Technical note: Bimodality in mesospheric OH rotational population distributions and implications for temperature measurements

Emissions from the OH Meinel bands are routinely used to determine rotational temperatures that are considered proxies for the kinetic temperature near the mesopause region. Previous observations determined OH rotational temperatures that show a dependence on the vibrational level, with the temperature rising overall as the OH vibrational quantum number v increases. The source of this trend is not well understood and has generally been attributed to deviations from thermodynamic equilibrium. This technical note demonstrates that the existence of bimodal OH rotational population distributions is an inherent feature of rotational relaxation in gases and can provide an explanation for the previously reported temperature trend. The use of only a few lines from rotational transitions involving low rotational quantum numbers to determine rotational temperatures does not account for the bimodality of the OH rotational population distributions and leads to systematic errors overestimating the OH rotational temperature. This note presents selected examples, discusses the relevant implications, and considers strategies that could lead to more reliable OH rotational temperature determination.</p

Data-driven shape analysis and processing

Data-driven methods serve an increasingly important role in discovering geometric, structural, and semantic relationships between shapes. In contrast to traditional approaches that process shapes in isolation of each other, data-driven methods aggregate information from 3D model collections to improve the analysis, modeling and editing of shapes. Through reviewing the literature, we provide an overview of the main concepts and components of these methods, as well as discuss their application to classification, segmentation, matching, reconstruction, modeling and exploration, as well as scene analysis and synthesis. We conclude our report with ideas that can inspire future research in data-driven shape analysis and processing

Environmental effects of ozone depletion, UV radiation and interactions with climate change : UNEP Environmental Effects Assessment Panel, update 2017

Peer reviewe

Remote oxygen sensing by ionospheric excitation (ROSIE)

The principal optical observable emission resulting from ionospheric modification (IM) experiments is the atomic oxygen red line at 630 nm, originating from the O(&lt;sup&gt;1&lt;/sup&gt;D–&lt;sup&gt;3&lt;/sup&gt;P) transition. Because the O(&lt;sup&gt;1&lt;/sup&gt;D) atom has a long radiative lifetime, it is sensitive to collisional relaxation and an observed decay faster than the radiative rate can be attributed to collisions with atmospheric species. In contrast to the common practice of ignoring O-atoms in interpreting such observations in the past, recent experimental studies on the relaxation of O(&lt;sup&gt;1&lt;/sup&gt;D) by O(&lt;sup&gt;3&lt;/sup&gt;P) have revealed the dominant role of oxygen atoms in controlling the lifetime of O(&lt;sup&gt;1&lt;/sup&gt;D) at altitudes relevant to IM experiments. Using the most up-to-date rate coefficients for collisional relaxation of O(&lt;sup&gt;1&lt;/sup&gt;D) by O, N&lt;sub&gt;2&lt;/sub&gt;, and O&lt;sub&gt;2&lt;/sub&gt;, it is now possible to analyze the red line decays observed in IM experiments and thus probe the local ionospheric composition. In this manner, we can demonstrate an approach to remotely detect O-atoms at the altitudes relevant to IM experiments, which we call remote oxygen sensing by ionospheric excitation (ROSIE). The results can be compared with atmospheric models and used to study the temporal, seasonal, altitude and spatial variation of ionospheric O-atom density in the vicinity of heating facilities. We discuss the relevance to atmospheric observations and ionospheric heating experiments and report an analysis of representative IM data

Solid phase microextraction to determine the migration of phthalates from plastic ware to drinking water

Summarization: Overall, the results revealed that significant quantities of phthalates are expected to be present in drinking water samples coming into direct contact with disposable plastic items at elevated temperatures. The contamination level is higher when a prolonged exposure to such temperatures is applied. Therefore, it is strongly advisable to control temperature during the transfer, storage and/or handling of these materials. Key words: SPME, phthalate esters, drinking water, water analysisΠαρουσιάστηκε στο: Proceedings of the 8th International Conference on Environmental Science and Technolog

Socioeconomic crisis and aggressive behaviour of Greek adolescents

Background: Aggressive behaviours are common during adolescence. In Greece, adolescents and their families experience a severe and enduring recession with potentially adverse impact on mental health. Aim: This study aimed to examine the correlation between adolescents&apos; aggressive behaviour and economic factors. Methods: The Buss-Perry Aggression Questionnaire (AQ) was used to measure aggression. Reduction in pocket money and three items of the Household Food Insecurity Access Scale were used to measure material deprivation as a result of the economic crisis. The questionnaires were administrated to a sample of 2,159 adolescent students of the Greater Athens Metropolitan Area. Results: Students who during the previous 4 weeks had experienced household food insecurity (anxiety/uncertainty about food, insufficient food quality or insufficient food intake) or had their pocket money decreased within the last 6 months scored on average significantly higher in the AQ compared to their counterparts who did not. Conclusion: The shortage in basic goods due to the actual Greek economic crisis seems to be related to aggressive behaviours during adolescence and we should take this into account in clinical practice. © SAGE Publications

Interleaver-Based Method for Full Utilization of the Bandwidth of Fiber Optical Parametric Amplifiers and Wavelength Converters

The study of an interleaver-based method for the full utilization of the bandwidth of fiber optical parametric amplifiers (FOPA) and wavelength converters was presented. The discussed method used two parallel FOPAs and two interleavers that allowed the amplification or the inversion of a broad spectrum. The novel interleaver method was based on the utilization of a full wavelength division multiplexing (WDM) spectrum aligned with the ITU grid. The study presented the analysis of a four-signal spectrum demonstrating the ability to remove the idlers from the amplified spectrum, with crosstalk below -18 db.link_to_subscribed_fulltex

High Repetition-Rate Pulsed-Pump Fiber OPA for 10Gb/s NRZ Modulated Signals

We demonstrated a pulsed-pump fiber optical parametric amplifier followed by a narrow optical filter for transparent signal amplification. Wide gain-bandwidth of 85nm, large gain of 43dB, and clear eye-opening were demonstrated for 10Gb/s-NRZ signals by a 20GHz asynchronous pulsed pump.link_to_subscribed_fulltex

Timing Jitter and Amplitude Noise Reduction by a Chirped Pulsed-Pump Fiber OPA

An optical reshaper based on a linearly-chirped pulsed-pump fiber optical parametric amplifier (OPA) was discussed. The optical reshaper was used to reduce timing jitter and amplitude noise. The reshaper consisted of saturation controller, chirped-pulse generator, OPA section and dispersive medium. The reshaper removed timing-jitter by a temporal lens effect, which was realised by a frequency chirp followed by optimum dispersion. The reshaper reduced amplitude noise of the input signal by optimizing gain saturation of the OPA.link_to_subscribed_fulltex