scholarly journals Results from the International Halocarbons in Air Comparison Experiment (IHALACE)

2013 ◽  
Vol 6 (4) ◽  
pp. 8021-8069 ◽  
Author(s):  
B. D. Hall ◽  
A. Engel ◽  
J. Mühle ◽  
J. W. Elkins ◽  
F. Artuso ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Trace Gases ◽  
Air Samples ◽  
Comparison Experiment ◽  
Atmospheric Data ◽  
Common Scale ◽  
Communication And Coordination ◽  
Document Relationships ◽  
Good Agreement

Abstract. The International Halocarbons in Air Comparison Experiment (IHALACE) was conducted to document relationships between calibration scales among various laboratories that measure atmospheric greenhouse and ozone depleting gases. Six stainless steel cylinders containing natural and modified natural air samples were circulated among 19 laboratories. Results from this experiment reveal relatively good agreement among commonly used calibration scales for a number of trace gases present in the unpolluted atmosphere at pmol mol−1 (parts per trillion) levels, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). Some scale relationships were found to be consistent with those derived from bi-lateral experiments or from analysis of atmospheric data, while others revealed discrepancies. The transfer of calibration scales among laboratories was found to be problematic in many cases, meaning that measurements tied to a common scale may not, in fact, be compatible. These results reveal substantial improvements in calibration over previous comparisons. However there is room for improvement in communication and coordination of calibration activities with respect to the measurement of halogenated and related trace gases.

scholarly journals Results from the International Halocarbons in Air Comparison Experiment (IHALACE)

2014 ◽  
Vol 7 (2) ◽  
pp. 469-490 ◽  
Author(s):  
B. D. Hall ◽  
A. Engel ◽  
J. Mühle ◽  
J. W. Elkins ◽  
F. Artuso ◽  
...  
Keyword(s):  
Large Scale ◽  
Sulfur Hexafluoride ◽  
Trace Gases ◽  
Carbonyl Sulfide ◽  
Comparison Experiment ◽  
Communication And Coordination ◽  
Document Relationships ◽  
Global Mean ◽  
Hcfc 142B ◽  
Good Agreement

Abstract. The International Halocarbons in Air Comparison Experiment (IHALACE) was conducted to document relationships between calibration scales among various laboratories that measure atmospheric greenhouse and ozone depleting gases. This study included trace gases such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs), as well as nitrous oxide, methane, sulfur hexafluoride, very short-lived halocompounds, and carbonyl sulfide. Many of these gases are present in the unpolluted atmosphere at pmol mol−1 (parts per trillion) or nmol mol−1 (parts per billion) levels. Six stainless steel cylinders containing natural and modified natural air samples were circulated among 19 laboratories. Results from this experiment reveal relatively good agreement (within a few percent) among commonly used calibration scales. Scale relationships for some gases, such as CFC-12 and CCl4, were found to be consistent with those derived from estimates of global mean mole fractions, while others, such as halon-1211 and CH3Br, revealed discrepancies. The transfer of calibration scales among laboratories was problematic in many cases, meaning that measurements tied to a particular scale may not, in fact, be compatible. Large scale transfer errors were observed for CH3CCl3 (10–100%) and CCl4 (2–30%), while much smaller scale transfer errors (< 1%) were observed for halon-1211, HCFC-22, and HCFC-142b. These results reveal substantial improvements in calibration over previous comparisons. However, there is room for improvement in communication and coordination of calibration activities with respect to the measurement of halogenated and related trace gases.

Prediction of Cutting Forces in Milling Stainless Steels using Chamfered Main Cutting Edge Tool

2005 ◽  
Vol 21 (3) ◽  
pp. 145-155 ◽  
Author(s):  
C.-S. Chang
Keyword(s):  
Stainless Steel ◽  
Cutting Forces ◽  
Steel Plate ◽  
Cutting Edge ◽  
304 Stainless Steel ◽  
Workpiece Material ◽  
Material Force ◽  
Force Data ◽  
Edge Tool ◽  
Good Agreement

AbstractTo study the cutting forces, the carbide tip's surface temperature, and the mechanism of secondary chip and main chip formation of face milling stainless steel with a chamfered main cutting edge has been investigated. Theoretical values of cutting forces were calculated and compared to the experimental results with SUS 304 stainless steel plate as a workpiece material. Force data from these tests were used to estimate the empirical constants of the mechanical model and to verify its prediction capabilities. A comparison of the predicted and measured forces shows good agreement. A preliminary discussion is also made for the design of special tool holders and their geometrical configurations. Next, the tips mounted in the tool holders are ground to a chamfered width and the tool dimensions are measured by using a toolmaker microscope.

scholarly journals Flight Demonstration of a 2-Micron, Double Plused CO2 IPDA Lidar Instrument

2020 ◽  
Vol 237 ◽  
pp. 03013
Author(s):  
Jirong Yu ◽  
Mulugeta Petros ◽  
Upendra Singh ◽  
Tamer Refaat ◽  
Karl Reithmaier ◽  
...  
Keyword(s):  
Column Density ◽  
High Energy ◽  
Density Difference ◽  
Lidar Measurement ◽  
Differential Absorption ◽  
Air Samples ◽  
Lidar Measurements ◽  
Langley Research Center ◽  
Good Agreement

NASA Langley Research Center (LaRC) developed a double pulsed, high energy 2-micron Integrated Path Differential Absorption (IPDA) lidar instrument to measure atmospheric CO2 column density. The 2-μm double pulsed IPDA lidar was flown ten times in March and April of 2014. It was determined that the IPDA lidar measurement is in good agreement with an in-situ CO2 measurement by a collocated NOAA flight. The average column CO2 density difference between the IPDA lidar measurements and the NOAA air samples is 1.48ppm in the flight altitudes of 3 to 6.1 km.

scholarly journals Multi-year comparisons of ground-based and space-borne Fourier transform spectrometers in the high Arctic between 2006 and 2013

2017 ◽  
Vol 10 (9) ◽  
pp. 3273-3294 ◽  
Author(s):  
Debora Griffin ◽  
Kaley A. Walker ◽  
Stephanie Conway ◽  
Felicia Kolonjari ◽  
Kimberly Strong ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Atmospheric Chemistry ◽  
Trace Gases ◽  
Correlation Coefficients ◽  
High Arctic ◽  
Atmospheric Research ◽  
Time Period ◽  
Experiment Validation ◽  
Mean Differences ◽  
Good Agreement

Abstract. This paper presents 8 years (2006–2013) of measurements obtained from Fourier transform spectrometers (FTSs) in the high Arctic at the Polar Environment Atmospheric Research Laboratory (PEARL; 80.05° N, 86.42° W). These measurements were taken as part of the Canadian Arctic ACE (Atmospheric Chemistry Experiment) validation campaigns that have been carried out since 2004 during the polar sunrise period (from mid-February to mid-April). Each spring, two ground-based FTSs were used to measure total and partial columns of HF, O3, and trace gases that impact O3 depletion, namely, HCl and HNO3. Additionally, some tropospheric greenhouse gases and pollutant species were measured, namely CH4, N2O, CO, and C2H6. During the same time period, the satellite-based ACE-FTS made measurements near Eureka and provided profiles of the same trace gases. Comparisons have been carried out between the measurements from the Portable Atmospheric Research Interferometric Spectrometer for the InfraRed (PARIS-IR) and the co-located high-resolution Bruker 125HR FTS, as well as with the latest version of the ACE-FTS retrievals (v3.5). The total column comparison between the two co-located ground-based FTSs, PARIS-IR and Bruker 125HR, found very good agreement for most of these species (except HF), with differences well below the estimated uncertainties ( ≤ 6  %) and with high correlations (R ≥ 0. 8). Partial columns have been used for the ground-based to space-borne comparison, with coincident measurements selected based on time, distance, and scaled potential vorticity (sPV). The comparisons of the ground-based measurements with ACE-FTS show good agreement in the partial columns for most species within 6  % (except for C2H6 and PARIS-IR HF), which is consistent with the total retrieval uncertainty of the ground-based instruments. The correlation coefficients (R) of the partial column comparisons for all eight species range from approximately 0.75 to 0.95. The comparisons show no notable increases of the mean differences over these 8 years, indicating the consistency of these datasets and suggesting that the space-borne ACE-FTS measurements have been stable over this period. In addition, changes in the amounts of these trace gases during springtime between 2006 and 2013 are presented and discussed. Increased O3 (0. 9  %  yr−1), HCl (1. 7  %  yr−1), HF (3. 8  %  yr−1), CH4 (0.5  % yr−1), and C2H6 (2. 3 % yr−1, 2009–2013) have been found with the PARIS-IR dataset, the longer of the two ground-based records.

scholarly journals Experimental airborne transmission ofSalmonellaAgona andSalmonellaTyphimurium in weaned pigs

2005 ◽  
Vol 134 (1) ◽  
pp. 199-209 ◽  
Author(s):  
C. J. B. OLIVEIRA ◽  
L. F. O. S. CARVALHO ◽  
T. B. GARCIA
Keyword(s):  
Stainless Steel ◽  
Weaned Pigs ◽  
Airborne Transmission ◽  
Air Samples ◽  
Pig Production ◽  
Faecal Samples ◽  
Rectal Swabs ◽  
Fumigation Chamber

SUMMARYThis study tested the hypothesis of airborne transmission ofSalmonellaAgona (Trial I) andSalmonellaTyphimurium (Trial II) in weaned pigs. The trials were performed using stainless-steel/glass isolation cabinets connected by air ducts to permit an unidirectional airflow from cabinet 1 (two control pigs) to cabinet 3 (two sentinel pigs), passing through cabinet 2 (two inoculated pigs). Air samples, pooled faecal samples from the floor and rectal swabs were collected daily and assessed by culture and PCR. A fumigation chamber and rubber gloves coupled to the cabinets allowed sampling without opening the system. Trials I and II lasted 15 and 19 days respectively. The recovery ofS. Agona andS. Typhimurium and detection of seroconversion in sentinel pigs indicate that airborneSalmonellatransmission in weaned pigs over short distances is possible. Further studies on the role of aerosols in the epidemiology ofSalmonellain intensive pig production should be performed.

The detection of clinical mastitis with in-line filters

1970 ◽  
Vol 37 (1) ◽  
pp. 133-137 ◽  
Author(s):  
J. B. Hoyle ◽  
F. H. Dodd
Keyword(s):  
Stainless Steel ◽  
Clinical Mastitis ◽  
Short Length ◽  
Stainless Steel Mesh ◽  
Steel Mesh ◽  
Service Production ◽  
Milking Machine ◽  
General Service ◽  
Good Agreement

SummaryA simple in-line filter is described which can be fitted into the milk tube of a. milking machine in order to detect clinical mastitis. It consists of a stainless steel mesh, on which the clots are retained, and it is fitted obliquely into a short length of clear plastics tube. The filter has been developed as an alternative to the fore-milk cup. Tests made over 9 months in a 60-cow herd show good agreement between the fore-milk cup and the in-line filter recordings. For general service production the filters are made by moulding.

Precipitation Behavior of a Maraging Stainless Steel

2012 ◽  
Vol 567 ◽  
pp. 92-95 ◽  
Author(s):  
Yue Jiang ◽  
Ying Ying Ai ◽  
Qi Ting Wang
Keyword(s):  
Stainless Steel ◽  
Treatment Process ◽  
Aging Treatment ◽  
Heat Treatment Process ◽  
New Materials ◽  
Precipitation Behavior ◽  
Thermo Calc Software ◽  
Calculation Results ◽  
Maraging Stainless Steel ◽  
Good Agreement

The changes of precipitation phases and matrix structures in Fe-13Cr-7Ni-4Mo-4Co-2W maraging stainless steel at different temperature were studied by using the Thermo-Calc software. The research was on the microstructures and precipitation behaviors of the maraging stainless steel, the performance is investigated through solution and aging treatment by TEMand SADP. The calculation results were in good agreement with the experiments, which demonstrated that when maraging stainless steel was treated in high temperature, the Laves-Fe2Mo precipitates became totally dissolved as the temperature was above 1050°C, and about 8% of R phase was found during aging. The calculation provides a guiding significant to the establishment of reasonable heat treatment process and the development of new materials.

Concerning a Creep Surface Derived From a Multiple Integral Representation for 304 Stainless Steel Under Combined Tension and Torsion

1978 ◽  
Vol 45 (4) ◽  
pp. 773-779 ◽  
Author(s):  
R. Mark ◽  
W. N. Findley
Keyword(s):  
Stainless Steel ◽  
Creep Rate ◽  
Integral Representation ◽  
Power Function ◽  
Multiple Integral ◽  
304 Stainless Steel ◽  
Creep Data ◽  
Creep Tests ◽  
Third Order ◽  
Good Agreement

It is shown that a creep surface, defined in terms of a prescribed creep rate, can be determined from the multiple integral formulation representing the creep data. The creep surface for 304 stainless steel was found to be in good agreement with a Mises ellipse. Observed creep rate vectors for this alloy were found to be normal to a Mises ellipse. These results were obtained from creep tests performed on 304 stainless steel under combined tension and torsion at 593°C (1100°F). Creep strains observed for at least 100 hr were adequately represented by a power function of time, the exponent of which was independent of stress. A third-order multiple integral representation together with a limiting stress below which creep does not occur was employed to describe satisfactorily the constant stress creep data.

Mechanical Bending Simulation of Thin Stainless Steel by Using Isotropic and Orthotropic Properties

2011 ◽  
Vol 421 ◽  
pp. 312-315
Author(s):  
Somsak Siwadamrongpong ◽  
Usanee Kitkamthorn ◽  
Chaiyapak Sajjawattana
Keyword(s):  
Stainless Steel ◽  
Material Properties ◽  
Mechanical Response ◽  
Thin Sheet ◽  
Disk Drive ◽  
Simple Calculation ◽  
Orthotropic Materials ◽  
Mechanical Bending ◽  
Orthotropic Properties ◽  
Good Agreement

The most important factors in hard disk drive suspension manufacturing is the suspension preload, so call “gram load”. The suspensions were generally made from cold rolled stainless steel (SUS304). The suspensions were formed by mechanical forming and gram load was adjusted by mechanical bending until reached a specification. The material properties in mechanical bending simulation of thin stainless steel were usually as isotropic for simple calculation. But the properties of thin stainless steel should be defined as orthotropic materials. Therefore, this work aimed to study gram load results of using isotropic and orthotropic properties. The thin stainless sheet was cut and test for mechanical properties in rolling and transverse directions. The properties of the thin sheet were applied to simulation model. It was found that orthotropic material properties shows a good agreement with the experimental results more than using isotropic material properties. Therefore, the results of this work could be used to explain and predict the mechanical response on the suspension manufacturing.

Effect of Nanoparticles on the Spreading of Bubble Triple Line on Top of a Stainless Steel Substrate Nozzle

2010 ◽  
Author(s):  
Saeid Vafaei ◽  
Dongsheng Wen
Keyword(s):  
Stainless Steel ◽  
Gas Flow ◽  
Stainless Steel Substrate ◽  
Liquid Droplet ◽  
Steel Substrate ◽  
Bubble Formation ◽  
Triple Line ◽  
Characteristic Points ◽  
Substrate Plate ◽  
Good Agreement

The purpose of this study is to investigate the effect of gold nanofluid on the formation of gas bubbles on top of a stainless steel substrate plate nozzle. The experiment reveals a unique phenomenon of enhanced pinning of the triple line of gold nanofluids for bubbles forming on the substrate plate, i.e the gold nanoparticles are found to prevent the spreading of the triple line during the bubble formation. Different to the liquid droplet measurement, the bubble contact angle is found to be slightly larger for formation of bubbles inside gold nanofluids. It is also observed that bubbles develop earlier inside the nanofluids with reduced bubble departure volume and increased bubble formation frequency. The shape of the bubble is found to be in good agreement with predictions of the Laplace-Young equation under the low gas flow rates inside water. Such a good agreement is also observed for bubbles forming inside nanofluids except a few characteristic points. The variation of solid surface tensions and the resultant force balances at the triple line are believed to be responsible for the modified dynamics of the triple line inside gold nanofluids and subsequent bubble formation.

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