Главная Случайная страница



List of topics for post-graduate exam

1. Мои научные интересы / мой исследовательский дипломный проект.

2. Глобальные проблемы и пути их решения (экологические, демографические и др.).

3. Современная система высшего образования в России (бакалавриат, магистратура, аспирантура).

4. СПбГПУ как научный центр. Мой факультет/ кафедра.

5. Актуальные научные события современного общества за последний год (присуждение почетных премий за достижения в науке и др.).

6. Исследования, открытия и инновации в странах изучаемого языка.

7. Исследования, открытия и инновации в России.

8. Перспективы работы по специальности.

    1. My scientific interests. My research diploma project.

Evolutionary dynamics of the Earth-Moon system

The aim of this work is to apply one of the little-known phenomena of the solid dynamics – their evolutionary behavior – due to the forces of internal dissipation to the description of the Earth-Moon system. In terrestrial systems these forces appear under free or induced vibrations of deformable bodies, accompanied by dissipation of energy due to mechanical hysteresis. Capacity of such dispersion is comparable to capacity of forces of external friction so process of dissipation is "fast" (duration of attenuation of free oscillations is estimated in tens periods of oscillations). A different mechanism of internal dissipation takes place in outer space, where there is no external friction, and activators of hysteresis phenomena in the body are the forces of inertia when it is non-uniform rotation, and also the external gravitational field, if present.

It is known that the distance between the Earth and the Moon is not constant but slowly changing time function. The question of the limit state of the system is interesting to be looked into, as the influence of the Moon on the life on the Earth can not be disregarded. It is proposed to use the model of the dissipative rigid body to describe the behavior of the Earth-Moon system.

At this stage, the problem of the effect on the energy dissipation of the field’s of volume forces and the forces of inertia changes over time in the case of two dissipative disks linked by a massless rod has been solved. The dissipation function, which allows deriving equations of motion with a small parameter at the highest (third) derivative of the generalized coordinates, has been designed. Numerical solution of these equations is a separate problem which was also solved successfully. The solution obtained showed that the model of a dissipative body is consistent and can be used in further studies.

To model the Earth-Moon system a similar problem but without a massless rod, which will allow the disks representing the Earth and the Moon to get either away from each other or close to each other, is to be considered. The solution will require rather complex numerical study as well as analytical work. Provided that at least 6 months and sufficient funding is given it is quite possible to approach to the answer of the question mentioned above.

    1. Global problems and ways of their solution

The debate about genetically modified crops rages on. Those excited about this new development claim that it’s the only way to solve the problem of food supply to parts of the world where at present people are dying of starvation. Special strains of plants can be created that are e.g. resistant to drought or to particularly high temperatures or certain pests, which allows them to flourish where other crops fail. At the same time, they say, chemical pesticides are no longer needed, so it’s better for environment too. Opponents are first and foremost worried about the unknown effects of GM food on our health. While in the short-term eating GM food appears to do no harm, it is not yet possible to predict how future generations may be affected. They also fear that even if GM crops are grown in clearly defined and fenced-off areas, seeds from GM plantations will unavoidably pollinate the surrounding vegetation, which may end up being genetically modified too. Playing around with genes, they argue, isn’t a game, and may result in untold damage to the human race and to the environment.

As medical science progresses, we are becoming an increasingly elderly society and, although living to a ripe old age can only be a good thing, it brings with it a large number of problems that we have yet to deal with properly. One such problem is that the burden of financing care for the elderly is falling on a reduced percentage of the working population. The gradual but steady trend towards smaller families means a smaller number of people to pay for the requirements of an increasingly elderly population. The services needed by the elderly are currently stretched to breaking point. Nursing homes, homecare, meals on wheels etc. all need more investment if we wish our elderly to live as fulfilled and independent life as possible. Young people today are encouraged to start saving with personal pension schemes as early as possible to ensure an adequately financed retirement, since it’s predicted that state pension levels in the future won’t be enough to guarantee a continuation of the lifestyle the have become used to, but at the moment we still have to cope with an expanding older population who are discovering too late that the steps they had taken to guarantee an income for their later years were not sufficient. Obviously, the pressure on public funds to subsidise this shortfall is enormous.

Последнее изменение этой страницы: 2016-08-11; просмотров: 300

lectmania.ru. Все права принадлежат авторам данных материалов. В случае нарушения авторского права напишите нам сюда...