An Objective Protocol for Movable Bridge Operation in High-Wind Events Based on Hybrid Analyses by European and American Design Code

Movable bridges play an integral role in modern transportation infrastructure. As means of passage for both vehicular and naval traffic at a single location, their reliable performance is a necessity. However, with the thousands of movable bridges in the US – which are typically located in coastal environments that are typically highly susceptible to extreme weather events – there are few objective protocols defining the environmental conditions in which they can be safely operated. In order to define such conditions, wind speed and temperature variable wind loads were developed using multiple, structural load development codes for a case study site: the Memorial Bridge in Portsmouth, NH. These loads were developed, examined, and combined to create hybrid load cases for input and analysis in SAP2000® to determine structural response levels in the bridge members. The results from SAP2000® were used to predict the demands the Memorial Bridge will experience in both its lifted and un-lifted positions in variable environmental conditions, such that the viability of a lift can be more objectively defined. These results were compiled in conjunction with bridge’s aerodynamic susceptibility and an investigation of the dynamics of the bridge’s counterweight system, both of which were found to be of minimal concern in terms of bridge structural safety. Following the future integration of structural health monitoring (SHM) and weather data acquisition systems at the case study site, the protocol will be refined and expanded to more accurately predict safe lifting conditions

Economic Implications of Environmental Sustainability for Companies: A Case Study of 3M

As awareness of sustainability grows, firms are being pressured to adopt social and environmental practices to keep pace with ethical standards and consumer demand. Firms must adapt to a changing marketplace, and new management strategies are being developed. Our central purpose in this paper is therefore to explore the economic implications of enhanced environmental sustainability through a case study of 3M, a chemical company that has been implementing sustainable solutions for over 30 years. We begin our case study by analyzing the effectiveness of the lifecycle management approach (LCM) currently advocated to businesses in search of sustainability. Although the LCM methodology is still developing at this stage, it has yielded great results for 3M when combined with employee expertise. We will then go on to analyze why these increases in sustainability have increased profits, and what effect tighter environmental legislation would have on competitive markets. The final section of this paper will analyze the performance of environmentally responsible firms on the stock market to determine whether increased sustainability makes firms more desirable to investors. Our critical analysis of the multi-faceted economic implications of enhanced environmental sustainability will therefore allow us to determine 1) the effectiveness of current approaches to sustainability; 2) the economic implications of enhanced corporate responsibility and legislation, and 3) the impact of enhanced sustainability on the performance of companies on the stock market

Acoustoelectric photoresponse in graphene

Journal ArticleThe acoustoelectric current in graphene has been investigated as a function of illumination, using blue (450nm) and red (735nm) light-emitting diodes (LEDs), and surface acoustic wave (SAW) intensity and frequency. The measured acoustoelectric current increases with illumination, more than the measured change in the conductivity of the graphene, whilst retaining a linear dependence on the SAW intensity. The latter is consistent with the interaction between the carriers and SAWs being described by a relatively simple classical relaxation model suggesting that the change in the acoustoelectric current is caused by the effect of the illumination on the electronic properties of the graphene. The increase in the acoustoelectric current is greatest under illumination with the blue LED, consistent with the creation of a hot electron distribution

Lesson Plan Helps Volunteers Improve Learning Among 4-H Youths in Animal Projects

Continued development and delivery of animal science programs for 4-H youths is a critical need in all livestock production regions. The large number of 4-H youth programs, their rural locations, and the small number of 4-H Extension professionals make delivery of new curricula challenging. In response, we developed animal science lessons for volunteer leaders. We evaluated the effectiveness of a quality assurance lesson delivered by untrained volunteers on learning among 4-H youths in 32 clubs across Idaho. Survey results indicate improved student learning and provide preliminary evidence that this delivery model can be effective for 4-H participants

Between the Eves of Allhallowmas

The forty poems arranged in this collection were all written within a two year period roughly corresponding to the lapse of time between the Eves of Allhallowmas of 1974 and 1976. The scheme of things is such that nothing of much importance is lost in opening the book at random

Thermal emission from large area chemical vapor deposited graphene devices

Copyright © 2013 AIP PublishingThe spatial variation of thermal emission from large area graphene grown by chemical vapor deposition, transferred onto SiO2/Si substrates and fabricated into field effect transistor structures, has been investigated using infra-red microscopy. A peak in thermal emission occurs, the position of which can be altered by reversal of the current direction. The experimental results are compared with a one dimensional finite element model, which accounts for Joule heating and electrostatic effects, and it is found that the thermal emission is governed by the charge distribution in the graphene and maximum Joule heating occurs at the point of minimum charge density.This research was supported by the Engineering and Physical Sciences Research Council, and the European Union under the FET-open grant GOSFELEngineering and Physical Sciences Research Council (EPSRC)European Unio

HIGH ASPECT RATIO ION EXCHANGE RESIN BED - HYDRAULIC RESULTS FOR SPERICAL RESIN BEADS

A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit

Origins of the sarsen megaliths at Stonehenge

The sources of the stone used to construct Stonehenge around 2500 BCE have been debated for over four centuries. The smaller “bluestones” near the center of the monument have been traced to Wales, but the origins of the sarsen (silcrete) megaliths that form the primary architecture of Stonehenge remain unknown. Here, we use geochemical data to show that 50 of the 52 sarsens at the monument share a consistent chemistry and, by inference, originated from a common source area. We then compare the geochemical signature of a core extracted from Stone 58 at Stonehenge with equivalent data for sarsens from across southern Britain. From this, we identify West Woods, Wiltshire, 25 km north of Stonehenge, as the most probable source area for the majority of sarsens at the monument

High background rates of positive tuberculosis-specific interferon-? release assays in a low prevalence region of UK: a surveillance study

Background: Background rates of latent tuberculosis infection in low prevalence regions of Britain are unknown. These would be valuable data for interpreting positive IGRA results, and guiding cost-benefit analyses. The management of a large outbreak of tuberculosis occurring in a rural district hospital provided an opportunity to determine the background rates and epidemiology of IGRA-positivity amongst unselected hospital patients in a low-prevalence region of U.K.Methods: As part of a public health surveillance project we identified 445 individuals exposed to the index cases for clinical assessment and testing by a TB-specific interferon-? release assay (IGRA): T-Spot.TB. Uniquely, an additional comparator group of 191 age-matched individuals without specific recent exposure, but with a similar age distribution and demographic, were recruited from the same wards where exposure had previously occurred, to undergo assessment by questionnaire and IGRA. Results: Rates of IGRA positivity were 8.7% (95%CI, 4.2-13, n=149) amongst unexposed patients, 9.5%(3.0-22, n=21) amongst unexposed staff, 22%(14–29, n=130) amongst exposed patients, 11%(6.1-16, n=142) amongst exposed staff. Amongst the individuals without history of recent exposure to the outbreak, IGRA-positivity was associated with prior TB treatment (OR11, P.04) and corticosteroid use (OR5.9, P.02). Background age-specific prevalences of IGRA-positivity amongst unexposed individuals were: age <40 0%(N/A), age 40–59 15%(12–29), age 60–79 7.0%(1.1-13), age?80 10%(5.9-19).Conclusions: Background rates of IGRA-positivity remain high amongst unselected white-Caucasian hospital inpatients in U.K. These data will aid interpretation of future outbreak studies. As rates peak in the 5th and 6th decade, given an ageing population and increasing iatrogenic immunosuppression, reactivation of LTBI may be a persistent hazard in this population for several decades to come