Analysis of Energy Conservation Options for USDOE Child Development Center, Final Summary Report

This report presents the results of a study that verifies the energy savings due to the individual ECOs through the use of a calibrated DOE-2 simulation. The results show that roughly 73% of the savings estimated by the GSA architect can be accounted for by the calibrated simulation. This compares very well when one considers that the large differences were contributed by the envelope improvements and the clerestory windows. If these two ECOs were omitted, 90% of the savings can be accounted for by the calibrated simulation.The U.S.D.O.E. Forrestal Child Development Center (CDC) was designed to be a "showpiece" model building. Its construction included energy efficient features such as efficient lighting, a photovoltaic system, an energy management system, lighting controls, envelope improvements, clerestory windows, energy efficient heat pumps, and a solar hot water system. The architect's estimate of the energy savings from these measures totaled 31.6 million Watt-hours per year (MWh/yr), an annual savings of about $1,580 (at$0.05/kWh). This study calculated a total annual energy savings of 23.2 MWh per year for the CDC; a savings of $1,160

Effect of the Grain Size on the Energy per Unit Volume at the Onset of Liquefaction

Recent exploratory work by the authors indicated the feasibility of relating the development of the pore water pressure leading to liquefaction of soils subjected to earthquake loading to the amount of unit energy imparted to the soil during the dynamic motion. This research also showed that regardless of the mode of stress application, sinusoidal or random, the unit energy needed to initiate liquefaction is nearly constant for a given effective confining stress and a specific relative density, demonstrating that the unit energy is independent of the shear strain amplitude. Data obtained during torsional shear tests on a given soil made possible the development of relationships between the unit energy required for liquefaction (as the dependent variable) and the effective confining pressure and the relative density (as the independent variables). This paper examines the effect of grain size, and in particular that of the amount of silt contained in the liquefiable soil, on the amount of unit energy required for liquefaction. The soils selected for study included soils that liquefied during the recent Northridge Earthquake (Lower San Fernando Valley Dam). Understanding the effect of grain size on the amount of unit energy needed to initiate liquefaction is fundamental if an energy-based method to determine the liquefaction potential of a soil deposit is to implemented

Field Verification of the Energy-Based Procedure to Predict the Liquefaction Potential of Soil Deposits

This paper presents field evidence in support of the energy-base procedure to predict the liquefaction potential of soil deposits. Two recorded earthquake events which occurred at the Wildlife Site: Elmore Ranch earthquake (11/23/1987) and Superstition Hills earthquake (11/24/1987), representing nonliquefaction and liquefaction case histories respectively, were utilized to verify the energybased procedure in field situations. The nonlinearity and the degradation of shear stiffness and strength of soil deposits subjected to earthquake loading under undrained conditions were incorporated in the reconstruction of the shear stress-stain response. The effects of multi-directional excitation on the liquefaction potential and the build-up of pore water pressure were also investigated. Finally, a unit energy-pore pressure model was confirmed by the comparison of the calculated and recorded pore ressure time histories

Validation of the Energy-Based Method for Evaluating Soil Liquefaction in Centrifuge

Extensive research has been conducted at Case Western Reserve University to introduce and evaluate the energy concept in defining the liquefaction potential of soils when subjected to dynamic loads. Generalized relationships were obtained by performing regression analyses between the energy per unit volume at the onset of liquefaction and liquefaction affecting parameters. This study deals with evaluating and examining the suitability of these relationships using centrifuge modeling. Centrifuge liquefaction testing of several soils with different grain-size characteristics made it possible to evaluate the validity of the energy method in determining the liquefaction potential of a soil deposit. Dynamic centrifuge tests were conducted on scaled pore fluid-saturated models, prepared in a laminar box, representing a prototype thickness of 7.6 m. A simplified procedure for estimating the energy per unit volume from the recorded horizontal accelerations and the lateral displacements at different depths is presented. The total energy at the onset of liquefaction is obtained from the stress-strain time histories from centrifuge testing results and compared with the same energy calculated from regression equations developed through torsional series tests. A rational procedure to decide whether or not liquefaction of a soil deposit is imminent can be formulated by comparing the calculated unit energy from the time series record of a design earthquake with the resistance to liquefaction in terms of energy, based on in situ soil properties

In situ study of the initial stages of diamond deposition on 3C-SiC (100) surfaces: Towards the mechanisms of diamond nucleation

The mechanisms involved in the diamond nucleation on 3C-SiC surfaces have been investigated using a sequential in situ approach using electron spectroscopies (XPS, XAES and ELS). Moreover, diamond crystals have been studied by HRSEM. The in situ nucleation treatment allows a high diamond nucleation density close to 4 x 10(10) cm(-2). During the in situ enhanced nucleation treatment under Plasma, a negative bias was applied to the sample. The formation of an amorphous carbon phase and the roughening of the 3C-SiC surface have been observed. The part of these competing mechanisms in diamond nucleation is discussed

Atlas Data-Challenge 1 on NorduGrid

The first LHC application ever to be executed in a computational Grid environment is the so-called ATLAS Data-Challenge 1, more specifically, the part assigned to the Scandinavian members of the ATLAS Collaboration. Taking advantage of the NorduGrid testbed and tools, physicists from Denmark, Norway and Sweden were able to participate in the overall exercise starting in July 2002 and continuing through the rest of 2002 and the first part of 2003 using solely the NorduGrid environment. This allowed to distribute input data over a wide area, and rely on the NorduGrid resource discovery mechanism to find an optimal cluster for job submission. During the whole Data-Challenge 1, more than 2 TB of input data was processed and more than 2.5 TB of output data was produced by more than 4750 Grid jobs.Comment: Talk from the 2003 Computing in High Energy Physics and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, 3 ps figure

Greener synthesis of dimethyl carbonate using a novel tin-zirconia/graphene nanocomposite catalyst

© 2017 A green, rapid and continuous hydrothermal flow synthesis (CHFS) route has been employed to synthesise highly efficient and active novel heterogeneous catalysts. Tin doped zirconia (Zr–Sn–O) and tin doped zirconia/graphene nanocomposite (Zr–Sn/GO) have been assessed as suitable heterogeneous catalysts for the synthesis of dimethyl carbonate (DMC). The catalysts have been extensively characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area measurement and X-ray photoelectron spectroscopy (XPS) analysis. Extensive batch studies for the synthesis of DMC via the transesterification of propylene carbonate (PC) and methanol (MeOH) using Zr–Sn/GO catalyst in a solvent free process were also conducted. The effect of various reaction conditions such as reactant molar ratio, catalyst loading, reaction temperature and reaction time has been extensively evaluated. Response surface methodology based on Box-Behneken Design (BBD) was employed to derive optimum conditions for maximising PC conversion and DMC yield. The correlations and interactions between various variables such as MeOH:PC ratio, catalyst loading, reaction temperature, reaction time and stirring speed were extensively studied. A quadratic model by multiple regression analysis for the PC conversion and DMC yield was developed and verified by several methods BBD revealed that optimum conditions for high yield values of DMC are 12.33:1 MeOH:PC molar ratio, 446.7 K, 4.08 h and 300 rpm using 2.9% (w/w) Zr–Sn/GO nanocomposite. The maximum predicted responses at the optimum conditions are 85.1% and 81% for PC conversion and yield of DMC respectively. Experimental results at optimum model predicted reaction conditions agree very well with the model predicted response, where 82.4% PC conversion and 78.2% yield of DMC were obtained. Catalyst reusability and stability studies have been conducted at optimum reaction condition to investigate the long term stability of Zr–Sn/GO and it has been found that the catalyst could be reused more than six times (about 42 h) without losing its catalytic activity. These experimental and model predicted values showed an excellent agreement for tin doped zirconia/graphene nanocomposite as a heterogeneous catalyst for the synthesis of DMC from PC and MeOH

Structure and Strength of Dislocation Junctions: An Atomic Level Analysis

The quasicontinuum method is used to simulate three-dimensional Lomer-Cottrell junctions both in the absence and in the presence of an applied stress. The simulations show that this type of junction is destroyed by an unzipping mechanism in which the dislocations that form the junction are gradually pulled apart along the junction segment. The calculated critical stress needed for breaking the junction is comparable to that predicted by line tension models. The simulations also demonstrate a strong influence of the initial dislocation line directions on the breaking mechanism, an effect that is neglected in the macroscopic treatment of the hardening effect of junctions.Comment: 4 pages, 3 figure

An integrated approach to unravel the structural controls on groundwater potentialities in hyper-arid regions using satellite and land-based geophysics: a case study in southwestern desert of Egypt

Published versio

Analysis of Energy Conservation Options for USDOE Child Development Center

This report presents the results of a study that verifies the energy savings due to the individual ECOs through the use of a calibrated DOE-2 simulation. The results show that roughly 84% of the savings estimated by the GSA architect can be accounted for by the calibrated simulation. Energy Systems Laboratory Texas A&M University Texas Engineering Experiment Station College Station, TexasThe Child Development Center (CDC) was designed to be a "showpiece" model building. Its construction included energy efficient features, including a photovoltaic system, solar hot water system, energy efficient lighting, and energy efficient heat pumps. The architect's estimate of the energy savings from these measures totaled 31.5 MWh per year, an annual savings of about $1,575 (at$0.05/kWh). The DOE-2 predicted total annual energy use for the CDC with all the ECO's installed is 146,317 kWh or 61,652 Btu/ft2-yr which is a 12% reduction from the DOE-2 predicted energy use of 166,559 kWh (70,181 Btu/ft2-yr using 1 kWh=3,413 Btu) if the ECOs had not been installed