Month: May 2020

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Sri Lanka elected as Chair of the Seventh Asia Pacific Forum on Sustainable Development (APFSD), in Bangkok

The Seventh Asia Pacific Forum on Sustainable Development (APFSD) held on 20th May in Bangkok-Thailand, was convened as a virtual meeting for the first time, complying with the ‘new normal’ in the COVID 19 context, and Sri Lanka’s Permanent Representative to the United Nations Economic and Social Council for Asia and the Pacific (UNESCAP), H.E. (Mrs.) Samantha K. Jayasuriya, Ambassador of Sri Lanka to Thailand, was elected by acclamation as the Chair of 7th APFSD and will serve for a period of one year.

The 7th APFSD was held under the theme ‘Accelerating action for and delivery of the 2030 Agenda in Asia and the Pacific’. Recalling that the UN has declared a ‘Decade of Action’ in realizing the 2030 Agenda, Ambassador Jayasuriya, addressing the Opening Session underscored the importance of multi-stakeholder partnerships and well coordinated response at national, and regional levels, including with all institutions and all members of society, as well as from the multilateral cooperation framework, in moving forward.

Joining the Opening Session online from New York was the United Nations Deputy Secretary-General Amina J. Mohammed, and the United Nations Under-Secretary-General and Executive Secretary of ESCAP Ms. Armida Salsiah Alisjahbana, and H.E. Mr. Don Pramudwinai, Minister of Foreign Affairs, Thailand, also addressed the Session. The speakers highlighted the need to change the challenges posed by COVID-19 crisis into new opportunities. They suggested on enhanced investments in social protection and health care, developing economic models aiming at green jobs, leveraging on innovations to advance technology based solutions while bridging the digital divide and enhancing scientific cooperation in the Asia Pacific Region etc.

Joining from Colombo, Dr. Sugath Yalegama, Director General of the Sustainable Development Council of Sri Lanka shared Sri Lanka’s responses to contain the COVID 19 and actions taken in accelerating progress on the 2030 Agenda for Sustainable Development. Emphasizing the necessity and importance of focusing on immediate and medium term strategies, in the post COVID 19 context, he also highlighted that the new realities need to be incorporated into the goals and targets of 2030 Agenda.

The Session was joined online by over 730 participants representing member States, major stake holders, civil society and NGOs, and was declared opened by H.E. Fidelis Magalhães, Minister for Legislative Reforms and Parliamentary Affairs of the Democratic Republic of Timor-Leste, as the outgoing Chair of the 6th APFSD. The annual Asia-Pacific Forum on Sustainable Development (APFSD) is an inclusive intergovernmental forum and a regional platform for supporting countries, in particular those with special needs, in the implementation of the 2030 Agenda for Sustainable Development.

Ms. Shiranthi Ratnayake, Additional Director General, National Planning Department, Ms. Samanthi Senanayake, Director and Ms. Sheron Hewawaduge, Assistant Director, Sustainable Development Council of Sri Lanka joined virtually from Colombo, and Mrs. Poornima Gunasekera, Head of Chancery, Mr. Anil Sirimanna, Counsellor (Commerce), and Ms. Saritha Ranatunga, Second Secretary of the Sri Lanka Mission in Bangkok also represented the GOSL delegation to the 7th APFSD.

 

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ROCKET PROPELLANTS

Propellant is the chemical mixture burned to produce thrust in rockets and consists of a fuel and an oxidizer. A fuel is a substance that burns when combined with oxygen producing gas for propulsion. An oxidizer is an agent that releases oxygen for combination with a fuel. The ratio of oxidizer to fuel is called the mixture ratio. Propellants are classified according to their state – liquid, solid, or hybrid.
The gauge for rating the efficiency of rocket propellants is specific impulse, stated in seconds. Specific impulse indicates how many pounds (or kilograms) of thrust are obtained by the consumption of one pound (or kilogram) of propellant in one second. Specific impulse is characteristic of the type of propellant, however, its exact value will vary to some extent with the operating conditions and design of the rocket engine.

Liquid Propellants

In a liquid propellant rocket, the fuel and oxidizer are stored in separate tanks, and are fed through a system of pipes, valves, and turbopumps to a combustion chamber where they are combined and burned to produce thrust. Liquid propellant engines are more complex than their solid propellant counterparts, however, they offer several advantages. By controlling the flow of propellant to the combustion chamber, the engine can be throttled, stopped, or restarted.

A good liquid propellant is one with a high specific impulse or, stated another way, one with a high speed of exhaust gas ejection. This implies a high combustion temperature and exhaust gases with small molecular weights. However, there is another important factor that must be taken into consideration: the density of the propellant. Using low-density propellants means that larger storage tanks will be required, thus increasing the mass of the launch vehicle. Storage temperature is also important. A propellant with a low storage temperature, i.e. a cryogenic, will require thermal insulation, thus further increasing the mass of the launcher. The toxicity of the propellant is likewise important. Safety hazards exist when handling, transporting, and storing highly toxic compounds. Also, some propellants are very corrosive; however, materials that are resistant to certain propellants have been identified for use in rocket construction.

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