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Archive for December, 2010

Some FORTRAN Subroutines

Posted by Syeilendra Pramuditya on December 30, 2010

Shortlink: http://wp.me/p61TQ-zb

Some standard libraries:

Some compact subroutines:

  • [ download ] MATINV – Subroutine for matrix inversion
  • [ download ] GETDET – Function to calculate matrix determinant
  • [ download ] TRIDAG – Subroutine to solve tridiagonal matrix system (source | mirror)
  • [ download ] MATMTP – Subroutine for matrix multiplication
  • [ download ] JACOBI – Subroutine to solve general linear equation system by Jacobi method
  • [ download ] JCBTRI – Subroutine to solve tridiagonal linear equation system by Jacobi method

You can download all the subroutines here (zipped).

Let me know if the links don’t work.

See also Fortran code to calculate water thermodynamic properties (density, specific heat capacity, thermal conductivity, dynamic viscosity, and saturation temperature) as functions of temperature.

Posted in software & simulation | Tagged: , , , , , , , | 3 Comments »

Global warming? global cooling?

Posted by Syeilendra Pramuditya on December 12, 2010

The reduction of Greenhouse gas emission until mid 21st century has been discussed internationally after the publication of IPCC 4th report.

What approach do you think effective for the mitigation of global warming?

Regarding this global warming phenomenon, actually to this day, world scientists, politicians, environmentalists, and so on, still do not agree each other about many aspects of global warming, several key issues still in debate are: Is the global warming really true? Is our planet getting warmer now? Is it true that global warming is unusual phenomenon we have to worry about? Is it true that global warming is solely caused by the over emission of CO2 to the atmosphere? Is it true that global warming is caused by human activities? These issues are very important, because before we think about the mitigation of global warming, actually we all first have to understand and convince that the global warming phenomenon is really true a threat to mankind.

According to Prof. (ret.) Timothy F. Ball from Winnipeg University, in 1970’s the consensus among scientists was that the earth is getting colder, so it was global cooling instead. For example it was an article in LA Times in 1978 entitled “No End in Sight to 30-Year Cooling Trend in Northern Hemisphere”, and in 1974 in TIME Magazine entitled “Another Ice Age?”. In fact, the earth temperature is always changing over time, in a fluctuative manner, for instance, in 1959, The New York Times published an article entitled “A Warmer Earth Evident at Poles”, but just two years later, the very same newspaper published the opposite article, entitled “Scientists Agree World is Colder”. As Prof. Ball said, “the climate changes all the time, it used to it”. Hence, in my opinion, earth temperature might be goes up now, but it also can be goes down in next decade, so the change of temperature is just natural phenomenon we do not have to worry about.

Probably we all have seen the graph showing CO2 concentration and temperature rise along the time, from this graph it seems that temperature rise is caused by CO2 concentration rise, but according to Prof. Ball, in fact the temperature changes before the CO2, so we can not blame CO2 for the temperature rise. Prof. Ball also explained that by the analysis of the history of ice layers, we now know that as the CO2 concentration goes up, the earth temperature goes down, and this is exactly the opposite of global warming theory today.

Dr. Patrick Moore, founding member of Greenpeace, reveals that it was a petition signed by about 19,000 scientists and professors who do not agree with the idea that mankind are causing the climate change. Even one of the IPCC reviewers, a climate expert Prof. Tad Murty from Carleton University, opposed the idea of global warming, he said that it is not a global warming, it is nothing more just the El Nino phenomenon.

Probably we all also have seen the very symbol of global warming, the famous “Hockey Stick” graph (also known as the MBH98 reconstruction) published by Prof. M.E. Mann from Pennsylvania State University, Raymond S. Bradley and Malcolm K. Hughes, in one of the early IPCC report. This graph shows average earth temperature profile for 1000 years, which depicts a relatively constant temperature for 900 years, and a sudden temperature rise of the past century. But in 2003, a Canadian analyst, Stephen MacIntyre, and Prof. Ross Kitrick from Guelph University, decided to reconstruct the graph from the original data, and they found a serious computer programming error in the Hockey Stick graph, their result shows that in around 15th century there was a temperature rise just as high as today, so it is might be true that temperature is increasing today, by it is just a natural fluctuating pattern of climate.

Even the founder of The Weather Channel, John Coleman, said that he wants to sue the top global warming activist today, and also former vice president of the U.S, Al Gore, for public fraud, Coleman claims that he has 30,000 scientists to support this legal action.

Hence, with all these facts, personally I am not convinced yet about this global warming, but in other case, if it is true that the global warming is a real man-made potential catastrophe, I have some opinions about how to mitigate it. The first thing to consider is of course to stop using any energy sources that emit a large amount of CO2. Some promising options for near future are the energy from nuclear fission, geothermal, and maybe fuel cell as well. Whereas for a quite distant future, I believe that nuclear fusion, with its virtually limitless fuel from the ocean, and also hazard-free characteristic, will become the most important energy source for mankind.

Some related reading materials:

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How really safe is nuclear power?

Posted by Syeilendra Pramuditya on December 12, 2010

I just found another interesting fact about nuclear power, this is it guys..

Average loss in life expectancy due to Various Causes

No. Cause Time [days]
1 Being unmarried for male 3500
2 Being unmarried for female 1600
3 Cigarette smoking for male 2250
4 Cigarette smoking for female 800
5 Being 30% overweight 1300
6 Cancer 980
7 Serving in the U.S. army in Vietnam 400
8 Drinking coffee 6
9 Radiation from nuclear industry 0.02
10 Nuclear reactor accident 0.02

Source: Nuclear Engineering, Theory and Technology of Commercial Nuclear Power, Second Edition. Ronald Allen Knief. 1992. Taylor & Francis Publishing Company, Pennsylvania, USA. Table 14-6, page 405.

So what does the table say? Ok let say that the God gives you 100 years of life in this world, so if you have 30% overweight, then there is a risk that your lifetime is reduced by 1300 days.

Being unmarried for male is 175,000 times more risky than a nuclear accident!
Cigarette smoking for male is 112,500 times more risky than a nuclear accident!
Even just become a fat person is 65,000 times more risky than a nuclear accident!

Nuclear power is so safe!

Still not convinced yet? Well, a very good explanation about the safety of nuclear power compare to other energy-generating technologies is available on this link, just read those facts dude.

Posted in nuclear engineering | Tagged: | 1 Comment »

Status of Fast Reactor Development in the World

Posted by Syeilendra Pramuditya on December 12, 2010

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A note on the utilization of solar energy

Posted by Syeilendra Pramuditya on December 12, 2010

Our planet receives an extremely gigantic amount of energy from the sun, in fact, of total energy flux entering the Earth’s surface, about 99.978% comes from the sun. For the whole Earth, the total solar energy rate is 174E+15 W. This 174 PW is the total rate of solar energy received by the Earth’s atmosphere, oceans, and land masses; about half, 89 PW, reaches the Earth’s surface.

According to 2005 data, the world primary energy consumption rate is about 15 TW (15E+12 W), with 86.5% derived from the combustion of fossil fuels. According to one research, with current fossil fuels reserve and energy consumption rate, then oil will be still available up to 43 years, gas 167 years, and coal 417 years. Some important issues with fossil fuels utilization are about pollution, climate change, energy security, and development sustainability, which are the reason why we should start to develop and utilize the renewable energies very soon, in particular solar energy. If we compare our current energy consumption rate with that of 89 PW of solar energy, we can see that solar energy is about 6,000 times more than those 15 TW of average power consumed by humans today. Hence, theoretically solar energy alone is much more than enough to supply our global energy consumption rate.

Considering those data mentioned above, it seems that the energy from the sun is one very promising renewable energy source for the future. This solar energy can be applied in many ways, including to generate electricity using photovoltaic solar cells/PV, concentrated solar power/solar thermal plant, and solar power satellites; to generate hydrogen using photo-electrochemical cells; to heat buildings, water, air, food; and many more.

Of all those kind of applications, probably the most popular to utilize solar energy are Photovoltaic cell (PV) and Solar Thermal Plant (STP). In PV cell, solar energy is converted directly into electricity, with average energy conversion efficiency available commercially on the market today, is between 12% and 18%. However, PV cell efficiency as high as 42% has been achieved at the University of Delaware. On the other hand, solar thermal plant work in a very different way, it works in a similar principle as a conventional heat engine. In STP, solar radiation is concentrated by using array of mirrors to heat and evaporate fluid, and this high pressure vaporized fluid finally will drive turbine to produce electricity. STP has average energy conversion efficiency from 19% to as high as 31.25% at the SandiaLab (SNL) testing facility.

Some advantages of solar technology are, no “fuel” is needed, pollution free during use, can operate with little maintenance after initial setup, extremely low operating costs (compared to existing power technologies), and additionally, solar electric generation has the highest power density (global mean of 170 W/m²) among renewable energies. On the other hand, some disadvantages are, solar electricity is often initially more expensive than electricity generated by other sources, solar cells produce DC which must be converted to AC when used in currently existing distribution grids, this cause an energy loss of 4-12%, and also, solar power technology is an intermittent power source, that may be uncontrollably variable than conventional power sources, and it is not available at night and is less available in cloudy weather.

A research about possibility of replacing all conventional energy sources by solar energy only has been conducted by Dr. M. Loster from UC Berkeley. In his research, he identified 6 areas worldwide (2 in America, 2 in Asia, 1 in Africa, and 1 in Australia), that are very suitable and optimal for installation of solar power systems. In this scenario, very vast solar farms will be built on these areas, each will cover an area of about 130,000 km2 to 180,000 km2, and the total area will be about 900,000 km2. He said that these only 6 solar farms (assuming a conversion efficiency of only 8%) could provide a little more than the world’s current total primary energy demand. That is, all energy currently consumed, including heat, electricity, fossil fuels, etc., would be produced in the form of electricity by PV cells.

Anyway, in my opinion, although solar energy looks so promising, still diversification of energy sources is always a wise decision, don’t ever to rely on only one single energy source, no matter how abundant, how make sense, and how easily-to-use that particular energy source. All kind of energy sources have their own advantages and disadvantages, all of them will raise some issues (and maybe problems), and I believe that there is no perfect energy source. Concerning the energy security issue, I think all we have to do is to find the optimal scheme of energy sources diversification, I mean we must find a “good enough” (instead of “correct”) formula to combine those various type of energy sources.

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On the 3E Problems: Energy, Environment, Economy

Posted by Syeilendra Pramuditya on December 12, 2010

First let me briefly discuss about what the three E problems are. During the last ten years, environmental protection and energy security have emerged as important international issues right along with the economic development. The central proposition appears to be that environmental concerns are inversely related to concern about energy security and the economic development. These issues are today popularly known as the “3E Problems (Energy-Environment-Economy)”. The environmental protection, energy security, and economic development are always strongly affected each others, hence balancing these priorities is critical to achieve sustainable development of the world.

Generally speaking, global environmental problems today include the following: global warming, the destruction of the ozone layer, acid rain, endangerment of biodiversities, deforestation, marine and atmospheric pollution, and many more. Among these, probably the issues of ozone layer leakage and the global warming deserve our most critical attention today. For the ozone layer problem, we can say that it is (partly) already solved, that is to replace the problem-causing substances to this problem (CFC, NOx, SOx), with other existing cleaner substances. But for the global warming issue, the problem is much more complicated. In particular, this is because the mainstream scientists today are believe that global warming is caused by CO2, and as we know that CO2 is mainly released as a by-product of our energy production processes. Energy consumption negatively affects the environment by increasing CO2 emissions but, at the same time, we cannot enjoy economic development without energy consumption.

The problem is that humankind will continue to aspire toward further improvement of the quality of life through economic development. But one thing is that economic growth does not merely increase the burden on the environment, economic growth also provides the conditions that are necessary to protect the environment by making it possible to bear the costs of environmental protection. Hence, the important thing here is maintaining a proper balance between the 3E which I mentioned earlier, that are for securing the energy supply for economic development without giving negative impacts to the environment. One more important point is that, not only we must reduce the CO2 emission rate, but we also must somehow reduce the current concentration of CO2 in the atmosphere, which it has been increased considerably from natural level, since the industrial revolution about 2 centuries ago.

So, environmental protection and economic growth, far from each other, should be thought of as interrelated concepts. It is fundamental, therefore, that maximum effort be exerted to secure the coexistence of these two notions, under the concept of the so called sustainable development.

The question is, how to reach that point of balance of the 3E problems? We all know that this is not so easy to be answered. Some feasible solutions are introduction of cleaner (CO2 free) energy sources, promotion of energy conservation, technology transfer, and innovative technological breakthroughs to reduce CO2 emission rate and concentration in the atmosphere. The research of cleaner energy sources is already begun, known as the renewable energy sources, these include: solar power, hydrogen/fuel cell technology, wind power, geothermal, hydro power, etc. Research about the reduction of CO2 concentration is also already begun, such as the Carbon Capture and Sequestration (CCS) scheme. The mitigation of CO2 emission could also be achieved by mean of political approach, such as that of the carbon tax scheme.

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Electrochemical systems in relation to environmental issues

Posted by Syeilendra Pramuditya on December 12, 2010

There are many environmental problems today, among them all, probably problems that can be considered related to the discussion of electrochemical systems are about global warming/green house gases, fossil fuels, pollutions, and energy security for sustainable development. Generally speaking, electrochemical system is any device used for generating electricity from chemical reactions. The basic working principle of any electrochemical system is the same, in which the electric current is generated by the chemical reactions releasing and accepting electrons at the different ends of a conductor. There are various types of electrochemical systems, such as fuel cells, super capacitors, various type of primary and secondary batteries, etc. Among them all, I think two most popular today, and also strongly related to the mitigation of some environmental problems, are the secondary batteries and the fuel cells.

The first one is the secondary battery. A secondary battery can be restored to full charge (recharged) by the application of electrical energy. In other words, they are electrochemical systems in which the electrochemical reaction that releases energy is reversible. Rechargeable electrochemical cells are therefore a type of accumulator. So what is the relation between these secondary batteries with the mitigation of environmental problems? As we know that CO2 emission today is released in a very large amount to the atmosphere, by the combustion of fossil fuel from conventional vehicles, one solution is to replace these conventional vehicles with the electric vehicles. These electric vehicles always need secondary batteries as their energy storage system, in this way the secondary batteries plays some role to reduce some environmental problems. Another technology that could mitigate the environmental problems is photovoltaic system, this system also always need secondary batteries to store the power generated from photovoltaic arrays during the day to be used at night or cloudy weather.

And the second one is the fuel cell. A fuel cell is an energy conversion device. Basically, an energy conversion device takes a fuel, and converts the energy in the fuel into something that we can use. There are several different types of fuel cells. The main differences between these fuel cells are the materials that they are made from and the temperature that they operate at. Both of these factors determine what type of fuel can be used. A typical fuel cell consumes H2 and O2 as input, and produce electricity and H2O as output. The big difference between a fuel cell and an internal combustion engine is that a fuel cell has no moving parts, no explosions, just electrochemical reactions. Fuel cells require the fuel to be a gas though. So, that is the basics of what a fuel cell is: fuel in, electricity out. Every fuel cell has 3 main components, which are: Cathode, Anode, and Electrolyte. The cathode and the anode are known as electrodes. In all fuel cells, the cathode breaks down oxygen (electrochemical reduction), the anode breaks down the fuel, such as H2 (electrochemical oxidation). Electrons that are produced at the anode, travel around an external circuit to the cathode, this movement of electrons is of course the electricity. There is one more thing in this system, the ion, which travels through the electrolyte. The type of ion and what electrode it is generated in, depends on the type of fuel cell. These ions can be H+, OH-, or O2-.

According to the explanation above, we can see that the working principle of a fuel cell is very environmentally friendly, it produce nothing but electricity, water, and some waste heat, no pollution at all. But there is one important thing to consider, unlike fossil fuels, hydrogen is not naturally available, that means that we must somehow produce it artificially. One potential problem is how to do this without raising another environmental problem. Hydrogen is usually produced from other energy sources via fossil fuel combustion or other renewable energy sources. Commonly used methods to produce hydrogen are steam reforming, electrolysis, or coal gasification. When hydrogen is produced through electrolysis, the energy usually comes from conventional power sources, such as fossil fuel, geothermal, or nuclear. Though the fuel cell itself will only emit heat and water as waste, pollution is often caused when generating the electricity required to producing the hydrogen that the fuel cell uses as its power source. This will be the case unless the hydrogen is produced using electricity generated by clean (CO2 free) power sources; hydrogen is only as clean as the energy sources used to produce it. An integrated approach has to take into consideration the environmental impacts of this hydrogen production process.

I believe that only if we able to produce hydrogen economically, efficiently, and environmentally friendly, we can utilize the fuel cell in a mass production scale. I agree that fuel cells are effectively useful as power sources for electric vehicles, gadgets, or in remote locations. But to power the entire big city or area, I think this is not a good practice. Hence, in my opinion, although electrochemical systems look quite promising, I think we still need that kind of centralized large power generation systems, such as geothermal plant, or nuclear power station.

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