Case study of a high efficiency home

The PowerHouse home in Newton, IA was designed and built with energy efficiency in mind. The main technology being studied is ZeroNet\u27s super envelope design, which incorporates expanded polystyrene bonded with a fiber-reinforced concrete coating on each side. The highly insulated walls and roof of the PowerHouse should reduce heating and cooling energy consumption by up to 50% throughout the year while the sophisticated HVAC equipment will improve air quality and human comfort by reducing pollutants inside the residence.;Research Goals. (1) Evaluate building envelope performance with regards to design heating and cooling loads; (2) Estimate the annual performance using a commercially available computer program simulation and compare it to actual performance; (3) Simulate the annual performance of a traditionally build home and compare it to the PowerHouse; (4) Monitor and analyze end-use electrical consumption for various HVAC and domestic equipment and appliances; (5) Evaluate the performance of the home as a whole using sub-metered data to calculate a performance index; (6) Compare the PowerHouse home\u27s annual energy performance index with various other homes and government indexes; (7) Find ways of improving the performance of the installed mechanical systems.;The design heating and cooling loads where calculated to be 31,659 Btu/hr and 24,828 Btu/hr, respectively. These design loads where calculated using the ASHRAE approved method outlined in the 2005 Fundamentals Handbook (ASHRAE, 2005).;The simulated annual energy consumption of the HVAC equipment was 18,217 kWh. The home actually consumed 19,167 kWh, so the simulation was fairly accurate. The annual energy consumption of a 2x6 built home of the same design was estimated to be 25,899 kWh. The 2x6 home uses 42% more energy for heating and cooling than the PowerHouse. This extra energy use equates to over 575 per year of extra utility bills. Considering a modest 2% fuel inflation rate, over a ten year period the ZeroNet design would save over 6,300. The higher U-value of the exterior walls and roof and the increased infiltration rate are the main factors contributing to the extra energy use.;In 2005, the PowerHouse consumed a total of 35,480 kWh of electricity. This corresponds to an energy intensity of 28.8 kBtu/ft2. According to the Energy Information Administration (EIA, 2004), in 2001 the average energy intensity of a single-family detached home in the Midwest was 49 kBtu/ft 2 (EIA, 2004). Thus, the PowerHouse home represents a 41% improvement in energy intensity than the average.;Detailed monitoring conducted from January, 2005 thru December 2005 showed that there are several steps that could be taken to lower the annual energy consumption of the Powerhouse home. The domestic hot water system has large standby losses due to a recirculation system that keeps hot water at all the taps in the home. While the home was unoccupied and no hot water was being used, the domestic water heater consumed over 500 kWh per month. A clean air system integrated into the air handling unit relies on the fan running at low speed 100% of the time, even when there are no loads, to circulate air and carry away heat from the ultraviolet bulb fixture.;Overall the PowerHouse was performing as expected. The detailed monitoring showed that there were still ways to greatly reduce the overall energy use. Utilizing a geothermal system\u27s higher coefficient of performance, the HVAC cost could be cut by over 60%. The domestic hot water load would also be supplemented by a de-superheater included with most heat pumps. The PowerHouse was already performing better than average, so applying these upgrades would make it all that much better

Incorporation of High-k HfO2 Thin Films in a-IGZO Thin Film Transistor Devices

In this study, HfO2 [hafnium oxide] thin films are investigated extensively as part of indium gallium zinc oxide (IGZO) thin film transistor (TFT) devices. They are incorporated into the TFTs, both as a gate insulator and a passivation layer. First, the HfO2 [hafnium oxide] films themselves are investigated through an annealing study and through I-V and C-V measurements. Then, HfO2 [hafnium oxide] is suggested as a replacement for commonly used SiO2 [silicon dioxide] gate insulator, as it has a dielectric constant that is 4 – 6 times higher. This higher dielectric constant allows for comparable TFT performance at a lower operation voltage (5 V vs. 20 V). Finally, HfO2 [hafnium oxide] is applied as a passivation layer in IGZO TFTs, and an annealing study is conducted to determine which processing steps will allow for optimal TFT performance. The HfO2 [hafnium oxide] passivation layer proves to show a good level of uniformity. Therefore, taking all results into consideration, both HfO2 [hafnium oxide] gate insulators and passivation layers can be used in conjunction with IGZO TFTs to produce a full electrowetting array, which should prove to be useful in “lab on a chip” studies

Starting Well: Facilitating the Middle School Transition

School-based mental health programming is a viable intervention because it can provide evidenced-based-treatment (EBT) while avoiding the typical service barriers. In this study, 119 students (ages 10 to 12) were randomly assigned to participate in either a 24-session Coping Power Program (CPP) or a control group. Using the Behavior Assessment Scale for Children-2 (BASC-2), teachers reported significant improvements over time for all students (Attention Problems, Hyperactivity, Externalizing Problems, and Withdrawal, and Study Skills). However, teachers reported that students participating in the CPP showed significantly greater improvement than controls (Learning Problems, School Problems, Behavior Symptom Index, Social Skills, and Adaptive Skills). Effect sizes ranged from small (.19 for Withdrawal) to large (.76 for Adaptive Skills). Teacher reports showed greater improvement by the more experienced group leaders. Results validate the use of this EBT as a viable protocol. The improvement in both groups may suggest a spillover effect for untreated controls. The differential effect of group leader suggests that clinical experience may enhance EBT

Genomic and proteomic profiling of responses to toxic metals in human lung cells.

Examining global effects of toxic metals on gene expression can be useful for elucidating patterns of biological response, discovering underlying mechanisms of toxicity, and identifying candidate metal-specific genetic markers of exposure and response. Using a 1,200 gene nylon array, we examined changes in gene expression following low-dose, acute exposures of cadmium, chromium, arsenic, nickel, or mitomycin C (MMC) in BEAS-2B human bronchial epithelial cells. Total RNA was isolated from cells exposed to 3 M Cd(II) (as cadmium chloride), 10 M Cr(VI) (as sodium dichromate), 3 g/cm2 Ni(II) (as nickel subsulfide), 5 M or 50 M As(III) (as sodium arsenite), or 1 M MMC for 4 hr. Expression changes were verified at the protein level for several genes. Only a small subset of genes was differentially expressed in response to each agent: Cd, Cr, Ni, As (5 M), As (50 M), and MMC each differentially altered the expression of 25, 44, 31, 110, 65, and 16 individual genes, respectively. Few genes were commonly expressed among the various treatments. Only one gene was altered in response to all four metals (hsp90), and no gene overlapped among all five treatments. We also compared low-dose (5 M, noncytotoxic) and high-dose (50 M, cytotoxic) arsenic treatments, which surprisingly, affected expression of almost completely nonoverlapping subsets of genes, suggesting a threshold switch from a survival-based biological response at low doses to a death response at high doses

Specificity and ligand affinities of the cocaine aptamer: impact of structural features and physiological NaCl

The cocaine aptamer has been seen as a good candidate for development as a probe for cocaine in many contexts. Here, we demonstrate that the aptamer binds cocaine, norcocaine, and cocaethylene with similar affinities and aminoglycosides with similar or higher affinities in a mutually exclusive manner with cocaine. Analysis of its affinities for a series of cocaine derivatives shows that the aptamer specificity is the consequence of its interaction with all faces of the cocaine molecule. Circular dichroism spectroscopy and 2-aminopurine (2AP) fluorescence studies show no evidence of large structural rearrangement of the cocaine aptamer upon ligand binding, which is contrary to the general view of this aptamer. The aptamer’s affinity for cocaine and neomycin-B decreases with the inclusion of physiological NaCl. The substitution of 2AP for A in position 6 (2AP6) of the aptamer sequence eliminated the effect of NaCl on its affinities for cocaine and analogues, but not for neomycin-B, showing a selective effect of 2AP substitution on cocaine binding. The affinity for cocaine also decreased with increasing concentrations of serum or urine, with the 2AP6 substitution blunting the effect of urine. Its low affinities for cocaine and metabolites and its ability to bind irrelevant compounds limit the opportunities for application of this aptamer in its current form as a selective and reliable sensor for cocaine. However, these studies also show that a small structural adjustment to the aptamer (2AP exchanged for adenine) can increase its specificity for cocaine in physiological NaCl relative to an off-target ligand

On direct measurement of the W production charge asymmetry at the LHC

The prospects for making a direct measurement of the W production charge asymmetry at the LHC are discussed. A modification to the method used at the Tevatron is proposed for measurements at the LHC. The expected sensitivity for such a measurement to parton distribution functions is compared to that for a measurement of the lepton charge asymmetry. The direct measurement approach is found to be less useful for placing constraints on parton distribution functions at the LHC than a measurement of the lepton charge asymmetry.Comment: 18 pages, 10 figures, v2: references and keywords updated v3: Additional paragraph discussing inclusion of W asymmetry in global fits adde

Net Shape Processing of Alnico Magnets by Additive Manufacturing

Alternatives to rare earth permanent magnets, such as alnico, will reduce supply instability, increase sustainability, and could decrease the cost of permanent magnets, especially for high temperature applications, such as traction drive motors. Alnico magnets with moderate coercivity, high remanence, and relatively high energy product are conventionally processed by directional solidification and (significant) final machining, contributing to increased costs and additional material waste. Additive manufacturing (AM) is developing as a cost effective method to build net-shape three-dimensional parts with minimal final machining and properties comparable to wrought parts. This work describes initial studies of net-shape fabrication of alnico magnets by AM using a laser engineered net shaping (LENS) system. High pressure gas atomized (HPGA) pre-alloyed powders of two different modified alnico “8” compositions, with high purity and sphericity, were built into cylinders using the LENS process, followed by heat treatment. The magnetic properties showed improvement over their cast and sintered counterparts. The resulting alnico permanent magnets were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and hysteresisgraph measurements. These results display the potential for net-shape processing of alnico permanent magnets for use in next generation traction drive motors and other applications requiring high temperatures and/or complex engineered part geometries