A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sens...A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra (DRS) revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.展开更多
Energy performance contracting(EPC)has emerged as a useful project financ-ing and delivery tool for building retrofits,particularly among building owner-ships which have experienced reduced funding for capital project...Energy performance contracting(EPC)has emerged as a useful project financ-ing and delivery tool for building retrofits,particularly among building owner-ships which have experienced reduced funding for capital projects.Through EPC,a contractor(called the EPC contractor or the energy service company)guaran-tees minimum energy savings performance and enables the building owner to finance the project using utility savings over the length of the project(which is typically 12-15 years,or longer).Despite its growing use,there is a dearth of lit-erature regarding a contractor’s risks related to the delivery and execution of EPC building retrofits.This is particularly important as the performance guarantee effec-tively transfers project performance risk from the owner to the EPC contractor.This research proposes a project factors-based risk framework for EPC building retrofits,initially developed through a comprehensive review of relevant literature and project documents and refined through the elicited expertise of 19 highly expe-rienced EPC contracting professionals.A Delphi technique-based expertise elici-tation strategy was used to confirm the findings of the a priori(literature-based)framework and provide additional analysis related to risk causes and control mea-sures as well as relative risk importance.This information was used to construct a refined risk framework which provides insight into the lengthy project performance period during the earliest phases of the project’s life cycle.This has the advantage of providing rapid screening of the project factors that can potentially lead to the greatest project performance risks.展开更多
Energy performance contracting provides guaranteed minimum energy savings to building owners,enabling them to finance project costs using utility savings over the duration of the project.This has been an attractive pr...Energy performance contracting provides guaranteed minimum energy savings to building owners,enabling them to finance project costs using utility savings over the duration of the project.This has been an attractive project delivery method for organizations with reduced budgets for capital projects,particularly among correctional facilities which frequently have lengthy periods of deferred maintenance and ongoing building operations and maintenance concerns.This research builds on a previously developed project factors risk framework for energy service companies undertaking building retrofits.This paper proposes a risk analysis and evaluation model that includes quantitative,expert-based,and probabilistically derived information.Expected cost was used to evaluate risks over lengthy project life cycles and a new metric was developed for use in the model-expected life cycle value.Model results reveal that the most critical risk factors relate to the reduced availability of“low-hanging fruit”energy conservation measures,work scopes based on traditional design-bid-build procurement,unavailable or inaccurate facility information,facility age and current code requirements,and conducting the investment grade audit too quickly.The life cycle cost-based risk model employed in this paper is proposed as an advancement over traditional risk management methods,and it is expected to be applicable,with modification,across other municipal and state government subdomains,especially high security projects.展开更多
基金This project was financially supported by Specialized Research Fund for the Doctoral Program of Higher Education (No. 20050225006)the National Natural Science Foundation of China (No. 30400339).
文摘A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra (DRS) revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.
文摘Energy performance contracting(EPC)has emerged as a useful project financ-ing and delivery tool for building retrofits,particularly among building owner-ships which have experienced reduced funding for capital projects.Through EPC,a contractor(called the EPC contractor or the energy service company)guaran-tees minimum energy savings performance and enables the building owner to finance the project using utility savings over the length of the project(which is typically 12-15 years,or longer).Despite its growing use,there is a dearth of lit-erature regarding a contractor’s risks related to the delivery and execution of EPC building retrofits.This is particularly important as the performance guarantee effec-tively transfers project performance risk from the owner to the EPC contractor.This research proposes a project factors-based risk framework for EPC building retrofits,initially developed through a comprehensive review of relevant literature and project documents and refined through the elicited expertise of 19 highly expe-rienced EPC contracting professionals.A Delphi technique-based expertise elici-tation strategy was used to confirm the findings of the a priori(literature-based)framework and provide additional analysis related to risk causes and control mea-sures as well as relative risk importance.This information was used to construct a refined risk framework which provides insight into the lengthy project performance period during the earliest phases of the project’s life cycle.This has the advantage of providing rapid screening of the project factors that can potentially lead to the greatest project performance risks.
文摘Energy performance contracting provides guaranteed minimum energy savings to building owners,enabling them to finance project costs using utility savings over the duration of the project.This has been an attractive project delivery method for organizations with reduced budgets for capital projects,particularly among correctional facilities which frequently have lengthy periods of deferred maintenance and ongoing building operations and maintenance concerns.This research builds on a previously developed project factors risk framework for energy service companies undertaking building retrofits.This paper proposes a risk analysis and evaluation model that includes quantitative,expert-based,and probabilistically derived information.Expected cost was used to evaluate risks over lengthy project life cycles and a new metric was developed for use in the model-expected life cycle value.Model results reveal that the most critical risk factors relate to the reduced availability of“low-hanging fruit”energy conservation measures,work scopes based on traditional design-bid-build procurement,unavailable or inaccurate facility information,facility age and current code requirements,and conducting the investment grade audit too quickly.The life cycle cost-based risk model employed in this paper is proposed as an advancement over traditional risk management methods,and it is expected to be applicable,with modification,across other municipal and state government subdomains,especially high security projects.