Jill Neal

Adaptive photovoltaic system

This paper discussed a new photovoltaic (PV) system topology that uses PV energy in efficient way in order to improve system power output during different operating conditions. The proposed topology provides flexible connection between PV modules to achieve different configurations of PV array. A new switching matrix has been developed to achieve the required configurations. Preliminary simulations provide promising results for an adaptive PV array. Comparison between traditional PV system configurations and adaptive configuration is considered. A significant improvement in power curves is achieved by the proposed topology.

An AHP-weighted aggregated data quality indicator (AWADQI) approach for estimating embodied energy of building materials

PurposeAggregated data quality indicator (ADQI) method has been used to estimate probability distributions of the input data in a life cycle assessment (LCA) to compensate for insufficient data in a statistical analysis. In a traditional ADQI, a multicriteria evaluation process, the impacts of various quality indicators under investigation are often equally weighted or unweighted despite the fact that some of them may weight more than the others on contributing to the overall data uncertainty. An unweighted ADQI (UWADQI) approach, though simple, may lead to incorrect conclusions. This paper aims to develop a weighted ADQI to overcome the deficiency of the unweighted ADQI to make it more reliable for LCA uncertainty analysis.MethodTo improve the UWADQI approach, an analytical hierarchy process (AHP) is introduced in this research for estimating weighting factors in the ADQI aggregation process. An AHP’s pairwise comparison function is used to determine the weighting of each data quality indicator. Three common building materials of concrete, steel, and glass were chosen to validate the presented method.Results and discussionUsing the published results from the statistical method as the benchmarks, it was found that the proposed AHP-weighted ADQI (AWADQI) method lead to better estimated probabilistic values of embodied energy intensity than the traditional UWADQI approach for the three building materials.Conclusions and recommendationsIn conclusion, using AHP to incorporate weighing factors into an ADQI process can improve the uncertainty estimate of embodied energy of building materials, and consequently, the method can improve the reliability of a building LCA.

Real Time Power Monitoring & integration with BIM

A Real Time Power Monitoring (RTPM) System is proposed in which end-use detailed energy consumption data is provided for each load level. The data will be integrated with a BIM (Building Information Modeling) Model to create a Realtime on-line electronic BIM Model. This paper describes the RTPM system and the process leading to its creation. The basic components of the proposed system were designed and tested using a prototype board.

The “BIM's 4D+” dimension: Real time energy monitoring

With the current trend towards Building Information Model (BIM), facility managers have a new tool for raising efficiency. This paper discusses the integration of the BIM software with a real-time monitoring (RTM) system, as a 4D+ dimension in BIM, to track the electrical usage at every location in a building. This ability could be invaluable in identifying what unnecessary loads are connected to a device and could be disconnected. This would result in elimination of needless loads and phantom loads during non-business hours, causing significant reduction in energy consumption. A prototype of the RTM was built and the results are in support of reduction in energy consumption. Real-time awareness is a major factor in facility management and essential to meet the strict guidelines presently being adopted.

Contributions of Internal and External Fouling to Transmembrane Pressure in MBRs: Experiments and Modeling

AbstractThis paper reports a new approach to understanding membrane fouling in membrane bioreactors (MBR). The foulants were categorized into those inside the membrane (internal fouling) and those on the membrane forming the so-called external fouling layer (external fouling). The volumes of the internal and external foulants were determined with the aid of a confocal laser scanning microscope (CLSM) after staining the foulants. Thus, the porosities of both the membrane and the external fouling layer were calculated, which explained the contributions of internal and external fouling to transmembrane pressure (TMP) from the standpoint of fundamental filtration theory. The categorical method indicates that external fouling may dominate the long-term operation of MBR with the formation of the external fouling layer, whereas internal fouling, in the form of pore constriction, may cause both initial and final TMP jumps under the operating conditions in the current study. In addition, a mathematical model was d...

Graywater reclamation by a shredded tire biofilter and a membrane bioreactor in series

AbstractThe search for sustainable and effective water reclamation technologies has been stimulated by increasingly urgent water scarcity. Graywater (GW) is an excellent potential resource for relieving the water scarcity problem because it has a relatively low pollution level and because it is abundant and accessible. GW makes up approximately 70% of domestic wastewater. A new technology, shredded tire biofilter (STB), combined with a membrane bioreactor (MBR), was demonstrated to be an efficient method for treating GW to a level that satisfies the USEPA’s water reuse guidelines. In the proposed technology, the MBR ensured adequate effluent water quality, and the STB pretreated the GW. The technology may significantly reduce the energy required to treat GW by MBRs alone. It was further observed that increasing hydraulic retention time and decreasing shredded tire particle size enhanced the removal of BOD5 in the STBs. Analysis of biofilms on shredded tire chips showed that microorganisms could attach and...

Variations in High-Intensity Precipitation under Climate Changes in the LMRB and Implications for Drinking Water Supply Security

14 15 A systematic temporal and spatial analysis is being conducted at the U.S. EPA on historical 16 precipitation and stream flow in the Lower Mississippi River basin (LMRB) and their 17 relationships with Atlantic hurricanes and flooding events. The objectives are to decipher the 18 periodicity and long-term trends exhibited in the hydroclimatic regime, and to determine their 19 implications on the security of community water supplies in the region and the Gulf Coast, the 20 parts of the continental U.S. prone to the negative impacts of extreme weather events under the 21 current and future climate conditions. 22 23 Statistical modeling using wavelet functions shows periodicity of continental precipitation and 24 hurricanes with characteristic changes of trends around 1890-1900, 1940-1960, and the 1990s. 25 These long-term decadal and multi-decadal changes were identified in a spatial modeling and 26 wavelet frequency analysis of the 24-hour daily precipitation data obtained from the National 27 Climatic Data Center. Long-term variations are also detected in hurricane and flooding events. 28 Based on these findings, one can incorporate the hydroclimatic periodicity and long-term 29 variations into the emergency water supply management and system designs. Measures such as 30 water intake protection, using decentralized water supply, and planning emergency management 31 are potential options in natural disaster preparedness. The results of the first phase investigation 32 are discussed. 33 34 35

Economic Input-Output Life Cycle Assessment of Water Reuse Strategies in Residential Buildings

1.0 Introduction The growth of cities is putting great strains on existing freshwater supplies in many areas, including the United States (Kloss, 2008). The United States Green Building Council (USGBC) has stated that buildings consume roughly 39% of all electricity and approximately 10% of all potable water (USGBC, 2008). The growing need for freshwater has lead to an increase in water reuse applications. However, some water reuse strategies actually result in an increase in energy usage and other environmental impacts. The objective of this study is to determine the environmental sustainability of three water reuse designs through economic input-output life cycle assessments (EIO-LCA). The water reuse designs include a simple greywater reuse system for subsurface landscape irrigation; an indoor greywater reuse system for toilet flushing and laundry washing; and a hybrid greywater and rainwater reuse system for landscape irrigation, toilet flushing, and laundry washing.

Managing Water Quality and Quantity under Drought Conditions

It is common practice to select the most pristine available water source when choosing a drinking water supply. However in many parts of the world and some parts of the United States both the quality and quantity of available source water is declining. This trend together with increasing populations in urban areas is making it increasingly difficult for drinking water utilities to find adequate water sources. Compounding this problem is the tightening of drinking water standards throughout the world. One consequence of this trend is the need to explore various options, including mixing and blending of water from several sources or the installation of advanced treatment in order to provide water of acceptable quality to consumers.