scholarly journals Structure transition of Au18 from pyramidal to a hollow-cage during soft-landing onto a TiO2(110) surface

2015 ◽  
Vol 51 (46) ◽  
pp. 9535-9538 ◽  
Author(s):  
Lei Li ◽  
Hui Li ◽  
Xiao Cheng Zeng
Keyword(s):  
Large Scale ◽  
Soft Landing ◽  
Structure Transition

Simulation of the soft-landing process of pyramidal Au18 onto a rutile TiO2(110) surface using large-scale BOMD simulation.

scholarly journals Enabling Continuous Commissioning through Building Management Systems

2021 ◽  
Author(s):  
◽  
Cara Askew
Keyword(s):  
Large Scale ◽  
Residential Buildings ◽  
Management Systems ◽  
Operating Efficiency ◽  
Cyclic Process ◽  
Soft Landing ◽  
Process Data ◽  
Building Management ◽  
Definition Of ◽  
Building Management Systems

<p>The use and application of energy efficient technologies within new and existing buildings is a growing global trend. However, if they aren’t being commissioned, controlled and operated in an efficient way, are they really making a valid impact on the energy efficiency of our buildings?  Building Management Systems (BMS) are installed within large scale non-residential buildings to control and govern the operation of Heating Ventilation and Air-Conditioning systems (HVAC). BMS monitor and process large amounts of data during their day-to-day operation, while the potential usefulness of BMS to implement energy optimising strategies is typically left un-utilised. There is a growing need to reduce building energy demand. Continuous Commissioning (CCx) may offer the potential to achieve this reduction through the ongoing or periodical assessment of building HVAC operation. As CCx is a cyclic process, and because BMS already monitor and process data in their day-to-day operations, they offer a potential, low overhead means of running CCx processes in buildings. This thesis reports a research project which explores this opportunity to assess and improve building operating efficiency by identifying what data and functional capabilities are required of a BMS to facilitate Continuous Commissioning.  A systematic assessment of existing research and standards has highlighted a gap in industry knowledge on the specification of data required to implement CCx assessments to HVAC. There was also no definition of what BMS capabilities were important to the Continuous Commissioning process. These research gaps inspired five secondary research questions around which a mixed-method survey was developed and implemented to bridge the gap between BMS and CCx.  The research methodology integrated a standard questionnaire and the Delphi method to explore user perceptions and develop a consensus of BMS requirements. Three survey rounds were distributed to New Zealand based industry experts. Each round informed the following round, with an element of feedback provided through the compilation of the previous round’s responses. This process enabled the industry experts to agree or disagree with the proposed consensus or provide an alternative insight to the questions asked.  The results of the surveys were compiled to establish a definition of the top five CCx assessments applied to typical HVAC systems, data point trending requirements and BMS functions important to facilitating Continuous Commissioning. These findings were used to create a guideline for specifying BMS to facilitate Continuous Commissioning and create a soft landing for assessing HVAC during the operation phase of a building’s life. The outcome of this research bridges the gap between the specification of Building Management Systems and the requirements of the Continuous Commissioning process.</p>

scholarly journals Enabling Continuous Commissioning through Building Management Systems

2021 ◽  
Author(s):  
◽  
Cara Askew
Keyword(s):  
Large Scale ◽  
Residential Buildings ◽  
Management Systems ◽  
Operating Efficiency ◽  
Cyclic Process ◽  
Soft Landing ◽  
Process Data ◽  
Building Management ◽  
Definition Of ◽  
Building Management Systems

<p>The use and application of energy efficient technologies within new and existing buildings is a growing global trend. However, if they aren’t being commissioned, controlled and operated in an efficient way, are they really making a valid impact on the energy efficiency of our buildings?  Building Management Systems (BMS) are installed within large scale non-residential buildings to control and govern the operation of Heating Ventilation and Air-Conditioning systems (HVAC). BMS monitor and process large amounts of data during their day-to-day operation, while the potential usefulness of BMS to implement energy optimising strategies is typically left un-utilised. There is a growing need to reduce building energy demand. Continuous Commissioning (CCx) may offer the potential to achieve this reduction through the ongoing or periodical assessment of building HVAC operation. As CCx is a cyclic process, and because BMS already monitor and process data in their day-to-day operations, they offer a potential, low overhead means of running CCx processes in buildings. This thesis reports a research project which explores this opportunity to assess and improve building operating efficiency by identifying what data and functional capabilities are required of a BMS to facilitate Continuous Commissioning.  A systematic assessment of existing research and standards has highlighted a gap in industry knowledge on the specification of data required to implement CCx assessments to HVAC. There was also no definition of what BMS capabilities were important to the Continuous Commissioning process. These research gaps inspired five secondary research questions around which a mixed-method survey was developed and implemented to bridge the gap between BMS and CCx.  The research methodology integrated a standard questionnaire and the Delphi method to explore user perceptions and develop a consensus of BMS requirements. Three survey rounds were distributed to New Zealand based industry experts. Each round informed the following round, with an element of feedback provided through the compilation of the previous round’s responses. This process enabled the industry experts to agree or disagree with the proposed consensus or provide an alternative insight to the questions asked.  The results of the surveys were compiled to establish a definition of the top five CCx assessments applied to typical HVAC systems, data point trending requirements and BMS functions important to facilitating Continuous Commissioning. These findings were used to create a guideline for specifying BMS to facilitate Continuous Commissioning and create a soft landing for assessing HVAC during the operation phase of a building’s life. The outcome of this research bridges the gap between the specification of Building Management Systems and the requirements of the Continuous Commissioning process.</p>

scholarly journals The Submillimeter Wave Astronomy Satellite

1990 ◽  
Vol 123 ◽  
pp. 251-251 ◽  
Author(s):  
G.J. Melnick
Keyword(s):  
Fine Structure ◽  
Chemical Composition ◽  
Ground State ◽  
Molecular Clouds ◽  
Large Scale ◽  
Rotational Transition ◽  
Submillimeter Wave ◽  
Important Species ◽  
Structure Transition ◽  
Large Scale Survey

AbstractThe Submillimeter Wave Astronomy Satellite (SWAS) is a NASA Small-Explorer Class experiment whose objective is to study both the chemical composition and the thermal balance in dense (NH2 > 103 cm−3) molecular clouds and, by observing many clouds throughout our galaxy, relate these conditions to the processes of star formation. To conduct this study SWAS will be capable of carrying out both pointed and scanning observations simultaneously in the lines of four important species: (1) the H2O (110–101) 556.963 GHz ground-state ortho transition, (2) the O2 (3,3–1,2) 487.249 GHz transition, (3) the CI (3P1 – 3P0) 492.162 GHz ground-state fine structure transition, and (4) the 13CO (J = 5–4) 550.926 GHz rotational transition. These atoms and molecules are predicted to be among the most abundant within molecular clouds and, because they possess low-lying transitions with energy differences (ΔE/k) between 15 and 30K (temperatures typical of many molecular clouds), these species are believed to be dominant coolants of the gas as it collapses to form stars and planets. A large-scale survey in these lines is virtually impossible from any platform within the atmosphere due to telluric absorption.

scholarly journals Level Structure and Properties of Open f-Shell Elements

Atoms ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Stephan Fritzsche
Keyword(s):  
Large Scale ◽  
Transition Probabilities ◽  
Level Structure ◽  
Shell Structures ◽  
Strong Correlations ◽  
Structure Transition ◽  
Shell Elements ◽  
Correlated Motion ◽  
Almost All ◽  
Accurate Computations

Open f-shell elements still constitute a great challenge for atomic theory owing to their (very) rich fine-structure and strong correlations among the valence-shell electrons. For these medium and heavy elements, many atomic properties are sensitive to the correlated motion of electrons and, hence, require large-scale computations in order to deal consistently with all relativistic, correlation and rearrangement contributions to the electron density. Often, different concepts and notations need to be combined for just classifying the low-lying level structure of these elements. With Jac, the Jena Atomic Calculator, we here provide a toolbox that helps to explore and deal with such elements with open d- and f-shell structures. Based on Dirac’s equation, Jac is suitable for almost all atoms and ions across the periodic table. As an example, we demonstrate how reasonably accurate computations can be performed for the low-lying level structure, transition probabilities and lifetimes for Th2+ ions with a 5f6d ground configuration. Other, and more complex, shell structures are supported as well, though often for a trade-off between the size and accuracy of the computations. Owing to its simple use, however, Jac supports both quick estimates and detailed case studies on open d- or f-shell elements.

Influence of Upper-Troposphere Stratification and Cloud-Radiation Interaction on Convective Overshoots in the Tropical Tropopause Layer

2021 ◽  
Author(s):  
Zeyuan Hu ◽  
Fayçal Lamraoui ◽  
Zhiming Kuang
Keyword(s):  
Vertical Velocity ◽  
Large Scale ◽  
Cloud Microphysics ◽  
Horizontal Resolution ◽  
Radiative Heating ◽  
Soft Landing ◽  
Upper Troposphere ◽  
Tropical Tropopause Layer ◽  
Tropical Tropopause ◽  
The Difference

AbstractIt is still debated whether radiative heating observed in the tropical tropopause layer (TTL) is balanced primarily by cooling from convective overshoots, as in an entrainment layer, or by adiabatic cooling from large-scale eddy-driven upwelling. In this study, three-dimensional cloud-resolving model simulations of radiative-convective equilibrium were carried out with three different cloud microphysics schemes and 1-km horizontal resolution. We demonstrate that overshooting cooling in the TTL can be strongly modulated by upper-troposphere stratification. Two of the schemes produce a hard-landing scenario in which convective overshoots reach the TTL with frequent large vertical velocity leading to strong overshooting cooling (~ −0.2 K day-1). The third scheme produces a soft-landing scenario in which convective overshoots rarely reach the TTL with large vertical velocity and produce little overshooting cooling (~ −0.03 K day-1). The difference between the two scenarios is attributed to changes in the upper-troposphere stratification related to different atmospheric cloud radiative effects (ACRE). The microphysics scheme that produces the soft-landing scenario has much stronger ACRE in the upper troposphere leading to a ~3K warmer and more stable layer which acts as a buffer zone to slow down the convective updrafts. The stratification mechanism suggests the possibility for the ozone variation or eddy-driven upwelling in the TTL to modulate convective overshoots. We further test the sensitivity of overshooting cooling to changes in model resolution by increasing the horizontal resolution to 100 m. The corresponding change of overshooting cooling is much smaller compared with the difference between the hard-landing and soft-landing scenarios.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

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