278 research outputs found
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Investigation of the Relationship between Green Design and Project Delivery Methods
The selection of the project delivery method (PDM) for any project is critical--it establishes communication, coordination, and contractual issues between the owner, contractor, and designer. With an increase in the number of green design projects, understanding the relationship between the PDM and green design is paramount to project and contract management. It is reasonable to assume that a positive relationship between green design and design-build (DB) exists since both theoretically are intended to foster an integrated, holistic, and collaborative project. This research examines the relationship between the design-bid-build (DBB), construction management (CM), and DB PDMs and green design with the goal of establishing best practices and identifying potential synergies between them. The research collected information by conducting primarily telephone interviews with approximately twenty-five individuals, including owners, contractors, and designers involved in completed green design projects, mainly in the public sector. The interviews developed a general understanding of the current state of knowledge and experience and not a rigorous quantitative analysis. Upon completion of the interviews, the tabulated results were summarized and green project characteristics and project-PDM interactions emerged. Existing published research was evaluated to reveal aspects of PDMs independent of green design. Best practices were ascertained by combining information from the interviews and published research. Best practices are as follows: (1) Project implementation features--The decision to use DB as PDM on green design or other projects should be based on the specific project features; e.g., well-defined scope and adequate owner staffing. DB will not produce successful results on all projects. (2) Collaboration--Project team collaboration early in the design and construction process is an important aspect of green projects, and collaboration was considered somewhat more important in projects that used DB. (3) Experience--Team experience is important on all green design projects independent of the PDM. Owners should use a 'best value' selection process, which is more prevalent in DB projects, and include team experience as a criterion. The owner's role is critical with DB. (4) Leadership--Leadership is an important feature for all contracting parties involved in green design projects and it is a dominant success factor in DB projects. (5) Scope of work--A well-defined scope of work is important on all projects, independent of the PDM. In DB, improving the scope of work definition by developing a set of documents, typically comparable to the design development phase, as the basis for awarding a contract is called DB bridging. Using contracting techniques such as DB bridging can result in better identification of expected quality and improves the owner's level of control. (6) Funding and Budget--Having adequate funding and budget for the given scope of work is particularly important in a green design project. Public funding restrictions may not allow use of certain PDMs, and the nature of public funding streams may make non-traditional PDMs more difficult. (7) Complexity and Flexibility--Complexity and flexibility is a project feature that is more specific to green design projects and is more frequently associated with DB. (8) Control and Accountability--Control and accountability is a problem associated with DB more than with DBB. It is not specific to green design projects. DB Bridging can be used to offset the lack of control with traditional DB. The use of green design and DB is increasing and understanding the linkage between the two is important. This research has found that while linkages do exist, the owner needs to carefully consider all aspects of a green design project before making the decision of the most appropriate PDM
Multi-Scale Life Cycle Impact Indicators of Freshwater Resources in the Built Environment
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Comparison and analysis of product stage and service life uncertainties in life cycle assessment of building elements
Life cycle assessment (LCA) has the potential to inform building decisions from the planning process to conceptual design. As such, there is intrinsic uncertainty that needs to be explored further to allow for proper decisions to be made. These uncertainties may be related to parameter definition, such as life cycle inventory or model as service life definition. This paper aims to analyze the influence of two recognized sources of uncertainties in LCA of buildings: product stage uncertainties and uncertainties from SL during the use stage. The Monte Carlo simulation method is applied to conduct uncertainty analysis of the LCA results of four building elements, namely, external cement plaster, external clay brick wall, external painting and internal painting. The functional unit is 1 m2 of each building element. Three different building reference study periods are considered: 50, 120 and 500 years. A global warming potential impact category is chosen since it is one of the most significant indicators for climate change mitigation strategies. Results indicate that SL uncertainties are greater than product stage uncertainties for the four building elements analyzed. Furthermore, based on the findings from this study, distribution choice influences the uncertainty analysis results in Monte Carlo simulation. Standardizing modeling of SL in the LCA of buildings could guide building LCA practitioners and researchers and lead to more comparable results
Hyperthermic Isolated Limb Perfusion with TNF α and Cisplatin in the Treatment of Osteosarcoma of the Extremities: A Feasibility Study in Healthy Dogs
Purpose. The feasibility of hyperthermic isolated limb perfusion
(HILP) with tumor necrosis factor-α (TNFα ) and cisplatin for the management of
osteosarcoma was studied in the canine model
Rim-to-Rim Wearables at the Canyon for Health (R2R WATCH): Physiological, Cognitive, and Biological Markers of Performance Decline in an Extreme Environment
Success in extreme environments comes with a cost of subtle performance decrements that if not mitigated properly can lead to lifethreatening consequences. Identification and prediction of performance decline could alleviate deleterious consequences and enhance success in challenging and high-risk operations. The Rim-to-Rim Wearables at the Canyon for Health (R2R WATCH) project was designed to examine the cognitive, physiological, and biological markers of performance decline in the extreme environment of the Grand Canyon Rim-to-Rim (R2R) hike. The study utilized commercial off-the-shelf cognitive and physiological monitoring techniques, along with subjective self-assessments and hematologic measurements to determine subject performance and changes across the hike. The multiyear effort collected these multiple data streams in parallel on a large sample of participants hiking the R2R, leading to a rich and complex data set. This article describes the methodology and its evolution as devices and measurements were assessed after each data collection event. It also highlights a subset of the patterns of results found across the data streams. Subsequent work will draw on this data set to focus on building more sophisticated, predictive statistical models and dive deeper into specific analyses (such as the physiological and biological profiles of hikers who were left behind by their hiking partners)
Driving factors for the adoption of green finance in green building for sustainable development in developing countries: The case of Ghana
While there are many motivating factors for green finance (GF) implementation, a comprehensive taxonomy of these variables is lacking in the literature, especially for green buildings (GBs). This study aims to analyze the criticality and interdependence of GFâinâGB's driving factors. This study develops a valid set of factors to justify the interrelationships among the drivers. The drivers of GFâinâGB are qualitative in nature, and uncertainties exist among them due to linguistic preferences. This study applies the fuzzy Delphi method to validate eight drivers under uncertainties. Fuzzy DecisionâMaking Trial and Evaluation Laboratory (FDEMATEL) with qualitative information is used to determine the interrelationships among the drivers. The drivers were grouped under two categories: prominent drivers and causeâeffect drivers. The findings revealed that âincreased awareness of GF models in GBâ and âpreferential capital requirements for lowâcarbon assetsâ are the top two most prominent/important drivers of GFâinâGB. In Ghana, the top three cause group drivers are âclimate commitment,â âimproved access to and lower cost of capital,â and âfavorable macroeconomic conditions and investment returns.â Drivers with the highest prominence values have the potential to affect and/or be affected by other drivers; therefore, managers and policymakers should prioritize promoting or pursuing these drivers in the short term. On the other hand, it is important to pay more than equal attention to the drivers with the highest net cause values because they have the largest longâterm impact on the entire system. The theoretical and practical implications of the study are discussed, enhancing understanding and decisionâmaking in GFâinâGB
Is habitat fragmentation good for biodiversity?
Habitat loss is a primary threat to biodiversity across the planet, yet contentious debate has ensued on the importance of habitat fragmentation âper seâ (i.e., altered spatial configuration of habitat for a given amount of habitat loss). Based on a review of landscape-scale investigations, Fahrig (2017; Ecological responses to habitat fragmentation per se. Annual Review of Ecology, Evolution, and Systematics 48:1-23) reports that biodiversity responses to habitat fragmentation âper seâ are more often positive rather than negative and concludes that the widespread belief in negative fragmentation effects is a âzombie ideaâ. We show that Fahrig's conclusions are drawn from a narrow and potentially biased subset of available evidence, which ignore much of the observational, experimental and theoretical evidence for negative effects of altered habitat configuration. We therefore argue that Fahrig's conclusions should be interpreted cautiously as they could be misconstrued by policy makers and managers, and we provide six arguments why they should not be applied in conservation decision-making. Reconciling the scientific disagreement, and informing conservation more effectively, will require research that goes beyond statistical and correlative approaches. This includes a more prudent use of data and conceptual models that appropriately partition direct vs indirect influences of habitat loss and altered spatial configuration, and more clearly discriminate the mechanisms underpinning any changes. Incorporating these issues will deliver greater mechanistic understanding and more predictive power to address the conservation issues arising from habitat loss and fragmentation
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Atmospheric Peroxyacetyl Nitrate (PAN): A Global Budget and Source Attribution
Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs) is the principal tropospheric reservoir for nitrogen oxide radicals . PAN enables the transport and release of to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30%), acetone (7%), and a suite of other isoprene and terpene oxidation products (19%). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37%) and alkanes (14%). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.Engineering and Applied Science
Pulmonary Disease and Age at Immigration among Hispanics. Results from the Hispanic Community Health Study/Study of Latinos
Rationale: Asthma has been reported to be more prevalent among Hispanics of Puerto Rican heritage than among other Hispanics and among Hispanics born in the United States or who immigrated as children than among those who came as adults; however, direct comparisons across Hispanic groups are lacking
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