scholarly journals Impact of an Antiresonant Oxide Island on the Lasing of Lateral Modes in VCSELs

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2195
Author(s):  
Marta Więckowska ◽  
Robert P. Sarzała ◽  
Rafał Ledzion ◽  
Maciej Dems
Keyword(s):  
Numerical Analysis ◽  
Current Crowding ◽  
Crowding Effect ◽  
Factors Influencing ◽  
Mode Selectivity ◽  
Lateral Mode ◽  
Mode Discrimination ◽  
Lateral Modes ◽  
The Impact ◽  
Side Mode

Use of antiresonant structures is a proven, efficient method of improving lateral mode selectivity in VCSELs. In this paper, we analyze the impact of a low-refractive antiresonant oxide island buried in a top VCSEL mirror on the lasing conditions of lateral modes of different orders. By performing comprehensive thermal, electrical, and optical numerical analysis of the VCSEL device, we show the impact of the size and location of the oxide island on the current-crowding effect and compute threshold currents for various lateral modes. If the island is placed close to the cavity, the threshold shows strong oscillations, which for moderate island distances can be tuned to increase the side mode discrimination. We are therefore able to pinpoint the most important factors influencing mode discrimination and to identify oxide island parameters capable of providing single-lateral-mode emission.

How to Psychologically Minimize Scratching Impulses

2014 ◽  
Vol 222 (3) ◽  
pp. 140-147 ◽  
Author(s):  
Ariane Sölle ◽  
Theresa Bartholomäus ◽  
Margitta Worm ◽  
Regine Klinger
Keyword(s):  
Cognitive Processes ◽  
Placebo Effect ◽  
Psychological Factors ◽  
Pharmacological Treatments ◽  
Physiological Basis ◽  
Psychological Mechanisms ◽  
Physical Complaints ◽  
Factors Influencing ◽  
The Impact ◽  
Placebo Model

Research in recent years, especially in the analgesic field, has intensively studied the placebo effect and its mechanisms. It has been shown that physical complaints can be efficiently reduced via learning and cognitive processes (conditioning and expectancies). However, despite evidence demonstrating a large variety of physiological similarities between pain and itch, the possible transfer of the analgesic placebo model to itch has not yet been widely discussed in research. This review therefore aims at highlighting potential transfers of placebo mechanisms to itch processes by demonstrating the therapeutic issues in pharmacological treatments for pruritus on a physiological basis and by discussing the impact of psychological mechanisms and psychological factors influencing itch sensations.

scholarly journals Modelling natural regeneration of European beech in Saxony, Germany: identifying factors influencing the occurrence and density of regeneration

2021 ◽  
Author(s):  
Maximilian Axer ◽  
Sven Martens ◽  
Robert Schlicht ◽  
Sven Wagner
Keyword(s):  
Natural Regeneration ◽  
Negative Binomial ◽  
European Beech ◽  
Seed Source ◽  
Permanent Plots ◽  
Forest Conversion ◽  
Ecological Knowledge ◽  
Statistical Tool ◽  
Factors Influencing ◽  
The Impact

AbstractThe potential utilisation of natural regeneration of European beech (Fagus sylvatica L.) for forest conversion has received little attention to date. Ecological knowledge is necessary to understand and predict successful natural regeneration of beech. The objective of this study was to improve understanding of what drives the occurrence of beech regeneration and, once regeneration is present, what drives its density. In the study, we utilised a forest inventory dataset provided by Sachsenforst, the state forestry service of Saxony, Germany. The dataset was derived from 8725 permanent plots. Zero-altered negative binomial models (ZANB) with spatial random effects were used to analyse factors influencing occurrence and density simultaneously. The results provided by the spatial ZANB models revealed that the probability of the occurrence of beech regeneration is highly dependent on seed availability, i.e. dependent on source trees in close proximity to a plot. The probability of beech regeneration rises with the increasing diameter of a potential seed tree and decreases with increasing distance to the nearest potential seed source. The occurrence of regeneration is affected by overstorey composition and competition exerted by spruce regeneration. Where sites are affected by groundwater or temporary waterlogging, the impact on the occurrence of regeneration is negative. Although distance to the nearest potential seed source has an influence on occurrence, this variable exerts no influence on density. A high regeneration density arises in conjunction with a high beech basal area in the overstorey. Beech regeneration density, but not occurrence, is negatively affected by browsing intensity. These variables can be used to predict the occurrence and density of beech regeneration in space to a high level of precision. The established statistical tool can be used for decision-making when planning forest conversion using natural regeneration.

scholarly journals Individual Condensation Trails in Aircraft Trajectory Optimization

2019 ◽  
Vol 11 (21) ◽  
pp. 6082 ◽  
Author(s):  
Judith Rosenow ◽  
Hartmut Fricke
Keyword(s):  
Global Warming ◽  
Trajectory Optimization ◽  
Wind Shear ◽  
Impact Factors ◽  
Factors Influencing ◽  
Order Of Magnitude ◽  
Aircraft Trajectory ◽  
The Impact ◽  
Arbitrary Trajectory ◽  
Significant Factors

Contrails are one of the driving contributors to global warming, induced by aviation. The quantification of the impact of contrails on global warming is nontrivial and requires further in-depth investigation. In detail, condensation trails might even change the algebraic sign between a cooling and a warming effect in an order of magnitude, which is comparable to the impact of aviation-emitted carbon dioxides and nitrogen oxides. This implies the necessity to granularly consider the environmental impact of condensation trails in single-trajectory optimization tools. The intent of this study is the elaboration of all significant factors influencing on the net effect of single condensation trails. Possible simplifications will be proposed for a consideration in single-trajectory optimization tools. Finally, the effects of the most important impact factors, such as latitude, time of the year, and time of the day, wind shear, and atmospheric turbulence as well as their consideration in a multi-criteria trajectory optimization tool are exemplified. The results can be used for an arbitrary trajectory optimization tool with environmental optimization intents.

The Impact of the SAGE & THYME Foundation Level Workshop on Factors Influencing Communication Skills in Health Care Professionals

2014 ◽  
Vol 34 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Michael Connolly ◽  
Joanne M. Thomas ◽  
Julie A. Orford ◽  
Nicola Schofield ◽  
Sigrid Whiteside ◽  
...  
Keyword(s):  
Health Care ◽  
Communication Skills ◽  
Health Care Professionals ◽  
Factors Influencing ◽  
The Impact

The Politics of Referendums

2021 ◽  
pp. 609-626
Author(s):  
Michael Gallagher
Keyword(s):  
Social Class ◽  
Minority Rights ◽  
Constitutional Change ◽  
Voting Behaviour ◽  
Representative Government ◽  
Factors Influencing ◽  
The Impact

Ireland has become one of the world’s biggest users of referendums, which are an important part of the system of governance. The use of the referendum is tightly related to constitutional change, and partly as a result, referendums have not been held on classic left–right tax and spend issues. Rather, the main issues that have generated referendums have been moral (particularly divorce and abortion) and the ratification of EU treaties. The chapter analyses the factors influencing referendum voting behaviour: the impact of party allegiance has been weakening, while social class and age are both strongly related to referendum voting behaviour, though the pattern varies depending on the issue. Referendums are sometimes accused of facilitating the suppression of minority rights, but that has not been the Irish experience. On the whole, the referendum experience in Ireland can be seen as an enhancement of, rather than a threat to, representative government.

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