A new source of renewable energy

Surplus and waste watermelons from farms harvests can be converted into energy now. 2.5 million gallons of clean, renewable ethanol fuel can be got from watermelons that are required for a year destined for your car, truck, or airplane's gas tank.

In United States, every year 360,000 tons of watermelons spoil in fields. Some local growers who are worried about this wondered whether the waste watermelons can be turned into ethanol, the clean-burning fuel derived from plant sugars. In a sequence of new experiments that was published in the journal Biotechnology for Biofuels, Fish and his team showed that they can.

Smog causes serious health problems.

Poor air quality is harmful to health. The primary target is the respiratory system, but air pollution also targets the heart and the immune system. Particle pollution poses particular risks to the cardiac system.

Sources of smog include:

• Nitrogen Oxides (NOx) come almost entirely from man-made sources: combustion of fuels in cars and trucks, coal-fired power plants, industrial boilers and gas-powered engines such as lawnmowers and leaf blowers. This occurs because nitrogen gas -- which accounts for about 80% of air -- also burns (oxidizes) when other fuels are burned.

• Volatile organic compounds (VOCs) are vapors that emanate from paint and print shops, gas stations, dry cleaners, lawn chemicals, and from combustion engines, such as those in cars and trucks, boats and diesel locomotives. Trees also release VOCs.

• Particle pollution, or particulate matter (PM), consists of a mixture of extremely small solids and liquid droplets that typically includes aerosols and fine solids, such as dust and soot. Sources include all types of combustion, including vehicle exhaust, power plants, wood burning, construction activity and agriculture.

Causes of tornadoes

Thunderstorms develop in warm, moist air in advance of eastward-moving cold fronts. These thunderstorms often produce large hail, strong winds, and tornadoes. Tornadoes in the winter and early spring are often associated with strong, frontal systems that form in the Central States and move east. Occasionally, large outbreaks of tornadoes occur with this type of weather pattern. Several states may be affected by numerous severe thunderstorms and tornadoes.

During the spring in the Central Plains, thunderstorms frequently develop along a "dryline," which separates very warm, moist air to the east from hot, dry air to the west. Tornado-producing thunderstorms may form as the dryline moves east during the afternoon hours.

Along the front range of the Rocky Mountains, in the Texas panhandle, and in the southern High Plains, thunderstorms frequently form as air near the ground flows "upslope" toward higher terrain. If other favorable conditions exist, these thunderstorms can produce tornadoes.

Tornadoes occasionally accompany tropical storms and hurricanes that move over land. Tornadoes are most common to the right and ahead of the path of the storm center as it comes onshore.

Working of satellites

A satellite works by receiving radio signals sent from the Earth and resending the radio signals back down to the Earth. In a simple system, a signal is reflected, or "bounced," off the satellite. For example, it is possible to bounce a signal off the surface of the Moon back down to Earth. Because the Moon is very far away, for this to work the signal from the Earth must be very strong and the receiver receiving the signal must be sensitive enough to detect the very weak signal receive back from the moon.

Unlike a passive satellite such as the moon or the early ECHO satellite, a modern communications satellite receives the radio signal and sends it back down to Earth stronger than it was received. This process is called "amplification" of the radio signal. In addition to amplifying the signal, a communications satellite also typically converts the radio from one frequency to another so that the signal getting sent down is not confused with the signal being sent up.

The Green Dinosaur

The Green Dinosaur is one of the common names for this tree, also known as Ribbonwood and Idiot Fruit. It has its own interesting story of life, extinction and rebirth as well as an unsolved mystery!

The Ribbonwood tree (Idiospermum australiense) is a relic species and has a most unusual characteristic which sets it apart from modern plants. All modern flowering plants produce seeds which have either one seed leaf (monocots) or two seed leaves (dicots) but the seeds of the Idiospermum can have between 2 to 6 seed leaves! Normally seeds will germinate and send up a single shoot but the Ribbonwood can sprout more than one shoot per seed. The fruit is large at 80mm (just over 3 inches) and globular, splitting into four segments on the ground. The red, spirally arranged flowers are also another indication of its primitiveness.

The Green Dinosaur was located in the late 1800's by timber cutters south of Cairns who brought it to the attention of a German botanist named Diels. By the time Diels returned to the spot where this tree was found, they had been clearfelled for sugarcane (one of the principal commercial crops of north Queensland). It was believed to be gone forever. However, in 1971, the species was rediscovered - not because someone identified the tree from its unusual tree-ring pattern - but because its fruit was turning up in the stomachs of dead cattle! We now know that its fruit is toxic.

There is another intriguing aspect to the Ribbonwood tree and that is how its seeds are dispersed. The successful continuance of most rainforest species depends on their seeds being dispersed away from the parent plant. The Green Dinosaur's seeds are large, heavy, do not float and are too poisonous for most animals to eat. Gravity dispersal may be why the Ribbonwood tree is only found in very wet lowland rainforest in very few locations.

Future Climate Change

Greenhouse gas concentrations in the atmosphere will increase during the next century unless greenhouse gas emissions decrease substantially from present levels. Increased greenhouse gas concentrations are very likely to raise the Earth's average temperature, influence precipitation and some storm patterns as well as raise sea levels (IPCC, 2007). The magnitude of these changes, however, is uncertain.

The amount and speed of future climate change will ultimately depend on:

• Whether greenhouse gases and aerosol concentrations increase, stay the same or decrease.

• How strongly features of the climate (e.g. temperature, precipitation and sea level) respond to changes in greenhouse gas and aerosol concentrations.

• How much the climate varies as a result of natural influences (e.g. from volcanic activity and changes in the sun’s intensity) and its internal variability (referring to random changes in the circulation of the atmosphere and oceans).