Lagrangian modelling of frazil ice in the ocean

A new modelling framework using Lagrangian particle tracking has been developed to assess dynamic and thermodynamic effects of underwater frazil ice. This frazil-ice model treats a Lagrangian particle as a bulk cluster of many frazil crystals, and calculates the thermodynamic growth of each particle and the corresponding budget of latent heat and fresh water. The effective density and viscosity of sea water depend on the mass fraction of underwater frazil ice, and hence affect ocean convection. An idealized experiment using our model successfully reproduces the formation of underwater frazil ice and its transition to grease ice at the surface. Because underwater frazil ice does not reduce the atmosphere/ocean heat exchange, surface heat flux and net sea-ice production in the experiment with frazil ice are relatively high compared with the experiment where surface cooling directly leads to columnar growth of a solid ice cover which effectively insulates the heat flux. These results suggest that large-scale sea-ice models which do not take account of the effects of frazil ice might underestimate atmosphere/ocean heat exchange, particularly at times of active new ice formation

Resonance absolute quantum reflection at selected energies

The possibility of the resonance reflection (100 % at maximum) is revealed. The corresponding exactly solvable models with the controllable numbers of resonances, their positions and widths are presented.Comment: 5 pages, 2 figure

Cooperation and competition in the cargo liner shipping industry

It is widespread international practice that cargo liners meet at regular conferences to fix prices and quotas for individual routes. Presently, however, the respective European regulation granting liners an exemption from competition laws is under review. Liners claim that conferences are a necessary pre-condition for the provision of reliable services. In contrast, we demonstrate that there is little evidence for a destabilizing effect of competition, while conferences can themselves give rise to instability. The liners association (ELAA) has, in response to the EU review process, proposed an information exchange system as an alternative. In our view this has some merits. Transfer of data might even be mandatory, information output should be aggregated and anonymized and made available to the general public. We are skeptical, however, about any discussions between liners that go further than anonymized information exchange. -- In der Containerseeschifffahrt ist es weltweit üblich, dass sich die Reeder in Konferenzen über Frachtraten und -quoten für spezifische Handelsrouten abstimmen. In Europa wird jedoch die Regulierung, die diese Ausnahme vom Wettbewerbsrecht erlaubt, von der EU-Kommission zur Zeit überprüft. Die Reeder argumentieren, dass Konferenzen nötig sind, um ein stabiles Angebot sicherzustellen. Wir kommen jedoch zu dem Schluss, dass es keine Anhaltspunkte für außerodentlich destabilisierende Effekte von Konkurrenz gibt. Im Gegenteil zeigt sich, dass eher die Konferenzen destabilisierende Effekte erzeugen können. Die Assoziation der Reedereien (ELAA) hat, unter dem Druck der Überprüfung durch die EU, als Alternative die Einrichtung eines Informationsaustauschsystems vorgeschlagen. Dies hat aus unserer Sicht einige Vorteile. Man könnte die Übermittlung von Daten sogar zur Pflicht machen; der daraus gewonnene Informations-Output sollte aggregiert und anonymisiert sein und der allgemeinen Öffentlichkeit zur Verfügung gestellt werden. Wir sind jedoch skeptisch gegenüber Diskussionen zwischen den Reedern, die über den anonymisierten Informationsaustausch hinausgehen.

Sea-Ice Production in Antarctic Coastal Polynyas Estimated From AMSR2 Data and Its Validation Using AMSR-E and SSM/I-SSMIS Data

Antarctic coastal polynyas are very high sea-ice production areas. The resultant large amount of brine rejection leads to the formation of dense water. The dense water forms Antarctic bottom water, which is the densest water in the global overturning circulation and a key player in climate change as a significant sink for heat and carbon dioxide. In this study, an algorithm was developed that uses Advanced Microwave Scanning Radiometer 2 (AMSR2) data (2012-present) to detect polynya area and estimates thin ice thickness by a method similar to that used to develop the algorithm for Advanced Microwave Scanning Radiometer for EOS (AMSR-E) data. Landfast sea-ice areas were also detected using AMSR2 data. Ice production in the polynyas was estimated by a heat flux calculation using AMSR2 sea-ice data. In four major polynyas, AMSR2 ice production was compared with AMSR-E (2003-2011) ice production through comparison of them with Special Sensor Microwave Imager (SSM/I) and Special Sensor Microwave Imager/Sounder (SSMIS) ice production. The comparison confirmed that the ice production from AMSR-E/2 data, which have higher spatial resolution than SSM/I-SSMIS data, can be used to analyze time series covering more than 10 years. For example, maps of annual ice production based on AMSR-E/2 data revealed detailed changes of the Mertz Polynya, where the ice production decreased significantly after the Mertz Glacier Tongue calving in 2010. Continuous monitoring of the coastal polynyas by the AMSR series sensors is essential for climate-change-related analyses in the Antarctic Ocean

Improvement of conditions for meshing spiral bevel gears

The effect of axial pinion displacement on gear meshing conditions during cutting and correction of the rolling chain gear ratio are analyzed. The so-called inverse problem-solving method is used

Keeping your eye on the rail: gaze behaviour of horse riders approaching a jump

The gaze behaviour of riders during their approach to a jump was investigated using a mobile eye tracking device (ASL Mobile Eye). The timing, frequency and duration of fixations on the jump and the percentage of time when their point of gaze (POG) was located elsewhere were assessed. Fixations were identified when the POG remained on the jump for 100 ms or longer. The jumping skill of experienced but non-elite riders (n=10) was assessed by means of a questionnaire. Their gaze behaviour was recorded as they completed a course of three identical jumps five times. The speed and timing of the approach was calculated. Gaze behaviour throughout the overall approach and during the last five strides before take-off was assessed following frame-by-frame analyses. Differences in relation to both round and jump number were found. Significantly longer was spent fixated on the jump during round 2, both during the overall approach and during the last five strides (p , 0.05). Jump 1 was fixated on significantly earlier and more frequently than jump 2 or 3 (p , 0.05). Significantly more errors were made with jump 3 than with jump 1 (p=0.01) but there was no difference in errors made between rounds

Simulated X-ray Cluster Temperature Maps

Temperature maps are presented of the 9 largest clusters in the mock catalogues of Muanwong et al. for both the Preheating and Radiative models. The maps show that clusters are not smooth, featureless systems, but contain a variety of substructure which should be observable. The surface brightness contours are generally elliptical and features that are seen include cold clumps, hot spiral features, and cold fronts. Profiles of emission-weighted temperature, surface brightness and emission-weighted pressure across the surface brightness discontinuities seen in one of the bimodal clusters are consistent with the cold front in Abell 2142 observed by Markevitch et al.Comment: Submitted to Monthly Notices Royal Astronomical Societ

Phenomenology: Exploring Women\u27s Experiences of First TIME IUD Insertion

Purpose: This study aims to explore Indonesian women\u27s experiences of first-time IUD insertion.Method: This study using phenomenological approach. Three Javanese women who lived in Malang Indonesia were interviewed using an unstructured process and the women\u27s native language was utilized. Soon after the interview, transcripts were translated from Indonesian into English, and phenomenological analysis of data was used.Result: The results revealed one major and three minor themes and identify embarrassment as the major contribution to women\u27s feelings of powerlessness. These feelings emerged because women experienced a lack of privacy during the insertion procedure. Women are vulnerable especially when there is no support received while facing a stressful medical procedure.Conclusion: Women need assistance from the health staff in order to deal with this traumatic experience. This improvement will includes the enhancement of clinic staff communication skills, the enrichment of health practice in providing better service and the upgrading of health policy that focuses on nurses/ doctors\u27 attitudes to give women-centered care