Hsueh MF et al. Analysis of “old” proteins unmasks dynamic gradient of cartilage turnover in human limbs. Science Advances, October 2019.

Humans may not be able to regrow amputated limbs, but a recent study showed that damaged cartilage may regrow through a process similar to that of animals such as salamanders and zebrafish. Scientists collected 18 specimens of joint tissue from the hips, knees, or ankles of patients who underwent surgery. They then placed the tissue in a mass spectrometer and measured the age of the cartilage proteins in the sample. These analyses showed that the age of cartilage largely depended on where it resided in the body. Cartilage in ankles is young, middle-aged in the knee, and old in the hips. This correlation between the age of human cartilage and its location in the body suggests that limb repair occurs in humans in a similar fashion to certain animals in which tissue regeneration takes place at the furthest tips such as the ends of legs or tails. This finding also helps to explain why injuries to people’s knees and, especially, hips take a long time to recover and often develop into arthritis, while ankle injuries heal quicker and less often become severely arthritic. The researchers further identified the molecules that are instrumental in the regulation of this region-specific regeneration process. They are called microRNAs and, not surprisingly, are present at very high levels in animals that are known for limb, fin, or tail repair including salamanders, zebrafish, and lizards. Scientists believe that these regulator microRNAs can be utilized in the regeneration of degenerated cartilage of an arthritic joint to reverse arthritis. Regeneration of part or all of an injured human limb may even be possible by finding components salamanders have and we don’t. Finally, it is also possible that this could be a fundamental mechanism of repair that could be applied to many tissues, not just cartilage, which might open up many new avenues in the regenerative medicine.

The universe might have many Earth-like exoplanets

Doyle AE et al. Oxygen fugacities of extrasolar rocks: Evidence for an Earth-like geochemistry of exoplanets. Science, October 2019.

New astrophysical and geochemical evidence suggests that Earth may not be that unique, and Earth-like planets may be common in the universe. All of the planets in our solar system orbit around the Sun. Planets that orbit around other stars are called exoplanets.  The first exoplanets were discovered in the early 1990s. Since then, thousands of exoplanets have been revealed with over 4,000 confirmed and a further 4,495 potential candidates. There have been major efforts to narrow down the exoplanets that may have properties similar to Earth with conditions suitable for life. This includes being a rocky planet that is not too hot or cold so that liquid water can exist. When searching for exoplanets that are similar to Earth, astronomers typically look for worlds in orbit around a type of star called a red dwarf or an M-dwarf. These types of stars are somewhat similar to our sun and make up about 70% of the stars in our galaxy. However, a new study shows that rocky exoplanets in orbit around a different type of star, a white dwarf, can have interiors that are surprisingly similar to our planet. White dwarf stars are dense remains of normal stars that have exhausted their nuclear fuel. These stars are typically composed of light elements such as hydrogen and helium, but in some cases they attract heavier elements such as magnesium, iron, and oxygen in their atmospheres due to their extreme gravity. These heavy elements are thought to be introduced when a rocky exoplanet crashes into a star, which gives astronomers evidence of what the exoplanets were like before they were destroyed. In this recent study, scientists looked at six white dwarfs located 200 to 665 light-years from Earth and rocks from the planets that once orbited it. Their analyses showed that five out of the six white dwarfs had sucked up fragments whose chemical composition is similar to rocks on Earth, Venus, and Mars. While the conditions suitable for life depend upon many additional factors, this study points towards the idea that many rocky planets are likely very familiar in terms of their general composition and, therefore, structure and behavior. This study also made a substantial leap forward in being able to make inferences for bodies outside of our own solar system and indicates that it is very likely that there are truly Earth analogs out there.

Artificial leaf points to a sustainable path to carbon-neutral fuels

Andrei V et al. Bias-free solar syngas production by integrating a molecular cobalt catalyst with perovskite–BiVO4 tandems. Nature Materials, October 2019.

An artificial leaf from which a “clean” fuel alternative to petrol could be produced has been developed. Synthetic gas can be obtained from the lead by using only sunlight, carbon dioxide, and water.

Synthetic gas, also called syngas, is typically a mixture of carbon monoxide and hydrogen. It is largely produced by exposing fossil fuels such as coal or natural gas to high temperature steam and pressure, and the process releases carbon dioxide. Syngas is broadly used in a wide range of commodities including fuels, plastics, and fertilizers. While the utilization of fossil fuels has enabled large-scale industrial development in human history, the burning of fossil fuels is the largest source of emissions of carbon dioxide, which is one of the greenhouse gases that contributes to global warming. For decades scientists have been trying to discover new ways to produce syngas in order to close the global carbon cycle and to establish a sustainable chemical and fuel industry. In a recent study, researchers got inspired by leaves. These perfect little machines use sunlight to convert carbon dioxide and water into fuel for plants through photosynthesis. An artificial leaf has been designed to have two light absorbers, similar to the molecules in plants that harvest sunlight, and a catalyst made from the naturally abundant element cobalt. When the leaf is immersed in water, one light absorber uses the catalyst to produce oxygen and the other one carries out the chemical reaction that reduces carbon dioxide and water into carbon monoxide and hydrogen, thus forming the syngas mixture. The scientists are now searching for ways to use their technology to produce a sustainable liquid syngas that could serve as an alternative to petrol. Although major efforts to generate renewable energy sources are being made, the development of synthetic petrol is critical as electricity can currently fulfill about 25% of our total global energy demand. There is a huge demand for liquid fuels to power heavy transport, shipping, and aviation sustainably.

Only 0.15 % of the energy that reaches the earth is used by the plants and the algae as a source of energy for photosynthesis. The energy that is stored in the form of chemical energy within the photosynthetic plants establishes the source of energy for the food that is consumed by the creation. The past creation, as a result of the physical-chemical processes, was fossilized and solar power has been stored in the form of fossil fuels (oil, coal, natural gas).

Energy consumption and the environment

Energy consumption is viable for every form of work; the waste is what remains in the environment. This waste does not pose a problem as long as they do not damage the sensitive ecologic balance. However, rapid industrialization and urbanization, which lead to excessive amounts of energy consumption, result in environmental problems. Since industrialization-urbanization is directly related to energy consumption – particularly with fossil fuels – industrialized countries are more vulnerable to experiencing environmental problems. In today’s world, it is climatic change – a product of global warming – among these problems that is of the greatest global importance.

The increase in the proportion of carbon dioxide, a greenhouse gas, in the atmosphere is the main factor for global warming. This increase is directly related to the consumption of fossil fuels. The rays of the sun, which are reflected from the earth, are trapped by carbon dioxide gases (chlorofluorocarbon, nitrous oxide and other greenhouse gases, such as water vapor) in the atmosphere, and they can not return to space. This, in turn leads to the atmosphere heating up (the greenhouse effect), eventually leading to an increase in heat throughout the world.

The main reason for the increase of carbon dioxide in the atmosphere is the consumption of fossil fuels (77%) and the decrease in the number of forests (23%). Coal gas is normally the last product of the anaerobic processes in nature. In recent years human intervention played the main role in this abnormal increase in gases. Playing an important part in this process is the expansion in rice fields (38%) in order to feed the increasing population, natural gas extraction and its transfer (16%), an increase in the number of cattle (14%), coal mining (12%), and the oxidation of produced biomass (6%). Chlorofluorocarbon is included in industrial products. As for the nitrous oxides, they are the by-products of reactions in the nitrogen cycle in nature. In recent years, as a result of the increase in the use of the nitrogenous manures (85%), forest fires and other fires (11%), and the oxidation of the produced biomass (7%) there has been a rise in nitrous oxide. Consequently, the rapid increase in greenhouse gases in the last years has lead to a 0.5°C increase in the average heat of the earth.

If the greenhouse gases continue to be accumulated at this speed, then by 2100 the average heat of the earth will record an increase of 2–4°C compared to the period before industrialization. Eventually, there will be a greater melting of the glaciers at the poles, which will lead to 0.5–1.5 % increase in sea level. Thus, residential areas by the seaside, agricultural areas, wetlands and industrialized areas will face the danger of being flooded. Moreover, the risks of climatic changes and desertification will become much more severe.

Some countries are investigating how to calculate the probable effects of a decline in water, food and energy resources and what precautions need to be taken accordingly as a result of global warming. In this sense, the problem was clearly indicated during the summit meetings in Vienna (1985), Rio (1982), and Kyoto (1997), however, they have not been sufficient to provide a solution.

Another important problem arising from the overuse of fossil fuels is the damage to the environment caused by air pollution and acid rain. During the consumption of fossil fuels, CO2, NOx, and SOx are emitted into the atmosphere and these, combining with water vapor, lead to the formation of carbonic acid (H2CO3), nitric acid (HNO3) and sulfuric acid (H2SO4). While normally the pH of rain water is 5.5–6, with these acids it falls down to 3.5–4. This and the resultant dissolution of the metals in the water pose a threat for both the land and the aquatic ecosystems (e.g. a decline in fish species in many lakes) and impair the ecologic balance.

The impact of alternative and renewable energy on the environment

The negative impact of fossil fuels on the environment and the decline in their reserves has accelerated the search for new energy resources. Even though nuclear energy is not a renewable resource, today it has come to be regarded as an alternative energy resource all around the world. Hydrogen, too, is another growing alternative resource. Geothermal energy is also a renewable energy resource, yet it is mostly restricted to the region where it originates.

With current technology, it costs us more to use solar energy rather than to extract fossil fuels. Moreover, there is a great need for the development of new technology that is aimed at producing wind, hydroelectric, bio-energy, tidal and wave energy in the most efficient way at the lowest cost.

Defeated by their ambitions, human beings, particularly in the last century, have destroyed the world and the environment that has been entrusted to them. Since the global impact and the cost of this process only emerged recently, it was too late before human beings realized that they needed to shift from energy systems based on fossil fuels. All the worries and concerns that have surfaced today is not because we have finally realized that the earth has been entrusted to human beings, but simply because the future seems to be promising nothing but destruction. Thus, the real solution to the problems is not related to acting to find a solution to the problems, but rather in being in compliance with the measures of the actual Owner of the world and the universe and avoiding form all types of extremism.

References

• Spiro Thomas G. and Stigliani William M. 1996. Chemistry of the Environment, Prentice Hall, Upper Saddle River, New Jersey, USA.
• Godish Thad. 1997. Air Quality, CRC Lewis Publishers, Boca Raton, New York.
• World Energy Outlook. 2004. International Energy Agency.

Original Article: Wang, M. et al., PNAS (published online before print on March 1, 2010).

Periodic injections of insulin to manage blood sugar levels is critical for the treatment of diabetes patients. It requires continuous monitoring of glucose levels in the blood and multiple injections of insulin in order to mimic the natural balance of sugar-insulin levels in the human body. Yet, it is often difficult to maintain this extremely sensitive hormone balance without major side effects. These complications include blindness, leg ulcers and amputations, heart vessels problems, renal insufficiency, stroke, and nerve damage in the legs and arms. Moreover, the long-term use of insulin causes the increase of body fat and bad cholesterol. A new research study on non-obese diabetic mice shows that adding leptin- a hormone responsible for appetite control- to the insulin therapy results in better control of blood sugar levels and decreases the bad cholesterol and body fat of Type 1 diabetic mice. This is promising, as it could reduce heart and circulatory complications of Type 1 diabetes. However, the leptin therapy may not have an effect on type 2 diabetes, adult type, because in this type patients already have high levels of leptin. However, it has to be shown that leptin therapy is safe and effective on humans as well. There is a long way to go before we can use leptin in practical areas.

2- Re-teaching speech with music

Original Source: Schlaug G, Annual Meeting of the American Association for the Advancement of Science (AAAS), San Diego (2010).

Nearly 800,000 people in the U.S. are faced with strokes each year, and a quarter of those are affected by aphasia, a deficit in language. Using a new melodic intonation therapy, therapists treat patients by teaching them how to sing words and phrases consistent with the underlying melody of speech. As a result, the patients continue to speak in a more “sing-songy” way than a person with normal speech patterns, according to Dr. Schlaug, professor of neurology at Harvard Medical School. After 15 weeks, 1.5 hour-long daily sessions with a therapist, the patients gradually learn to piece the sung words together into organized speech. There are two separate brain networks associated with vocal output, with the one in the left hemisphere being engaged with speech and the other one in the right hemisphere strongly responding to music and melody. For the stroke patients that had damage to the left hemisphere, this therapy may help to train similar areas on the right hemisphere, helping them to initiate a speech region in the right hemisphere. Singing facilitates necessary engagement to the right hemisphere. Images of patients’ brains before and after the therapy reveal striking structural and functional changes in the right hemisphere. This study also reminds us of the brilliance of musical therapies employed in early hospitals in the Islamic world.

3- Renewable Jet-Fuels

Original Article: Bond, J.Q. et al., Science 327, 1110 (2010).

The global need for sustainable energy resources is ever increasing and the use of renewable fuels offer promising solutions. Among others, biofuels are especially important due to the presence of direct conversion routes from plant-based waste materials to conventional liquid fuels. However, high synthesis costs and complex processing steps are major hurdles to overcome before putting biofuels forward as economically viable alternatives to fossil fuels. Researchers are therefore trying to come up with more efficient methods -and one group, from the University of Wisconsin appears to have done so. Unlike commonly utilized routes involving microorganisms, they use a novel and environmentally-friendly chemical process which is easier to control and maintain. By using an inexpensive catalyst, they convert the majority of the wasted biomass to gaseous butene and carbon dioxide, with a water-based solution of gamma valerolactone as the intermediate chemical. The butene gas is then easily transformed to high-energy transportation fuels such as gasoline and jet fuel. As an added advantage, the stream of carbon dioxide can be efficiently captured, preventing the atmospheric release of this major greenhouse gas. Under optimized conditions, the system can operate uninterrupted for 90 hours with an overall efficiency of over 75%. Successful work like this will help make biofuels cheaper for mass production, pending the meticulous analysis of its economics.

4- Salt controversy: How much is too much?

Original Article: Bibbins-Domingo, K. et al., NEJM 362, 590 (2010).

Modern humans suffer from high rates of obesity (for instance, 64% of Americans are classified as either overweight or obese) and cardiovascular diseases, with the latter being the no.1 cause of all deaths. A recent study conducted by researchers at the University of California at San Francisco suggests that reducing dietary salt by half a teaspoon a day (~ 3g) would lower the annual number of new coronary heart disease, stroke and myocardial infarction cases. Strikingly, such a modest decrease is expected to decrease deaths from any cause by 44,000 to 92,000. According to the National Salt Reduction Initiative, Americans eat at least twice as much salt as they need where 80 percent of the salt in the American diet comes from processed or restaurant-prepared foods. However, eating too much salt is not a problem for people with healthy kidneys since kidneys are designed to flush out unneeded salt. However, when people have a high salt diet, then their kidneys are over-worked. Taking into account that modest salt reduction in one’s diet won’t likely cause harm and taste buds will likely adapt to this minor change effortlessly, it seems wise to refrain from using too much salt. This would trigger bigger health benefits ranging from not overworking the kidneys to reducing the risk of deadly diseases.

5- Why don’t we get thirsty during sleep?

Original Article: Trudel, E. & Bourque, C.W., Nature Neuroscience (published online before print on February 28, 2010).

In mammals, the “internal-standard-time” is kept by a particular subset of brain cells known as “clock-neurons” which display high activity during the day and low activity during the night. A group of scientists recently reported that the clock-neurons also function as a dimmer for water regulation, allowing bodily water content to be controlled by the body. A specialized group of cells, called osmo-sensory-neurons, detect and regulate water levels in the body, through balancing the water intake via thirst and loss via urine production. When water levels are low, the sensory-neurons communicate with some hormone-releasing cells which instruct the body to store water by ceasing urine production. By using isolated brain slices from rats, the researchers showed that the clock-neurons – when active – interfere with the communication between sensory-neurons and hormone-releasing-cells to suppress the water-storage-hormone release. In contrast, when the clock-cells are inactive (i.e., ‘sleep period’) the communication is restored, resulting in an increase of hormone levels to enable water-storage. Such regulation is the reason why we are not much disturbed during sleep by neither frequent trips to the bathroom, nor excessive thirst (that would both impair the sleep quality), and reminds us the verse from the Holy Qur’an: “..and He has made the night for rest…” (Chapter Al-Anaam, 96).

6- A passage to vegetative state through fMRI

Original Article: Monti MM et al., NEJM 362, 579 (2010).

Consciousness in medicine is defined as the patient’s alertness and responsiveness to the outside world. If a patient does not respond to external stimuli, his/her medical state is considered a “vegetative state”. Researchers from Cambridge, England performed functional magnetic resonance imaging (fMRI) experiments on 54 patients who had been previously classified as either “vegetative” or “minimally conscious”. Interestingly, 5 of 54 patients exhibited distinct neuronal activities in the corresponding regions of their brains, when they are given imaginary motor and spatial tasks. For the motor task, patients are asked to imagine playing a tennis game. For the spatial task, patients are asked to imagine navigating through a familiar location. A 22 year-old man who had been in coma for five months was further evaluated by being subjected to a simple set of yes-or-no questions such as “Do you have any brothers?” and was instructed to answer these questions using one type of mental imagery, that is a motor imagery for “Yes” and a spatial imagery for “No”. He answered 5 out of 6 questions correctly. This is the first evidence that through fMRI approach one can reach the residual cognitive activity in vegetative patients and establish functional communication, raising question marks about our current handling of these so-called vegetative patients.

Our current source of energy is mostly fossil fuels such as oil, coal, and natural gas. Fossil fuels are nonrenewable. In other words, they are finite resources and they will diminish significantly in future; hence, they will be very expensive to use and environmentally harmful to recover. In contrast, solar, wind, biomass, hydrogen, geothermal, ocean, and hydro power are renewable energy resources, that is, they are constantly replenished and will not run out. Renewable energy is not only important for our energy needs but also has significant advantages over fossil-based energy resources in the protection of the environment. Besides, the environmental aspect of renewable energy also has a religious dimension, since preservation of the earth and its inhabitants is regarded as a duty for humankind.

Among these energy resources, solar energy is generally used for electricity generation or for hot water heating. It also finds uses in solar cooling, and in direct heating and lighting of buildings and homes. Solar panels are made of photovoltaic (PV) cells. The term “photovoltaic” means “converting light into electricity.” Solar energy technology has been around since the late nineteenth century. Yet, its share in energy production constitutes a very small fraction (less than 0.1%) of production around the world. This stems from the higher cost of electricity generation with solar panels in comparison to use of fossil fuels. In the US, electricity generated from PV cells costs $0.30 to $0.40 per kilowatt-hour while consumers pay only $0.10 per kilowatt-hour to the electric utility companies. Nonetheless, with recent advances in this technology, it will be possible in the near future to decrease the cost and make this technology viable for our energy needs as we face shrinkage in fossil fuels around the globe.

One of the factors that increases cost is the low power-conversion efficiency of current PV cells. The PV cells used in the market are mostly fabricated from silicon crystals and these cells show a power conversion efficiency of 15%. That means, 85% of photons go to waste when harvesting energy from sunlight. In fact, the theoretical limit of light harvesting in silicon-based solar panels is only 31% because of the low band gap of silicon, which only partially absorbs sunlight to form charge carriers in the device. To solve this problem, scientists have utilized three different crystals in a single PV cell to absorb more sunlight, and these studies have yielded a device efficiency of 37%. Just recently, scientists at the National Renewable Energy Laboratory (Golden, Colorado) and Boeing-Spectrolab have achieved a world-record conversion efficiency of 41% by using the same idea, establishing a new milestone in sunlight-to-electricity performance. Although such studies are very promising in this field, when it comes to production cost, these inorganic PV cells are still an expensive technology for power generation compared to fossil fuels.

Organic photovoltaics

An alternative solution to decrease the cost is to use devices with lower power efficiency but a very low cost of production. Organic-based PV materials offer such an alternative with easy and fast production techniques such as solution processing and printing. Conjugated polymers (polymers with alternating single and double bonds in their polymeric backbone) are especially important in this regard, since they exhibit semiconductor properties. The best organic PV cell efficiencies reported in recent years are around 5%. This number must double in order for the cells to be used in solar panels, assuming that the cell displays high photostability and conductivity. Many research groups are now focusing on organic-based solar systems as an alternative technology to their inorganic counterpart.

Although we are all familiar with solar energy, most of us do not know how electricity is produced from sunlight. To show the mechanism for photovoltaic activity, one first should look into an anatomy of a typical organic PV cell which is shown in Figure 1. This cell is based on an organic PV cell. The organic layer is sandwiched in between two electrodes where light absorption and charge separation occurs. Typically, glass is used for support but plastic materials can also be used as alternatives. The anode is usually indium tin oxide (ITO) and the cathode can be aluminum, calcium, gold, or magnesium. The electrodes must be semi-transparent to facilitate light absorption. Specifically designed conjugated polymers are utilized for sunlight absorption, where the wavelength range of absorbed light may vary from ultraviolet-visible to near infrared depending on the material used in the device. The efficiency of the device is determined by the extent of light absorption, efficiency of charge separation, and charge diffusion to the electrodes. The morphology of the organic layer has been found to be very important for device characteristics and cell efficiency. In an organic PV, an electron is promoted from the highest occupied molecular orbital (HOMO) level to the lowest unoccupied molecular orbital (LUMO) level upon light absorption (Figure 2). This transition results in an electron-hole pair which is then separated by the electric field formed by the different ionization energy of electrodes (Φ). Therefore, the electron moves to the cathode and the hole moves to the opposite side. This process causes charge flow between the electrodes and hence electricity is generated in the process.

Despite all the improvements in organic PV technology, current cell efficiencies are still low for electricity generation. The stability of organic PV materials must be improved as most of them are prone to degradation by oxygen and humidity in the air. The large-scale production of organic solar panels is possible, and yet the feasibility of current methods has not been investigated extensively so far.

Solar energy is a clean, renewable resource of energy and is projected to have significant role in the energy market in near future. Funding in the field of solar energy has been increasing in recent years due to the increasing need for energy and the likely reduction of fossil fuels towards the end of this century. Yet, our research efforts are still not sufficient for the advancement of this technology.

Importance of renewable energy for the environment: an Islamic perspective

Solar energy, like other renewable energy resources, is environmentally friendly. Its use should be promoted, as fossil fuels play a dominant role in the increase in greenhouse gases, which are believed to be responsible for the increased rate of global warming and hence climate change. Global warming may cause rises in sea level and changes in the amount and pattern of precipitation. These changes may in turn increase the frequency and intensity of extreme weather events, such as floods, droughts, heat waves, hurricanes, and tornados. Other consequences may include higher or lower agricultural yields, glacial retreat, reduced summer stream flows, and species extinctions. Warming is expected to affect the number and magnitude of the events mentioned above; however, it is difficult to connect particular occurrences to global warming.

In any case, focusing on renewable energy and energy-efficient technologies is one of the best options to secure the future of our planet and all existing forms of life on it. Our effort should not only be due to the expected shortage of fossil fuels in future. Rather, it must be seen as a duty and moral act to save the environment since use of renewable energy resources has little or no negative impact on nature. Religious awareness and guidance in this area is necessary so that each individual may take active part in the protection and development of the environment. Much environmental degradation is due to our ignorance of what our Creator requires of us. People should be educated to realize that the conservation of the environment is a religious duty demanded by God. This fact is expressed in Qur’an in a number of places such as, “Do good, even as God has done you good, and do not pursue corruption in the earth. Verily God does not love corrupters” (Qasas 28:77), “And do not follow the bidding of the excessive, who cause corruption in the earth and do not work good” (Shu’ara 26:151–152), “And do not cause corruption in the earth, when it has been set in order” (A’raf 7:56). Any deliberate damage to the natural environment and its resources is a kind of corruption which is forbidden by Islam.

As Muslims, we should protect and preserve the environment because by doing so we protect the creatures which pray to God and praise Him. Although we do not know how they praise God, the Qur’an clearly points this out: “The seven heavens and the earth, and all beings therein, declare His glory: There is not a thing but celebrates His praise, and yet you understand not how they declare His Glory!” (Isra 17:44). Islam is established on the concept of good (khayr). Since it is scientifically proven that protecting the environment is of great significance for all animals and plants on earth, Muslims should see it as khayr. In the last two verses of chapter Zalzalah (99:7–8), God says, “And whoever does good an atom’s weight will see it then. And whoever does ill an atom’s weight will see it then.”

Protecting God’s creatures and the environment is a duty of humankind because human beings are the “agents” of God on earth. This task cannot be performed by other creatures. Therefore, as the Muslim community we should all commit ourselves to the preservation and to the protection of the environment. Surely, investing in and promoting improvement of the technologies based on renewable energy is one way to go.

References

• http://www.nrel.gov/learning/re_basics.html
• http://www.islamonline.net
• http://lfw.pennnet.com/Articles/Article_Display.cfm?Section=ARTCL&ARTICLE_ID=257239&VERSION_NUM=3&p=12 (PHOTOVOLTAICS: Research targets more-efficient photovoltaics)
• http://lucy.mrs.org/publications/jmr/jmra/2005/dec/0407.html (Organic and nano-structured composite photovoltaics: An overview)
• http://www.orgchem.science.ru.nl/molmat/mm-web/education/caput-college/SolEnergMatCells-2004-83-125.pdf (A brief history of the development of organic and polymeric photovoltaics)
• http://en.wikipedia.org/wiki/Global_warming
• http://www.islamset.com/env/index.html

One of the most important reasons for the last two world wars was the sharing of energy sources. 60 years on from the last world war, the world is now very close to confronting the same problem. There has been an enormous rise in energy demand since the middle of the last century. This increase has resulted from both rapid industrial development and population growth. As shown in Figure 1 and 2, the world population is 4.8 times greater, and the total energy requirement has increased more than 30 fold from between 1850 and 2000. Many studies have demonstrated that while global demand increases by at least 2-3% per year, the current oil fields are depleting at an average of 3-5% per year. If this demand continues at this rate, we will reach a point of crisis in oil sometime after 2010, and the same will be true for natural gas somewhat later, between 2020 and 2030 [1, 3]. The basic energy source of the world, hydrogen, is a new hope for solving the energy problem. It is likely that this century will be the century of the fuel cell. This technology uses hydrogen as fuel, and offers the prospect of supplying the world with clean, sustainable electrical power.

Hydrogen, which is the simplest element in space, was discovered in the 16th century and its inflammable property was understood in the 18th century. Ninety percent of the known universe consists of this simple element. Hydrogen is colorless, odorless, nonpoisonous, and 14.4 times lighter than air. In its liquid phase it has a temperature of -252.77 °C. It is the fuel of the sun and other stars, hence the main energy source of the universe. Hydrogen is not found as a free element in nature, but rather it is found as a compound, particularly as water. Hydrogen has the largest energy amount per unit mass among known fuels. The energy of 1 kg of hydrogen equals 2.1 kg of natural gas and 2.8 kg gasoline. However, its volume per unit energy is higher. It is 1.33 times more efficient compared with fossil fuels as an energy source. When hydrogen is used to produce heat or propulsion, only liquid water or water vapor emerge, making it an extremely clean energy source.

Hydrogen can be used with fuel cells to produce electricity. At the present time, the cost of this method is 3 times more expensive when compared to other fuels. Fuel cells use hydrogen, or hydrogen containing compounds to produce electrical energy and heat. A fuel cell has no moving parts and makes no noise when operating. A single fuel cell contains three layers, as shown in Figure 3. These are the anode-electrode layer, the membrane layer, and the cathode-electrode layer.

There are three types of fuel cells; Polymer Electrolyte Membrane (PEM), Direct Methanol Fuel Cell (DMFC), and Solid Oxide Fuel Cell (SOFC), each named after the material used as fuel. The PEM fuel cell is fueled by pure hydrogen. In the anode, hydrogen is split into its basic elements, a proton and an electron. While the proton migrates through the membrane of the fuel cell, the electron travels around the membrane and goes to the cathode, creating an electrical current. In the cathode-hydrogen proton the electron reacts with oxygen to form water, which is rejected as waste. The basic system is the same for the DMFC and the SOFC fuel cells. The DMFC is fueled by a mixture of methanol and water. Before reaching the anode electrode, the methanol is split into CO²and hydrogen. The SOFC fuel cell can use different kinds of fuels that contain methane and hydrogen. All the reactions are shown in Table 1. One fuel cell can produce 0.6 of a volt. To get enough power, several fuel cells are piled in a stack. The space between fuel cells is filled with gas that helps to distribute the hydrogen and oxygen gas to the membranes.

Although hydrogen energy is a new source, the production of hydrogen is not a new concept. Every year, 500 billion m³ of hydrogen is produced, stored, transported, and utilized in the world. Initially, hydrogen was used for the production of ammonia, but today hydrogen utilization has expanded tremendously to incorporate applications in chemical and petroleum refining, metallurgy, the hydrogenation of edible fats and oils, space and weather programs, fuel cells, and the manufacture of high quality electronic components. The most important consumer is in the petroleum- chemistry industry.

Hydrogen can be obtained by using different methods. Hydrogen can be produced from electricity, using electrolysis to split water into hydrogen and oxygen. Reforming is another method that produces hydrogen. In this method, hydrogen is extracted from a gas with a high concentration of methane, such as natural gas. This process uses hot steam to obtain hydrogen from the methane. When methane gas is mixed with hot water vapor, the gas is split into carbon monoxide and hydrogen.

Although hydrogen can be stored as a gas or liquid, storing and handling hydrogen is difficult as compared to gasoline. While gasoline is a liquid, hydrogen is a gas. At atmospheric pressure at sea level (pressure at sea level is 1.0 atm = 1.01325 bars), hydrogen has a volume 3,100 times greater than gasoline. To decrease the volume of the hydrogen, pressure is used. Hydrogen can be stored under pressure up to 700 bars. At this pressure, hydrogen has a volume 6.4 times greater than that of gasoline.

Another method for storing hydrogen is in the liquid phase. In this phase, hydrogen has a volume 3.6 times greater than gasoline. Liquid hydrogen can be stored under high pressure in steel tubes. Hydrogen should be cooled to -252.77 °C to become liquid. The cooling process requires energy. 25% of hydrogen energy is used for the cooling process. The largest liquid hydrogen tank is at the Kennedy Space Center in Florida. It contains up to 3,400 m³ liquid hydrogen.

Hydrogen can also be stored in metal hydrides. When cooling is applied, the hydrogen atoms diffuse inside the metal hydrides. To release the hydrogen, the reverse process, heating, is needed. Due to the large storage necessary, aluminum and boron hydrides have been used extensively over the last 10 years. In particular, boron hydrides are important as they can be used in liquid conditions. Metal hydride storage is very safe because of the low pressure and the fact that there is little free hydrogen inside the storage tank. Another advantage of this way of storing is that metal hydrides hold hydrogen at very low volumes.

It seems that hydrogen may be the major energy source in the future. Eventually, it will be used to supply the energy needed in the economy, being used for transportation, central and distributed electric power, and combined heat and power for buildings, and industrial processes. However, hydrogen technology is currently in the pre-production stage of development. Hydrogen energy is not cheap when compared to other energy sources at this time. There are some challenges that need to be overcome, such as producing, storing, and using hydrogen efficiently before we use hydrogen instead of fossil fuels. However, hydrogen is the key to solving the energy problems of the world. Hydrogen is available in every country, everywhere. Using hydrogen as an energy source will prevent many conflicts between countries. This energy source will help address concerns about energy security, global climate change, and air quality. It seems that the views of Jules Verne, quoted at the beginning of this article, will be realized one day in the future. And people will thank God not only for water, but also for the hydrogen in it.

References

1. “Energy Wars” by David Chapman – a director of Bullion Management Services the manager of the Millennium BullionFund (www.bmsinc.ca).

2. Cook B., ‘An Introduction to Fuel Cells and Hydrogen Technology’, Heliocentris, 2001.

3. www.un.org

4. www.census.gov

5. www.worldenergy.org

6. www.fuelstore.com

7. www.minihydrogen.dk