Laboratory rotational ground state transitions of NH3_3D+^+ and CF+^+

Aims. This paper reports accurate laboratory frequencies of the rotational ground state transitions of two astronomically relevant molecular ions, NH3D+ and CF+. Methods. Spectra in the millimeter-wave band were recorded by the method of rotational state-selective attachment of He-atoms to the molecular ions stored and cooled in a cryogenic ion trap held at 4 K. The lowest rotational transition in the A state (ortho state) of NH$_3$D$^+$ ($J_K = 1_0 - 0_0$), and the two hyperfine components of the ground state transition of CF$^+$($J = 1 - 0$) were measured with a relative precision better than $10^{-7}$. Results. For both target ions the experimental transition frequencies agree with recent observations of the same lines in different astronomical environments. In the case of NH$_3$D$^+$ the high-accuracy laboratory measurements lend support to its tentative identification in the interstellar medium. For CF$^+$ the experimentally determined hyperfine splitting confirms previous quantum-chemical calculations and the intrinsic spectroscopic nature of a double-peaked line profile observed in the $J = 1 - 0$ transition towards the Horsehead PDR.Comment: 7 pages, 2 figure

Hazard Perception, Presence, and Simulation Sickness—A Comparison of Desktop and Head-Mounted Display for Driving Simulation

Driving simulators are becoming increasingly common in driver training and assessment. Since virtual reality is generally regarded as an appropriate environment for measuring risk behavior, simulators are also used to assess hazard perception, which is considered to be one of the most important skills for safe driving. Simulators, which offer challenges that are indeed comparable to driving in real traffic, but at a very low risk of physical injury, have the potential to complement theoretical and practical driver trainings and tests. Although configurations and fidelity differ considerably between driving simulators, studies comparing the impact of their distinct features on driving performance and test validity remain rare. In this context, prior research demonstrated that a wider field of view (three monitors compared to a single monitor) led to earlier speed adjustments in response to potential hazards—especially for experienced drivers. The wider field of view was assumed to cause the drivers to be more present in the virtual world, which in turn provoked more natural scanning of the road and therefore, earlier hazard detection in experienced drivers. Research on spatial presence in other contexts support this assumption. The present experiment investigated whether this effect could be enhanced by an even more immersive presentation technique for driving simulation: a head-mounted display (HMD). Moreover, we studied the interplay between display mode, sense of presence and simulation sickness. Eighty experienced and less experienced drivers completed six simulation-based hazard perception scenarios, which were displayed either via a triple-monitor set-up or an HMD. Results indicate that the experienced drivers showed very similar driving and risk behavior as the inexperienced drivers in both experimental conditions. However, there were significant differences between the two display conditions. The use of an HMD resulted in a clearer and more abrupt speed reduction, more virtual presence, and a higher degree of simulation sickness. However, the interrelation between these three variables could not be conclusively clarified in the present study and thus represents a research aim that could be addressed in future studies

The art of designing for biodiversity : a comparative case study on how biodiversity is described in the city of Stockholm and the city of Malmö

Denna uppsats syftar till att undersöka hur två svenska storstadskommuner beskriver gestaltning av biologisk mångfald i urbana miljöer. I takt med ökad urbanisering, klimatförändringar och minskad artdiversitet blir det allt viktigare att urbana miljöer främjar biologisk mångfald. Samtidigt kan det vara en utmaning att gestalta biologisk mångfald i stadsmiljö, eftersom miljöer med stor biologisk mångfald inte alltid upplevs estetiskt tilltalande. I kommunernas övergripande policydokument finns riktlinjer som reflekterar idéer och antaganden om gestaltning av biologisk mångfald, som i sin tur ger signaler till utförarna om den politiska viljan och riktningen framåt. I uppsatsen görs därför en kvalitativ analys av policydokument från storstadskommunerna Stockholms stad och Malmö stad, för att jämföra hur de beskriver gestaltning av biologisk mångfald i urbana miljöer. Resultatet visar att de undersökta kommunernas beskrivningar är relativt samstämmiga. Biologisk mångfald förs fram som en del i städernas visuella karaktär och identitet och som en bidragande faktor till vacker gestaltning. Den ses också som en av många funktioner i den täta stadens mångfunktionella gestaltning, vilket framför allt exemplifieras med två gestaltningsgrepp; öppen dagvattenhantering och gröna väggar och tak. Insamlad data diskuteras i förhållande till två teorier om estetik och ekologisk hållbarhet formulerade av Joan Iversson Nassauer och Elizabeth K. Meyer. Teorierna beskriver de krockar som kan uppstå mellan människors estetiska landskapspreferenser och naturens verkliga utseende, men också hur dessa utmaningar kan lösas genom gestaltning och i förlängningen skapa både intresse och förståelse för ekologisk hållbarhet. I fallet Stockholms stad och Malmö stad är det tydligt att de exempel på gestaltningsgrepp som förs fram, ligger i linje med Nassauers förespråkande av inramning för att signalera omhändertagande. Att kommunerna beskriver biologisk mångfald som en viktig del av kommunernas visuella identitet och skönhet utgör en god grund. Men när biologisk mångfald samtidigt ses som en av många funktioner i en mångfunktionell gestaltning som prioriterar mänskliga behov, är risken att gestaltningen inte presterar ekologiskt. För att skapa reella rum för biologisk mångfald i staden, förespråkas separation som ett komplement till Nassauers ordnade formspråk och Meyers resonemang kring estetiska upplevelser. Genom att ta fasta på det kulturella formspråket och samtidigt skapa separerade gröna miljöer för biologisk mångfald som också ger upplevelsevärden, kan landskapsarkitekter bidra till en större förståelse för vikten av biologisk mångfald i stadsrummet. Detta kräver inte mindre utan mer fokus på gestaltning i framtidens stadsutvecklingsprojekt. Det är en konst att gestalta biologisk mångfald.This paper aims to investigate how two Swedish metropolitan municipalities describe designing for biodiversity in urban environments. As urbanisation, climate change and reduced diversity of species increase, it is becoming increasingly important for urban environments to promote biodiversity. At the same time, designing for biodiversity in the urban environment can be a challenge, as environments with high biodiversity are not always perceived as aesthetically pleasing. In the municipalities' policy documents, there are guidelines that reflect ideas and assumptions about designing for biodiversity, which in turn give signals to practitioners about the political will and direction for the future. A qualitative analysis of policy documents from the metropolitan municipalities the City of Stockholm and the City of Malmö is conducted, to compare descriptions of designing for biodiversity in urban environments. The results show the descriptions are relatively consistent. Biodiversity is presented as part of the visual character and identity of the cities and as a contributing factor to beautiful design. Biodiversity is also seen as one of many functions in the multifunctional design of the dense city, which is mainly exemplified by two design concepts: open stormwater management and green walls and roofs. Collected data are discussed in relation to two theories on aesthetic sustainability formulated by Joan Iversson Nassauer and Elizabeth K. Meyer. The theories describe clashes that can arise between people’s aesthetic landscape preferences and the actual appearance of nature. But they also show how these challenges can be solved through design and increase both interest and understanding of the importance of ecological sustainability. In the case of the City of Stockholm and the City of Malmö, the examples of design approaches put forward are in line with Nassauer’s advocacy of orderly frames as cues to care. The fact that the municipalities describe biodiversity as an important part of their visual identity and beauty is a good basis. But when biodiversity is seen as one of many functions in a multifunctional design that prioritises human needs, there is a risk the design does not perform ecologically. To create real spaces for biodiversity in the city, separation is advocated as a complement to Nassauer’s orderly frames and Meyer’s aesthetic experiences. By utilising the cultural design language while creating separated green environments for biodiversity providing experiential values, landscape architects can contribute to a greater understanding of the importance of biodiversity in urban space. This requires not less but more focus on design in future urban development projects. It is an art to design for biodiversity

Search for anions in molecular sources: C4H- detection in L1527

We present the results of a search for the negative ion C4H- in various dark clouds, low mass star-forming regions and photon-dominated regions (PDRs). We have also searched for C6H-, C2H- and CN- in some of the sources. The millimeter-wave observations were carried out with the IRAM-30m telescope. We detect C4H-, through the J = 9-8 and J = 10-9 rotational transitions, in the low mass star-forming region L1527. We thus confirm the tentative detection of the J = 9-8 line recently reported toward this source. The [C4H-]/[C4H] ratio found is 0.011 %, which is slightly lower than the value observed in IRC +10216, 0.024 %, but above the 3 sigma upper limit we derive in TMC-1, < 0.0052 %. We have also derived an upper limit for the [C6H-]/[C6H] ratio in the Horsehead Nebula, and for various anion-to-neutral ratios in the observed sources. These results are compared with recent chemical models.Comment: 4 pages, 1 figure; accepted for A&A Letter

Infrared predissociation spectroscopy of the hydrocarbon cations C3H+, C2H+, and C3H2+

Reactive hydrocarbon cations play an important role in the astrochemistry of the interstellar medium, but spectroscopic data, needed for their identification in astronomical observations, is sparse. Here we report the first gas-phase vibrational spectra of the linear C$_3$H$^+$ ($^1 \Sigma$), the radical cation C$_2$H$^+$ ($^3 \Pi$), and the linear-/cyclic-C$_3$H$_2^+$ ($^2 \Pi$ /$^2$A$_1$, resp.). Broadband spectra were recorded by Ne- and He-messenger infrared-predissociation (IR-PD) action spectroscopy in a cryogenic ($4-11$~K) ion trap instrument (FELion) in the $250-3500$~{\wn} range using a free electron laser and a MIR-OPO at the FELIX (Free-Electron Laser for Infrared eXperiments) laboratory. The band positions (determined with a precision of $1-2$~\wn) covering the C-H and C-C stretching as well as several bending modes are compared to high-level (CCSD(T) with large basis sets) quantum-chemical calculations with an emphasis on anharmonic effects and on the influence of the rare-gas messenger atom. The experimental and theoretical data provide a solid basis for subsequent IR high-resolution studies, with the ultimate goal to predict and measure accurate rotational spectra for a radio-astronomical search of these molecular ions in space

Infrared action spectroscopy as tool for probing gas-phase dynamics: Protonated Dimethyl Ether, (CH3_3)2_2OH+^+, formed by the reaction of CH3_3OH2+_{2}^{+} with CH3_3OH

Methanol is one of the most abundant interstellar Complex Organic Molecules (iCOMs) and it represents a major building block for the synthesis of increasingly complex oxygen-containing molecules. The reaction between protonated methanol and its neutral counterpart, giving protonated dimethyl ether, (CH$_3$)$_2$OH$^+$, along with the ejection of a water molecule, has been proposed as a key reaction in the synthesis of dimethyl ether in space. Here, gas phase vibrational spectra of the (CH$_3$)$_2$OH$^+$ reaction product and of the [C$_2$H$_9$O$_2$]$^+$ intermediate complex(es), formed under different pressure and temperature conditions, are presented. The widely tunable free electron laser for infrared experiments, FELIX, was employed to record their vibrational fingerprint spectra using different types of infrared action spectroscopy in the $600-1700$ cm$^{-1}$ frequency range, complemented with measurements using an OPO/OPA system to cover the O-H stretching region $3400-3700$ cm$^{-1}$. The formation of protonated dimethyl ether as a product of the reaction is spectroscopically confirmed, providing the first gas-phase vibrational spectrum of this potentially relevant astrochemical ion.Comment: 15 pages, 6 figures, Molecular Physics, Published online: 22 Jun 2023, for associated data files see Zenodo repository at https://doi.org/10.5281/zenodo.786855

Assessment of noticing of classroom disruptions: a multi-methods approach

Teachers’ noticing as a basic precondition for effective teaching is characterized by focusing on relevant events in the classroom and ignoring the irrelevant. In recent years, many researchers have used eye-tracking methodology in classroom observations to gather information about the continuous attentional processes of teachers. Despite the general validity of the eye–mind assumption, methodological triangulation is necessary to draw conclusions about the where and why of the focus of attention. Although in previous studies, different data sources like gaze and verbal data have been used, the analyses were mostly conducted separately, instead of directly combining the data. In our study, we collected verbal data (retrospective think-aloud; RTA) and a reaction-based concurrent measure (keystroke) to assess the noticing process of novice and experienced teachers (N  =  52) while they watched staged videos of classroom situations. For a direct triangulation, we combined these data with eye-tracking data. The aim of the study was to combine both measures with eye-tracking parameters that indicate attentional processes (fixation count, mean fixation duration, and revisits), and with expertise. We found that participants who were aware of the critical incidents in the videos (they gave a keystroke or mentioned the incident in the RTA), showed—as expected—a higher number of fixations and more revisits to the appropriate area, but a comparable mean fixation duration. However, expertise differences regarding accuracy in both measures could not be shown. We discuss methodological issues regarding the implementation of RTA and keystroke as measurements for the noticing process because—despite only partially significant results—both methods are promising as they allow complementation and possible correction of eye-movement-only data