Renewable energy sources – including biomass, geothermal, ocean, solar, and wind energy, as well as hydropower – have a huge potential to provide energy services for the world. The renewable energy resource base is sufficient to meet several times the present world energy demand and potentially even 10 to 100 times this demand. This chapter includes an in-depth examination of technologies to convert these renewable energy sources to energy carriers that can be used to fulfill our energy needs, including their installed capacity, the amount of energy carriers they produced in 2009, the current state of market and technology development, their economic and financial feasibility in 2009 and in the near future, as well as major issues they may face relative to their sustainability or implementation.
Present uses of renewable energy
Since 1990 the energy provided from renewable sources worldwide has risen at an average rate of nearly 2% a year, but in recent years this rate has increased to about 5% annually (see Figure 11.1.) As a result, the global contribution of renewables has increased from about 74 EJ in 2005 to about 89 EJ in 2009 and represents now 17% of global primary energy supply (528 EJ, see Figure 11.2). Most of this renewable energy comes from the traditional use of biomass (about 39 EJ) and larger-scale hydropower (about 30 EJ), while other renewable technologies provided about 20 EJ.
Many children show traits of behaving in an impulsive, inattentive and restless fashion. These behaviours, when not severe, need not constitute a problem. When extreme, however, they present a risk for the psychological development of the individual. Severe levels of ‘hyperactivity’ (the combination of impulsiveness, restlessness and overactivity) make children more likely to develop an antisocial adjustment, and more likely to show various aspects of personality dysfunction in later adolescence and adult life. Children's hyperactivity can also be very unpleasant for the caregivers. Both teachers and parents can find it hard to live with a hyperactive child, and their tolerance and ability to cope may determine whether it is presented as a problem. Children with hyperactivity rarely ask for help themselves, and are often not aware of a problem. The presentation to the clinician is therefore a complex blend of the skills and tolerance of adults surrounding the child and the qualities of the children themselves. They constitute the commonest reason for referral to child mental health or behavioural paediatric services in many countries. Effective physical and psychological treatments are available, and the management needs to be long term. Hyperactive behaviour problems therefore make up a large part of the work of most community mental health services for children.
Definition and classification
ICD 10 criteria
The ICD-10 definition of hyperkinetic disorder is based upon the simultaneous presence of all three main behavioural problems: attention deficit, overactivity and impulsiveness.
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