Evaluation of the Atmospheric Minor Species Measurements: a Priori Statistical Constraints Based on Photochemical Modeling

2019 ◽  
Vol 61 (8-9) ◽  
pp. 574-588
Author(s):  
M. V. Belikovich ◽  
M. Yu. Kulikov ◽  
A. A. Nechaev ◽  
A. M. Feigin
Keyword(s):  
A Priori ◽  
Photochemical Modeling

scholarly journals Photochemical modeling of molecular and atomic oxygen based on multiple nightglow emissions measured in situ during the Energy Transfer in the Oxygen Nightglow rocket campaign

2020 ◽  
Vol 20 (4) ◽  
pp. 2221-2261 ◽  
Author(s):  
Olexandr Lednyts'kyy ◽  
Christian von Savigny
Keyword(s):  
Energy Transfer ◽  
Atomic Oxygen ◽  
A Priori ◽  
Lower Thermosphere ◽  
Reaction Rates ◽  
Data Sets ◽  
Electronically Excited ◽  
Photochemical Modeling ◽  
Mlt Region

Abstract. Electronically excited states of molecular and atomic oxygen (six O2 and two O) were implemented in the proposed Multiple Airglow Chemistry (MAC) model as minor species coupled with each other as well as with the ground states of O2 and O to represent the photochemistry in the upper mesosphere and lower thermosphere (MLT) region. The MAC model combines chemical processes of well-known photochemical models related to identified O2 and O species and some additional processes. Concentrations of excited O2 and O species were retrieved using the MAC model on the basis of the multiple nightglow emissions measured in situ during the Energy Transfer in the Oxygen Nightglow (ETON) rocket campaign. The proposed retrieval procedure to obtain the concentrations of these minor species in the MLT region is implemented by avoiding a priori data sets. Unknown and poorly constrained reaction rates were tuned, and the reaction rates of the well-known models were updated with the MAC model by comparing in situ and evaluated emission profiles as well as in situ and retrieved O concentration profiles. As a result, precursors of O2 and O species responsible for the transitions considered in the MAC model are identified and validated.

scholarly journals Photochemical modeling of molecular and atomic oxygen based on multiple <i>in-situ</i> emissions measured during the Energy Transfer in the Oxygen Nightglow rocket campaign

2019 ◽  
Author(s):  
Olexandr Lednyts'kyy ◽  
Christian von Savigny
Keyword(s):  
Energy Transfer ◽  
Atomic Oxygen ◽  
A Priori ◽  
Lower Thermosphere ◽  
Reaction Rates ◽  
Data Sets ◽  
Electronically Excited ◽  
Photochemical Modeling ◽  
Mlt Region

Abstract. Electronically excited states of molecular and atomic oxygen (six of O2 and two of O) were implemented in the proposed Multiple Airglow Chemistry (MAC) model as minor species coupled with each other as well as with the ground states of O2 and O to represent the photochemistry in the upper Mesosphere and Lower Thermosphere (MLT) region. The MAC model is proposed combining chemical processes of the well-known photochemical models related to identified O2 and O species and some additional processes. Concentrations of excited O2 and O species were retrieved using the MAC model on the basis of the multiple in-situ nightglow emissions measured during the Energy Transfer in the Oxygen Nightglow (ETON) rocket campaign. The proposed retrieval procedure to obtain concentrations of these MLT minor species is implemented avoiding a priori data sets. Unknown and poorly constrained reaction rates were tuned and reaction rates of the well-known models were updated with the MAC model comparing in-situ and evaluated emission profiles as well as in-situ and retrieved O concentration profiles. As a result, precursors of O2 and O species responsible for transitions considered in the MAC model are identified and validated by calculations with the MAC model.

Application of cross correlation to HREM images of surfaces

1987 ◽  
Vol 45 ◽  
pp. 754-755
Author(s):  
D. E. Luzzi ◽  
L. D. Marks ◽  
M. I. Buckett
Keyword(s):  
Cross Correlation ◽  
A Priori ◽  
Matrix Material ◽  
Correlation Method ◽  
Accurate Knowledge ◽  
Complex Image ◽  
Fourier Filtering ◽  
The Matrix ◽  
Low Pass ◽  
Data Reduction Technique

As the HREM becomes increasingly used for the study of dynamic localized phenomena, the development of techniques to recover the desired information from a real image is important. Often, the important features are not strongly scattering in comparison to the matrix material in addition to being masked by statistical and amorphous noise. The desired information will usually involve the accurate knowledge of the position and intensity of the contrast. In order to decipher the desired information from a complex image, cross-correlation (xcf) techniques can be utilized. Unlike other image processing methods which rely on data massaging (e.g. high/low pass filtering or Fourier filtering), the cross-correlation method is a rigorous data reduction technique with no a priori assumptions.We have examined basic cross-correlation procedures using images of discrete gaussian peaks and have developed an iterative procedure to greatly enhance the capabilities of these techniques when the contrast from the peaks overlap.

Towards 1-Ångstrom-resolution STEM

1993 ◽  
Vol 51 ◽  
pp. 996-997
Author(s):  
H.S. von Harrach ◽  
D.E. Jesson ◽  
S.J. Pennycook
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Phase Contrast ◽  
Spherical Aberration ◽  
A Priori ◽  
Dark Field ◽  
Image Resolution ◽  
Objective Lens ◽  
Annular Dark Field ◽  
First Results

Phase contrast TEM has been the leading technique for high resolution imaging of materials for many years, whilst STEM has been the principal method for high-resolution microanalysis. However, it was demonstrated many years ago that low angle dark-field STEM imaging is a priori capable of almost 50% higher point resolution than coherent bright-field imaging (i.e. phase contrast TEM or STEM). This advantage was not exploited until Pennycook developed the high-angle annular dark-field (ADF) technique which can provide an incoherent image showing both high image resolution and atomic number contrast.This paper describes the design and first results of a 300kV field-emission STEM (VG Microscopes HB603U) which has improved ADF STEM image resolution towards the 1 angstrom target. The instrument uses a cold field-emission gun, generating a 300 kV beam of up to 1 μA from an 11-stage accelerator. The beam is focussed on to the specimen by two condensers and a condenser-objective lens with a spherical aberration coefficient of 1.0 mm.

Treating Velopharyngeal Inadequacy Using Bilateral Buccal Flap Revision Palatoplasty

2019 ◽  
Vol 4 (5) ◽  
pp. 878-892
Author(s):  
Joseph A. Napoli ◽  
Linda D. Vallino
Keyword(s):  
Systematic Review ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
A Priori ◽  
Sufficient Evidence ◽  
Obstructive Sleep ◽  
Before And After ◽  
Buccal Flap

Purpose The 2 most commonly used operations to treat velopharyngeal inadequacy (VPI) are superiorly based pharyngeal flap and sphincter pharyngoplasty, both of which may result in hyponasal speech and airway obstruction. The purpose of this article is to (a) describe the bilateral buccal flap revision palatoplasty (BBFRP) as an alternative technique to manage VPI while minimizing these risks and (b) conduct a systematic review of the evidence of BBFRP on speech and other clinical outcomes. A report comparing the speech of a child with hypernasality before and after BBFRP is presented. Method A review of databases was conducted for studies of buccal flaps to treat VPI. Using the principles of a systematic review, the articles were read, and data were abstracted for study characteristics that were developed a priori. With respect to the case report, speech and instrumental data from a child with repaired cleft lip and palate and hypernasal speech were collected and analyzed before and after surgery. Results Eight articles were included in the analysis. The results were positive, and the evidence is in favor of BBFRP in improving velopharyngeal function, while minimizing the risk of hyponasal speech and obstructive sleep apnea. Before surgery, the child's speech was characterized by moderate hypernasality, and after surgery, it was judged to be within normal limits. Conclusion Based on clinical experience and results from the systematic review, there is sufficient evidence that the buccal flap is effective in improving resonance and minimizing obstructive sleep apnea. We recommend BBFRP as another approach in selected patients to manage VPI. Supplemental Material https://doi.org/10.23641/asha.9919352

Project MATCH secondary a priori hypotheses

Addiction ◽  
1997 ◽  
Vol 92 (12) ◽  
pp. 1671-1698 ◽  
Author(s):  
Project Match Research Group
Keyword(s):  
A Priori ◽  
Project Match

Vergleich einer Papier-Bleistift- und einer computergestützten Version des Leistungsprüfsystems (LPS)

Diagnostica ◽  
2002 ◽  
Vol 48 (3) ◽  
pp. 115-120 ◽  
Author(s):  
Stefan Troche ◽  
Beatrice Rammstedt ◽  
Thomas Rammsayer
Keyword(s):  
A Priori

Zusammenfassung. Der zunehmende Einsatz computergestützter diagnostischer Verfahren führt zwangsläufig zur Frage nach der Äquivalenz zwischen konventionellen Papier-Bleistift-Versionen und entsprechenden Computertranspositionen. Zur Überprüfung der Äquivalenz zwischen der computergestützten Version des Leistungsprüfsystems (LPS) im Hogrefe Testsystem und der Papier-Bleistift-Version wurden 131 Versuchspersonen mit beiden Verfahren getestet. Heterogene Ergebnisse zwischen der Papier-Bleistift- und der Computerversion belegen, dass nicht a priori von der Äquivalenz beider Versionen ausgegangen werden kann, und weisen nachdrücklich auf die Notwendigkeit systematischer Äquivalenzprüfungen hin. Eine an Hand einer zweiten Stichprobe von 40 Testpersonen durchgeführte Überprüfung der Retest-Reliabilität der computergestützten Version des LPS ergab für ein Retest-Intervall von zwei Wochen Reliabilitätskoeffizienten zwischen rtt = 0.55 und rtt = 0.94. In der Diskussion werden mögliche Gründe für die Nicht-Äquivalenz der beiden LPS-Versionen identifiziert.

Effects of a Priori Liking on the Elicitation of Mimicry

2010 ◽  
Vol 57 (6) ◽  
pp. 412-418 ◽  
Author(s):  
Mariëlle Stel ◽  
Rick B. van Baaren ◽  
Jim Blascovich ◽  
Eric van Dijk ◽  
Cade McCall ◽  
...  
Keyword(s):  
A Priori ◽  
The Relationship

Mimicry and prosocial feelings are generally thought to be positively related. However, the conditions under which mimicry and liking are related largely remain unspecified. We advance this specification by examining the relationship between mimicry and liking more thoroughly. In two experiments, we manipulated an individual’s a priori liking for another and investigated whether it influenced mimicry of that person. Our experiments demonstrate that in the presence of a reason to like a target, automatic mimicry is increased. However, mimicry did not decrease when disliking a target. These studies provide further evidence of a link between mimicry and liking and extend previous research by showing that a certain level of mimicry even occurs when mimicry behavior is inconsistent with one’s goals or motivations.

Collection of Ego-Centered Network Data with Computer-Assisted Interviews

Methodology ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Joachim Gerich ◽  
Roland Lehner
Keyword(s):  
Survey Methods ◽  
A Priori ◽  
Dynamic Structure ◽  
Computer Assisted ◽  
Network Data ◽  
Great Effort ◽  
Self Administration ◽  
Face To Face ◽  
Full Network

Although ego-centered network data provide information that is limited in various ways as compared with full network data, an ego-centered design can be used without the need for a priori and researcher-defined network borders. Moreover, ego-centered network data can be obtained with traditional survey methods. However, due to the dynamic structure of the questionnaires involved, a great effort is required on the part of either respondents (with self-administration) or interviewers (with face-to-face interviews). As an alternative, we will show the advantages of using CASI (computer-assisted self-administered interview) methods for the collection of ego-centered network data as applied in a study on the role of social networks in substance use among college students.

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