration and stewardship of the tallgrass prairie in the Chicago Wilderness region (Illinois, USA), especially in the...
The environmental and plant physiological correlates of plant growth and reproductive effort in the locally threatened orchid, Cypripedium candidum Muhl. ex Willd were examined in the context of a conceptual model of demographic and reproductive trade-offs, focusing on three Illinois populations. This study addresses the current status and long-term trends...
Because long-chain n-alkanes (n-C21 to n-C37) are found in the epicuticular leaf waxes of all vascular plants and are stable, long-lived molecules, the study of their molecular and isotopic compositions stands to serve as a potentially powerful tool in the fields of modern chemotaxonomy and paleoecology. This study attempts to...
A randomized experiment was conducted to assess the effectiveness of three forms of e-mail appeals to prospective members of a newly formed professional group. The baseline condition consisted of an impersonal appeal; prospective members were sent a mass e-mail encouraging them to join. Participants in the personal condition received an...