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Kaplan L.,University of Massachusetts Boston | Lentz D.L.,University of Cincinnati | Slotten V.,University of Cincinnati | Sheets P.,University of Colorado at Boulder | Hood A.N.,GAI Consultants Inc.
Economic Botany | Year: 2015

Phaseolusfrom Cerén—A Late Classic Maya Site. : Archaeological investigations at Cerén, a well–preserved Classic period Maya site in El Salvador, have recovered an abundance of carbonized bean remains, both Phaseolus vulgaris and P. lunatus. Surprisingly, the Cerén P. vulgaris bean remains were derived from both wild and domesticated populations. This find reveals that the Late Classic inhabitants continued to draw upon wild food sources even though they had clear access to a full array of domesticated food crops. This discovery not only offers insights into human behavior patterns of the past, but also has implications for the genetic interchange between wild types and cultivars. This potential genetic proximity helps to explain the multiple origins of Phaseolus domestication and the proliferation of its varieties. © 2015 The New York Botanical Garden Source


Naito C.,Lehigh University | States J.,GAI Consultants Inc. | Jackson C.,Applied Research Associates Inc. | Bewick B.,Protection Engineering Consultants, LLC
Journal of Materials in Civil Engineering | Year: 2014

To address the ever-increasing quantity of scrap tires produced in the United States, a study is conducted on the use of crumb rubber in concrete for use in structures against near-field blast and ballistic demands. Crumb rubber concrete (CRC) is produced by replacing a volume percentage of the traditional coarse and/or fine aggregate with crumb rubber particles. Crumb rubber is produced in various gradations from used vehicle tires through a variety of shredding processes. The influence of crumb rubber on the constitutive and structural performance of concrete under quasi-static loading has been examined in past research. CRC has been shown to have decreased strength and stiffness while still being a useable structural material. This research study examines the use of CRC for the specialized application of blast and ballistic protection. The program characterizes resistance of CRC to contact and near-contact high explosive detonations, and examines depth of penetration, and perforation using V50 methods. The results of the experimental and analytical investigation found that (1) the addition of crumb rubber results in decreased resistance to ballistic demands and near-field blast loads, (2) the reduction is less than that estimated by accepted predictor methods, and (3) when normalized by weight rather than thickness, the use of CRC results in an improvement in resistance to ballistic and near-field blast demands. © 2014 American Society of Civil Engineers. Source


Pardee J.,GAI Consultants Inc.
Geotechnical Special Publication | Year: 2012

A large pedestrian bridge at an Orlando theme park had settled about 13 cm at two supports (see Figure 1). Construction of a new wizard-themed land forced action to correct the settlement. Park managers urgently needed to level and stabilize the structure even though funding and time were limited. The working team of engineer, contractor, and planner encountered buried obstacles, limited access, red tape and other hurdles. After days of toil and failed attempts, the pressure grouting finally took hold and lifted the bridge in less than 15 minutes. This project illustrates the economical and successful use of shallow, highly-fluid pressure grouting as a method of lifting and leveling a structure in certain situations. © 2012 American Society of Civil Engineers. Source


Kaplan L.,University of Massachusetts Boston | Lentz D.L.,University of Cincinnati | Slotten V.,University of Cincinnati | Sheets P.,University of Colorado at Boulder | Hood A.N.,GAI Consultants Inc.
Economic Botany | Year: 2015

Archaeological investigations at Cerén, a well- preserved Classic period Maya site in El Salvador, have recovered an abundance of carbonized bean remains, both Phaseolus vulgaris and P. lunatus. Surprisingly, the Cerén P. vulgaris bean remains were derived from both wild and domesticated populations. This find reveals that the Late Classic inhabitants continued to draw upon wild food sources even though they had clear access to a full array of domesticated food crops. This discovery not only offers insights into human behavior patterns of the past, but also has implications for the genetic interchange between wild types and cultivars. This potential genetic proximity helps to explain the multiple origins of Phaseolus domestication and the proliferation of its varieties. © 2015, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A. Source


Link A.,Clarkson University | Link A.,U.S. Army | Chen M.,Clarkson University | Chen M.,GAI Consultants Inc. | And 2 more authors.
Water Research | Year: 2010

Extensive research has been done to characterize transport of bacteria in porous media; however, little is understood on how the presence of non-aqueous phase liquids (NAPLs) coupled with the growth state and carbon source of bacteria affect bacterial transport. The objective of this research is to quantify the bacterial adhesion of Pseudomonas saccharophilia P15 (P15), which is known to biodegrade polycyclic aromatic hydrocarbons (PAH) and to interact with coal tars, within a NAPL-water-mineral system. Through a series of short-pulse column experiments, the transport and deposition of P15 in porous media (quartz sand) as a function of growth state and carbon sources (peptone and naphthalene), and in the presence and absence of residual NAPL (hexadecane), is measured and evaluated. Coating 20% of the quartz grain with hexadecane as a model NAPL increased the retention of P15 by as much as a factor of 26 as compared to the retention exhibited in quartz sand with no NAPL present. P15 grown on peptone and in the late exponential growth state exhibited a greater amount of deposition within the hexadecane column than when it was grown on naphthalene or was in early exponential growth phase. During early growth stage P15 grown on naphthalene adhered stronger to the porous media compared to when grown on peptone. Results were compared with results of MATH assays, where P15 partitioning to hexadecane was evaluated as a function of carbon source and growth state. © 2010 Elsevier Ltd. All rights reserved. Source

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