Impact of the COVID-19 Large-scale Social Restrictions on NO2 and CO Concentrations in the Most Populated Cities in Java Island, Indonesia

Steady incompressible turbulent air flow and transient carbon monoxide transport in an empty Rochester-style human exposure chamber have been numerically simulated and compared with experimental data sets. The system consisted of an inlet duct with a continuous carbon monoxide point source, 45- and 90-degree bends, a round diffuser, a round-to-square transition, a rectangular diffuser, the test chamber, a perforated floor, and again transition pieces from the chamber to an outlet duct. Such a configuration induced highly nonuniform vortical flow patterns in the chamber test area where a pollutant concentration is required to be constant at breathing level for safe and accurate inhalation studies. Presented are validated momentum and mass transfer results for this large-scale system with the main goals of determining the development of tracer gas (CO) distributions in the chamber and analyzing the contributions to CO-mixing. Numerical simulations were conducted employing a k-ε model and the latest available RNG k-ε model for air and CO-mixing. Both models predict similar velocity fields and are in good agreement with measured steady and transient CO-concentrations. It was found that secondary flows in the inlet section and strong vortical flow in the chamber with perforated flooring contributed to effective mixing of the trace gas at breathing levels. Specifically, in the height range of 1.4 m<h<2.0 m above the chamber floor, predicted CO-concentrations rapidly reached a near constant value which agrees well with experimental results. This work can be extended to analyze trace gas mixing as well as aerosol dispersion in occupied test chambers with or without flow redirection devices installed in the upstream section. A complementary application is particle transport and deposition in clean rooms of the electronic, pharmaceutical, and health care industries. [S0098-2202(00)01702-8]

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Decadal trends in global CO emissions as seen by MOPITT

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-13433-2015 ◽

2015 ◽

Vol 15 (23) ◽

pp. 13433-13451 ◽

Cited By ~ 34

Author(s):

Y. Yin ◽

F. Chevallier ◽

P. Ciais ◽

G. Broquet ◽

A. Fortems-Cheiney ◽

...

Keyword(s):

Large Scale ◽

Western Europe ◽

Model Simulation ◽

Recent Decade ◽

The United States ◽

Global Scale ◽

Emission Inventories ◽

Co Concentration ◽

Co Concentrations ◽

Atmospheric Inversion

Abstract. Negative trends of carbon monoxide (CO) concentrations are observed in the recent decade by both surface measurements and satellite retrievals over many regions of the globe, but they are not well explained by current emission inventories. Here, we analyse the observed CO concentration decline with an atmospheric inversion that simultaneously optimizes the two main CO sources (surface emissions and atmospheric hydrocarbon oxidations) and the main CO sink (atmospheric hydroxyl radical OH oxidation). Satellite CO column retrievals from Measurements of Pollution in the Troposphere (MOPITT), version 6, and surface observations of methane and methyl chloroform mole fractions are assimilated jointly for the period covering 2002–2011. Compared to the model simulation prescribed with prior emission inventories, trends in the optimized CO concentrations show better agreement with that of independent surface in situ measurements. At the global scale, the atmospheric inversion primarily interprets the CO concentration decline as a decrease in the CO emissions (−2.3 % yr−1), more than twice the negative trend estimated by the prior emission inventories (−1.0 % yr−1). The spatial distribution of the inferred decrease in CO emissions indicates contributions from western Europe (−4.0 % yr−1), the United States (−4.6 % yr−1) and East Asia (−1.2 % yr−1), where anthropogenic fuel combustion generally dominates the overall CO emissions, and also from Australia (−5.3 % yr−1), the Indo-China Peninsula (−5.6 % yr−1), Indonesia (−6.7 % y−1), and South America (−3 % yr−1), where CO emissions are mostly due to biomass burning. In contradiction with the bottom-up inventories that report an increase of 2 % yr−1 over China during the study period, a significant emission decrease of 1.1 % yr−1 is inferred by the inversion. A large decrease in CO emission factors due to technology improvements would outweigh the increase in carbon fuel combustions and may explain this decrease. Independent satellite formaldehyde (CH2O) column retrievals confirm the absence of large-scale trends in the atmospheric source of CO. However, it should be noted that the CH2O retrievals are not assimilated and OH concentrations are optimized at a very large scale in this study.

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

International Astronomical Union Colloquium ◽

10.1017/s0252921100031493 ◽

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.

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Evolution of Large-Scale Coronal Structures

International Astronomical Union Colloquium ◽

10.1017/s0252921100024945 ◽

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.

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Large-scale Motion of Solar Filaments

International Astronomical Union Colloquium ◽

10.1017/s0252921100064502 ◽

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.

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Some applications of electron beam microanalysis techniques in VLSI process evaluation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007463x ◽

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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Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131449 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1362-1363

Author(s):

V. C. Kannan ◽

A. K. Singh ◽

R. B. Irwin ◽

S. Chittipeddi ◽

F. D. Nkansah ◽

...

Keyword(s):

Integrated Circuits ◽

Large Scale ◽

Hexagonal Phase ◽

Microscopy Study ◽

Electron Microscopy Study ◽

Process Conditions ◽

Tin Films ◽

Wide Range ◽

Fcc Phase ◽

Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

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Evolution of the microstructure of Cu(Ti)/SiO2 layers annealed in NH3

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138634 ◽

1995 ◽

Vol 53 ◽

pp. 452-453

Author(s):

J. Liu ◽

N. D. Theodore ◽

D. Adams ◽

S. Russell ◽

T. L. Alford ◽

...

Keyword(s):

Thermal Stability ◽

Titanium Nitride ◽

Large Scale ◽

Standard Procedure ◽

Alloy Film ◽

Electron Beam Evaporation ◽

Copper Metallization ◽

Nominal Composition ◽

Ti Alloy ◽

Thermally Grown

Copper-based metallization has recently attracted extensive research because of its potential application in ultra-large-scale integration (ULSI) of semiconductor devices. The feasibility of copper metallization is, however, limited due to its thermal stability issues. In order to utilize copper in metallization systems diffusion barriers such as titanium nitride and other refractory materials, have been employed to enhance the thermal stability of copper. Titanium nitride layers can be formed by annealing Cu(Ti) alloy film evaporated on thermally grown SiO2 substrates in an ammonia ambient. We report here the microstructural evolution of Cu(Ti)/SiO2 layers during annealing in NH3 flowing ambient.The Cu(Ti) films used in this experiment were prepared by electron beam evaporation onto thermally grown SiO2 substrates. The nominal composition of the Cu(Ti) alloy was Cu73Ti27. Thermal treatments were conducted in NH3 flowing ambient for 30 minutes at temperatures ranging from 450°C to 650°C. Cross-section TEM specimens were prepared by the standard procedure.

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Immunogold labeling of CMP-KDO synthetase produced by recombinant E. Coli cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128900 ◽

1987 ◽

Vol 45 ◽

pp. 924-925

Author(s):

F. A. Durum ◽

R. G. Goldman ◽

T. J. Bolling ◽

M. F. Miller

Keyword(s):

Inclusion Bodies ◽

Large Scale ◽

Recombinant Dna ◽

Test System ◽

Cell Protein ◽

Gram Negative Bacteria ◽

Cytoplasmic Inclusions ◽

Isolation And Purification ◽

E Coli ◽

Low Concentrations

CMP-KDO synthetase (CKS) is an enzyme which plays a key role in the synthesis of LPS, an outer membrane component unique to gram negative bacteria. CKS activates KDO to CMP-KDO for incorporation into LPS. The enzyme is normally present in low concentrations (0.02% of total cell protein) which makes it difficult to perform large scale isolation and purification. Recently, the gene for CKS from E. coli was cloned and various recombinant DNA constructs overproducing CKS several thousandfold (unpublished data) were derived. Interestingly, no cytoplasmic inclusions of overproduced CKS were observed by EM (Fig. 1) which is in contrast to other reports of large proteinaceous inclusion bodies in various overproducing recombinant strains. The present immunocytochemical study was undertaken to localize CKS in these cells.Immune labeling conditions were first optimized using a previously described cell-free test system. Briefly, this involves soaking small blocks of polymerized bovine serum albumin in purified CKS antigen and subjecting them to various fixation, embedding and immunochemical conditions.

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The Structure and Properties of MoSi2 Thin Film in Mos Process

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001379 ◽

1980 ◽

Vol 38 ◽

pp. 326-327

Author(s):

C.K. Wu ◽

P. Chang ◽

N. Godinho

Keyword(s):

Thin Film ◽

Integrated Circuits ◽

High Performance ◽

Large Scale ◽

Process Development ◽

Structure And Properties ◽

Metal Silicides ◽

High Oxidation ◽

Important Approach ◽

High Oxidation Resistance

Recently, the use of refractory metal silicides as low resistivity, high temperature and high oxidation resistance gate materials in large scale integrated circuits (LSI) has become an important approach in advanced MOS process development (1). This research is a systematic study on the structure and properties of molybdenum silicide thin film and its applicability to high performance LSI fabrication.

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