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Highlights • Developed of a building energy assessment resource for small commercial. • Implemented in 13 buildings with 49 tenants in food service, office, and retail. • Exhibited accuracy in different space types, sizes and complexity. • Demonstrated novelty in portraying food service end-use energy consumption. Abstract Small commercial buildings represent 94% of U.S. commercial buildings by number and consume approximately 9% of national total primary energy. However, advancements in building efficiency technologies have focused on large commercial building systems, while these buildings also have the financial support and personnel resources to invest in implementing improvements. Pragmatic and easy to use tools to assist small commercial building stakeholders in making informed and effective energy decisions are scarcely available. One approach is to synergize existing research and resources into a single package. This research presents the development of a building energy assessment resource (BEAR) and implementation in thirteen buildings. BEAR performed similarly and favorably in estimating tenants’ total energy consumption across all three enterprise types: food service, retail and office. Results reveal a weighted average absolute difference between BEAR and utility bills of 4.7% for electricity and 13.3% for natural gas estimation. Potential factors impacting BEAR's accuracy include assumptions made for modal parameters, e.g. power and time in mode, in addition to fuel flow rate controls in commercial cooking equipment. Discussions on the broader implications of the developed energy resource include applicability across small commercial enterprise sectors and future advancements directed towards policy makers and energy service providers. [ABSTRACT FROM AUTHOR]

Front-end planning is arguably the most impactful activity in the management of construction projects. Small projects oftentimes have minimal planning completed prior to the start of the design and construction, much to the detriment of the project success. This paper summarizes the research efforts to develop a front-end planning tool specifically for small projects, namely the project definition rating index for small industrial projects (PDRI-SIP). A set of 41 specific elements relevant to the planning of SIPs was developed. Five separate workshops were held in which 65 industry professionals evaluated and prioritized the proposed elements. The tool was validated by more than 50 completed and ongoing SIPs. Statistical analysis showed that projects with better scope definition had significantly improved cost and schedule performance than projects with lesser scope definition. Comparison of front-end planning practices for small and large industrial projects showed planning for project execution over project feasibility being significantly more important on small projects. This paper contributes to the body of knowledge by detailing the development of a novel front-end planning tool designed for use on the most prevalent project type in the industrial construction sector and in-depth analysis of front-end planning practices for small and large industrial construction projects. [ABSTRACT FROM AUTHOR]

With the advent of sustainable building ordinances in the USA and internationally, contractors are increasingly required to deliver sustainable projects; however, they have traditionally not been considered partners in developing the sustainability goals and objectives for projects. Moreover, as alternative project delivery methods become more popular, contractors have an opportunity and - in an increasing number of cases - a requirement, to take a larger role in sustainability efforts across the building life cycle. Understanding the contractor's self-perceived role, in addition to their incentives for participation, in the sustainable construction industry is imperative to providing insight into their future role within the industry. This paper presents data from and analysis of a survey of US-based general contractors. The survey asked general contractors for their opinions and viewpoints regarding sustainable construction; respondents provided feedback about corporate profitability, growth forecast and specific obstacles to sustainable building. The authors present a potential path from the current state of sustainable construction industry in the USA to a projected future state (both characterised by the survey responses). Finally, factors that will affect the transition to the future state of the sustainable construction industry are discussed. [ABSTRACT FROM AUTHOR]

The popularity of Building Information Modeling (BIM) as an integral concept in the Architecture, Engineering, and Construction (AEC) industries has motivated its necessary inclusion in Construction Management (CM) education. Implementing BIM as a mainstream, elective or integrated subject within an established undergraduate curriculum is challenging due to limitations such as available teaching time, knowledge retention in students and the flexibility of the curriculum to adapt with a fast developing technology. Pedagogy must combine fundamental learning of theory, practical experience and the use of technology in a collaborative environment to effectively implement BIM. Vertical integration is one such method that was implemented and evaluated to promote BIM education in the undergraduate Construction Management program at Arizona State University. This article discusses the evolution of the BIM curriculum and focuses on the vertical integration of upper-division and lower-division students for a Site Logistics assignment to improve upon the BIM education continuum. Evaluation and surveys revealed that this methodology increased the appreciation for learning BIM, promoted the use of BIM tools for in-class projects and created an understanding of the importance of information management. [ABSTRACT FROM PUBLISHER]

This paper presents a novel finance project delivery concept, savings to sustainability (S2S), that bridges the existing gaps between energy projects implemented using alternative financing mechanisms, sustainability initiatives, and greenhouse gas (GHG) reductions. Bridging these three areas will have a synergistic effect in terms of meeting federal and other agency goals for energy, water, and GHG reduction. The most common finance project delivery method used in the federal sector to date is the energy savings performance; however, these contracts are driven by financial, rather than energy consumption or GHG, savings. The aggressive requirements pertaining to sustainability and GHG reduction goals requires an integrated and more holistic approach to retrofit and renovation projects. The S2S finance project delivery method enables existing buildings to achieve net zero carbon through a phased approach that begins with energy and water efficiency, then on-site renewable power generation, and finally green power procurement. We present here two case studies implementing key elements of the S2S concept; the first is a federal agency project covering three campuses in Puerto Rico, the second is a university campus in central California. [ABSTRACT FROM AUTHOR]

Existing buildings, or those constructed before 2000, make up approximately 90% of the commercial building stock in the U.S. Existing buildings represent a large opportunity for reducing energy consumption in the U.S., because they account for approximately 16% of the country's energy consumption each year. This paper presents a design process, in the form of a set of recommended practices, for achieving successful, deep energy retrofits (those that reduce energy consumption by 30% or more) in commercial buildings. These practices include forming an integrated design team, developing a process map for the design phase of the retrofit project that facilitates collaboration and communication, and routinely evaluating the energy performance of the project. This paper focuses on the predesign, schematic design, design development, and construction documents phases of a retrofit project and proposes tasks required in each of these phases to achieve deep energy savings in a retrofit project. [ABSTRACT FROM AUTHOR]

We explore the ultimate behavior of the graphene transistor in the quantum capacitance limit. The quantum capacitance formulation allows for an exactly solvable model, and the ideal assumptions provide an upper bound on performance, including peak currents of 1 mA/μm with mobilities as low as 2000 cm2/V s for channel length of 1 μm, as well as linearly increasing transconductance not observed in conventional transistors. A negative differential resistance is predicted under certain conditions, with a maximum peak-to-valley-current ratio of 4. Finally, the effects of oxide scaling are elucidated and the oxide capacitances required for quantum capacitance limited behavior are quantified. [ABSTRACT FROM AUTHOR]

The conversion efficiency of field-effect transistors with even-odd symmetry is elucidated in this work. From symmetry considerations, this work reveals that even symmetry, due to electron-hole symmetry in graphene, affords efficient even-harmonic multiplication. Odd symmetry, associated with linear charge transport, affords suppression of odd-harmonic signals. For the ideal symmetric transistor multiplier, conversion efficiency with relatively large power gain is achievable, while for practical graphene transistors, the efficiency can be substantially less than unity due to non-idealities such as contact resistance, high impurity densities, and low gate capacitance. In the quantum capacitance limit of graphene transistor, near-lossless conversion efficiency is available. [ABSTRACT FROM AUTHOR]

Interest in graphene device physics and technology has been growing rapidly, especially for very high frequency transistor applications. However, the predicted intrinsic performance has not been fully realized due to impurity and parasitic issues introduced in device fabrication. Through a self-consistent model, we show that the normalized contact resistance has an exponentially detrimental impact on the peak transconductance, which is a defining transistor parameter. In addition, we reveal that very high current-gate voltage linearity or input invariant transconductance can be achieved in the limit of negligible contact resistances, a desirable feature for linear electronic systems. [ABSTRACT FROM AUTHOR]

Small and medium commercial buildings account for nearly half of the energy consumed by commercial buildings in the United States. While energy retrofits can significantly reduce building energy consumption, buildings' owners often lack the capital and experience to perform detailed energy audits and retrofit assessments. The purpose of this paper is to introduce a low-investment, bottom-up and simplified methodology for identifying energy retrofit opportunities that benefit the owners of small and medium sized office buildings In particular, the paper addresses small and medium commercial buildings on a university campus as a proof-of-concept for other owner-operators that have small and medium commercial facilities in their portfolio. The methodology consists of an eight-step framework using publicly-available and simplified tools. While energy audits and retrofit opportunity assessments are not new, a low-cost methodology for owner-operators of small and medium commercial buildings to analyze energy consumption and identify retrofit opportunities represents a contribution to knowledge. A medium office building on a university campus in Arizona served as a case study to validate the methodology. The case study showed a maximum potential energy reduction of an estimated 50%, but the figure varies based on the types of retrofit (deep versus light), energy conservation measures selected and implemented, invested resources, and interactive effects between measures. This methodology is extensible to other owner-operators that have building utility data and would like to perform retrofit opportunity assessments themselves. [ABSTRACT FROM AUTHOR]

Highlights • A smart meter study of electric appliances in a food service and office tenant. • Bottom-up analysis is capable of providing stakeholders meaningful energy information. • Uncertainty in estimating modal power drives error in quantifying electricity use. • Esoteric appliance modal data inhibits stakeholder-friendly electricity estimation methods. • Novel energy contour plots use spatial relationships to deliver information to visual learners. Abstract Small commercial buildings (<50,000 ft2 in floor area) consume 44% of all U.S. commercial primary electricity, with plug loads accounting for 31% of that portion and growing. In response, a bottom-up building energy assessment resource (BEAR) was previously developed as a practical approach to disaggregating building energy use, including plug loads. This article examines the performance of BEAR in estimating plug load consumption, specifically appliance energy consumption, through use of smart meters in two building types, food service and office. Results of the analysis reveal that BEAR is capable of providing building stakeholders with meaningful energy information. Accuracy of BEAR's energy consumption estimates could be improved by 25% to 59% through better data on modal (i.e. appliance operating mode such as standby mode) usage and power demand, respectively. These results stress the importance of detailed modal information, because when modal power information was available the median difference between BEAR and the smart meter measured data was 36% compared with 223% in appliances where modal data was not available. In response to these findings, this study develops and presents energy contour plots, a visual tool for plotting modal usage and modal power in a two-dimensional form of energy consumption contours. Moreover, it is the recommendation of this study that increased transparency of modal power be implemented at the manufacturer label or specification to achieve increased accuracy of targeted energy improvements. [ABSTRACT FROM AUTHOR]

Despite the need to reform, maintain, and expand U.S. infrastructure, the construction industry often struggles to deliver infrastructure projects that meet their target budget and schedule. One successful tool that assists in planning, assessing risk, and managing such projects is an evidence-based tool, the Project Definition Rating Index (PDRI), which supports the front-end planning (FEP) for projects. PDRI–Infrastructure Projects and PDRI–Small Infrastructure Projects effectively facilitate FEP efforts for large and small infrastructure projects, respectively. This article provides a definition of a small infrastructure project through survey respondents' identification and ranking of 16 characteristics that differentiate both types of infrastructure projects. These resulted in identifying the total installed cost (TIC) to be the main differentiator between small and large infrastructure projects, with small infrastructure projects having a TIC cap of $20 million. Also, the article provides details of qualitative and quantitative similarities and differences between both PDRI tools in support of improved planning efforts for their respective project types. Specifically, the study distinguishes between the two PDRIs in terms of their structure, content and weight of the elements, most critical planning elements, and target score. The goal of the comparison is to help project teams improve project planning and manage project risks by focusing on specific project definitions or identifying elements that may not need to be thoroughly investigated during FEP. The analyses show that small and large infrastructure projects require similar levels of project definition during FEP to support predictable performance outcomes, confirming that the management of such projects requires selecting the appropriate PDRI tool prior to its implementation. This article supports project teams in planning, assessing risks, and managing infrastructure projects by identifying the characteristics of small infrastructure projects and differentiating between the two PDRI tools. [ABSTRACT FROM AUTHOR]

Energy efficiency represents the most cost-effective way to achieve energy goals, as it does not require investment in renewable energy and is often achievable through low-cost technology retrofits or behavior modifications. This study investigates the impacts of energy efficiency measures on the effectiveness of pre-cooling in residential buildings as a means of reducing operating peak loads and costs in a home. This study simulated (and validated the simulation through monitoring) a typical residential building in Phoenix, Arizona to analyze the impact of upgrading a residential building that implements pre-cooling with two scenarios: (1) match the benchmark of ASHRAE 90.2–2007, and (2) surpass the standard by enhancing its properties to reduce the total energy demand by 20%. This article contributes to the body of knowledge by demonstrating a method to identify and select those types of efficiency measures that best enhance the effectiveness of pre-cooling strategies in residential buildings in a hot–arid climate. [ABSTRACT FROM PUBLISHER]

A correction to the article "Impact of Contact Resistance on the Transconductance and Linearity of Graphene Transistors," by Kristen N. Parrish and Deji Akinwande that appeared in the December 7, 2011 online issue is presented.

Highly bendable graphene field-effect transistors are fabricated on polyimide films. The device offers robust performance against various conditions including immersion in liquids, and dynamic loading tests, which are hazardous to conventional electronics. Bendability of the sample is tested with the bending radius of down to 1.3 mm; the devices remain fully functional with less than 8.7% reduction and no reduction in the electron and hole mobility after repeated bending tests, respectively. Multi-finger electrodes are implemented on flexible substrates to enhance its current drive. Silicon-nitride passivation offers efficient chemical protection over diverse liquids and robust mechanical protection against impacts. [ABSTRACT FROM AUTHOR]

Small commercial buildings, or those comprising less than 50,000 square feet of floor area, represent 94% of U.S commercial buildings by count and consume approximately 8% of the nation's primary energy; as such, they represent a largely unexploited opportunity for energy savings. Small commercial buildings also represent a large economic market—the National Institute of Building Sciences (NIBS) estimated the small commercial retrofit market at USD 35.6 billion. Despite the prominence of small commercial buildings and the economic opportunity for energy retrofits, many energy efficiency programs focus on large commercial buildings, and create efficiency solutions that do not meet the needs of the small commercial market. This paper presents an analysis of 34 small commercial case study projects that implemented energy efficiency retrofits. This paper contributes to the existing building retrofit body of knowledge in the following ways: (1) it identifies the decision criteria used by small commercial building stakeholders that decided to complete an energy retrofit; (2) it identifies the most commonly implemented efficiency measures in small commercial buildings, and discusses why this is the case; and (3) it provides empirical evidence about the efficacy of installing single energy efficiency measures (EEMs) compared to packages of EEMs in small commercial buildings by reporting verified energy savings. To the authors' knowledge, this paper is the first to catalog decision criteria and energy savings for the existing small commercial buildings market, and this research illustrates that small commercial building decision-makers seem most motivated to retrofit their spaces by energy cost savings and operational concerns. Furthermore, small commercial building decision-makers opted to implement single-system retrofits in fifteen (15) of the thirty-four cases studied. Finally, this research documents the improved savings, in the small commercial buildings market, associated with a more integrated package of EEMs compared to a single-system approach, achieving approximately 10% energy savings for a single-system approach and more than 20% energy savings for integrated approaches. These savings translate to CO2 savings of 1,324,000 kgCO2/year to 2,647,000 kgCO2/year, respectively, assuming small commercial buildings are retrofit at a rate of 0.95% of the stock annually. [ABSTRACT FROM AUTHOR]

As the United States' population grows and power delivery needs continue to expand, utility companies are presented with a unique opportunity to improve reliability, increase capacity, and provide innovations to power and pipeline production and delivery infrastructure. While there is research dedicated to the impacts of the regulatory environment on project performance and the profitability of power and pipeline projects, there has been no research dedicated to identifying the differences in planning processes for such projects. Therefore, this paper contributes to the construction body of knowledge by explicitly documenting how the regulatory environment impacts the planning metrics involved in power and pipeline utility projects. This paper explores how capital project planning varies for power and pipeline projects in both regulated and nonregulated environments through an analysis of 770 projects in the Independent Project Analysis (IPA), project database. This paper presents a statistical comparison of pipeline and power project planning indicators—front-end loading (FEL) score, budget spent on front-end planning, and stakeholders engaged in front-end planning—to understand the impact of the regulatory environment on project planning. The results suggest that for some planning indicators studied, regulated projects outperform nonregulated projects, and for other indicators, the reverse is true. In particular, results show that regulated pipeline projects have better a project definition at the time of project authorization than nonregulated pipeline projects based on the FEL score; the reverse is true for power projects. Regulated pipeline and power projects spend more in a budget on front-end planning than nonregulated pipeline and power projects. Lastly, key stakeholders are represented in both regulatory environments with little difference between nonregulated and regulated environments in both pipeline projects, but power projects in regulated environments engage the key stakeholders for more time. [ABSTRACT FROM AUTHOR]

Building energy assessment is essential to accomplish the sustainable energy targets of new and present buildings. Retrofitting of the existing buildings by assessing them through energy models is the most prominent method. Studies revealed that there is still blank information about the building stocks, and these affect the valuation of building energy efficiency policies. Literature also recommends that the existing energy models are too complex and unreliable to predict the energy use. Reliability of such energy models would improve through a better alignment of the input parameters and the model assumptions. The authors hypothesized that the reliability of models would be improved through identification of the most relevant energy use parameters for the building stocks in different regions and models. One of the most commonly accepted methods for detecting the most dominant input parameters is sensitivity analysis, though its shortcomings include the need for a large number of data samples and long computing time. In this research, the Energy, Carbon, and Cost Assessment for Buildings Stocks (ECCABS) model is adopted to identify the most important parameters of the presented model. The research team uses the model that has been validated by studies conducted for the UK building stock. Moreover, by assessing the feasibility study with the stepwise regression to identify the significant input parameters have been discussed. Results show that stepwise regression method could produce the same results compared to sensitivity analysis. This paper also indicates that stepwise regression is considerably faster and less computationally intensive compared to common sensitivity analysis methods. [ABSTRACT FROM AUTHOR]

As continued globalization of the world's economic, environmental, and societal interactions strains the planet to meet anthropogenic demands, universities are striving to integrate sustainability education into engineering curricula intended to prepare students for global challenges facing today's engineers. Concurrently, the Accreditation Board for Engineering and Technology (ABET) has potential changes related to outcomes related to sustainability. Current practice is to evaluate many student educational outcomes, including those in sustainability, at the end of collegiate careers, primarily through the senior design course. This study compares results from the application of a comprehensive holistic sustainability rubric assessment tool to three years of student projects in two stand-alone sustainable engineering courses and two senior design courses, intended to assess dissimilarities in student outcomes and locate causality, in the context of sustainability. The authors present two potential factors contributing to discrepancies in student outcomes: (1) rubrics do not contain clear elements of sustainability; and (2) senior design course syllabuses are full, and offer strategic approaches to overcoming these barriers institutionally and nationally. [ABSTRACT FROM AUTHOR]

High-frequency performance of graphene field-effect transistors (GFETs) has been limited largely by parasitic resistances, including contact resistance (RC) and access resistance (RA). Measurement of short-channel (500 nm) GFETs with short (200 nm) spin-on-doped source/drain access regions reveals negligible change in transit frequency (fT) after doping, as compared to ~23% fT improvement for similarly sized undoped GFETs measured at low temperature, underscoring the impact of RC on high-frequency performance. DC measurements of undoped/doped short and long-channel GFETs highlight the increasing impact of RA for larger GFETs. Additionally, parasitic capacitances were minimized by device fabrication using graphene transferred onto low-capacitance quartz substrates. [ABSTRACT FROM AUTHOR]