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Occupancy-based strategies for reducing energy used for heating, ventilating, and air conditioning (HVAC) benefit building owners and help meet state and federal energy and climate goals. However, this value has not previously been quantified beyond typical building owner energy savings. The objective of this research is to estimate the national-level potential added-value of occupancy-based HVAC controls in small office buildings relative to a constant setpoint or to programmable thermostats. Value is defined based on the building owner perspective (energy cost), as well as societal based perspectives of fossil fuels consumed and greenhouse gas, NOx and SOx emissions. A generic small office building with two different HVAC systems is simulated in EnergyPlus and applied to five climate zones representative of the United States. Specific building envelope, electricity supplies, utility costs and total area of small office buildings are adjusted for each climate zone. Results demonstrate that occupancy-based strategies for HVAC control are highly effective, yielding 22-50%and 47-87% reduction in electricity and natural gas use, respectively, compared to no thermostat control. Results vary substantially across climate zones and HVAC systems. With occupancy sensors installed in all small office buildings, the U.S. national savings would be 15 - 66 million GJ fossil fuel use, 0.9–3.7 million metric tons CO 2 e emissions, and 168 - 658 million dollars for utility cost. [ABSTRACT FROM AUTHOR]

Estimating unique soil hydraulic parameters is required to provide input for numerical models simulating transient water flow in the vadose zone. In this paper, we analyze the capability of six soil hydraulic functions to provide unique parameter sets for sandy soils from multi-step outflow data. Initial parameter estimates and experimental boundary conditions were explored to determine their affect on the uniqueness of soil hydraulic functions. Of the hydraulic functions tested, the lognormal distribution–Mualem (LDM) function provided the best performance and a unique solution for error-free numerically generated multi-step outflow data. For experimental multi-step outflow data with inherent measurement errors, the LDM function again showed better performance and uniqueness than the van Genuchten–Mualem and Gardner–Mualem functions. In experiments with different boundary conditions, the LDM function provided the best fitting ability, resulting in unique parameter sets when the intrinsic permeability (k) was fixed at its measured value. The experiment that had a greater number of pneumatic pressure steps, thereby causing a lower flow rate, provided better fitting ability and more unique solutions than faster experiments. [Copyright &y& Elsevier]

Abstract: Extensive research has been done to characterize transport of bacteria in porous media; however, little is understood on how the presence of non-aqueous phase liquids (NAPLs) coupled with the growth state and carbon source of bacteria affect bacterial transport. The objective of this research is to quantify the bacterial adhesion of Pseudomonas saccharophilia P15 (P15), which is known to biodegrade polycyclic aromatic hydrocarbons (PAH) and to interact with coal tars, within a NAPL–water–mineral system. Through a series of short-pulse column experiments, the transport and deposition of P15 in porous media (quartz sand) as a function of growth state and carbon sources (peptone and naphthalene), and in the presence and absence of residual NAPL (hexadecane), is measured and evaluated. Coating 20% of the quartz grain with hexadecane as a model NAPL increased the retention of P15 by as much as a factor of 26 as compared to the retention exhibited in quartz sand with no NAPL present. P15 grown on peptone and in the late exponential growth state exhibited a greater amount of deposition within the hexadecane column than when it was grown on naphthalene or was in early exponential growth phase. During early growth stage P15 grown on naphthalene adhered stronger to the porous media compared to when grown on peptone. Results were compared with results of MATH assays, where P15 partitioning to hexadecane was evaluated as a function of carbon source and growth state. [Copyright &y& Elsevier]

Abstract: Firms engaged in industrial ecology hope to reduce environmental impacts and costs, improve resource efficiency, and create symbiotic relationships that reduce transaction costs and enhance information flow. However, current LCA tools do not explain firms'' incentives to implement the principles of industrial ecology, or how an individual or firm can affect the products and processes at other firms. Game theory, on the other hand, allows investigation of the willingness of producers and consumers to seek strategies that promote the common interest of the system while not harming their own interests. This paper applies game theory to the lifecycle of bottle packaging, and presents a framework for analysis of the choice between refillable and disposable bottles. Although refillable bottles may be more cost effective in the long run, bottlers only have incentive to use refillable bottles when they are sure that consumer return rates will be reasonably high. It has been found that consumers who keep or dispose of refillable bottles, or respond to deposit/refund return incentives by reducing their demand, may drive costs up and encourage adoption of disposables. A simple model is provided which finds the optimal bottler strategy as a function of the bottler''s expectations for consumer cooperation. [Copyright &y& Elsevier]

Abstract: Capillary pressure (P c)–saturation (S)–relative permeability (k r) relationships must be quantified to accurately predict non-aqueous phase liquid (NAPL) distribution in the subsurface. Several experimental techniques are presented here for two-fluid P c–S–k r relationships for various saturation paths to better define the effect of fractional wettability on these relationships. During the primary drainage path of the P c–S curves, the air–water system showed no distinct trend as a function of the fraction of sand treated by organosilane (S) to render it non-water wetting. In a NAPL–water system, however, a consistent decrease of capillary pressure with increase of the fraction of non-water wetting sands was observed. The much lower contact angle for air–water (a–w) system may result in the observed insensitivity of the a–w P c–S curves to fractional wettability, at least for the PD pathway. For the main imbibition path of NAPL–water system, capillary pressure decreased as the fraction of the S component increased, requiring forced imbibition (negative capillary pressures) for a certain range of saturations. Systems with an increasing percentage of the S component also exhibited a higher water k r and lower NAPL or air k r at a given saturation for the primary drainage and main imbibition paths in both air–water and NAPL–water systems. The increase of water k r with increase of the fraction of the S component can be explained by the ability of water to occupy larger and highly conductive pores in such a system. Experimental k r–S data for the primary drainage path of NAPL–water system presented here were used to test the Bradford et al. [Bradford SA, Abriola LM, Leij FJ. Wettability effects on two- and three-fluid relative permeabilities. J Contam Hydrol 1997;28:171–91] model and the modified Mualem model for estimating the k r–S curves from measured P c–S data as a function of fractional wettability. Both models predicted significantly less variation in the k r–S curves than measured indicating that they did not adequately represent the system under investigation. [Copyright &y& Elsevier]