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Energy studies
Questions related to Energy
Question
usually the power grid needs to provide as much power as consumer need 24-7.
BUT! The energy from renewable energies like wind and sun is not available 24-7.
So a form of storage needs to be found.
Audi and the SolarFuel GmbH (Austrian German cooperation) are building prototype facilities to do exactly this.
Methane can also be used to power cars and cook or make electricity of it.
I am currently working on a production system which uses the old sabatier reaction but in a new way. An electron beam reactor using low power generates molecular vibration which causes high heat within the molecules of hydrogen and carbon dioxide. Using a specific catylist the energy gain in the chemical reaction by fare out gains the energy input.
Funding for this project has been difficult and still is, it seems nobody wants this to come to market, the end product would be home based methane production which could be used for all energy needs including cars.
Question
I am attempting to calculate the flammability limits of several gaseous mixtures containing hydrocarbons, hydrogen, inerts and oxygen all at high pressures of around 100 bar. It appears there is a simple (but proven) Le Chatalier's Law which can be used to calculate LEL and UEL for these mixtures at atmospheric pressure, but could someone tell me how this would be adapted for the mixtures at 100 bar and where I can find data for LEL/UELs of flammable gases at 100 bar?
Our research group has performed experiments in this area in the past. Please see the attached.
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IEEE Journals preferred. Thanks!
I have one (attached) but I am not sure if it will be of any help.
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I am working with a set of data, I want to find the optimum condition using Pareto optima technique.
As already mentioned, in nontrivial multiobjective optimization problems with conflicting objective functions, there does not exist a single solution that simultaneously optimizes each objective. Instead you get a set of nondominated/noninferior pareto optimal solutions along a so called pareto frontier. However, once you reach this point it's up to you (and your problem specific preferences) to choose an adequate solution from that set.
Pareto optimization is conceptually linked to pareto analysis (the efficient/optimal selection of tasks to achieve a certain goal within a given amount of time).
Question
These iron oxides deposit in amine absorber contactors that remove CO2 from natural gas. Mechanical cleaning has been the primary method of removing these deposits. By using a chelating agent, the process of removal should be faster and complete. Can anyone provide some tips on how to speed up the reaction?
It depends on the structural material of the reactor in which the iron oxide is deposited.
If you hematite, and stainless steel reactor, nitric acid is a simple solution, because hematite dissolves in acids easily with or without EDTA. Magnetite is harder question, because that does not dissolve in acids easily, only in hot and concentrated aciods, but these would destroy your instruments as well. In this case have higher role of complex-forming agents like EDTA aor NTA. If you a mixture of magnetite and hematite, the dissolve dhematite will help do remove the non-dissolving magentite particles as well.
If you have black steel material, you havr to use inhibitors.
Furthemore, to form stable complex of EDTA and Fe(3+), the pH is essential, so subsequent treatment is suggested with acids (formicacid, sulphamic acids, nitric acid, etc.) and with EDTA at a pH value good for Fe(3+) chelation.
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Diminishing fossil resources, their rising prices and their negative effects on our living environment have shifted researchers' attention toward renewable sources to access fuel and chemicals as vital necessity.
Glycerol as byproduct of biodiesel, produced by transesterification of vegetable oils or animal fats can undergo a variety of reactions, specific to its chemical structure, including oxidation, reduction, dehydration, etherification and esterification which convert it into valuable products.
It also influences some expenses of biodiesel production processes:
Economic views are more likely to be of interest in this field.
And some researches have been conducted to show its application in some physiopathological mechanisms :
BioEssays
Volume 23, Issue 6, pages 534–542, June 2001
Question
What aspects of the energy sector needs artificial intelligence and robotics? How about in the defense? Any concrete examples of AI and or robotics project existing for both the energy and defense sector.
Automated target acquisition is one application for defense sector.
Question
I want to estimate cost of a PSA system for hydrogen production. Required cost is only high level estimate, and numerically solving a complex system of PDEs is out of scope of the project. I am looking for alternate methods to estimate the PSA size.
Using this reference and some very conservative estimates of uptake at equilibrium for the impurities in the gas, cycle time, etc.. may give you enough to make a +/- 75% estimate of cost. Don't forget the regen costs and cost of media.
Question
Utilizing carbon nanotubes and graphene nanoribbons to enhance the thermal performance of nanocomposites have been an active research topic. What are other potential applications nanotechnology/nanomaterials in energy-related areas?
There is also a brand new Elsevier journal on this subject. Take a look.
Question
In a recent discussion we talked about a capacitance increasing when a capacitor is exposed near a variable magnetic flux: someone observed a gain factor of 16x (1600%).
Personally I'm at the experimental phase so I can't give any appreciable results, at least not yet.
At a theoretical level I'm not so skilled to produce any valuable theory but, making an analogy with gases (similarly to the analogy between water and electric flow) I think that electrical particles, or the electrical charges, could be "compressed" to obtain an increased energy density if they are "pushed" one over another one by a strong variable magnetic flux.
This can result in a new way of energy storage reducing the size by 16 times, e.g. of a super-capacitor, with the same output power of the biggest one, or, maintaining the same size, accumulating 16 times the energy it normally can store.
Nowadays the super-capacitors can totally replace the common batteries but they require 10 times the space to allocate the same joules: if the compression factor is really 16 times, we achieved a new energy horizon.
Hallo Cyril, in truth my experiments are not as sophisticated ... if I had at my disposal a university laboratory, or a research lab with lot of funds, I could have done so much more!
But this is not the point: I'm an on-field researcher so my fields of investigation ranging from electronics, to physics, to mechanics, mingling with one another, so often I do not have the awareness of the branch in which I am working because for me the result is the primary goal.
I've recently broken my rotor's shaft so, now, I have to build another one; after that I will try to charge a capacitor to its maximum capacitance, then I will put it in front of my magneto-rotor to investigate if applying a more power input, it will be charged more, reaching the the target of 1600% of the nominal capacitance (I'm a little scared about the possibility that it can explode, but I'll adopt some security measures).
Hope to post successful results soon.
Question
Let us perform an imaginary thought experiment where we have an instrument that can magically convert a particle of mass, m, without moving it, totally into energy via E=mc^2.
If we perform this experiment on two identical particles, one at the bottom of a mountain and one at the top top of a mountain of height, h, will we obtain the same energy in both cases? Or will we get mgh more energy out of the particle on the mountain, relative to the lower particle?
Explain what is going on. If you think you will get more energy for the higher particle, explain how this looks to a stationary versus a moving observer.
In the context of relativity the conservation of energy comes from the independence of the metric tensor on the time coordinate, i.e. as $g_{\alpha\beta,t} = 0 \quad \forall \quad \alpha, \beta$. The geodesic equation tells us that $t$ component of the energy-moment one-form (covariant vector) is a constant $p_t = E$, and this constant is usually called energy.
For particle of mass $m$ that is momentarily stationary ($\mathbf{p}=0$) at the top of a mountain its energy is calculated from the invariance of the rest mass, i.e.,
\begin{eqnarray}
g^{\alpha\beta} p_\alpha p_\beta & = & -m^2 \\
g^{tt}E^2 & = & -m^2 \\
-\left( 1-\frac{2M_{\earth}}{R_{\earth} + h}\right)^{-1}E^2 & = & -m^2 \\
E &= &m\sqrt{ 1-\frac{2M_{\earth}}{R_{\earth} + h}}
\end{eqnarray}
Note these equations are written in natural units, $G=c=1$.
From the above expression we can see that there is no decoupling of the rest mass energy $m$ and the classical potential energy $V = \frac{mM_{\earth}}{R_{\earth} + h}$. However your magic machine works it can not convert just the rest mass energy of the particle because that can not be decoupled from the potential energy''. Hence you will get more energy from your machine at the top of the mountain than the bottom.
Question
I am looking for a relationship between thermal conductivity of water as a function of temperature. Can anyone give me some idea about that?
You can use the following function(Kays et al., 2005):
k_water=-8.354e-6T^2+6.53e-3T-0.5981,
Regards,
P.S.
W. Kays, M. Crawford, B. Weigand, Convective Heat and Mass Transfer, fourth ed., McGraw-Hill, Singapore, 2005.
Where can i get a detailed tutorial on homer and scilab in addition to their help guide?
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Just need another material to look at so i can fully understand how best to make use of them.
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Hello everyone. I wish to solicit idea on the best catalyst that can be impregnated to HZSM-5 in order to denitrogenate the nitriles, amides and amines in my bio-oil? Thanks.
Any particular reason you have selected a zeolite as the support? I would tend to think of using a standard HDN catalyst for this. Something along the lines of a sulfided NiMo/Al2O3. I base that on experience with petroleum and coal oils however, not bio-oils.
Question
My thinking is that alternative energy is any type of energy that's not fossil fuels but may not be renewable, for example nuclear energy. While renewable energy, are also alternative energy but have the carbon neutrality or lower carbon footprint advantage. Sustainable energy are mostly renewable and has the added benefit of meeting the criteria of sustainability such as social and economic impacts. I will appreciate more distinctive definition and/or comments.
The question about which term to apply to a given product, not just an energy source, certainly needs to be considered across all aspects of its use ... social, economical, political, environmental, safety, and so forth. I would add to the list the term recyclable and include timescales.
Sustainable: After each use, it can be carried forward to be used again exactly as it was to start, ideally forever and with no loss. Perfectly sustainable would be the ideal case.
Renewable: After each use, it can be remade or reconstituted to be used again at exactly the same usage standards. Perfectly renewable would be the ideal case.
Recyclable: At some point, after being used, it can be recast for some other use. Fully recyclable would mean everything in the original is reused for something else.
Alternative: It is not the current norm or predominant item in use.
Finite (Limited) or Infinite: By any practical measure, it will or will not last forever.
The terms can apply in different ways. An alternative product need not be sustainable or recyclable. Alternatively speaking, an alternative energy source should absolutely not be call alternative solely because it is renewable or sustainable.
The fundamental issue with any energy source is, once it is used, it disappears. This really means, at the purist level of thinking, even sunlight or wind is not "captured and regenerated again exactly as is". Therefore, at the purist level, even these two sources are just as unsustainable as oil or gas. The difference here is, oil and gas are a finite resource, while sun and wind representan infinite supply by practical comparison.
So, if we list energy sources and suggest that many of them are unsustainable, non-renewable, and non-recyclable (in the purist sense because they disappear), we might then say this ...
Fossil Fuels: not alternative, finite
Bio-Fuels: alternative, infinite
Syn-Fuels: alternative, renewable?, infinite
Nuclear: recyclable?, alternative, infinite?
Solar + Wind: alternative, infinite
The problem of definition of the terms sustainable, renewable, and recyclable is not the case for such hardware products like cell phones or cars or washing machines or ... that do not disappear when used. Perhaps for energy sources, the term sustainable or renewable has come to mean something equivalent to infinite in supply. Hence nuclear, solar, wind, bio-fuels, and syn-fuels are presented as sustainable, whereas fossil fuels are not.
Question
In the search of active Ni materials for ethanol/glycerol reforming sustems we observed that specific Ni-CeO2 materials with enhanced metal-support interaction showed high activity, low selective for side reaction (methane-related) and stability. We believe that such strong interaction is the key issue but the molecular mechanism influencing catalytic properties was not fully identified. I want to ask for relevant information related to this issue.
Although reaction conditions are a little bit different, answer to this question could be, (in part) given in another Angew. Chem. paper. see below Highly Efficient and Stable CeNiHZOY Nano-Oxyhydride Catalyst for H2 Production from Ethanol at Room Temperature** Cyril Pirez, Mickal Capron, Herv Jobic, Franck Dumeignil, and Louise Jalowiecki-Duhamel Angew. Chem. Int. Ed. 2011, 50, 1–6
Is there any option to model/simulate generator in ASPEN PLUS????
Question
I am going to work on the modeling/simulation of electric generator.
I am working with Aspen Plus V 8.0. Will it contains the generator model?
What are suggestions for the future research in the field of small wind turbine blade?
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In aerodynamics developments in blade, airfoil shape
I'l make you a couple of suggestions. - I'm sure some, if not all, of these are already researched, but one does not see much of it in industry. * Noise limitation at Horizonatal Axis turbine blade tips. * High solidity wind turbines (more blades) * Low stall wind tubine blades * Overspeed control by controlled turbine blade stall * Comparrison of horzontal and vertical axis configurations etc.. Hope this gets you going with some more ideas..
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I would like to learn how to determine the gas production of EDLC in glove box and Ar enviroment.
And one more point: with CuCN you obtain a Cu-complex that behaves as an inorganic salt. The best reagent to decompose it is NaCN, if it's a problem, an excess of diethylenetriamine or similar polyamine works also.
Question
I'm writing a paper on conservation and I'm trying to contextualize what the numbers really mean. 2.75 billion m3 of natural gas means very little to most people. What would be a good bench mark comparator so that non engineers and scientist can understand the amount of energy that really represents?
Hello, you should try to help them contextualize with some comparison, with everyday thing they knew (like the average consumption of a family of 4, etc )
Question
I am trying to get the IRC path for my molecule. I get the IRC curve, which is not the expected one (the curve looks like stair case structure). Even though I am getting the optimized structure, the output file is the same as that of input file.
Can any one suggest how to get the correct IRC?
Input file is like this......
%nprocshared=8
%mem=2GW
# irc=(rcfc,maxcyc=200) b3lyp/6-31g(d) nosymm scf=(qc,maxcyc=200) geom=connectivity
Title Card Required
0 1
coordinates
Chethan
Sorry but I did not understand the problem. The input file looks ok. I guess you are using the transition state as input geometry, right? Because the calculation will use it as starting point to follow the gradients toward reactants in one side and to products in the other side of the IRC. If the calculation works fine, you should get a number of optimized structures and a list of energy points along the reaction coordinate. I have attached an example output file. In this case, the calculation died because it exceeded the number of iterations in one of the last steps, but I think it can help you.
Question
Though it has a bandgap (which is unlike graphene) it has a good mobility advantage. Does anyone know of any firm (or high impact paper) reports of MoS2 used for supercapacitor application?
There are some papers on MoS2 super capacitors.. ex: doi: 10.1149/1.2778851 from KP Loh's group...
and don't judge a paper by IF...
Power consuption
Question
If we compress a certain amount of gas from 200mbar-1bar, will the required power be the same with the suction from 1bar to 200mbar using a vacuum pump?
If the initial temperatures are equal, efficiency = 100 % and both processes have the same polytropic index, but polytropic index is not equal to 1 than no, it will not be the same.
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I am intrested in finding the influence of EU energy directives on deepening of the energy poverty situations in new members of EU.
It could be useful to consider the contents of the paper titled "Researching the Influence of Energy Consumption on Energy Poverty in Eastern and Adriatic Croatia", in which the research is focused on the energy consumption in households. Energy consumption in relation to energy poverty is researched in the paper, which is presented at the 3rd International Scientific Symposium 'Economy of Eastern Croatia – Vision and Growth' in 2014. Furthermore, the energy needs are presented and the energy costs in relation to the available household income are considered in the aforementioned paper.
Question
I see synchrotrons as exemplary investments in science for areas such as structural biology, medicine, and materials science where collaborative efforts coupled with invested government funding have provided enormous benefits to society. I am interested in how others see this investment and what are perceived as examples of major payoffs in the last decade. Also if you agree that synchrotron research seems to have retained merit-based competition, which can frequently be damaged by block funding intended to provide stability, why might this be the case?
In addition to all the amazing and exciting things mentioned by Gebhard Schertler that can be done now and will be done in the future at synchrotrons and their relatives, synchrotron data collection has become the powerful engine of macromolecular structure determination. Along with cryo-protection of samples, synchrotron data collection has made phase determination using anomalous diffraction routine and has made it possible to obtain accurate diffraction data from small and huge macromolecules. The number of macromolecular structures deposited in the Protein Data Bank based on synchrotron data increased from about 1200 in the year 2000 to 5500 in 2010, while the number based on all other sources remained constant at about 1000 per year (see Berman et al., Protein Science 21, 1587, 2012).
Question
What should be the roadmap for sustainable energy ?
You need to identify what the objectives are. In many countries (like South Africa), sustainable energy is linked to poverty reduction through increased local employment. This means you don't simply import the best technology and put it up in your country - you examine the expertise of local companies and universities, the needs of the rural communities and then find technologies and partners that give you the best balance of Renewable Energy and Jobs at a reasonable cost.
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Are there any other contributions that this work brings to the engineering community?
thank you very much Babak sir, for your valuable inputs
Question
I'm constructing a different current-voltage curve using a potenciometer of 50 kΩ and 250 kΩ, but the results are bad. I'm using the system showed in the attachment. How can I improve this system?
The main problem I have with DSSC is the slow response time. Your circuit is manual so you will have to wait 1 to 10 seconds per point to let the current settle out. As pointed out by others your range of resistances is very limited. to get within 10 mV of 0 volts with 0.1 A you will need a load resistor=0.01/0.1=0.1 ohms. The power rating of your resistors needs to be at least 6 (10 better) times Isc*Isc*Resistor value. We also use a power supply to cover the entire curve.
Do the component efficiencies of the compressor and the turbine changes with the load changes?
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As the temperature and flow rate changes.
If the non-dimensional operating point in the turbine or compressor map changes then the component efficiency will also change.
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I'm trying to get a paper, and the author is unresponsive. It's from the early 80's, so the author may be retired and not practicing anymore.
Why do not you put the paper title and reference here? Maybe someone on the internet can help you.
Is transmission of power supply possible using wireless applications?
Question
There are many technical applications using wireless transmission as signals. What is it in the case of electricity using multi-pole wireless transmission after generation? What is the risk?
I recommend you following webinar http://spectrum.ieee.org/webinar/wireless-power-transfer-and-microwave-energy-harvesting
Do you think water can be used as a next generation fuel and why?
Question
HHO from H2O has been established and tested. It will be a practical solution for energy generation.
wiki/Fuel : "Fuels are any materials that store potential energy in forms that can be practicably released and used as heat energy." H2O is the highest oxidation achievable by Hydrogen and cannot be oxidized further. Hence, water as such, cannot be used as a fuel, be it from sea water or DDW. One can break the O--H bonds to get Hydrogen which then can be used as a fuel. When Hydrogen is used as a fuel, the product one gets is water. So, essentially what we are doing is taking water, splitting it, get the hydrogen thus derived, oxidize it back to water. There is no net energy gain from the process and hence water cannot be used as a fuel like petrol or diesel or CNG (As Barry indicated). Splitting water using solar energy and using the Hydrogen is just a method of harvesting solar energy indirectly. The major limitation being faced is not in the water splitting reaction but in the efficiency of solar energy panels which is much less than the conventional fuel oxidation. This is not a viable solution at this moment from commercial point of view. Improving solar energy capture efficiency is the way to do it. It it were the case, one can directly use the solar energy rather than the roundabout way through water. In conclusion, water cannot be used directly as a fuel in any method whatsoever, but can be used as an intermediate to convert one form of energy to the other.
Question
Is nuclear energy a real alternative for the generation of electricity in the European region?
Due to different reasons, and particularly after the nuclear accident at Fukushima Daiichi nuclear power plant, the debate about the future role of nuclear energy for electricity generation in the energy mix of several countries was reopened once again in the European region. There are several reasons for this. The first of these reasons is the high price of oil. The second reason is the need to reduce the CO2 emissions to the atmosphere. The third reason is the dependency of the EU and other European States to the import of fossil fuels.
During the consideration of the role that nuclear energy should have in the energy balance in the European States in the coming years, three main realities should be taken into account:
-The level of criticisms of the use of nuclear energy for electricity generation is rising again in several European States after the nuclear accident at Fukushima Daiichi nuclear power plant. Germany has shut down 8 of its 17 nuclear power reactors in operation in 2011. The UK shuts down 2units in 2012; other countries such as Switzerland, Belgium and Sweden have plans to shut down all nuclear power reactors currently in operation or have cancelled the expansion of their nuclear programs or the introduction of this type of programs for the generation of electricity in the future.
-Economics comparison. Whether the use of nuclear energy for electricity generation is more economical or not than the use of other energy sources will depend on how cheap it is compared to other alternative energy sources;
-Is nuclear energy a secure energy source for the generation of electricity or it is very dangerous bearing in mind the Three Miles Island, Chernobyl and Fukushima Daiichi nuclear accidents? Does the world have in their hands now any other alternative energy sources that are more secure, can provide the level of electricity generation that the countries need when is needed, and it is clean and economic than nuclear energy? If the reply is yes, then they can be used immediately to generate the total energy electricity produced by the 436 nuclear power reactors operating in 31 countries in 2012, before the nuclear accident at Fukushima Daiichi nuclear power plant?
Currently, the European region (including Russia and Ukraine) generates around 31 % of its electricity from 195 nuclear power reactors currently in operation in 17 countries.
According to some expert’s opinion, it is a fact that nuclear energy is already making a substantial contribution to an energy policy that is low in carbon, cost-effective and that provides assured supply.
Today, a strong debate is happening among the oldest and most industrialized EU Member States, which do not want to slow down their economic growth and wish to overcome the current economic and social crisis that some of them are now facing.
This crisis is putting in danger not only the stability of several countries but also the common currency of 23 States (the euro). For this reason, a group of countries is thinking to continue using nuclear energy for the generation of electricity as a real alternative, even after the nuclear accident at Fukushima Daiichi nuclear power plant. On the other hand, others countries are taking measures to slow down the expansion of their current nuclear power programs or will shut down some or all of their nuclear power reactors in the coming years. The problem that the world is now facing is how to meet the foreseeable increase in the demand of energy using all available energy sources in the most efficient and economic manner and without increasing the emission of CO2 to the atmosphere.
Undoubtedly, one of the available types of energy sources that have proved in the past that can be effectively used for the generation of electricity is nuclear energy. The International Energy Outlook for 2011 (IEO 2011) indicated that electricity generation from nuclear power worldwide is expected to increase from 2.6 trillion kWh in 2008 to 4.9 trillion kWh in 2035, an increase of 88 %. However, there is a great concern about building new nuclear capacity due to construction costs, energy security and greenhouse gas emissions in several regions of the world.
Every year, the IAEA makes low and high projections of global nuclear power generating capacity: this year's low projection indicates 17 per cent growth in world total nuclear power capacity by 2030, while the high projection suggests a 94 per cent growth, i.e. nearly a doubling in global generation capacity. In other words, growth in nuclear power following the Fukushima Daiichi nuclear accident is expected to continue, however at a rate lower than estimated prior to the accident. http://www.iaea.org/newscenter/news/2013/np2020.html
The annual projections made since 2011 have indicated that growth has slowed, but not reversed. The 2013 updates, taking into account developments through April 2013, reinforce this conclusion. Over the short term, the low price of natural gas and the promotion of renewable energy sources in some energy policies are expected to impact nuclear growth prospects in several regions of the developed world. These low natural gas prices are partly due to low demand as a result of macroeconomic conditions, as well as technological advances, notably with fracture techniques to extract shale gas. Moreover, the on-going financial crisis continues to present challenges for capital intensive projects such as nuclear power.
"Nuclear energy can be viewed as a critical component of a country's energy infrastructure, providing a clean and dependable long-term source of energy," says David Shropshire, Head of the IAEA's Planning and Economic Studies Section.
In the long run, nuclear generating capacity is expected to play an important role in the energy mix due to growth in population and in demand for electricity in the developing world, as well as climate change concerns, security of energy supply and price volatility for other fuels.
Challenges remain, and policy responses to the Fukushima Daiichi nuclear accident are still evolving. However, over the past year, most countries have finalized their nuclear safety reviews, providing greater clarity with respect to nuclear power development. The final result of those reviews, reactor safety modifications, and in some cases even reactor shut-downs, is that greater confidence in nuclear power is expected as a safe and secure energy source.
In the 2013 updated low projection, the world's installed nuclear power capacity grows from 373 gigawatts (GW(e)) today to 435 GW(e) in 2030. In the updated high projection, it grows to 722 GW(e) in 2030 (A gigawatt, or GW(e), equals one billion watts of electrical power).
The strongest projected growth is in regions that already have operating nuclear power plants, led by Asian countries, including China and the Republic of Korea. From 83 GW(e) at the end of 2012, capacity grows to 147 GW(e) in 2030 in the low projection and to 268 GW(e) in the high projection.
Eastern Europe, which includes Russia, as well as the Middle East and South Asia, which includes India and Pakistan, also show strong growth potential. Nuclear capacities grows from 48 GW(e) in 2012, to 79 GW(e) and 124 GW(e) in the low and high cases, respectively.
Western Europe shows the biggest difference between the low and high projections. In the low projection, Western Europe's nuclear power capacity drops from 114 GW(e) at the end of 2012 to 68 GW(e) in 2030. In the high projection, nuclear power grows to 124 GW(e).
In North America, the low case projects a small decline, to 101 GW(e) in 2030, while the high projection shows an increase from 116 GW(e) at the end of 2012 to 143 GW(e), or a 24 per cent increase.
Question
I want to intentionally flood and dry a PEM fuel cell, and look at the polarization curves. Is there a model that will allow me to do that?
There are lot of models in the literature that can be used to understand the effect of water concentration on the polarization curve of a pem fuel cell. For sure several parameters are affected by water concentration such as membrane conductivy, and binary diffusion coefficient in the piorous layer. Moreover if two phase model have to be considered you have to take in to account also the effect of liquid water blockage in to the channels . Generally speaking the flooding is reflected in the concentration (polarization) part of the IV curve , otherwise the drying is more pertinent to the ohmic part of the IV curve . In any case flooding or drying the whole polarization curve is affected.
Question
Available inputs are population previous values of GWh, GDP, peak loads, number of customers.
It's a good question and it depends on a lot of parameters and a good way to know it in your case is to do econometric try to explain in the past data, the impacts of "usual suspects" like in generation events (technology disposability + time to respond +….):
and "offer parameters".
But they are also demand parameters because you produce them needed!
GDP evolutions have an impact
Weather conditions (degrees and sun exposure + wind?)
and demand driven cause by sociological event (world cup, olympics….)
It depend also on degree of precision you want!
If you have a look to the enclosed link in the french TSO, you will see for every day the past year the prevision they used and in real time the unexpected changes or errors of prevision.
Good luck to your work !
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Looking for the technology or vender.
Hi Feng Zhu, you can have a look at my company website : http://www.sil-tronix-st.com/home/silicon-wafers. We do very thin/ or thick Si Wafer (from 120µm to 15mm).
Question
Is the energy that is dissociated from the fluid converted to any other form?
Hi Satya Sagar! The fluid pressure you are referring is the static pressure ,which is normal to the direction of flow.Assume the fluid stream coming out of the pipe as 'virtual stream/ tube of fluid'. The moment the pipe ends, the stream tube begins. Now the static pressure exerted by the atmosphere on the fluid at any cross section of that stream should be equal to the static pressure exerted by the fluid. In a way its a simple force balance.The fluid pressure you mentioned about is only the external static pressure that would be applied on the fluid stream.There is no conversion/dissociation of any sort. Now, instead of atmosphere, if you pump/discharge the fluid into a vessel with a different ambient pressure, then the static pressure at the exit would be equal to that corresponding ambient pressure. For more detailed understanding you might look into a some terms like 'Back Pressure', 'Under Expansion','Perfect Expansion', 'Over Expansion' of jets.
Question
I need someone to help me in clarifying on how the open circuit potential (OCP) defined and included in the Bulter-Volmers Equation.
Simple expression for Bulter-Volmers equation
j=ai[exp(f(phis-phi-OCP)-exp(-f(phis-phi-OCP)]
Normally, this OCP is defined by using the Nernst equation which containing concentrations of the species involved in the electrochemical reaction. So, now this is the case. Assume that the reaction takes place throughout a rectangular porous electrode where the species (reactants) are continuous circulating across the electrode with galvanostatic current applied to it. The concentration of the species will be varied across the electrode when the reactant consumed in the reaction. I am wondering that what is the best way to handle this OCP term under this condition. Should I set the OCP constant over the entire porous electrode domain (by having OCP calculated based on the inlet species concentration) or allow the OCP varying (by having OCP calculated based on the local species concentration)?
I have this concern as most of the models for PEMFC don't include the OCP in the overpotential term still they can evaluate cell potential. (You can actually refer to Bernardi and Verbrugge PEMFC model [1] on the cell potential estimation.)
[1] D.M. Bernardi, M.W. Verbrugge Mathematical Model of a Gas Diffusion Electrode Bonded to a Polymer Electrolyte., AIChe Journal, 37 No.8, 1151 (1991)
Dear Ching Liang Chen,
I think that to handle the issue you raised, you should take into consideration the internal, "in-plane" resistance of your gas-diffusion electrode.
If this resistance is large enough, you might have areas of electrode at different potentials; a detailed treatment should also take into consideration the exact path of the reagents on the electrode, the map of the flow of electrons "in-plane", and how electrons are redistributed by the bipolar plate with which the GDL is in contact (which will have its own resistance). That's a very complicated modelling.
However, I would like to point out that in most practical applications:
1) near OCP, currents are very small; thus, a low consumption of reagents is expected, leading to a high uniformity of reagent concentration;
2) at low currents, ohmic drops are very small; in general the materials used to fabricate the cell (GDLs, bipolar plates) are highly conductive.
For these reasons, it is usually safe to assume that near OCP, each electrode has one single value of potential.
Hope it helps.
Best Regards
Enrico
Question
The weak Casimir's force is interpreted as resulting from an asymmetry of the pressure exerted by vacuum fluctuations on a thin pair of parallel metal plates. As a force does exist that can be put to work the question arises whether one could extract energy from vacuum.
See:
Casimir’s force is a relativistic correction to the van der Waals force. Van der Waals force varies as r^-6, and the corrected force varies as r^-7.
- H. B. G. Casimir and D. Polder, Phys. Rev. 73, 360–372 (1948), The Influence of Retardation on the London-van der Waals Forces
- Robert L. Forward* Phys. Rev. B 30, 1700–1702 (1984), Extracting electrical energy from the vacuum by cohesion of charged foliated conductors
The Casimir force is sort of a Van de Waals force between the plates. Zero point fluctuation isn't an energy but a choice of the energy origin. If it were energy, it would be possible to extract it from the Casimir force, but it isn't. Speculation about vacuum that isn't vacuum is metaphysics.
Question
I'm looking for hard data to back up low energy building designs. Have low energy buildings performed, were there any issues with constructions, are there any lessons learned?
Following you on RG so you can view my profile to answer your question on performance of building energy as well as its low exergy consumption. please check one or two of my articles in my profile, if they can be of help to you.
Question
I want to know the procedure of calibration of a petrol emission analyzer.
You can compare with published result
Has anyone worked with a biomass gasifier?
Question
I need to find a prototype bagasse gasifier, which is not much different from any biomass gasifiers I see advertised in China.
In case of Biomass gasifier, design is dependent upon fuel and end use. So first you have to know the accessible fuel nearby, sustainability and then the end use. Design or Product can be easily accessed!!
Question
I am interested in knowing about conversion of pressure energy into mechanical, electrical or any type of energy.
At low power and high pressure volumetric expanders are better.
But in volumetric systems, the pressure drop at inlet and outlet gets too big at high power.
High power is something >100kW.
Low pressure high power is good for turbines.
It is a matter of leak flow and pressure drop.
It is very difficult to make small turbines at high pressure where the leak flow behind the impeller is well controlled.They also need very high rotational speeds.
I was at the concept of piston expanders of a spin-off compagny Alenco, but you will not find it on internet.
Normally I'm good at the electric and electronic part of them.
Question
The energy-meter (present in households) measures only the active component of power used, but what happens to the reactive component of the power?
There is no or very less usage of reactive power in houses and mostly mentain power factor near to supply's PF (0.9 to 0.95 is commonly supply PF).However Constructing and using (WATT+VAR) or (KVA+casO) in such a large number is not very fesible.Hower whwn home load become more then a certain limit Distribution companies start thinking of using meters for reactive power measurement
Question
I am calculating the total area of a solar panel for a particular load demand by considering the power, but if I consider total energy required for a day and do my designing according to energy demand for a day then how will it affect total solar area?
Lets assume that you want to install 10 solar panels rated at 100 Watts each and having a conversion efficiency of 18%. The total power output of the solar system can be calculated as:
Total Power Output=Total Area x Solar Irradiance x Conversion Efficiency
We know the required Total Output Power is 1000 Watts (10 panels x 100 Watts), the Solar Irradiance for a surface perpendicular to the Sun’s rays at sea level on a clear day is about 1000 Watt/m2 and the Conversion Efficiency is 18%. Plugging these number in the above equation we get:
1000 Watts = Total Area x 1000 Watts/m2 x 0.18
or Total Area = 5.56 m2
I you are going to install all the panels in one line you would need a space of approximately 1 m x 5.56 m (each panel having a size of 1 m x 0.556 m) on your rooftop. There you go. You have a rough estimate of the space required by the solar panels of your system.
1. Do remember that solar panels are usually installed at an angle to the earth surface and this may change the results somewhat.
2. Imagine a solar panel has a conversion efficiency of 100% i.e. it converts all the solar energy into electrical energy then all you would need is a 1 m2 solar panel to produce 1000 Watts of electrical energy.
Based on the above in my opinion the best formula is the first one
Area =(kw)/((kw/m^2)) but you have to consider the conversion efficiency in this formula
Question
Scientist and engineers have developed many new nanomaterial and their related applications .Nanomaterials as defined in a 2011 Commission Recommendation are materials which often have specific properties due to their small particle size.Nanotechnology/Manufactured Nanomaterials is an exciting new field that promises a broad array of benefits to humans and our environment. However, with these clear benefits come potential risks to the environment and human health - risks that, to-date, are not fully known.
Chemists develop 'fresh, new' approach to making alloy nanomaterials.Chemists in The College of Arts and Sciences have figured out how to synthesize nanomaterials with stainless steel-like interfaces. Their discovery may change how the form and structure of nanomaterials are manipulated, particularly those used for gas storage, heterogeneous catalysis and lithium-ion batteries.
Question
My question is about the selection of plant systems. If we need to select the plant according to cost effectiveness than whether I should go for a system which is less efficient and less cost per unit generated or a system which is more efficient than previous one having more efficiency and more cost per unit generated?
I believe that the system's efficiency can be modeled in the running cost of the system so it can be converted to "cost" and you will optimize (or minimize) your total cost.
For example, if I have two generators:
Generator A has an initial cost of $1000 and 60% efficiency Generator B has an initial cost of$500 but with 30% efficiency
If you assume that the lifespan of both generators is the same, and you neglect the inflation and other maintenance costs, then by simple calculations you can compare the total cost of A and that B.
If X is the running cost of A, then it will be 2X for B (modelling the efficiency - A is two times more efficient than B).
=> 1000 + X is to be compared with 500 + 2X to decide which is better.
(Note that I have simplified the calculations to one variable, but it can be done for more. You may need some sensitivity analysis later).
Question
Geothermal Heat Pumps are a promising technology for reducing primary energy consumption and improving the air quality in our cities. What are the greatest research challenges in this field for the future?
Where to begin?
-Methods for determining if rock formations exist within the first 10 feet of a geofield without drilling a test well. This is important for lateral run lines as it's easier/cheaper to run them through dirt than rock. Is there a way of testing ~10,000 ft (~1,000 m2) quickly?
-Pressure drop vs. laminar/turbulent analysis. A higher pressure drop results in turbulent flow which improves heat transfer, but increases pump power consumption. Given that load profiles of buildings vary, the load may be very low so the flow rate may be low. How low should you go? Maybe a design or control optimization. Maybe there is a cutoff for smaller systems that it makes more sense to use constant volume pumping.
-A refrigerant that works efficiently in a heat pump up to 180F (82C). Typically heat pumps generate 130F (54C) to have an efficient COP, but it becomes challenging to utilize 130F hot water in cold climates where 180F is standard. To make 130F work, reduced building envelope loads are required and/or larger radiant perimeter heating systems such as radiant panels, etc. Target a COP of 3.5 at 180F hot water.
-Better geoexchange energy models that work well with current energy modeling software such as eQuest or EnergyPlus. This includes complex field geometries as geofields can be many shapes depending on the building site.
-General materials conductivity research: pipes, grout, etc.
-General tubing geometry research: u-tube, pipe in a pipe, etc.
-Quantifying underground water flow and the impact on geofield performance.
As you can see there is a lot that is unknown or uncertain when it comes to designing geoexchange systems. The firm I work for has designed and implemented over a dozen geofields of various sizes, and there are many concerns that arise. Solving the questions above will allow engineers to reduce the size of the geoexchange systems, therefore making the cheaper and more likely to be implemented as they are often too expensive under current market conditions.
A personal note: please don't use the term geothermal when talking about heat pumps. It often confuses people into thinking geothermal power, which involves drilling miles into the Earth to generate electrical power from the Earth's heat. Ground source heat pumps works, but it's a mouthful. I like geoexchange because you're exchanging heat between your building and the ground.
Fred
Question
I found a solar cell block in Matab. Now I have to use it as an array so how should I connect this block? Otherwise I have my designed model of a cell, which will be better for an array of 10 KW.
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As I am using matlab, I heard about homar, digisilent many. Which is best?
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Is there any possibility to covert an anergic form of heat energy into useful work?
No, because that is unavailable part of energy
Question
Except Mg(ClO4)2 .
Question
I made a model of a pv cell and i want to intersect all MPP by one line, but I can't because the points aren't on the same line. I think there is a problem with my model, any help will be appreciated.
this line isn't related to Vmax it's just a line have slope 17.2 to intersect so if i removed this line and looked at points with the naked eye i would see the deviation of points .so there is error in the initialization i can't discover
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Something like Carrier or any excel sheet for the routine formula or calculations
Hi Zahra, if you are looking at measurement, firstly decide what methodology to use. Try ASHRAE or CIBSE methodology and then consider the method of assessment. Most software developed by manufacturers or suppliers is skewed in their favour, as an academic I would stay away from those. Perhaps look at SAP, RDSAP and BREAM developed Building Research Establishment in UK. RET is also good.
Question
Challenges including the legal and regulatory requirements businesses in the energy and utilities sector will have to meet in the future, near or far, any ideas on this will be greatly appreciated.
Jeremy Rifkin wrote a fine book on the third industrial revolution that presents challenges to come in the field of energy and shows that in the future, renewable energy will play an important role in the energy mix. So, energy systems, highly centralized today, will know a wide decentralization to the extent that each building would be able to produce sufficient energy for its own needs. It also shows that the future will be strongly influenced by the convergence of this new energy paradigm and ITC. Smart grids and smart meters prefigure that energy future.
The environmental challenges shall be also taken into account in future strategies in the business of energy and utilities.
But, the most important thing is the quality of the service to the customer in an increasingly competitive environment with pressure on prices that do not leave indifferent politicians and governments.
Question
The ground state of two hard core bosons in 1-D box of impenetrable walls and size L as reported in:
[M. Girardeau; “Relationship between systems of impenetrable bosons and fermions in one dimension,” J. Math. Phys. Vol. 1, (1960), 516-523]
is characterized by single particle momentum $k_1 = - k_2 = \pi/L$ and energy $E_o = 2(h^2/8mL^2)$. The fact that this $E_o$ is exactly equal to the ground state energy of two non-interacting bosons trapped in the box implies that hard core interaction has no impact on $E_o$ and seems to question mark its accuracy. On the contrary another study reported in:
(Y.S. Jain, Cent. Eur. J. Phys. 2, 709 (2004)) and [ http://arxiv.org/abs/quant-ph/0603233 ]
concludes that the ground state should be characterized by $q = -q = 2\pi/L$ rendering $E_o = 8(h^2/8mL^2)$ which is 4 times higher than that reported by Girardeau and this indicates that $E_o$ is really affected by hard core nature of bosons. For the reason that we have correct understanding of the physics I invite all concerned to conclude what is right.
Dear Yatendra Jain,
An interesting question, if the two papers you mention were both correct.
On starting the second reference something worries me already in the beginning. It might be that you can explain away my misgivings easily.
The Schrödinger equation for two particles in a one-dimensional box interacting through a \delta potential for a wavefunction \Psi(x_1,x_2) can indeed be re-written in center-of-mass coordinates x = x_1 - x_2 and X = (1/2)(x_1 + x_2).
However, one should also take good care of the boundary conditions. If (sligtly different than your second reference) 0 < x_1,x_2 < L then the boundaries of the CM coordinates is formed by the four lines x = 2 ( + or - ) X and x = 2 ( + or - ) ( L -X ), i.e. a sort of lozenge. On these lines the wavefunction \Psi(x,X) must vanish.
The product-splitting of the wavefunction stated in your second reference cannot agree with these boundary condition and can at best be viewed as a (not very good) approximation. It should thus not come as a surprise that the energy is different (higher) than that found in your first reference.
Again, the matter of scalar boson- and fermion-like particles in one dimension is both interesting and subtle. I think the result of the1960 reference holds.
Kind regards, Henk Smid
Question
If it is mathematically possible, it would be very interesting to work with this.
well Eder the main problem with the warp drive spacetime is still the energy requirements to distort the spacetime geometry
look to the energy density in the Alcubierre spacetime
rho = -(c^2/G)*(vs^2/(8*pi))*(sigma^2/(4*rs^2))*[df(rs)/drs]^2
written in normal SI units....Alcubierre worked with the geometrized system of units c=G=1
now look to the energy density in the Natario spacetime
rho = -(c^2/G)*(vs^2/(8*pi))*[3*n´(rs)^2+cos^2(theta) + (n'(rs)+(rs/2)*n''(rs))^2 * sin^2(theta)]
written in normal SI units...Natario also worked with the geometrized system of units c=G=1
in both equations the term c^2/G appears it is the so-called Spacetime Coupling Factor
c^2=9 x 10^16
G= 6,67 * 10^-11
dividing c^2/G and neglecting the numbers 9 and 6,67 we have 10^16/10^-11 = 10^27
the mass of Earth is 6 x 10^24 in kilograms
so the term c^2/G in nearly 1000 times the mass of the Earth in kilograms
not to mention the square of the velocity vs
in order to make an interstellar travel in a reasonable amount of time for a star at 20 light years away...200 times faster than light is a good velocity...we could reach Gliese 581 in months
so 200 times light speed 200 x 3 x 10^8 = 2 x 10^2 x 3 x 10^8 = 6 x 10^10
but the energy density uses the square of the speed
this means vs^2 = 3,6 x 10^21 the magnitude of the mass of Earth in tons
in order to neutralize these huge numbers in the equations of the energy density the derivatives of the shape functions must be so low in order to obliterate these numbers
but the major problematic issue remains....where is the negative energy???how can it be generated???
Question
I'm running a charge-discharge analysis using autolab. I have a problem where it creates a bubble on the counter Pt electrode and after 500 cycles the working electrode is etched on the electrolyte.. Does anybody have a solution for me?
I think your problem is that the surface area of your counter electrode (CE) is not sufficiently high.
There is the same current on CE passing as on working electrode, WE (opposite sign, of course). Thus, if you increase the surface area of CE without changing the surface area of WE, the current density on CE will be lower. Thus, hydrogen will rather be dissolved in electrolyte and diffuse away than be accumulated into the gas bubble. It might be even possible to avoid hydrogen generation on CE, if its surface is very high.
Try platinizing your CE. With potentiostatic platinization from PtCl6^2- or PtCl4^2- solutions you can increase surface area aspect by factor 100 or more.
Question
If you want to reduce your energy bill, it is quite possible to insulate the roof and walls. However windows are a more difficult subject, and they let out significant amounts of heat. Are there any solutions that can reduce this loss?
Dear Prof.
Using Energy+ and design builder software can be helpful.
Best regards,
Question
For building materials like concrete, burnt brick, mortars, etc...
A details heat transfer analysis is required if possible (Conduction, Convection, & Radiation through pores and solid matrix)
I think that apparent thermal proprieties (they matter) can be measured with standard techniques. steady state apparent thermal conductivity, for instance, and maybe transient test to reveal influence of vapor evaporation-migration -condensation. If the use is for building materials it appears reasonable to investigate properties in conditions similar to the actual ones , that is from an apparent , averaged, macroscpoic perspective.
Question
. But only a fraction of heat can be transformed in work, this fraction being always less than the Carnot
A little remark, the subject relates irreversibility nor the Clausius-Clapeyron equation related with the change of pressure against temperature (dp/dT)in the phase coexistence. In solid-solid phase transitins the pressure was changed by the stress. In your case, the potential for diffusion is, probalby, the chemical potential.
Question
Aggregators are currently energy service providers in the Smart Grid, but this needs to be clarified. What are the key roles of aggregators in distribution networks.
Aggregators are actually new actors in the sector and their role is not yet clearly defined as they does not exist in practice yet (as to my knowledge). However, several projects have used their own definition to these actors. One definition is the one used in ADDRESS project which says :
"An aggregator is seen as a mediator between the consumers and the market, gathering flexibilites and contributions of customers, collecting requests and signals from markets and participants, with different levels of optimization to meet the requirement of topologically dependent services."
You can find some reports of the project on http://www.addressfp7.org/
Hope this helps!
Question
We are trying to produce bio diesel from waste vegetable oil.
Yes indeed.....however ethanol is better option as it can be prepared through bio based processes...methanol is more preferred due to easy availability, lower cost.
Question
Tokyo, June 29 (Jiji Press)–A Japanese anesthesiologist made up a total of 172 fictitious research papers between 1993 and 2011, an academic society said Friday.
Yoshitaka Fujii, a 52-year-old former associate professor at Toho University, has denied fabricating research, according to the Japanese Society of Anesthesiologists.
The number of papers that he allegedly faked is the largest ever for any medical researcher, both in Japan and overseas, according to sources familiar with the field.
The society surveyed 212 articles written by Fujii that were published in a total of 41 Japanese and international journals. Of them, it found 172 fake research reports and three articles backed by real research. It was unable to assess 37 articles due to lack of scientific evidence.
Coauthors of Fujii’s articles were not sure of the content of his research, the society said.
When Maria Skłodowska-Curie was inventing a method of extraction of radium and polonium, she had to repeat her research with other researchers to prove that her method is repetitive and every one can obtain these elements with her method. Honestly, before publication, few manuscripts from current issue should be randomly chosen, and part of the research should be repeated by other researchers. It would generate costs, but the quality of science would be improved. And no one would dare to publish fake results.
Question
I have successfully generated Pt Nanoparticles using methods described in the attached document. I have isolated the Pt Nanoparticles and tried to inject them to Hydrogen Gas in effort to see if they would react. They did not. I believe the Sodium PolyAcrylate used as the Capping agent is insulating the entire particle and not providing Hydrogen access to the Platinum.
How would you begin to remove the Sodium PolyAcrylate to give the Hydrogen "access" to the Platinum Nano Structure? (I am looking for a relatively simple way to do this ...if it's possible.)
Jerome or anyone...do you think that the capping agent is infact blocking hydrogen access to the collected particles that I have collected?
Question
I'd like to present some questions based on testing of 2 cyclists. The data and questions are translated from Spanish.
A cyclists (rider A) weighing 70 kg, is 170 cm tall and has a VO2max of 82 ml kg-1 min-1, the threshold determined by the method described by Billat was a VO2 40 ml kg-1 min-1, pedaling at an intensity of 315 W at a frequency of 80 rpm for 10 minutes his blood lactate capillary earlobe was 6 mmol.l-1, with a respiratory quotient 0.98. His maximum heart rate was 192 beats / min. His blood hemoglobin concentration: 142 g / L.
Another cyclist (B) weighs 73 kg, measured 189 cm and has a VO2max of 70 ml kg-1 min-1, the threshold determined with the method described by Billat was a 56 VO2 ml kg-1 min-1, pedaling at an intensity of 310 W at a frequency of 80 rpm for 10 minutes, blood lactate capillary earlobe was 2.0 mmol.l-1, with a respiratory quotient of 0.9. His maximum heart rate was 187 beats / min. and blood hemoglobin concentration at 140 g / L.
Both riders are subjected to a program of training and competitions of 6 months. After this program tests were repeated and it was observed that rider A had a VO2max of 79 ml kg-1 min-1, the threshold determined by the method described by Billat, VO2 was a 50 ml kg-1 min-1, pedaling at an intensity of 335 W with a frequency of 80 rpm for 10 minutes his blood lactate capillary earlobe was 3 mmol.l-1 and the respiratory quotient was 0.88. His maximum heart rate was 189 beats / min. His blood hemoglobin concentration increased to 152 g / L and body mass (weight) decreased to 65 kg. Cyclist B had a VO2max of 80 ml kg-1 min-1, the threshold determined by the method described by Billat was 58 ml kg-1 min-1, pedaling an intensity of 375 W with a frequency of 80 rpm for 10 minutes his blood lactate capillary earlobe was 2.0 mmol.l-1 and the respiratory quotient was 0.91.
His maximum heart rate was 184 beats / min. His blood hemoglobin concentration changed to 130 g / L and body mass did not change. Both tests were performed under similar conditions on the two cyclists before and after training. None had signs of overtraining.
Extract.
Question
It is nessessary to know something om In what direction are the wood energy: definition, objectives and challenges in South East Europe
Question
Can anyone please tell me, how to detect or find any unknown compounds (like organics, carbohydrates or some enzymes secreted by algae.) present in water samples?
If you can expect few compounds it may contain from literature, it will be easy to go for chemical tests for those compounds, otherwise GC-MS is the best option to clear spectrum of compounds that the algae secretion contain.
Question
Can anyone tell me the latest technology advancements and improvements in recent trends of KERS (Kinetic Energy Regenerative System) used in Automobile Braking?
It is only Used in Racing Technology.
In serial Cars it singt considered behause the power Need is much lower so everybody is using hybrids.
Since the rules in Formular One are going to change i doubt that this Technology will be Further Developed
Question
Hi there, hope someone could help me. I am looking for a graph showing the sum of electricity generated by conventional and renewable energies over the course of one or several days. Location is not so important, but it should be either a real profile from today or a realistic estimation of a future scenario (best would be both :-).
I attached an example for Germany, unfortunately without renewables. Help is much appreciated! Thanks! Stefan
Question
Metals like Nickel which will give more hydrogen production.
Question
It is proposed on the basic point of zero magnetic point at which it can generate energy to make it rotate and produces external energy which is used to convert this mechanical energy to electric energy.
it depends on the basic principle of earth which is at zero magnetic point.such that it can produce energy to make it rotate continiously.
Gare,
As you seem to have some knowledge of this, may I state that I am unaware of *any* case in which a magnet, through being depolarized, liberates energy. If you can indicate a text, peer-reviewed paper, or well-established principle, that would be a good starting point.
Note, one generally has to perform work on a material (ie, heat it past the Curie temperature) to depolarize a magnet. I know of no way to do the opposite - but am open to new information.
Question
The growth of particle in vapour phase synthesis takes place due to supercooling and condensation. But what factor decides the formation of different shapes of particles.
Which energy technology do you think will have the biggest impact on our lives in the near future?
Question
Huge efforts and imagination are being deployed to find alternative ways to generate energy with less harmful effects on our environment, so in which energy technology should we invest? And which one will have the biggest impact in the future?
Georgi I hope the below article will convince you that nuclear fusion is more than a 'bright dream' and will help to remove a lot of the misconceptions that many people have regarding the cost of fusion research. "Fusion research is a wise investment The United States must not give up its place in the world fusion research program A consortium of six nations plus the EU is constructing the world’s first burning-plasma device, the ITER tokamak in France, which will produce 10 times more fusion power than external power put in to heat the plasma. The rest of the world sees the tremendous potential of magnetic fusion energy. It’s also important to note how modest the fusion research budget is: Alcator C-Mod employs 120 skilled staff and supports the jobs of 200 more, and trains 30 graduate students at a time, on an annual budget of $28 million. The entire domestic magnetic fusion program costs the taxpayer$298 million per year. This is a mere 0.03% of the U.S. defense budget, or about the cost of buying two of the new F-35 fighter jets. Magnetic fusion research suffers from numerous misconceptions, dating back to the early years of the research program when, buoyed by the spectacular first results from the tokamak in the late 1960s, a few pundits made optimistic predictions about how long it would take to build an economical fusion reactor. Later, in the 1970s and ’80s, new phenomena were discovered that at first were mostly bad news, like turbulence that caused heat to leak out of the plasma much faster than originally predicted. But more recent discoveries have been hugely beneficial, and have propelled fusion research toward the goal of an economical reactor. The past few decades have seen spectacular increases in fusion performance, due to discoveries like a region of parameter space called H-mode, which halves the energy leak rate for tokamaks and led to experiments in the U.S. and the U.K. that produced more than 16 MW of fusion power. A more recent development is the I-mode, which promises to keep the plasma clean and hot without edge instabilities that act like solar flares and damage wall components. It was discovered right here at MIT, on Alcator C-Mod, and is being actively studied as an operating scenario for ITER. Furthermore, every time something new is discovered to better control fusion plasmas, our designs for fusion reactors drop in cost and size. The state-of-the-art ARIES-AT reactor study concludes that a fusion reactor is cost-competitive with a fission reactor, and has none of the proliferation or high-level waste issues. Further advances will continue this trend, but these advances will only come about with a strong experimental program in place. The U.S. will only be poised to take advantage of the results from ITER and take the next step to build a real prototype electricity-producing magnetic fusion reactor if fusion researchers exist in the U.S. We do not know exactly how long it will take to reach an economical reactor — indeed, this uncertainty defines scientific research. But the progress that fusion research has made, as demonstrated by the ability to simulate and then build tokamaks like EAST and ITER, shows that this is one research risk that the U.S. would be foolish not to take. The potential reward is far too great to ignore. http://tech.mit.edu/V132/N9/olynyk.html
Question
(heat generation inside of the glass).
If the film is truly absorbing (reflecting to IR light sould be preferable) it should obviously be placed on the intended warmer side of the cavity, the outer one in case heating up from the sun should be blocked. Generally, the gas filled cavity provides most of the insulation in a double pane window. Convection with the cavity is actually unwanted and apart from the mechanical design one reason limiting its width, the distance between the window panes. Trying to answer your original question I would expect an increase in convection flow, although the usually quite uniform distrbution of heat source / sinks on the two sides and the unfavourable geometry (1:100 width:height ratio) will keep the total amount of convective heat flow quite small in most cases.
Question
I have a lot of data which are ready to train ANN algorithm. I want to get the approximate data of the target site using this algorithm and compare it with real data (which I have already, too). But I don't know how to do an unsupervised ANN training using MATLAB Toolbox.
Use 'nntool' in matlab and follow the steps as below:
-call the input variable in the toolbox
-choose the appropriate learning algo. using the menu selection(by default it uses BPN algo., which is of supervised ANN type).
-train your network by selecting the network structure(number of layers,neurons etc...)
- choose the stopping condition
Is there any evidence for creating methane or methanole from CO2 plus H2 on a large industrial scale?
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There is a vivid discussion on sequestration of Carbon Dioxide here in Germany. On the other hand there are some projects of creating CH4 (methane) from CO2 and H2 which are generated by the renewables. However this is, as far that I know, only on a lab-scale (Prof. Michael Sterner in Regensburg). Therefore it might be interesting to know how far the energy industry is pursuing these ideas. The idea behind creating methane is to store that gas within the normal gas pipes which already exist.Thus there will be a relatively big storage for energy which otherwise will be wasted due to fluctuation of the renewables (at least wind, solar)
I'm not sure about the CO2 and H2 process, however, syngas is mostly CO and H2.and is converted to heavier hydrocarbons with the FT (Fischer Tropch) process. Methane can be produced that is used as SNG (Substitute Natural Gas), where Natural gas mostly consists of CH4 in any case. Methane is a good gaseous fuel, however, the products of combustion is CO2 and H2O. CO2 is at least a much "friendlier" greenhouse gas than CH4. Despite any negative sentiments we may have about fossil fuels, they are going to be with us for a long time to come and we better do what we can to be more energy efficient and advance cleaner energy sources.
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Lignin is a potential source for the generation of fuels and chemicals. It is a perfect time for the biorefineries to valorize lignin by identifying the efficient route for the conversion of lignin to liquid. Let's discuss the existing biorefinery approaches of lignin liquefaction and its future possibilities.
Holger, Thanks for the post. It must be the production of ethanol from the cellulosic part after delignification, & not lignin. The large waste of pulp and paper industry, ie lignin is of low value till date.
Question
What are the latest challenges in lithium battery research, and do researchers feel that we have reached a mature stage in its development or is there still plenty of room to improve their energy density and lifespan?
Vivek, I just found out that you have to save the download before reading it. Maybe that was the reason for failure.
Question
SI=International System of Units
pu=per unit
I presume you are using Simpower or the Power Systems blockset which has two such Asynchronous Machine models available. One for SI and the other for PU.
The internal machine models are identical and will provide the same results the only difference is that the SI unit model requires one to enter the model parameters both electrical and mechanical in actual SI engineering units, kW, amps, ohms, Henries etc whereas the pu requires the same SI parameters be converted from SI units and entered in pu.
To help you the developers of the blockset provides a conversion tool which allows you to enter the standard nameplate machine parameters in SI and will convert to SI or pu for you see
power_AsynchronousMachineParams
just type this in the Matlab command line and the menu will pop up.
You can then use these in both the SI and pu models and both should give the same results.
Once you have done this I then suggest that study the PU system that the developers of the blockset use and try and do the same exercise by hand.
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example for induction machine Which is modeled as follows ( 1st order ):
FT=id/Vd=Iq/Vq= 1/(Rr+sigma*Lr*s) open loop
a reponse time in closed loop is imposed tr (in seconds)
then in SI system: the parameters of PI are Ki=3Rr/tr and Kp=3sigma*Lr/tr assuming that: PI=Kp+Ki/s
In pu what will be the difference?
This will depend on the per unit system and type of parks Transform you are using.
There are two commonly used systems pu systems. One uses a time base of Tb = 1/Wo and the other uses a time base Tbase = 1 sec.
The former is / was popular in the US and was used for analogue computers and does time scaling so that simulation time is effectively t*Wo and the pu synchronous speed is 1 pu whereas the latter is / was popular in the UK and where pu time and actual time are equal as is pu and actual speed.
It will also depend upon the type of Parks Transform you use. If you use the power invariant transform then ABC and DQ parameters are equal whereas in the power invariant transform 1 ohm in ABC is 1.5 ohm in DQ.
Once in pu they all end up the same but in actual units one has to account for both the PU system and parks Transform being used.
As such I would expect that in the former the time constant will be Tau(pu) = Tau*Wo whereas in the latter it will be Tau(pu) = Tau/ 1sec where Tau(pu) = Tau/Tbase
Specific energy consumption for CO2 capture.
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Considering different processes for CO2 capture e.g. absorption, membrane and cryogenics, how could we compare the energy consumption? In chemical absorption, the main energy consumption comes from the stripper reboiler (heat duty), while in a membrane process, the main energy consumption comes from the compressors and vacuum pumps (power or electricity) and cooler (heat duty). We know the price between heat and power is different, so how can we convert to the same base to compare the specific energy consumption (GJ/tonne CO2 capture) in different processes?
You must take into account all energy needed for each unit operation or process for CO2 removal. For instance in gas absorption you have to come to a nt value of energy (in J) needed for capture of 1 ton of CO2. Do not forget anything: calculate the energy you need for the reboiler, pumps, energy released from the absorption column and balance these items. Then you will arrive to the net specific energy consumption (J/ton CO2). Do the same for other processes and you will be able to compare them. Also take a look on the following paper which is, actually, a classic on this topic: Rao and Rubin, Env. Sci. Tech., 36, 4457/4475, 2002.
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Has anyone done work in quantifying the economic benefits of being able to switch fuel sources? (ie. not get stuck on Natural Gas and be able to switch to say biomass or something else if/when costs escalate).
There's obviously a benefit, what metrics would you use to evaluate it? Any suggestions are appreciated.
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The climatic conditions required to protect the buildings from global warming. So the solution lies in a lot of green areas, because the small percentage of green areas in residential neighborhoods or urban area leads to the aggravation of heat waves. Therefore, the development of urban areas alter the effects of climate change on cities and imposes a variety of challenges and multiple solutions.
For healthy environment it is recommanded to design friendly walkable commuinty. Therefore, when streets are designed only for cars, they deny people the opportunity to choose more active ways to get around, such as walking and biking. Even where sidewalks exist, large intersections and speeding traffic may make walking unpleasant or even unsafe - discouraging any non-motorized travel.
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In region where two streams at different temp (20-25 celcius ) met and it is possible to  utilise the thermocouple effect.  It could warm water at the seabed and cooler water at the surface or vice-versa.
What trade-offs to make for desired properties of fuel cell catalyst?
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An ideal fuel cell catalyst should have certian properties such as 1) ease of manufacture- easy to mass produce 2) low cost this is a major problem with the Pt compouds 3) power output - some catalyst are low powered 4) effiency no H2O2, and complete oxidation of fuel 5) Durable. Corrosion of carbon supports and metal migration, ostwald ripening et. ect 6) resistance to CO and other poisoning. However, if one must trade, for example, durablity for "reactivity" that is efficiency, complete oxidation, but at the cost of the catalyst corrosion, is this a good trade off? Are the first three the most critical? If forced to trade which properties are most important?
Dear James, Perhaps this paper might be of interest to you. It offers no solution but describes the most fundamental challenges in detail. Best Regards Ulrich
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Now there are many control types; PID, fuzzy, robust, sliding mode, neural, etc. techniques.
Which method do you prefer and why? If someone decided to learn a new control method (other than PID), which one is the best in terms of simplicity, accuracy and quickness?
As you mention there are many ways in which to skin the cat. However, I go with Dave. The best strategy is to start with the old classical PI controller. From my perspective it is best to try and understand how and what any controller is trying to control from a systems viewpoint whilst trying to achieve its control objective. Only then can one makes sensible rules for Fuzzy Logic, sliding mode control and neural networks.
Regardless of controller any and all power converters simply control the flow of electrical energy from source to load and vice versa. Whether one uses classical control, fuzzy, or neural all require sufficient information to be able achieve the control objective and this may not be "violated". In all power converters the only things we can normally control is the voltage and its phase and frequency. Whether one has current loops, speed loops, position loops or any other, one may only control the magnitude, phase and frequency of the output voltage.
If we take a variable speed AC drive for example, the fundamental control objective is to transfer electrical energy, via the converter and store this within, the mechanical inertia of the motor or drive system as fast and as stable as is possible. In reality we only have physical machines with physical properties (R, L, J etc) and physical converters with practical static limits (Vmax, Imax) and in reality we only have open loop parameters through which to transfer energy.
Through fast acting control we can make it appear we have faster time constants but all we are doing is controlling the voltage. The higher the voltage the more the ability or capability to transfer energy more rapidly between load and source and vice versa within the physical limits of the power electronics converter. The achievable closed loop time constant depends on the voltage limit we may apply and very little else. Hence we have to understand each design aspect of the system being controlled.
Why am I saying this is that many believe one may simply implement fuzzy and neural controllers without much knowledge of the system or system parameters but this is not true. When in fact you actually do this you realise that the Fuzzy rules depend on your (in depth) knowledge and experience of what is actually going in the old PID controller and the system it is trying to control. Same as for neuro controller what input, outputs, number of neurons / nodes etc. This is why I stated that all controllers must have sufficient information and as Dave has said the starting point is the old classical PID controller.
The answer to your question probably lies in what is most widely used in the industry. At very low levels like washing machines, disc drives etc fuzzy is being used, but at high power levels where risk, deterministic, reliable and repeatable operation and performance is required the old classical controller still rules with some non-linear add on's here and there gained from operational experience
As an example sliding mode control was quite popular when robotics emerged as it offered robust 3D point to point trajectory based control. However, this required inner stable speed and current loops which normally used classical old PI controllers and of course the power converter had to be able to provide the energy to allow the robot arm be able to robustly follow the said trajectory.
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I'm trying to compare options for municipal waste wood. Does anyone have GHG information or even process information for
1. GHG emissions to turn waste wood into high quality much.
2. GHG emissions to turn waste wood into municipal compost
3. GHG emissions to turn waste wood into biofuels.
IPCC Guidelines for National Greenhouse Gas Inventories (2006) might be helpful. There are separate guidelines and worksheets for Energy and Waste. I don't think they include CO2 emissions from waste wood to the national totals of GHG emissions, because the carbon is of biogenic origin and renewable. However, if incineration of waste is used for energy purposes, both fossil and biogenic CO2 emissions are estimated.
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I measured a power solar, which gives the power /m2. I need a formula between solar energy and wavelength? How to calculate the wavelength from Energy (Watt/m2)?
I've received a solar radiometer (photocellulare), so it is the energy received by the Earth is 1000 watt / m2 per minute but it changes for one minute
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I am writing a feature on biofuels for the Economist - my Deadline 25 March. Would it be possible for anyone to answer some of the following questions about the issues raised by biofuels.
1. What, if any, is the environmental case for encouraging production and usage of biofuels in order to reduce carbon emissions ?
2. What , if any, is the economic case for imposing targets on biofuel production and usage in transport and district heating systems?
3. How would you justify the current policy of subsidies for biofuels R&D, production & refining ?
4. Given the financial constraints on both sovereign governments and energy consumers can you envisage any change in government biofuel policy with respect to both targets and cuts in subsidies.
5. Is there a need for global leadership to determine realistic policies for bio-fuels?
Thank you!
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Under the title of renewable energy for rural areas.
It is our pleasure to cooperate with you, but unfortunately Germany is not included, it includes Finland, Belgium, Switzerland, Norway and Turkey. I'm sorry.
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We have to find one is gas chromotography, any other method to find the gas
In gas analysis
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According to Van der Waals rule if T>Tinv, then repulsion works between the molecules of gas which causes a temp. decrease during expansion (Joule Thomson effect ) and when T<Tinv, then attractive inter molecular forces cause a temp. increase (Rev. Joule Thomson effect).
In neutral molecules like Ar or N2, the electron distribution is such that there is no permanent dipole or similar imbalance *on the average*. But *at each instant*, the electrons have to be somewhere, and their locations in space may be such that a temporary electric dipole moment, quadrupole moment, etc., results. If another molecule is near, the temporary electric moment will affect its electron distribution, which gives rise to a weak attraction that is approximately proportional to r^(-6) [r: center-center distance].
Look for "London forces", "van der Waals forces" or "dispersion forces" on the Internet if you want to know more about this effect.
Please note that these forces always act between molecules; this is not a matter of temperature! But whether these forces can affect the molecules of a gas enough to cause a positive Joule–Thomson effect or condensation, that depends on density and temperature.
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In particular on the technologies developed in function of government incentives. The target market can be both in Europe and in the rest of the world.
Hi Benedetto, surely as you are within the European community you should know of Feed in Tariffs (FIT) to encourage “renewable” sources, in UK in particular see http://www.gov.uk/feed-in-tariffs/overview , especially for domestic generation, the majority uptake was in PV installation as ways of making extra money. Further to that Renewable Heat Incentive (RHI) for both non/domestic were introduced, see http://www.energysavingtrust.org.uk/Generating-energy/Getting-money-back/Renewable-Heat-Incentive-RHI
Generally the idea is to have everyone to encourage to promote the FITs see
In Germany this has been in legislation for some time and fully implemented in 2000, see http://www.erneuerbare-energien.de/fileadmin/ee-import/files/pdfs/allgemein/application/pdf/eeg_2012_bf.pdf (translated version on Chrome).
Hope this helps. BTW: I talked about UK & Germany mainly from personal experience.
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Which microorganisms, types of reactor, butanol recovery process, etc.?
If you are looking for an acetone-butanol-ethanol (ABE) host, I would recommend you take a look at Clostridium acetobutylicum - there is a recent paper from the group of Harvey Blanch in nature that presents a very nice chemical extraction route as well....http://www.nature.com/nature/journal/v491/n7423/abs/nature11594.html
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Which are you using?
Thank you for your answers, they will be really useful for me
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I am looking at how crude inventory, forecast inventory, price forecasts can be used to support crude exposure and risk management.
Dear Faheem Hamid
See the attached two files related for your question about risk management
Best Regards,
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As it is a new ISO management standard, there is no data about benefits/difficulties, etc.
Certainly. For the moment, close to 5,000 sites (from ~1500 organisations) are ISO 50001 certified. You can see an overview of them on the link below. Almost 50% of these organisations are in Germany.
The above list gives an overview of organisations that adopt ISO 50001 and go through certification. There must be many more organisations using ISO 50001 but not planning to certify, or not yet certified. I'd be very interested in an indication of wider ISo 50001 adoptions.
ISO publishes an annual survey giving an overview of the adoption of its various management standards, including the new ISO 50001. The latest (2012) edition is available from their website:
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