Vanguard: a new development in experimental astrobiology

Alex Ellery and David Wynn-Williams propose a new UK astrobiology project, in which a micro-rover would deploy ground-penetrating moles to burrow into the Martian subsurface.
One of the linchpins of the UK's contribution to the burgeoning field of astrobiology is the Beagle 2 mission, due to fly to Mars in 2003 on the Mars Express bus. Given that NASA has declared its intention to focus on "whole planet" geological investigation in its future Mars missions, beginning with the Mars Exploration Rovers which are due to fly in 2003/2004, the UK is well placed to consider post-Beagle 2 astrobiology-focused Mars missions to ensure its leadership in the future in astrobiology. In this paper we present such a proposal – Vanguard.     

International collaboration on marine bioinvasions--the ICES response

The International Council for the Exploration of the Sea (ICES) noted the risks associated with uncontrolled species introductions and transfers more than 40 years ago and launched two working groups to address the issue, i.e. the ICES Working Group on Introductions and Transfers of Marine Organisms (WGITMO) to deal with the movement of non-indigenous species for e.g. aquaculture purposes and the ICES/IOC/IMO Working Group on Ballast and Other Ship Vectors which focuses on species movements with ships. Both groups are actively working until today and the key achievements of the groups are outlined.     

Un exemple de collaboration internationale en hydrologie

Summary

Forecasts of the discharge of the Rhine at Basel have been studied in Zurich since 1954.

In this programme have cooperated hydro-power companies of Switzerland, Germany and France, French shipping-firms, and the Dutch water management authorities. For the Netherlands the forecast of the summer yield of the Rhine is of great concern, since it is the main resource of fresh water.

The studies have resulted in:

— since 1955, annual forecasts of the yield from snowmelt for periods of one to eight months beginning with March, and monthly and bi-monthly forecasts in winter

— since 1960, forecasts issued 2 to 5 times per week for the next three days, from October to March.

The forecast method is the least squares multiple regression, based on the observations of more than 50 years.

For the short term forecasts, the significant predictors are discharge and rainfall, eventually the snow cover percentage on the Swiss midland plateau. The largest errors of forecast were encountered in thawing conditions. Meteorological forecasts are provided by the Swiss Meteorological Institute.

For the long range forecasts, the alpine snow pack (in practice represented by the cumulative winter precipitations) and the levels of the Swiss lakes play an important role.

The forecasts are used by the hydro-power plants in their operation programmes for maintenance planning, and for proper timing of construction work.

In the future, the probability graduation of these forecasts will also be introduced in the optimisation of power production according to the methods of operations research.     

Environmental technology education: Models for international collaboration

International collaboration within environmental technology education is seen as one of the tools for an international dimension in the prevention and cure of environmental problems. Several different models for international collaboration have been found: researcher education, university-enterprise collaboration, summer universities, international organizations' activities, East-West and North-South university collaboration. International collaboration is found both within pollution prevention and pollution control. Tools found are: PhD programme, researcher course programme, student courses, student exchange, student-placement exchange in enterprise, university-university exchange, university-enterprise exchange, train-the-trainers activities, transfer of concepts, exchange of concepts, workshop and conferences, surveys and inventories, and working groups.     

Why utilities respect geomagnetically induced currents

It has been well known for more than 50 years that electric utilities in northern latitudes can have geomagnetically induced currents (GICs) flowing in their transmission lines and transformer ground points, and that these are caused by geomagnetic storms. Initially, these GICs were considered harmless and very little attention was paid to them. However, in the last 40 years it was realized that large GICs can flow in power systems and become problematic and even severe enough to cause a complete system shutdown. Utilities susceptible to GIC do not expect to rely on luck that the geomagnetic storm will not affect them, or if it does, the loading conditions at the time will allow enough margin to ride through it. This is precisely why many utilities today are studying the cause, effect, and mitigation of GICs and why utilities respect GICs. This paper presents a detailed discussion on how electric utilities are affected by GICs and what can be accomplished to mitigate the harmful effects.     

巨大地震的发生为什么总是出人意料

如果你依稀觉得,与为数众多的令人恐惧的大地震相比,科学预料总是迟到一步或与之相悖,那么你的感觉是正确的.2004年12月以来"特大"地震(8级或8级以上地震)的发生率大约是20世纪平均发生率的2.5倍.2004年12月26日苏门答腊-安达曼9.2级地震引发了毁灭性海啸,造成印度洋附近23万多人死亡.     

Displacement–acceleration control via stiffness–damping collaboration

An approach is presented to stiffness–damping simultaneous optimization for displacement–acceleration simultaneous control. To make a shear building model stiffer, the sum of mean-square interstorey drifts to stationary random excitations is minimized or the mean-square top-floor absolute acceleration is maximized subject to the constraints on total storey stiffness capacity and total damper capacity. Optimality conditions are derived and a two-step optimization method using the optimality conditions is devised. In the first step, the optimal design is found for a specified set of total storey stiffness capacity and total damper capacity. In the second step, a series of optimal designs is found with respect to a varied set of total storey stiffness capacity and total damper capacity. While increase of total stiffness capacity and increase of total damper capacity are both effective in reduction of deformation, only increase of total damper capacity is effective in reduction of acceleration. Acceleration control is carried out in the second step via increase of total damper capacity. It is shown through numerical examples that the proposed method is efficient and reliable. Copyright © 1999 John Wiley & Sons, Ltd.     

Why cone models can represent the elastic half-space

In lieu of the rigorous elastodynamical approach, many problems in foundation dynamics may be solved quite accurately via simple cone models of the soil. Although these cone models are amenable to very simple analysis, they have not yet been widely accepted in engineering practice. The reservations against their use are possibly due to the fact that cones are based on non-rigorous strength-of-materials assumptions, they neglect large portions of the half-space, and cannot represent Rayleigh surface waves. These potential objections are investigated step by step and proven to be unfounded. It turns out that cone models indeed incorporate and provide valuable insight into all the salient features of rigorous solutions; the aspects omitted by cones are revealed to be of minor physical importance.