Rising Surface Ozone Reduces Plant Growth And Adds To Global Warming

Increasing ozone near the Earth's surface could lead to significant reductions in regional plant production and crop yields.

Scientists from three leading UK research institutes have just released new findings that could have major implications for food production and global warming in the 21st century.

Experts from the Met Office, the University of Exeter and the Centre for Ecology & Hydrology, have found that projections of increasing ozone near the Earth's surface could lead to significant reductions in regional plant production and crop yields. Surface ozone also damages plants, affecting their ability to soak up carbon dioxide from the atmosphere and accelerating global warming.
Near-surface ozone has doubled since 1850 due to chemical emissions from vehicles, industrial processes, and the burning of forests. Dr Stephen Sitch, a climate impacts scientist at the Met Office Hadley Centre and lead author of the article, said: "Climate models have largely ignored atmospheric chemistry but in this research we have identified a cause of potentially increased warming with elevated levels of surface ozone likely to suppress plant growth."
Plants and soil are currently slowing--down global warming by storing about a quarter of human carbon dioxide emissions, but the new study suggests that this could be undermined by further increases in near-surface ozone. As a result more carbon dioxide would accumulate in the atmosphere and add to global warming. Co-author, Professor Peter Cox of the University of Exeter, explains: "We estimate that ozone effects on plants could double the importance of ozone increases in the lower atmosphere as a driver of climate change, so policies to limit increases in near-surface ozone must be seen as an even higher priority."
The research is published online in Nature July 25, 2007

GLOBAL WARMING

Global warming is 'irreversible'



The scientists concluded global temperatures could remain high for 1,000 years, even if carbon emissions can somehow be halted.
Their report was sponsored by the US Department of Energy and comes as President Obama announces a review of vehicle emission standards.
It appears in the journal Proceedings of the National Academy of Sciences.
The scientists have been researching global warming and the consequences for policymakers. The team warned that, if carbon levels in the atmosphere continued to rise, there would be less rainfall in already dry areas of southern Europe, North America, parts of Africa and Australia.
The scientists say the oceans are currently slowing down global warming by absorbing heat, but they will eventually release that heat back into the air.
They say politicians must now offset environmental damage already done by man-made pollution.
"People have imagined that if we stopped emitting carbon dioxide the climate would go back to normal in 100 years, 200 year - that's not true," said researcher Susan Solomon, the lead author of the report, quoted by AP news agency.
Their conclusions come as President Obama ordered the US Environmental Protection Agency to review rules on carbon emissions from passenger vehicles

Higher River Levels Predicted As More Carbon Dioxide Makes Plants Less Thirsty

Higher River Levels Predicted As More Carbon Dioxide Makes Plants Less Thirsty

Rising carbon dioxide levels will increase river levels in the future, according to a team of scientists from the Met Office Hadley Centre, the University of Exeter and the Centre for Ecology & Hydrology.

The findings, published on 30 August 2007 in the journal Nature, suggest that increasing carbon dioxide will cause plants to extract less water from the soil, leaving more water to drain into rivers which will add to the river flow increases already expected due to climate change.
Last year, members of the research team showed that this effect can already be seen in historical river flow records.
This new study shows that the effect of plant responses to carbon dioxide could be as important as those of increased rainfall due to man-made climate change.

CBSE SCIENCE MODEL QUESTION 10th STD

CBSE - SCIENCE

X – SECTION – A

PHYSICS AND CHEMISTRY


1. What is meant by the statement, “ potential difference between points A and B in an electric field is 1 volt.

2. Refractive index of media A, B, C and D are

i. A 1.33
ii. B 1.52
iii C 1.44
iv D 1.65
In which of the four media is the speed of light (i) maximum (ii) minimum.

3.What sign convention has been given to the focal length of a convex mirror

4.During summer season, a milkman usually adds a very small amount of baking soda to fresh milk. Give one reason.

5.What is the colour of phenolphthalein indicator in an acidic solution.

6.Why does magnesium powder react much more rapidly than magnesium ribbon with dil.H2SO4

7.A student performs an experiment to study the magnetic effect of current around a current carrying straight conductor. He reports that the direction of deflection of the north pole of a compass needle kept at a given point near the conductor remains unaffected even when the terminals of the battery sending current in the wire are inter changed.for a given battery, the degree of deflection of a N-pole decreases when the compass is kept at a point farther away from the conductor.Which of the above observations of the student is incorrect and why?

8. What is the meaning of the term ‘frequency’ of an alternating current?What is value in India?
Why is an alternating current considered to be advantageous over direct current for long
range transmission of electric energy?

9. What are the two major shortcomings of Mendeleev’s periodic table? How have
these been removed in the modern periodic table?

10.Give reasons for the following.
i) Metals are regarded as electropositive elements.
ii) Articles made of Aluminium donot corrode even though Al is an active metal.

11.Draw the electron dot structures of ethane, ethene, and ethyne molecule.

12. Give reasons for the following.
Why do unsaturated hydrocarbons show addition reactions.
Why is the conversion of ethanol to ethanoic acid an oxidation reaction.
Alcohol supplied for industrial purposes is mixed with CuSO4

13. i. State Ohm’s law.
ii. Draw a schematic diagram of the circuit for studying ohm’s law
A wire of length L and resistance R is stretched so that its length is doubled and area of cross section is halved. How will its
i. resistance change, ii. Resistivity change.

14. A 14 year student is not able to see clearly the questions written on the black board placed at a distance of 5m from him.
Name the defect of vision he is suffering from.
With the help of labeled ray diagrams show how this defect can be corrected.
Name the type of lens used to correct this defect



15. Explain the construction and working of a electric motor.

OR

Give reasons for the following
:
i)The sky appears to be blue during day time to a person on earth.
ii) The sky near the horizon appears to have a reddish heu at the time of sunset and sunrise
iii) The sky appears dark instead of blue to an astronaut.
iv) The stars appears to twinkle
(v) The planets do not twinkle.







16. You are given the following materials:
Iron nails
Copper sulphate solution
Barium chloride solution
Copper powder
Ferrous sulphate crystals
Quick Lime

Identify the type of chemical reaction taking place when.

(a) Barium chloride solution is mixed with copper sulphate solution and a white
precipitate is observed.
(b) On heating copper powder in air in a China dish, the surface of copper powder
turns black.
(c) On heating green coloured ferrous sulphate crystals, reddish brown solid is left and smell of a gas having odour of burning sulphur is experienced.
(d) Iron nails when left dipped in blue copper sulphate solution become brownish in colour and the blue colour of copper sulphate fades away.
(e) Quick lime reacts vigorously with water releasing a large amount of heat.

OR
Four metals A, B, C and D are, in turn, added to the following solutions one by one. The observations made are tabulatd below:


Answer the following questions based on above information.
(i) Which is the most active metal and why? (ii) What would be observed if B is added to a solution of copper (II) sulphate and why?
(iii) Arrange the metals A, B, C and D in order of increasing reactivity.
(iv) Container of which metal can be used to store both zinc sulphate solution and
silver nitrate solution.
(v) Which of the above solutions can be easily stored in a container made up of any of
these metals?

CHANDRAYAAN-1

CHANDRAYAAN-1

The primary objectives of Chandrayaan-1 are:

1. To expand scientific knowledge about the moon

2. To upgrade India's technological capability

3. To provide challenging opportunities for planetaryresearch to the younger generation of Indian scientists

Record High Performance With New Solar Cells

Researchers in China and Switzerland are reporting the highest efficiency ever for a promising new genre of solar cells, which many scientists think offer the best hope for making the sun a mainstay source of energy in the future. The photovoltaic cells, called dye-sensitized solar cells or Grätzel cells, could expand the use of solar energy for homes, businesses, and other practical applications, the scientists say.
The research, conducted by Peng Wang and colleagues — who include Michael Grätzel, inventor of the first dye-sensitized solar cell — involves photovoltaic cells composed of titanium dioxide and powerful light-harvesting dyes. Grätzel cells are less expensive than standard silicon-based solar cells and can be made into flexible sheets or coatings.

Although promising, Grätzel cells until now have had serious drawbacks. They have not been efficient enough at converting light into electricity. And their performance dropped after relatively short exposures to sunlight.

In the new study, researchers describe lab tests of solar cells made with a new type of ruthenium-based dye that helps boost the light-harvesting ability. The new cells showed efficiencies as high as 10 percent, a record for this type of solar cell. The new cells also showed greater stability at high temperatures than previous formulas, retaining more than 90 percent of their initial output after 1,000 hours in full sunlight.

INDIAN SPACE RESEARCH

INDIAN SPACE PROGRAMMES -- 2008 -- 1962


2008


PSLV-C9 successfully launches CARTOSAT-2A, IMS-1 and 8 foreign nano satellites from Sriharikota (April 28, 2008).

PSLV-C10 successfully launches TECSAR satellite under a commercial contract with Antrix Corporation (January 21, 2008).


2007


Successful launch of of GSLV (GSLV-F04) with INSAT-4CR on board from SDSC SHAR (September 2, 2007).

ISRO's Polar Satellite Launch Vehicle, PSLV-C8, successfully launched Italian astronomical satellite, AGILE from Sriharikota (April 23, 2007).

Successful launch of INSAT-4B by Ariane-5 from Kourou French Guyana, (March 12, 2007).

Successful recovery of SRE-1 after manoeuvring it to reenter the earth’s atmosphere and descend over the Bay of Bengal about 140 km east of Sriharikota (January 22, 2007).

ISRO's Polar Satellite Launch Vehicle, PSLV-C7 successfully launches four satellites - India’s CARTOSAT-2 and Space Capsule Recovery Experiment (SRE-1) and Indonesia’s LAPAN-TUBSAT and Argentina’s PEHUENSAT-1 (January 10, 2007).


2006



Second operational flight of GSLV (GSLV-F02) from SDSC SHAR with INSAT-4C on board. (July 10, 2006). Satellite could not be placed in orbit.


2005



Successful launch of INSAT-4A by Ariane from Kourou French Guyana, (December 22, 2005).

ISRO's Polar Satellite Launch Vehicle, PSLV-C6, successfully launched

CARTOSAT-1 and HAMSAT satellites from Sriharikota(May 5, 2005).


2004



The first operational flight of GSLV (GSLV-F01) successfully launched EDUSAT from SDSC SHAR, Sriharikota (September 20, 2004)


2003


ISRO's Polar Satellite Launch Vehicle, PSLV-C5, successfully launched RESOURCESAT-1 (IRS-P6) satellite from Sriharikota(October 17, 2003).

Successful launch of INSAT-3E by Ariane from Kourou French Guyana, (September 28, 2003).

The Second developmental launch of GSLV-D2 with GSAT-2 on board from Sriharikota (May 8, 2003).

Successful launch of INSAT-3A by Ariane from Kourou French Guyana, (April 10, 2003).


2002


ISRO's Polar Satellite Launch Vehicle, PSLV-C4, successfully launched KALPANA-1 satellite from Sriharikota(September 12, 2002).

Successful launch of INSAT-3C by Ariane from Kourou French Guyana, (January 24, 2002).


2001


ISRO's Polar Satellite Launch Vehicle, PSLV-C3, successfully launched three satellites -- Technology Experiment Satellite (TES) of ISRO, BIRD of Germany and PROBA of Belgium - into their intended orbits (October 22, 2001).

The first developmental launch of GSLV-D1 with GSAT-1 on board from Sriharikota (April 18, 2001)


2000


INSAT-3B, the first satellite in the third generation INSAT-3 series, launched by Ariane from Kourou French Guyana,(March 22, 2000).


1999


Indian Remote Sensing Satellite, IRS-P4 (OCEANSAT), launched by Polar Satellite Launch Vehicle (PSLV-C2) along with Korean KITSAT-3 and German DLR-TUBSAT from Sriharikota (May 26, 1999).

INSAT-2E, the last satellite in the multipurpose INSAT-2 series, launched by Ariane from Kourou French Guyana, (April 3, 1999).


1998


INSAT system capacity augmented with the readiness of INSAT-2DT acquired from ARABSAT (January 1998).


1997


INSAT-2D, fourth satellite in the INSAT series, launched (June 4, 1997). Becomes inoperable on October 4, 1997. (An in-orbit satellite, ARABSAT-1C, since renamed INSAT-2DT, was acquired in November 1997 to partly augment the INSAT system).

First operational launch of PSLV with IRS-1D on board (September 29, 1997). Satellite placed in orbit.


1996


Third developmental launch of PSLV with IRS-P3 on board (March 21, 1996). Satellite placed in polar sunsynchronous orbit.


1995


Launch of third operational Indian Remote Sensing Satellite, IRS-1C (December 28, 1995).

INSAT-2C, the third satellite in the INSAT-2 series, launched (December 7, 1995).


1994


Second developmental launch of PSLV with IRS-P2 on board (October 15, 1994). Satellite successfully placed in polar sunsynchronous orbit.

Fourth developmental launch of ASLV with SROSS-C2 on board (May 4, 1994). Satellite placed in orbit.


1993


First developmental launch of PSLV with IRS-1E on board (September 20, 1993). Satellite could not be placed in orbit.

INSAT-2B, the second satellite in the INSAT-2 series, launched (July 23, 1993).


1992


INSAT-2A, the first satellite of the indigenously-built second-generation INSAT series, launched (July 10, 1992).

Third developmental launch of ASLV with SROSS-C on board (May 20, 1992). Satellite placed in orbit.


1991


Second operational Remote Sensing satellite, IRS-1B, launched (August 29, 1991).


1990


INSAT-1D launched (June 12, 1990).


1988


INSAT-1C launched (July 21, 1988). Abandoned in November 1989.

Second developmental launch of ASLV with SROSS-2 on board (July 13, 1988). Satellite could not be placed in orbit.

Launch of first operational Indian Remote Sensing Satellite, IRS-1A (March 17, 1988).


1987


First developmental launch of ASLV with SROSS-1 satellite on board (March 24, 1987). Satellite could not be placed in orbit.


1984


Indo-Soviet manned space mission (April 1984).


1983


INSAT-1B, launched (August 30, 1983).
Second developmental launch of SLV-3. RS-D2 placed in orbit (April 17, 1983).


1982


INSAT-1A launched (April 10, 1982). Deactivated on September 6, 1982.


1981


Bhaskara-II launched (November 20, 1981).

APPLE, an experimental geo-stationary communication satellite successfully launched (June 19, 1981).

RS-D1 placed in orbit (May 31, 1981)

First developmental launch of SLV-3.


1980


Second Experimental launch of SLV-3, Rohini satellite successfully placed in orbit. (July 18, 1980).


1979


First Experimental launch of SLV-3 with Rohini Technology Payload on board (August 10, 1979). Satellite could not be placed in orbit.

Bhaskara-I, an experimental satellite for earth observations, launched (June 7, 1979).


1977


Satellite Telecommunication Experiments Project (STEP) carried out.


1975-1976


Satellite Instructional Television Experiment (SITE) conducted.


1975


ISRO First Indian Satellite, Aryabhata, launched (April 19, 1975).

Becomes Government Organisation (April 1, 1975).


1972-1976


Air-borne remote sensing experiments.


1972


Space Commission and Department of Space set up (June 1, 1972). ISRO brought under DOS.


1969


Indian Space Research Organisation (ISRO) formed under Department of Atomic Energy (August 15, 1969).


1968


TERLS dedicated to the United Nations (February 2, 1968).


1967


Satellite Telecommunication Earth Station set up at Ahmedabad.


1965


Space Science & Technology Centre (SSTC) established in Thumba.


1963


First sounding rocket launched from TERLS (November 21, 1963).


1962


Indian National Committee for Space Research (INCOSPAR) formed by the Department of Atomic Energy and work on establishing Thumba Equatorial Rocket Launching Station (TERLS) started.