Exercise keeps brain connections alive

Casaletto K et al. Late‐life physical activity relates to brain tissue synaptic integrity markers in older adults. Alzheimer’s & Dementia, January 2022.

Physical activity has myriad benefits, including enhancement of cardiovascular health, lowering blood pressure, and promoting mental health. A recent study showed that when older adults stay physically active, their brains are activated to produce more of a protein type that enhances the connections between neurons to maintain healthy cognition. The beneficial effects of physical activity on cognition have been shown in many times in laboratory animals but it has been much harder to demonstrate in people. Neurons are separated from each other by tiny clefts known as synapses. Nerve signals that travel along the nerve cells must cross these gaps for the information to reach its destination. Synaptic proteins located at the vicinity of synapses are tasked to provide the chemical mechanism whereby information is transmitted and link the neurons into cognitive networks. In this study, the late-life physical activity of 404 elderly people, who agreed to donate their brains when they died, have been tracked through annual actigraphy monitoring. Next, their postmortem brain tissue has been analyzed for the levels of key synaptic proteins. Strikingly, elderly people who remained active had higher levels of synaptic proteins that are known to facilitate the exchange of information between neurons.

Researchers also found that increased synaptic proteins were not limited to specific cognitive-related brain regions; physical activity seemed to exert a global effect on brain connectivity beyond the parts of brain that are directly involved in cognition. Maintaining the integrity of these connections between neurons may be a key protection for the age-related cognitive disorders such as dementia and Alzheimer’s. Physical activity is a readily available medicine that can boost our cognitive and mental health, free of charge and with no prescription. This study emphasizes one more time that we should continue being physically active, particularly as we age.

Oxygen production by microbes without sunlight

Kraft B et al. Oxygen and nitrogen production by an ammonia-oxidizing archaeon. Science, January 2022.

Oxygen is vital for life on Earth. Most oxygen on land and in the sea is produced

as a result of photosynthesis, a process in plants, algae, and cyanobacteria that requires sunlight. Now a research team made a surprising discovery that some deep-sea microbes are also tasked to produce oxygen but in a completely different way. By investigating these microbes which live deep in the darkness, the researchers have focused on a microbe named Nitrosopumilus maritimus, which was previously found out to be converting ammonia to produce nitrogen by using oxygen. The team decided to observe these microbe cultures in airtight containers that are kept in the dark to mimic the deep ocean conditions. They have found that these cultures first used up all the oxygen in the water, and then to everyone’s surprise, within minutes, oxygen levels started increasing again. At first glance, they seem to produce just enough oxygen for them to survive and scientists thought that these low levels may not possibly be enough to influence oxygen levels on earth. However, when this effect is considered at a global scale, it is conceivable that the oxygen produced by Nitrosopumilus maritimus can be quickly taken by other nearby organisms. This means that this microbe is ultimately contributing to overall oxygen levels in oceans, if not for the whole atmosphere. The exact mechanism of how these archaea bacteria can produce oxygen without light is not known and it has been now the focus of future research efforts. This study opens up the possibility that there may be many different deep sea species with a whole different metabolism functioning. It also emphasizes the importance of studying and protecting the deep oceans.

70 mysterious rogue planets discovered

Miret-Roig N et al. A rich population of free-floating planets in the Upper Scorpius young stellar association. Nature Astronomy, December 2021.

Rogue planets are the freely floating cosmic objects in our solar system that roam the universe on their own without orbiting a host star. Scientists knew very little about these planets until now. A team of astronomers using data from several telescopes worldwide identified at least 70 rogue planets in the Milky Way. Since rogue planets are not illuminated by a nearby star, they used to be almost impossible to capture and image. After few million years of their formation, these planets are still hot enough to glow and become detectable by extra sensitive cameras in large telescopes. After extensive analyses of all the data they could gather revealed at least 70 rogue planets and up to 170 candidate planets that are close to a star-forming region near the Sun, located within the Scorpius and Ophiuchus constellations and 420 light-years from Earth. These findings suggest that there could be many more of these planets roaming the galaxy. Rogue planets could have been either formed from a cloud of gas and dust – the same way stars do – or they could have once been a part of a star system before getting ejected. The team hopes that by studying the large group of rogue planets, they will be able to identify their origins and how they formed and evolved. New developments in space-watching technology are very encouraging for astronomers, as they hope that by studying this large group of rogue planets, they will be able to understand their origins and ultimate fates.

The morning had withheld its sunlight and left only a gray hue to open its doors when the man turned aside to his wife facing him, her Cantu-scented curls waving in his face. The sunlight compliments her already perfect face even though the gray brings gloom to others, but not him. The sounds of breakfast cooking brew an ambience that acts as lenses onto her beauty while her eyes secure her innocence. The appreciation of sunlight comes natural for those who don’t have it, but alternatives are the only option with no availability. As a result, he finds the sunlight captured in her beauty while her eyes take the picture.

“Want some eggs,” she asks, her words softly layered.

“With syrup please,” he replies as his words stick to his mouth.

Her response echoes through the whole house, her laughter bounces off the walls. Her eyes close when she laughs and he wonders what she sees. The sight she sees contains an expression of her love with him at the center of her photograph. In the meanwhile, a whole dictionary was consumed in the process of describing what she feels towards what she sees.

The day passes them by in a swirl of heartfelt emotions. A haze of old music lingers in the house as she takes two steps back while he takes two steps forward.

She asks, “Where did the day go?”                                                                                      

“With you in my arms,” he responds.

“Ha-Ha-Ha,” she says sarcastically.

Her laugh gets softer and softer as he feels the heat escape her body. Her eyes flash red not with pain but with a warning. “Low Battery! Charge Now!” but a recharge isn’t possible, at least not in an electrical sense. With this he holds her memory tightly, tighter than the grip of death itself. He carries her soul in his heart as he steps to the cellar. Her brown hair now twisted with curls, rooted in the insecurities of others. The door creaks open to deliver a gust of contempt for death and a sense of resurrection. Human sized tubes litter the wall. The same face stares back at him at least a dozen times, providing twelve instances of relief. A transaction is made with his heart and mind, and one of the tubes opens. He feels elated but the air still chills around him, and an aura steps out followed by a hand reaching for him.

The morning withholds its sunlight and leaves only the gray to open its doors when the man turns aside to his wife facing him, her strawberry scented hair waving in his face.

Some insight for leaves

Leaves are in charge of respiration in plants. They consist of the main mechanism producing food for plants, using sunlight via photosynthesis through which food for many more organisms, animals, and humans are provided. Having been assigned to convert solar energy to food, which they’ve been doing for millions, perhaps billions, of years, plants have been a significant instrument for sustaining life on or planet. It is as if plants turn their leaves upward in prayer to ask for food on behalf of all living things.

Morphology of a leaf

Leaves are composed of three sections: the base, blade, and petiole. The blade is the most important part of the leaf; it is wide and flat. The exact shape of leaves vary according to climate, geographical conditions, life span and risk of consumption by other organisms. In tropical climates, the blade is often very wide. In drier climates, it is usually smaller, in order to reduce water loss.

Leaves of some plants undergo a transformation called “metamorphosis” to fulfill different tasks. For example, some leaves have a thorny shape and protect the plant form herbivorous animals. Some leaves are designed to store water, and some are converted into a trap in order to capture insects to nourish the plant.

On the cross section of a leaf, one can observe that four layers constitute the inner part. The first one is the epidermis, which covers the leaf from top to bottom. This layer protects the leaf against external elements and is lined with a waterproof, waxy substance.

The palisade parenchyma is located on the upper side of the inner tissue and it houses chloroplast rich cells, which are lined up densely and carry out photosynthesis. The spongy layer under the palisade tissue forms the intercellular air spaces and this layer is responsible for the respiration of the plant.

For photosynthesis to occur, the leaf needs to receive the maximum amount of sunlight. The sun must hit the leaf at a perpendicular angle; thus, the leaf must be amply wide and must sit level. Because the sun hits different latitudes at different angles, plants have branches of different lengths facing different directions, and leaves have different curvatures. Furthermore, leaves are also lined up in a way so as not to block the sun’s rays. For this to happen, it is required for the leaf base to be thin and the leaves to be lined up in a spiral fashion that enables both lower and higher ones to harvest sunlight in the most efficient way. This type of arrangement exemplifies the golden ratio, which is observed among many structures in nature.

Each leaf sprouts at an angle of either 222.5 or 137.5, derived from division of 360 degrees, from the previous leaf under. This spiral leaf growth provides them with the most suitable place to harvest sunlight maximally. This way the gaps around branches are minimized and a maximum number of leaves is positioned without reducing the light capture capacity of the plant.

Seasons and leaves

Plants work like factories during spring and summer, producing a great deal of food through photosynthesis. Some of these foods help the plant grow and some are stored as starch for winter. With the onset of autumn, a majority of plants outside tropical zones go through hibernation, like many organisms do, and enter a dormant period. In order for plants, like trees and bushes, to survive the cold, their leaves are shed to minimize their surface area and conserve energy. Perennial green plants lose their aerial parts, too, including stems and leaves, and hibernate underground as roots, bulbs, and tubers. They sprout back from their roots once spring brings warmer weather.

Many leaves begin to fade and fall once autumn arrives. The leaves of some hardy plants – like cypress, pine, and spruce trees – continue to function through winter. In some of these trees, like the bay tree and the Indian sandalwood, there are protective layers covering the leaves against the cold. Other leaves, like pine needles, are created in a spiny shape to resist the cold.

Colors of autumn

Leaves seem green during the spring and summer months because the chlorophyll found in them absorbs all wavelengths other than green. The other major pigments found in leaves are carotene (orange) and xanthophylls (yellow). These two pigments are the most common pigments in nature.

As autumn approaches, and photosynthesis begins to end, chlorophyll starts to degrade and the other pigments begin to show. Thus, leaves turn yellow and bright red.

As the weather gets colder, the chloroplasts that are near the leaf’s bottom are broken apart, and sugar levels begin to elevate. The sugars produced during this season accumulate in the leaves day by day due to lower photosynthetic speed and reduced transportation to other parts of the plant. These sugars are converted into anthocyanins. At first, leaves appear yellow. A couple weeks before they fall, most leaves shift from yellow to red. Under abundant sunlight, due to concentrated anthocyanins, leaves seem brighter and more colorful – and thus red. Once the live tissues die completely, all leaves turn brown. This is due to the high concentration of tannin.

Leaf color varies not only because of plant genetics and external factors, but also because of climate. Temperature, humidity, soil composition, and levels of sun exposure all affect color. There is a higher degree of color change in the leaves of trees that grow in lower temperatures.

The composition of soil plays a major role in the color of leaves. Leaves that turn yellow early indicate a nitrogen shortage; on the other hand, the presence of a strong red color indicates very acidic soil. A high alkaline ratio is present in places where leaves are purple.

Walking among fallen leaves and the colorful scenery in a forest in autumn can trigger unique emotions. Depending on the psychological state of a person, the colors of autumn sometimes remind us about the briefness of this world, but they can also hint at the infinite life to come.

The motifs and patterns of leaves

Receiving sufficient sunlight is a significant matter for leaves. Therefore, they are created differently. No two plant leaves are the same.

Some of the leaves are simple and some are compounds. According to their arrangements, opposite, alternate, whorled, and rowed forms exist. Leaf blades can be ovals, kidneys, triangles, or even hearts. Edges can be smooth, serrated, toothed, or lobed. Leaf veins can also have many different motifs.

Each plant species has its own leaf motif. The alfalfa leaf has a triple pattern of specific angles; walnut leaves have an opposite arrangement of eight to ten. A hand-like motif, like the fingers of a praying hand, formed of seven leaves, can be observed on chestnut trees.

I am the barrier between your body and the outer world and I am responsible for this area. I can sense every change in the outer world, including heat, cold, humidity, pressure, various radiations, and the effects of many harmful chemicals and physical phenomena. When I become aware of the presence of something that is harmful, I warn your organs to act according to these changing conditions. That is why everybody knows me primarily as a sense organ.

However, in addition to being a sense organ, I have many other important duties; however, if I were to list them here, this article would take up the entire magazine. In order to ensure your good health I have to carry out my duties, be they aesthetic, protective or metabolic, perfectly. Even if you only examine my appearance, you will see how beautiful I am. You should visit an anatomy laboratory one day and watch the medical students performing an autopsy. Examine the cadaver whose skin has been pulled back to allow the students to study the internal organs. Look, if you can! Although the body is miracle, if the skin is not present, it would lose its splendor and become ugly and horrible. The beauty and meaningful existence of all the other organs are only complete with me. Our Lord God Almighty has created me and dressed you with me as a garment that fits each part of your body. He has lined your palms and soles with a thick outer lining made of keratin; this enables you to walk and use some hand tools easily. If on the foot or hand I were as thin as I am in the lip area, then I would easily get punctured and injured while walking or using a tool. God has created special joints where your fingers and toes join the feet and hands. These joints allow your fingers, hands and feet to move in many different ways. In order to protect your head from the sun and cold God has changed some of my cells into hair and has given it the ability to grow constantly. God also protects your eyes with special hairs that we call eyelashes and eyebrows. With these He also completes the beauty of your face. However, these do not grow constantly like the hair on our heads. Just think, otherwise you would have to trim both your eyebrows and eyelashes everyday in order to see. The special hairs in your nose and ears help prevent the entry of harmful particles, like dust or harmful microorganisms. You may think “How important is that? Just a few strands of hair?” Of course, hair is not the most important thing of all, but is life nothing more than staying alive? Of course not! There is also an aesthetic aspect to life. We can understand this if we look at a person who has no eyebrows or eyelashes! Certainly, God has made human beings beautiful creations and the hair is an important part of this beauty. As with everything He does, the significance of the hair is much more meaningful than when first seen.

In addition to my aesthetic beauty, I should also tell you about my protective functions. My first and most vital job is to balance the level of liquid in your body and to prevent its loss. The liquid level and the amount of minerals inside your body are very important. If it were not for me your kidneys would not be able to regulate the level of these liquids. It is for this reason that people who have burns that take up two-thirds of their skin or more cannot live; the water loss in their bodies is too great. In burn care centers, they try to control the loss of liquids using very sensitive devices; however, with serious burns this is usually unsuccessful. My protective functions are not limited to liquids; I also protect your body from all kinds of bacteria, funguses and viruses. As you know, your skin can get inflamed and infected from even a thorn. If the skin becomes damaged or broken over a large area you could face serious infections. This is because if I am not present many microorganisms will invade your body and make you ill.

Your body is very sensitive to heat and cold. The temperature of your inner body normally should be between 370C and 38 0C (96.8 0F and 98.6 0F); if it increases above this temperature, then you are unwell. If you remain for a long time in cold conditions and your inner body temperature falls off, many of your organs, especially the lungs, stomach, and kidneys are damaged and cannot work properly. You could die if the temperature is too low for too long. And in contrast, if you stay too long in the heat and your inner body temperature increases, your nervous system can be damaged, as the brain is very sensitive. Then your heart and other organs will start to fail, which eventually results in death. Indeed, human beings live everywhere, from the deserts to the poles and everywhere people are able to maintain an inner core temperature that is constant between 96.8 0F and 98.6 0F. I play a very important part in this system. Although the main control center is the brain, it acts according to stimuli that I send and I carry out important functions when the brain responds to these stimuli. Later, I will tell you how I can both warm and cool you.

Before telling you about my other functions, I would also like to tell you about my structure, which appears quite basic from the outside. Of course, I am not simply a cover that wraps your flesh. First of all, I am a living organ that is being nourished, that grows, that is repaired and which is very flexible. As I get rid of dead cells, I replace them with new ones; I am aware of everything that happens in my surroundings and I allow you to feel the world around you. I consist of two major layers: the epidermis (outmost layer) and the dermis (the inner level). The visible layer, the epidermis, consists of cells that gradually die off and stiffen. Those cells are toughened with a protein called keratin which is absorbed inside their structure; everyday I shed dead skin cells. This is part of the “dirt” that is removed from your body with every shower. This outer layer contains bacteria, funguses or other parasites that have been transmitted from the outside world and which may cause diseases. These parasites are removed as the dead skin cells are shed. The innermost layer (stratum germinativum) of the epidermis has a great capacity for cell division and it constantly produces new cells from the bottom to the outermost level. These cells start out life as cylinders, but as they move towards the outer surface they become cubical and then flatten out. At the same time keratin is being produced in those cells, and as a result they stiffen and start to die off. When the cells arrive at the outermost level, they are already dead. Some of those dead cells do not fall off. They accumulate and combine to make up the structures that we call nails and calluses. In this way the cells protect those areas that are most sensitive or most often used.

You will be surprised to see what great biological activities take place in the epidermis. Even when a person dies, this layer does not die right away. After death the nails and beard continue to grow. This occurs because of the activities in the germinative epithelium, which makes up the basal layer of the epidermis.

Beneath the epidermis is the dermis, a relatively thick layer. This is the layer which keeps the skin lively and firm and which produces the color. Many works of arts are present in this layer to complete my splendid structure. This layer consists of connective tissue with fiber bundles that is made of collagen protein. As people get older, their skin dries up and starts to lose its collagen proteins. Once the fibers start to decrease, I lose my firmness, and then I start to wrinkle. Although people are not happy with wrinkles, which are inevitable, I don’t think this is something to worry about; wrinkles are also a sign of maturity and experience. In the structure of my dermis there are other parts that have very important functions: The sweat glands, which are in the shape of coiled tubes, spread throughout the body act as ventilators; in addition, the hair follicles, the sebaceous gland, which helps to nourish and moisturize the hair, the chromatophores (pigment-containing cells) that determine the skin color, the hair muscles that give your hair flexibility and the blood vessels that nourish me are all important. I also have special receptor cells that can sense temperature, pressure and pain and there are nerve endings scattered among these cells.

In different parts of the body I am more sensitive to particular sensations. My sense receptors (corpuscles) vary in shape and you human beings have named them after the scientists who discovered them. There is Pacini’s corpuscle, Meissner’s corpuscle, Ruffini’s corpuscle and Krause’s corpuscle. Each of those receptors is thought to be receiving independent stimuli, but this has not been proven by experiment yet.

Do you ever wonder why you and your friends have so many different skin tones? This is the result of the work of the chromatophores (cells that contain pigment) which are located in the dermis, at the point closest to the epidermis. These cells, which have a number of branches, move in relation to the intensity of the light, and their branches can stretch and shrink back. These movements cause the pigment granules (melanin granules) to disperse within the cell or aggregate towards the center. This is how they can lighten or darken the skin color, causing you to get a “tan.” The seasons, the length of the day and the intensity and duration of the sunlight all affect the movement of these cells. These cells darken your skin color during the summer and lighten it during the winter. But, why is this necessary? This is a wonderful physiologic mechanism that has so many amazing purposes and meanings. I am sure you have noticed that people who live in Northern Europe and North America have a lighter complexion than those who live in the more southerly regions of the earth. This is because the countries in these northern regions are exposed to a less intense sunlight for a shorter time. The further north you go the more rainy and cloudy it is. However, sunlight also plays a very important role in the synthesizing of vitamin D in your body. The molecule known as 7-dehydrocholesterol can be converted into vitamin D only with sunlight. Vitamin D is a fat-soluble vitamin that is highly important for calcium absorption and bone metabolism. If you do not have enough exposure to the sun, then vitamin D cannot be produced; this could result in disorders like rickets (most common), as well as several other bone diseases and skeletal complications. However, it is interesting that sunlight is a two-edged sword. Neither too much nor too little sunlight is good for you. Too much exposure to the sunlight damages my health, causing such diseases as skin cancer and eye disorders. Our Lord God Almighty has made all parts of the earth suitable for human life. He knows well, of course, what people need in order to be able to live in places that have less sunlight and in other places that have a great deal of sunlight. In order to allow people to benefit from the sunlight everywhere, He has given the necessary qualities to my chromotaphores and the melanin granules that they contain. In places that have less sunlight, my chromotaphores synthesize less melanin. The melanin disperses throughout the cells or the cells move downwards, and my color lightens. This allows more sun absorption and this sunlight is used for vitamin D production. In sunny places, however, people are more exposed to the ultraviolet rays of the sun as well as other forms of radiation. This is why the risk of my cells becoming mutant and cancerous is greatly increased. In order to avoid such a situation, more melanin is synthesized in people who live in sunny places. The melanin in the chrotaphores gathers towards the center of the cell and my color darkens. Thus, excess sunlight is absorbed by my melanin pigments thanks to their special structure and function. This prevents other sensitive cells from becoming damaged and cancerous.

During hot weather, in order to balance your inner body temperature, the blood vessels that pass through the skin expand and more blood is carried through the skin. I give off the water in my blood through my sweat glands. While this warm water called “sweat” spreads over my surface and evaporates, an important amount of heat is released into the air. Thus, your inner body temperature does not increase and you remain cool inside. Thanks to the work of my sweat glands, I can also get rid of some nitrogenous waste and thus support your kidneys. During cold weather, however, the activities of my sweat glands decrease, and this helps you to stay warm. The blood vessels narrow so that the blood in me is reduced. More warm blood is channeled into your body so that your important inner organs do not become cold. The muscles of my hairs contract and the hairs straighten, thickening the layer of hair that covers me. It feels like you are covered with a blanket. If your body temperature falls off significantly, my receptors stimulate the muscles that lie under me and these muscles produce heat by vibrating. That is why you shiver from cold! Women have fewer hairs on their body. Do you think this is unfair? Of course not! Unlike men, women’s bodies are created in such a way that they can store a greater percentage of fat among the tissues under the skin. This hypodermic fatty tissue not only protects women from cold, but it is also used as extra storage for nutrients that they use when breastfeeding. It also helps protect women’s muscles and bones against bumps and shocks from the outside. So, this tissue works both as a temperature isolator and as a “shock absorber.” There is nothing unfair about this. And, it proves that God gives each of His creation exactly what they need and deserve.

Some people say that the skin is a mirror of the body’s health; this is true. The fact that I am visible and can be examined easily makes me the first organ to display symptoms of many diseases that lie below. Abnormalities that appear on me are usually a sign of metabolism disorders, ulcers and other glandular disorders in the body. For example, if your liver is being affected by a poisonous substance, this shows up as red spots on the hands. But not only physical ailments affect, me; I am also affected by your spiritual condition. Of course, the opposite can happen, too. That is, diseases on the skin can affect your inner organs.

I have mentioned before that my ability to renew and repair myself is very great. God willing, I can repair mild burns, bruises and cuts easily under normal circumstances. However, if the bruise goes as deep as my basal layer, there might be a scare there to remind you in the future and to give thanks to God for your health. In addition, in diseases like diabetes, my ability to renew and repair myself is weakened and I cannot easily heal. In such cases, you have to take the utmost care to keep me clean so that I do not get infected.

Well Peter, I think that I have said enough about myself. I will not continue to go on about the many symptoms of diseases that can be seen on me, including, allergies, itchiness, and infections. However, it is important for you to know that I can demonstrate hundreds of different conditions that are caused by a great range of factors, such as genetically transmitted diseases, immune system disorders, and bacterial, viral, and fungal infections. But don’t worry! As you can see, the majority of people live a healthy life despite these risks. The Creator has provided your body with a protective mechanism and has taught you how to take care of yourself. My job here is to indicate the Creator and how He has made me a flawless work of art that demonstrates deep meanings behind its complexity. Rather than continuing to give you a lecture on dermatology, it would be better if you were to live according to God’s consent. If you do so, you will be protected from diseases; even if you do become ill, you will have greater patience and moral strength. You will also be more thankful to God for your health.

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

Daylighting is becoming more popular in commercial buildings and manufacturing facilities in the United States. After Thomas Edison invented the electric light, most architects changed their building plans and designed for more and more artificial lighting. As a result, only a very small percentage of the light used in major buildings and facilities came directly from the sun. Recently, the Europeans have realized the importance of daylighting and begun to use a reasonable percentage of sunlight in their buildings. The Rocky Mountain Institute, Snow-mass, Colorado, has investigated the benefits of daylighting and reported that daylighting increased productivity and reduced absenteeism by 15 percent. Also, sunlight reduces the heating and cooling bill.

In 1993, Wal-Mart Stores Inc. opened a prototype store in Lawrence, Kansas, with nine special skylights designed by Andersen Corp., Bayport, Minnesota. The architectural firm of Leo A. Daly, Omaha, Nebraska, opened an office building in 1983 with l5ft high window walls and a glazed roof. About 50% of its electricity bill for lighting was saved as a result (Reno Gazette-Journal, November 27, 1995). Daylighting is an inexpensive way of lighting interiors since the sun is a ‘free’ light source which can be further exploited by installing skylights on the roof. On an overcast day, the light entering through a 2 sq. ft skylight area is equivalent to three 100-watt light bulbs.

There are two additional reasons for installing skylights. First, the cooling load of a building can be reduced by using daylight. The reason for this is that whereas about 80% of the power of an electric light is converted to heat, sunlight has a far lower heat content and therefore requires far less air-conditioning. Second, just at the time when there is the heaviest demand for electricity (and other utilities) from manufacturing facilities, namely during the summer, sunlight is at its most plentiful and available: in short, skylights can significantly reduce peak load stresses and costs.

An illumination level of 50 footcandles (540 Lux) at the work site is the design standard in industrial facilities. A large portion of this illumination level comes from electric lights of fluorescent and incandescent lamps. Almost 5% of electricity consumption in the US is used up to provide adequate illumination in commercial and industrial buildings.

In production facilities generally, there is a lack of awareness about the energy conservation potential of skylights. Some manufacturers are so unaware about the cost savings that can be achieved by daylighting that they do not have skylights in their production areas, and leave lamps on in work areas throughout daylight hours. In other places which do have them, skylights have been neglected to the extent that they are so dirty they block the incoming sunlight.

Since heating and cooling load are increased with increased skylight surface area, there is a limitation associated with this measure. Some authorities have suggested that the optimum skylight surface area should be reckoned at between 2 and 4% of roof surface area. However, since the measure depends upon local climate conditions, the range should be allowed to vary between 2 and 10%. In many potential sites, heating only (and not cooling) is the principal consideration. Generally, therefore, building designers with heating costs in mind tend to prefer 2% for cold climates and 10% for warm climates.

Heating load and costs will increase when skylights are installed. However, the increase in heating cost is considerably smaller than the saving from reduced lighting cost. The average unit cost of electricity is three times greater than that of natural gas (typically preferred for heating). In any case, heat loss from the skylights can be minimized by double glazing them. In view of the favourable financial balance and the productivity improvements to be expected from daylight working, the benefits from installing skylights generally offset any negative consequences of doing so.

The amount of savings in electric lighting consumption and costs depends on climate and operating periods. The payback period for installing skylights ranges from one to five years. They can be an expensive roof aperture, but it is relevant to note that the lifetime of a skylight is more than twenty years. The skylights need to be cleaned at least once annually, which means that service and maintenance costs are negligible. Skylights are most cost- effective in uninsulated ceilings in climates, like that of southern California, which have no heating season. In such climates, the workplace roof is typically covered with corrugated metal sheets making skylights both easy and cheap to install: corrugated fibreglass sheets can be cut and fitted in place of the metal sheets wherever the skylights are required.

References 

• MURDOCH, B. J. (1985) Illumination Engineering: From Edison’s Lamp to the Laser, Macmillan Publishing Company, New York.
• NUTFER, D. W., BRITTON A. J. and HEFFINGTON W. M. (1993) ‘Conserve Energy to Cut Operating Costs’, Chemical Engineering, September, pp.126-37.
• PIERSON, J. (1995) ‘Natural light gets warm welcome’, Reno Gazette-Journal, November 27, pp.2ff.