Simulation of Shade Tree Effects on Residential Energy Consumption in Four U.S. Cities

Strategically placed trees can modify urban temperatures by casting shade and thus affect energy consumption for residential cooling and heating. Energy conservation benefits are influenced by the quantity as well as the quality of tree shade upon building surfaces. In this study, we employed an energy simulation program called EnergyPlus as a means to evaluate the effect of a single shade tree upon a structure model having a floor area of 200 m2 in four U.S. cities. Results of EnergyPlus simulations with various single tree planting configurations showed that a large tree on the west aspect of a structure could decrease annual energy costs by up to 160 kWh (valued at $18) in southern cities with longer cooling seasons. Whereas, the same tree on the south aspect could increase annual energy costs by up to 134 kWh (−$15) in northern cities with longer heating seasons. In addition to tree placement around the structure, interactions between sun angle, tree form, and tree distance were observed to influence the effects on energy consumption. Understanding the fundamental interactions between tree form, tree placement, and geographic settings, which influence both the quantity and quality of shade provision, is critical for improving energy conservation benefits of trees in urban settings

Trees on K-12 School Campuses in Virginia

Trees and saplings growing on K-12 school campuses were investigated in 105 school districts across Virginia. There were 2812 trees (\u3e12.5 cm stem diameter at 1.4 m above ground level) inventoried across all campuses. The mean and median campus tree population was 27 and 18, respectively. Loblolly pine (Pinus taeda L.) was the most abundant species, accounting for 11% of all inventoried trees. Red maple (Acer rubrum L.) was the most frequently inventoried species, present on 44% of the campuses. Sapling (trees with 2.5-12.5 cm stem diameter at 1.4 m above ground level) populations were similar to tree populations. The mean and median campus sapling population was 23 and 13, respectively. Flowering dogwood (Cornus florida L.) and red maple were the most abundant sapling species, each accounting for about 10% of all inventoried saplings. Flowering dogwood, red maple, Bradford pear (Pyrus calleryana Decne. ‘Bradford’), willow oak (Quercus phellos L. ), and ornamental cherry (Prunus spp. ) were the most frequently inventoried sapling species, each present on more than 25% of the campuses. Across all campuses, species diversity was relatively low: less than 10 species accounted for over 50% of the inventoried trees and saplings. Prominent Virginia natives, in particular Carya and Quercus species, were under represented in the inventory

Use of Urban Tree Canopy Assessments by Localities in the Chesapeake Bay Watershed

Urban tree canopy (UTC) in the Chesapeake Bay watershed (CBW) provides numerous environmental, economic, and societal benefits. UTC assessments use remote sensing technology to deliver a comprehensive spatial snapshot of a locality’s existing UTC. Because UTC assessments delineate the extent and location of tree canopy cover in the context of other land covers (including plantable space), they are important for establishing tree canopy goals, creating and implementing strategies to achieve those goals, and monitoring progress. Over the past decade, UTC assessments have been completed for numerous localities in the CBW as a result of the Chesapeake Bay Program identifying UTC as a key strategy for Bay restoration. Our research investigated the prevalence of UTC assessments within the CBW and studied how localities are using them. We conducted two surveys: 1) a pilot survey of Virginia localities that received UTC assessments as part of the Virginia UTC project; and 2) a comprehensive survey of all 101 localities in the CBW with populations over 2,500 for which a UTC assessment existed as of May 2013. Surprisingly, 33% of localities in the CBW reported being unaware that a UTC assessment had been performed for their jurisdiction. In general, counties and cities were more likely to be aware of the assessments than were towns (or their jurisdictional equivalent). Most localities that were aware of their assessment were using it in some manner for urban forest planning and management; however, the most frequent activities were also the most basic uses, including: educating officials or citizens about the importance of tree canopy (57%), providing a baseline for evaluating progress toward UTC goals (49%), creating a locality-wide tree canopy goal (47%), planning and prioritizing tree plantings (45%), and informing larger initiatives (43%). All other uses of the assessments (i.e., specialized uses) were reported by 33% or fewer of the CBW localities. Our findings point to the need for outreach to local governments about UTC assessments and their potential uses, particularly in light of increasing emphasis in the CBW on managing urban forests and optimizing UTC as a Bay restoration strategy

First-year Experience Course: Problem Solving, Inquiry, and Integration

In an effort to address academic deficiencies outlined in recent studies, Virginia Tech’s College of Natural Resources and Environment redesigned its first-year experience class to fit their activities into three components of activities: problem solving, inquiry, and integrative learning. The problem solving component required students to define a problem, identify problem-solving strategies, and propose solutions and hypotheses. The inquiry component of the first-year experience included selecting a research topic, learning how to access information about the topic, learning how to evaluate existing information about the topic, and deciding which information to use to achieve desired results about the topic. The final component of the program, integration of learning, connected different programs of study with in-class learning and outside experience. This component also stressed exploring the relationship between student’s self and their learning experiences. To evaluate these three categories, the Motivated Strategies for Learning Questionnaire and the Information Literacy Test surveys were administered to the students at the beginning of the semester and the end of the semester in order to evaluate student growth in each category, as well as students’ own self-awareness. Quantitative analysis of these two surveys illustrates the effectiveness of the assignments associated with each component. Knowledge gained from the redevelopment of the class, quantitative analysis of the surveys, and plans for additional amendments to the class will be shared during conference proceedings

Sustainability Beliefs of First-year Students in Natural Resources

A crux of the environmental problem is change resistance and few college students possess the critical analysis and persuasive communication skills needed to engage in this dialogue. Furthermore, there is little appreciation among college students for the diversity of beliefs regarding sustainability issues. We surveyed students enrolled in a First-Year Experience class in Virginia Tech’s College of Natural Resources and Environment. We used the Dunlap and Van Liere New Environmental Paradigm (NEP) measurement scale to assess the individual student orientations toward nature and the environment. The students enrolled in this class had enrolled voluntarily based on their interest in the study of the environment or natural resources. Therefore, it was no surprise that the score reflected a belief orientation towards sustainability. Survey results allowed these first-year students to discover the range of opinion among members of a relatively homogeneous sample. The survey provided insights regarding the human-centered or eco-centered orientation of their student peers. We used these findings to encourage revision of a draft problem-solving essay. We plan further use of the NEP measurement scale in our curriculum and encourage its adoptions by instructors involved in pedagogy of sustainable thinking

One-sided Device-Independent Quantum Key Distribution: Security, feasibility, and the connection with steering

We analyze the security and feasibility of a protocol for Quantum Key Distribution (QKD), in a context where only one of the two parties trusts his measurement apparatus. This scenario lies naturally between standard QKD, where both parties trust their measurement apparatuses, and Device-Independent QKD (DI-QKD), where neither does, and can be a natural assumption in some practical situations. We show that the requirements for obtaining secure keys are much easier to meet than for DI-QKD, which opens promising experimental opportunities. We clarify the link between the security of this one-sided DI-QKD scenario and the demonstration of quantum steering, in analogy to the link between DI-QKD and the violation of Bell inequalities.Comment: v2 replaces the 3-page abstract posted as v1: our results are now given with all necessary details. v3: published versio

Using Online Digital Tools and Video to Support International Problem-Based Learning

The goal of this study is to examine how to facilitate cross-cultural groups in problem-based learning (PBL) using online digital tools and videos. The PBL consisted of two video-based cases used to trigger student-learning issues about giving bad news to HIV-positive patients. Mixed groups of medical students from Canada and Hong Kong worked with facilitators from each country along with an expert facilitator. The study used AdobeConnect to support the international model through synchronous video interaction and shared applications. This study examines strategies and challenges in facilitating PBL across distance and cultures. Discourse was analyzed using both an inductive and deductive approach where the later used the Community of Inquiry coding scheme. The international context provides a way to facilitate multiple perspectives about how to communicate bad news to patients from different cultural backgrounds. In addition, we present the results of an exploratory analysis of pre and post tests using a standardized patient that demonstrate that the students’ pattern of communication showed qualitative change. Several conjectures were developed for future research

Reconstruction of the joint state of a two-mode Bose-Einstein condensate

We propose a scheme to reconstruct the state of a two-mode Bose-Einstein condensate, with a given total number of atoms, using an atom interferometer that requires beam splitter, phase shift and non-ideal atom counting operations. The density matrix in the number-state basis can be computed directly from the probabilities of different counts for various phase shifts between the original modes, unless the beamsplitter is exactly balanced. Simulated noisy data from a two-mode coherent state is produced and the state is reconstructed, for 49 atoms. The error can be estimated from the singular values of the transformation matrix between state and probability data.Comment: 4 pages (REVTeX), 5 figures (PostScript

Binary-induced collapse of a compact, collisionless cluster

We improve and extend Shapiro's model of a relativistic, compact object which is stable in isolation but is driven dynamically unstable by the tidal field of a binary companion. Our compact object consists of a dense swarm of test particles moving in randomly-oriented, initially circular, relativistic orbits about a nonrotating black hole. The binary companion is a distant, slowly inspiraling point mass. The tidal field of the companion is treated as a small perturbation on the background Schwarzschild geometry near the hole; the resulting metric is determined by solving the perturbation equations of Regge and Wheeler and Zerilli in the quasi-static limit. The perturbed spacetime supports Bekenstein's conjecture that the horizon area of a near-equilibrium black hole is an adiabatic invariant. We follow the evolution of the system and confirm that gravitational collapse can be induced in a compact collisionless cluster by the tidal field of a binary companion.Comment: 9 Latex pages, 14 postscript figure