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At least 595 records · Page 33

Energy Assessments under the Top 10,000 Program - A Case Study for a Steel Mill in China

One of the largest energy-savings programs for the Chinese industrial sector was the Top-1,000 Program, which targeted the 1,000 largest industrial enterprises in China. This program was launched in 2006, implemented through 2010, and covered 33% of national energy usage. Because of the success of the Top-1000 initiative, the program has now been expanded to the Top-10,000 program in the 12th Five-Year Plan period (2011-2015). The Top-10,000 program covers roughly 15,000 industrial enterprises, or about two-thirds of China s total energy consumption. Implementing energy audit systems and conducting industrial energy efficiency assessments are key requirements of the Top-10,000 program. Previous research done by Lawrence Berkeley National Laboratory (LBNL) has shown that there is a significant potential for improvement in energy assessment practices and applications in China. Issues such as lack of long term policy mechanisms, insufficient motivation for industrial enterprises, limited technical scope of energy assessments, and lack of systematic standardization have been identified. Through the support of the U.S. Department of Energy (DOE) and the U.S. State Department (with additional co-funding from the Energy Foundation China), LBNL, Oak Ridge National Laboratory, the Institute for Sustainable Communities (ISC), and DOE Energy Experts worked collaboratively with Chinese local organizations and conducted a series of industrial energy efficiency assessment demonstrations in selected Chinese industrial plants. The project aimed to not only introduce standardized methodologies and tools for energy assessments, but also to bring the systems approach for energy system analysis to the Top 10,000 enterprises. Through the project, five energy system assessments were conducted, and more than 300 Chinese experts from local energy conservation centers, universities, research organizations, energy service companies, and plant engineers were trained. This paper begins by introducing China s national energy intensity and carbon intensity reduction targets. Then, this paper explains the development of Top 10,000 program, including program requirements, the method for target allocation, key supporting policies, as well as challenges in implementing the program. By focusing on a process heating energy system assessment conducted in a Chinese steel mill, this paper presents an example of an energy system assessment conducted on steel reheating furnaces, including overall energy efficiency levels, areas of heat loss, and the potential for energy savings. In addition, the paper provides energy-savings recommendations that were identified during the assessment, as well as potential energy and energy costs savings. To conclude, this paper presents key findings that could further improve the Top 10,000 program by implementing a systems approach for energy assessments.

China Energy Efficiency↗

Incremental rotary rolling mill and method

A rolling mill system for Incremental rotary shaping of an elongated workpiece is provided that includes first and second workpiece holders. A support frame has a track with the first and second workpiece holders being movably associated with the track, the workpiece holders and an associated workpiece being movable in unison along the track. A radial chuck is mounted to the frame that includes a plurality of jaws that are movable radially inwardly and outwardly. Each jaw has a tool mounted thereto that is rotatable about an axis of rotation, with the axis of rotation of each tool being oriented at a skew angle relative to the longitudinal axis of a workpiece. A source of electric current and an electrically conductive flow path are provided for flowing electrical current through a workpiece. A controller is provided that is configured to control the operation of each of the first motor, second motor and third motor, and to control the flow of current flowing through the tools to the workpiece.

Zeng, Qiang↗

Regulatory Oversight of the Legacy Gunner Uranium Mine and Mill Site in Northern Saskatchewan, Canada - 13434

As Canada's nuclear regulator, the Canadian Nuclear Safety Commission (CNSC) is responsible for licensing all aspects of uranium mining, including remediation activities at legacy sites. Since these sites already existed when the current legislation came into force in 2000, and the previous legislation did not apply, they present a special case. The Nuclear Safety and Control Act (NSCA), was written with cradle-to- grave oversight in mind. Applying the NSCA at the end of a 'facilities' life-cycle poses some challenges to both the regulator and the proponent. When the proponent is the public sector, even more challenges can present themselves. Although the licensing process for legacy sites is no different than for any other CNSC license, assuring regulatory compliance can be more complicated. To demonstrate how the CNSC has approached the oversight of legacy sites the history of the Commission's involvement with the Gunnar uranium mine and mill site provides a good case study. The lessons learned from the CNSC's experience regulating the Gunnar site will benefit those in the future who will need to regulate legacy sites under existing or new legislation. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Geochemical Reactions Controlling Contaminant Transport in Groundwater at a Former Uranium Mill Site - 19576

The historical operation of a uranium mill near Tuba City, Arizona, contaminated the underlying groundwater. Initial characterization led to a compliance strategy using groundwater extraction and treatment, which operated from 2002 through 2014. Remediation progress was inhibited primarily by aquifer productivity. Geochemical testing was undertaken to better understand future potential for contaminant plume migration. Results indicated the presence of solid-phase uranium in the subsurface, which can continue to feed the groundwater plume, along with limited uranium sorption on uncontaminated material. Future transport modeling will incorporate the laboratory-quantified geochemical reactions and be used to evaluate site compliance strategies. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Transforming the Bootstrap: Using Transformers to Compute Scattering Amplitudes in Planar N = 4 Super Yang-Mills Theory

We pursue the use of deep learning methods to improve state-of-the-art computations in theoretical high-energy physics. Planar N = 4 Super Yang-Mills theory is a close cousin to the theory that describes Higgs boson production at the Large Hadron Collider; its scattering amplitudes are large mathematical expressions containing integer coefficients. In this paper, we apply Transformers to predict these coefficients. The problem can be formulated in a language-like representation amenable to standard cross-entropy training objectives. We design two related experiments and show that the model achieves high accuracy (> 98%) on both tasks. Our work shows that Transformers can be applied successfully to problems in theoretical physics that require exact solutions.

Lance, Dixon↗

Gravitational form factors of glueballs in Yang-Mills theory

This work presents preliminary results of the first determination of the energy-momentum tensor form factors of the scalar glueball, referred to as gravitational form factors (GFFs). The calculation has been carried out in lattice Yang-Mills theory at a single lattice spacing. Using variationally optimized operators, the matrix elements are extracted from ratios of three-point functions to two-point functions. The glueball GFFs and their kinematic dependence are compared to those of other hadrons from previous calculations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

On the ground state of Yang-Mills theory

Highlights: > The ground state overlap for sets of meson potential trial states is measured. > Non-uniform gluonic distributions are probed via Wilson loop operator. > The locally UV-regulated flux-tube operators can optimize the ground state overlap. - Abstract: We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Shelf-life of ball-milled catalyst inks for the fabrication of fuel cell electrodes

A major factor driving fuel cell costs is the quantity of precious metal required. Therefore, it is important to understand a timeframe where inks can be reused. Here, in this work, we explore differences between a freshly prepared catalyst ink and one that has been stored for over a year – comparing ink properties, cathode catalyst layer microstructure, and their respective fuel cell performance. Ink studies revealed smaller agglomerate sizes and a decrease in shear viscosity for the aged ink. Longer storage time also results in fewer cracks and a more uniform ionomer distribution, as evidenced by microscopy characterization of rod-coated electrodes. Lastly, polarization curves show improved performance at higher current densities for the electrode prepared from the aged ink. We rationalize such effect in terms of enhanced ionomer adsorption onto the catalyst over time.

08 HYDROGEN↗

Deposition of metallic gallium on re-crystallized ceramic material during focused ion beam milling

We report a new kind of artifact observed in the preparation of a TEM sample of zirconia by FIB, which consists in the deposition of metallic gallium nano-dots on the TEM sample surface. High resolution TEM images showed a microstructure of fine equiaxed grains of ∼ 5 nm, with some of them possessing two particular characteristics: high contrast and well-defined fast Fourier transform. These grains could not be identified as any phase of zirconia but it was possible to identify them as gallium crystals in the zone axis [110]. Based on HRTEM simulations, the possible orientations between zirconia substrate and deposited gallium are discussed in terms of lattice mismatch and oxygen affinity. - Highlights: • We show a new type of artifact induced during preparation of TEM samples by FIB. • Deposition of Ga occurs due to its high affinity for oxygen. • Materials with small grain size (∼ 5 nm) could promote Ga deposition. • Small grain size permits the elastic accommodation of deposited Ga.

36 MATERIALS SCIENCE↗

Realization of Critical Distance during the Interplay between Re-deposition and Secondary sputtering from Milling of Angular Side Wall with a Focused Ion Beam

In-situ observation of critical distance (CD), a distance where secondary sputtering effects diminish and re-deposition starts to dominate is realized during controlled focused ion beam (FIB) sputtering. The experiments were performed on representative high density Nialloy and lower density porous Ni-YSZ. For the Ni-alloy case, it was observed that linear extrapolation of re-deposited layer width coincides with CD suggesting uniform sputtering and re-deposition effects. Estimation related to percentage of re-deposition from FIB etched layer at an angle of 50 degrees between the lower membrane and FIB etched side wall clearly demonstrated dominant secondary etching, neutralizing sputtering/redeposition and dominant re-deposition regions. Although the angle between FIB etched angular side wall and re-deposited/etched membrane adds some complication, the suggested overall experimental approach would substantially simplify to develop more realistic models than previously considered complex situations dealing with interplay between the re-deposition and secondary etching.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

On the Infrared Behaviour of Landau Gauge Yang-Mills Theory with Differently Charged Scalar Fields

Recently it has been argued that infrared singularities of the quark-gluon vertex of Landau gauge QCD can confine static quarks via a linear potential. It is demonstrated that the same mechanism also may confine fundamental scalar fields. This opens the possibility that within functional approaches static confinement is an universal property of the gauge sector even though it is formally represented in the functional equations of the matter sector. The colour structure of Dyson-Schwinger equations for fundamental and adjoint scalar fields is determined for the gauge groups SU(N) and G(2) exhibiting interesting cancellations purely due to colour algebra.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Modelling and Development of a High Performance Milling Process with Monolithic Cutting Tools

Critical aerospace components usually require difficult to machine workpiece materials like nickel based alloys. Moreover; there is a pressing need to maximize the productivity of machining operations. This need can be satisfied by selection of higher feed velocity, axial and radial depths. But there may be several problems during machining in this case. Due to high cutting speeds in high performance machining, the tool life may be unacceptably low. If magnitudes of cutting forces are high, out of tolerance static form errors may result; moreover in the extreme cases, the cutting tool may break apart. Forced vibrations may deteriorate the surface quality. Chatter vibrations may develop if the selected parameters result in instability. In this study, in order to deal with the tool life issue, several experimental cuts are made with different tool geometries, and the best combination in terms of tool life is selected. A force model is developed and the results of the force model are verified by experimental results. The force model is used in predicting the effect of process parameters on cutting forces. In order to account for the other concerns such as static form errors, forced and chatter vibrations, additional process models are currently under development.

36 MATERIALS SCIENCE↗

Gravity and Yang-Mills amplitude relations

Using only general features of the S matrix and quantum field theory, we prove by induction the Kawai-Lewellen-Tye relations that link products of gauge theory amplitudes to gravity amplitudes at tree level. As a bonus of our analysis, we provide a novel and more symmetric form of these relations. We also establish an infinite tower of new identities between amplitudes in gauge theories.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗