Optimum sizing of bare-tape tethers for de-orbiting satellites at end of mission

De-orbiting satellites at end of mission would prevent generation of new space debris. A proposed de-orbit technology involves a bare conductive tape-tether, which uses neither propellant nor power supply while generating power for on-board use during de-orbiting. The present work shows how to select tape dimensions for a generic mission so as to satisfy requirements of very small tether-to-satellite mass ratio mt/MS and probability Nf of tether cut by small debris, while keeping de-orbit time tf short and product tf ×× tether length low to reduce maneuvers in avoiding collisions with large debris. Design is here discussed for particular missions (initial orbit of 720 km altitude and 63° and 92° inclinations, and 3 disparate MS values, 37.5, 375, and 3750 kg), proving it scalable. At mid-inclination and a mass-ratio of a few percent, de-orbit time takes about 2 weeks and Nf is a small fraction of 1%, with tape dimensions ranging from 1 to 6 cm, 10 to 54 μμm, and 2.8 to 8.6 km. Performance drop from middle to high inclination proved moderate: if allowing for twice as large mt/MS, increases are reduced to a factor of 4 in tf and a slight one in Nf, except for multi-ton satellites, somewhat more requiring because efficient orbital-motion-limited electron collection restricts tape-width values, resulting in tape length (slightly) increasing too.

The Berlin Republic and the real end of the post-war era. OSW Commentary No. 67, 2011-12-07

In the post-war era, Germany has undergone a deep change almost like clockwork every two decades. In 1949, the foundations were laid for the establishment of the two German states: the Federal Republic of Germany and the German Democratic Republic; 1968–1969 was the time of the student revolt as a harbinger of the democratisation and liberalisation of society; and in 1989–1990, the process of unification took place, with all its consequences. Two decades later, another deep revision of the values is happening, as a consequence of which Germany is bidding a final farewell to the post-war epoch and its inherent certainties: its advancing society, the homogeneous national state and the faith in Europe as a solution to the ‘German question.’ This revision will not be revolutionary. However, as with the previous turning points, Germany is becoming a different state and a different society, which Europe will have to build its relations with anew.

The end of fiscal waterboarding? CEPS Commentary, 23 February 2015

In this Commentary, Daniel Gros argues that linking the primary surplus demanded of the new Greek government to the state of the economy is a sound approach. Some flexibility is warranted on this account, but the concept should be used to distribute the effort better over time, not to wriggle out of it.

Regulation on ‘cross-border portability’ of online content services: Roaming for Netflix or the end of copyright territoriality? CEPS Commentary, 15 February 2016

In a communication to the Parliament and the Council entitled “Towards a modern, more European copyright framework” and dated 9 December 2015,1 the European Commission confirmed its intention to progressively remove the main obstacles to the functioning of the Digital Single Market for copyrighted works. The first step of this long-term plan, which was first announced in Juncker’s Political Guidelines2 and the Communication on “A Digital Single Market strategy for Europe”,3 is a proposal for a regulation aimed at ensuring the so-called ‘cross-border portability’ of online services giving access to content such as music, games, films and sporting events.4 In a nutshell, the proposed regulation seeks to enable consumers with legal access to such online content services in their country of residence to use the same services also when they are in another member state for a limited period of time. On the one hand, this legislative proposal has the full potential to resolve the (limited) issue of portability, which stems from the national dimension of copyright and the persisting territorial licensing and distribution of copyright content.5 On the other hand, as this commentary shows, the ambiguity of certain important provisions in the proposed regulation might affect its scope and effectiveness and contribute to the erosion of the principle of copyright territoriality.

The end of globalisation? CEPS Commentary, 10 March 2016

China has just announced that its exports declined on an annual basis last year, for the first time since the country began opening up its economy to the world at the end of the 1970s. And that is not all; in value terms, global trade declined in 2015. The obvious question is why?

The American cottage cookery-book, or, Housekeeping made easy, pleasant and economical in all its departments : the result of many years' practical experience and observation, and designed as a reliable aid to those who study economy of time and materials /

Includes sections on food preparation, cooking for the sick, and household hints; some recipes include wine or liquor as an ingredient. Sample recipes: Alamode beef, Cold slaw, Little plum cakes that will keep a year, Currant jelly.

The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability

Purpose: To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability. Methods: Thirty-nine subjects (22.1. ±. 3.5 years) were randomised to wear each of 3 silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for one week. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16. h after lens insertion. Hyperaemia, non-invasive tear break-up time, tear meniscus height and comfort were also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal. Results: Lens fit assessments were not different between brands (P > 0.05), with the exception of the movement at blink where narafilcon A was more mobile. Overall, lag reduced but push-up speed increased from 8 to 12. h (P <. 0.05), but remained stable from 12 to 16. h (P > 0.05). Movement-on-blink was unaffected by wear-time (F = 0.403, P = 0.670). A more mobile lens fit with one brand did not indicate that person would have a more mobile fit with another brand (r = -0.06 to 0.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (P > 0.01). Conclusions: Among the lenses tested, objective lens fit changed between 8. h and 12. h of lens wear. The weak correlation in individual lens fit between brands indicates that fit is dependent on more than ocular shape. Consequently, substitution of a different lens brand with similar parameters will not necessarily provide comparable lens fit.

Concentrations of major and minor constituents of samples from the lower end of the cores from the eastern Mediterranean Sea (Table 2)

The pore water chemistry of mud volcanoes from the Olimpi Mud Volcano Field and the Anaximander Mountains in the eastern Mediterranean Sea have been studied for three major purposes: (1) modes and velocities of fluid transport were derived to assess the role of (upward) advection, and bioirrigation for benthic fluxes. (2) Differences in the fluid chemistry at sites of Milano mud volcano (Olimpi area) were compiled in a map to illustrate the spatial heterogeneity reflecting differences in fluid origin and transport in discrete conduits in near proximity. (3) Formation water temperatures of seeping fluids were calculated from theoretical geothermometers to predict the depth of fluid origin and geochemical reactions in the deeper subsurface. No indications for downward advection as required for convection cells have been found. Instead, measured pore water profiles have been simulated successfully by accounting for upward advection and bioirrigation. Advective flow velocities are found to be generally moderate (3-50 cm/y) compared to other cold seep areas. Depth-integrated rates of bioirrigation are 1-2 orders of magnitude higher than advective flow velocities documenting the importance of bioirrigation for flux considerations in surface sediments. Calculated formation water temperatures from the Anaximander Mountains are in the range of 80 to 145 °C suggesting a fluid origin from a depth zone associated with the seismic decollement. It is proposed that at that depth clay mineral dehydration leads to the formation and advection of fluids reduced in salinity relative to sea water. This explains the ubiquitous pore water freshening observed in surface sediments of the Anaximander Mountain area. Multiple fluid sources and formation water temperatures of 55 to 80 °C were derived for expelled fluids of the Olimpi area.

Radiocarbon dating, oxygen isotopes, and sea-level reconstruction of sediment core GeoB5844-2 from the northern end of the Red Sea

Based on a radiocarbon and paleomagnetically dated sediment record from the northern Red Sea and the exceptional sensitivity of the regional changes in the oxygen isotope composition of sea water to the sea-level-dependent water exchange with the Indian Ocean, we provide a new global sea-level reconstruction spanning the last glacial period. The sea-level record has been extracted from the temperature-corrected benthic stable oxygen isotopes using coral-based sea-level data as constraints for the sea-level/oxygen isotope relationship. Although, the general features of this millennial-scale sea-level records have strong similarities to the rather symmetric and gradual Southern Hemisphere climate patterns, we observe, in constrast to previous findings, pronounced sea level rises of up to 25 m to generally correspond with Northern Hemisphere warmings as recorded in Greenland ice-core interstadial intervals whereas sea-level lowstands mostly occur during cold phases. Corroborated by CLIMBER-2 model results, the close connection of millennial-scale sea-level changes to Northern Hemisphere temperature variations indicates a primary climatic control on the mass balance of the major Northern Hemisphere ice sheets and does not require a considerable Antarctic contribution.