A Meticulous Perspective...

A battery is an arrangement of several electrochemical cells connected in series that can be used as a source of direct electric current. A cell is one that contains only one anode and cathode, but a battery contains several anodes and cathodes.   TYPES OF BATTERIES: (a) Primary Battery or Primary Cells In the case of a primary battery, the electrode and the electrode reactions cannot be reversed by passing an external electrical energy. The reactions occur only once and after use, they become dead. Therefore, they are not rechargeable. Example: Dry cell, Mercury cell (b) Secondary Battery or Secondary Cells In case of a Secondary battery, the electrode reactions can be reversed by passing an external electrical energy. Therefore, they can be recharged by passing an electrical current and used again again. These are called storage cells or accumulators. Example: Lead-acid storage cell, nickel-cadmium cell

  ADVANTAGES of Reverse Osmosis: This method has greater advantages of removing ionic, non-ionic, colloidal and high-molecular weight organic matter. The lifetime of the membrane is quite high (2 years). The membrane can be replaced within a few minutes. It provides nearly uninterrupted water supply. Due to low capital cost, low operating cost and high reliability, this method is superior than other methods. DISADVANTAGES of Reverse Osmosis: Reverse Osmosis plays a major role in providing portable water defined by the WHO criterion of < 500 ppm of total dissolved solids (TDS). Extremely high-quality water required for nuclear power plants can be made from sea water by the reverse-osmosis process. Sugar concentration, waste-water recovery and beverage uses are a few of the current popular applications of the reverse-osmosis process.

  It is a membrane process by which water is separated from saline water. Osmosis is defined as the spontaneous flow of 'water' from dilute to more concentrated solution through a semipermeable membrane. The driving force in this phenomenon is called osmotic pressure . A semipermeable membrane is one which permits only water molecules to pass through it. Examples of semipermeable membranes are cellulose acetate, polyamide, polymide, etc. This natural process can be reversed by applying pressure higher than the osmotic pressure on the concentrated side. Thus the solvent is forced to move from concentrated side to dilute side across the membrane. This principle is known as r everse osmosis. In the reverse osmosis process, the pure water (free from ions) is separated from the contaminated brine water (salty water). This membrane filtration is also called super filtration (or) hyper filtration. For advantages and disadvantages of reverse osmosis refer  https://meticulousperspectiv

  ZEOLITES: Zeolites are naturally occuring hydrated sodium alumino silicate minerals. LIMITATIONS of Zeolite Process: If the supplied water is turbid, the suspended matter must be removed first by coagulation, filtration, etc. Otherwise, the turbidity will clog the pores of zeolite bed making it inactive. If the water contains coloured ions (Mn2+, Fe2+), these ions should be removed first because these ions produce manganese and iron zeolite, which cannot be regenerated. If any mineral acid present in the water, it will destroy the zeolite bed, therefore it is neutralised first with soda (Na2CO3). ADVANTAGES of Zeolite Process: Water quality of below 5 ppm hardness is obtained. This equipment is compact and occupies small space. It requires less time for softening.  It requires less skill for maintenance and operation. No sludge is formed during this process. Its operation is also easy. DISADVANTAGES of Zeolite Process: This process cannot be used for turbid and acidic water as they w

  Zeolites are naturally occuring hydrated sodium alumino silicate minerals.  Na2O. Al2O3. xSiO2. yH2O where x = 2 to 10 and   y = 2 to 6. Natural zeolites are nonporous. The synthetic form of zeolite is known as permutit. Synthetic zeolite is represented by Na2Ze. Synthetic zeolites are porous and have a jelly structure. They are prepared by heating together china clay, feldspar and soda ash. These zeolites have higher exchange capacity per unit weight than natural zeolites. In this synthetic zeolite process, the hard water is allowed to percolate through sodium zeolite. The sodium ions which are loosely held in Na2Ze are replaced by Ca2+ and Mg2+ ions present in the water. Process: In   this process , the hard water is passed through a bed of sodium zeolite (Na2Ze). The hardness-causing ions (Ca2+, Mg2+) in hard water is replaced by loosely held sodium ions in zeolite bed. The outgoing soft water contains only sodium ions. Na2Ze + Ca(HCO3)2  --> CaZe + 2NaHCO3 Na2Ze + Mg(HCO3)2  -

  Hardness is the characteristic of water which does not give good lather with soap. This property of water is due to the presence of bicarbonates, chlorides and sulphates of calcium, magnesium and other salts. Some important disadvantages of hard water are the following: Hard water is not useful for various domestic purposes, viz washing, bathing, drinking, etc. The ions responsible for the hardness convert soluble soaps to insoluble precipitates. This causes wastage of soap in washing and bathing. Also, presence of iron salts may result in staining of cloth. Hard water is harmful for many industries such as textile, sugar, paper, laundry, etc. Dissolved calcium, magnesium and iron salts may react and affect the following properties: May cause coloured spots on fabrics in textile industry.  May cause difficulties in the crystallisation of sugar in sugar industry. May cause wastage of lot of soap in laundry. Giving a smooth and glossy finish to paper in paper industry.  Hard water is a

  Galvanizing is the process of coating of zinc or iron or stainless steel sheets. Process: The iron or stainless-steel article surface is first cleaned by acid pickling with dilute H2SO4 solution for 15-20 minutes at 60-90 degree celsius. This treatment removes any scale, rust (oxide layer) and impurities on the metal surface. The article is then washed well with water and dried. It is then dipped in the bath containing molten zinc maintained at 425-430 degree celsius. The surface of the bath is kept covered with a flux, i.e. ammonium chloride, which is used for cleaning the surface of the metal and also to prevent oxide formation. When the article is taken ort, it is found to have been coated with a thin layer of zinc. In order to get uniform thickness, it is passed through a pair of hot rollers, which removes any superfluous (excess) of zinc. Then, it is annealed at a temperature of 650 degree celsius and finally, cooled slowly. Uses: It is most widely used for protection of iron fr

Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Biogas originates from biogenic material and is a type of biofuel. Biogas is made from organic waste matter after it is decomposed. The decomposition breaks down the organic matter, releasing various gases. The main gases released are methane, carbon dioxide, hydrogen and hydrogen sulphide. Bacteria carry out the decomposition or fermentation. The conditions for creating biogas have to be anaerobic. That is without any air and in the presence of water. The organic waste matter is generally animal or cattle dung, plant wastes, etc. These waste products contain carbohydrates, proteins and fat material that are broken down by bacteria. The waste matter is soaked in water to give the bacteria a proper medium to grow. Absence of air or oxygen is important for decomposition because bacteria then take oxygen from the waste material itself and in the process break them down. The c

LPG is a predominant mixture of propane and butane with a small percentage of unsaturates (propylene and butylene)and some lighter C2 as well as heavier C5 fraction. Included in the LPG range are propane, propylene, normal and isobutane and butylene. It is obtained as one of the top fractions in the fractional distillation of petroleum. LPG may be defined as those hydrocarbons, which are gaseous at normal atmospheric pressure, but may be condensed to the liquid state at normal temperature, by the application of moderate pressures.  Although they are normally used as gases, they are stored and transported as liquids under pressure for convenience and ease of handling. Liquids under pressure for convenience and ease of handling. Liquid LPG on evaporation produces 250 times more volume of gas. Composition of LPG: n-butane = 70% Isobutane = 17% n-propane = 11% Butylene and ethane = rest Calorific Value: Its calorific value is 27,000 kcal/m3. Uses: Used as a fuel for domestic cooking. Used

  The chemical energy stored as nutrients in the bodies and wastes of organisms flows through ecosystems from one trophic (feeding) level to another. For example, a plant uses solar energy to store chemical energy in a leaf. A caterpillar eats the leaf, a robin eats the caterpillar, and a hawk eats the robin. Decomposers and detritus feeders consume the wastes and remains of all members of this and other food chains and return their nutrients to the soil for reuse by producers. A sequence of organisms, each of which serves as a source of food or energy for the next, is called a food chain . It determines how chemical energy and nutrients move along the same pathways from one organism to another through the trophic levels in an ecosystem—primarily through photosynthesis, feeding, and decomposition. Every use and transfer of energy by organisms involves a loss of some degraded high-quality energy to the environment as heat. In natural ecosystems, most consumers feed on more than one type

  Forces inside the earth’s mantle and near its surface push, stress, and deform rocks. At some point the stress can cause the rocks to suddenly shift or break and produce a transform fault, or fracture in the earth’s crust. When a fault forms, or when there is abrupt movement on an existing fault, energy that has accumulated over time is released in the form of vibrations, called seismic waves , which move in all directions through the surrounding rock. This internal geological process is called an earthquake .  Most earthquakes occur at the boundaries of tectonic plates , when colliding plates create tremendous pressures in the earth’s crust or when plates slide past one another at transform faults. The place where an earthquake begins, often far below the earth’s surface is called the focus . The earthquake’s epicenter is located on the earth’s surface directly above the focus. The energy of the earth’s tremendous internal stress is released in the form of seismic (shock) waves, wh

  Forests provide highly valuable ecological and economic services. For example, through photosynthesis, forests remove CO2 from the atmosphere and store it in organic compounds (biomass). By performing this ecological service as a part of the global carbon cycle, forests help to stabilize average atmospheric temperatures and slow projected climate change. Forests also provide us with oxygen, hold soil in place, and aid in aquifer recharge and flood control. Scientists have attempted to estimate the economic value of this and other ecological services provided by the world’s forests and other ecosystems. ECOLOGICAL SERVICES PROVIDED BY FORESTS: Support energy flow and chemical cycling. Reduce soil erosion. Absorb and release water. Purify water and air. Influence local and regional climate. Store atmospheric carbon. Provide numerous wildlife habitats. ECONOMICAL SERVICES PROVIDED BY FORESTS: Fuelwood Lumber Pulp to make paper Mining Livestock grazing Recreation Jobs

  Forests are lands dominated by trees. The three main types of forest—tropical, temperate, and cold (northern coniferous, or boreal)—result from combinations of varying precipitation levels and varying average temperatures. 1. TROPICAL FORESTS: Tropical rain forests are found near the equator, where hot, moisture-laden air rises and dumps its moisture. These lush forests have year around, uniformly warm temperatures, high humidity, and almost daily heavy rainfall. This fairly constant warm and wet climate is ideal for a wide variety of plants and animals. These forests are often called jungle, but that word refers to the thickest and most dense parts of a tropical rain forest. Tropical rain forests have a very high net primary productivity. They are teeming with life and possess incredible biological diversity. Although tropical rain forests cover only about 2% of the earth’s land surface, ecologists estimate that they contain at least half of the earth’s known terrestrial plant and a

  Grasslands occur mostly in the interiors of continents in areas that are too moist for deserts to form and too dry for forests to grow. Grasslands persist because of a combination of seasonal drought, grazing by large herbivores, and occasional fires—all of which keep shrubs and trees from growing in large numbers.  The three main types of grassland—tropical, temperate, and cold (arctic tundra)—result from combinations of low average precipitation and varying average temperatures. 1. TROPICAL GRASSLAND: One type of tropical grassland, called a savanna, contains widely scattered clumps of trees such as acacia, which are covered with thorns that keep some herbivores away. This biome usually has warm temperatures year-round and alternating dry and wet seasons. Tropical savannas in East Africa are home to grazing (mostly grass-eating) and browsing (twig- and leafnibbling) hoofed animals, including wildebeests, gazelles, zebras, giraffes, and antelopes, as well as their predators such as

  In a desert, annual precipitation is low and often scattered unevenly throughout the year. During the day, the baking sun warms the ground and evaporates water from plant leaves and the soil. But at night, most of the heat stored in the ground radiates quickly into the atmosphere. Desert soils have little vegetation and moisture to help store the heat and the skies above deserts are usually clear. This explains why in a desert you may roast during the day but shiver at night. The lack of vegetation, especially in tropical and polar deserts, makes them vulnerable to sandstorms driven by winds that can spread sand from one area to another. Desert surfaces are also vulnerable to disruption from vehicles such as SUVs. A combination of low rainfall and varying average temperatures creates tropical, temperate, and cold deserts. 1. TROPICAL DESERTS: Tropical deserts such as the Sahara and the Namib of Africa are hot and dry most of the year. They have few plants and a hard, windblown surfac

Water pollution is any change in water quality that can harm living organisms or make the water unfit for human uses such as irrigation and recreation. It usually involves contamination by one or more chemicals or excessive heat (thermal pollution).  Sources: Water pollution can come from a single (point)source, or from a larger, more dispersed (nonpoint) source.  Point sources discharge pollutants into bodies of surface water at specific locations through drain pipes, ditches, or sewer lines. Examples include factories, sewage treatment plants (which remove some, but not all, pollutants), underground mines, and oil tankers. Because point sources are located at specific places, they are fairly easy to identify, monitor, and regulate. Most of the world’s more-developed countries have laws that help control point-source discharges of harmful chemicals into aquatic systems. In most of the less-developed countries, there is little control of such discharges. Nonpoint sources are broad a

Hydropower uses the kinetic energy of flowing and falling water to produce electricity. It is an indirect form of solar energy because it is based on the evaporation of water, which is deposited at higher elevations where it can flow to lower elevations in rivers as part of the earth’s solar-powered water cycle. The most common approach to harnessing hydropower is to build a high dam across a large river to create a reservoir. Some of the water stored in the reservoir is allowed to flow through large pipes at controlled rates to spin turbines that produce electricity. Hydropower is the world’s leading renewable energy source used to produce electricity. The use of microhydropower generators may become an increasingly important way to produce electricity. These are floating turbines, each about the size of an overnight suitcase. They use the power of flowing water to turn rotor blades, which spin a turbine to produce electric current. They can be placed in any stream or river without

Nanotechnology , or tiny tech, uses science and engineering to manipulate and create materials out of atoms and molecules at the ultra-small scale of less than 100 nanometers. A nanometer equals one billionth of a meter. It is one hundred-thousandth the width of a human hair, and the period at the end of this sentence is about 1 million nanometers in diameter. At the nanoscale level, conventional materials have unconventional and unexpected properties. Scientists plan to use atoms of abundant substances such as carbon, silicon, silver, titanium, and boron as building blocks to create everything from medicines and solar cells to automobile bodies. Nanomaterials are currently used in more than 800 consumer products and the number is growing rapidly. Such products include stain-resistant and wrinkle free coatings on clothes, odor-eating socks, self-cleaning coatings on sunglasses and windshields, sunscreens, deep-penetrating skin care products, and food containers that release nanosilver

Modern industrialized agriculture produces large amounts of food at prices that are relatively low, mostly because the harmful environmental and health costs of such agriculture are not included in the market prices of food. But to a growing number of analysts, this form of agriculture is unsustainable, because it violates the three principles of sustainability ( https://meticulousperspectives.blogspot.com/search?q=three+principles+of+sustainability ). It relies heavily on use of fossil fuels, which adds greenhouse gases to the atmosphere and thus contributes to climate change. It also reduces biodiversity in areas where food is grown and agrobiodiversity, and it reduces the cycling of plant nutrients back to topsoil. Thus, it becomes must to shift towards a more sustainable form of agriculture. One component of more sustainable agriculture is organic agriculture . From a nutrient standpoint there is no clear-cut evidence that organic foods are nutritionally healthier to eat than conve

Humans are destroying or degrading terrestrial biodiversity in a variety of ecosystems. We can reduce this destruction and degradation by using the earth’s resources more sustainably. We must be aware of the importance of simply planting trees; the importance of protecting species and ecosystems in nature reserves such as parks and wilderness areas; And also the importance of preserving what remains of richly diverse and highly endangered ecosystems (biodiversity hotspots). Preserving terrestrial biodiversity as it is done in the Green Belt Movement involves applying the three principles of sustainability (Refer -  https://meticulousperspectives.blogspot.com/search?q=three+principles+of+sustainability ). First, it means respecting biodiversity and understanding the value of sustaining it. Then, in helping to sustain biodiversity by planting trees for example, we also help to restore and preserve the flows of energy from the sun through food webs and the cycling of nutrients within eco

  Air pollution is the presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems, or human-made materials, or to alter climate. Note that almost any chemical in the atmosphere can become a pollutant if it occurs in a high enough concentration. The effects of air pollution range from annoying to lethal. Sources: Air pollutants come from natural and human sources.  Natural sources include wind-blown dust, pollutants from wildfires and volcanic eruptions, and volatile organic chemicals released by some plants. Most natural air pollutants are spread out over the globe or removed by chemical cycles, precipitation, and gravity. But in areas experiencing volcanic eruptions or forest fires, chemicals emitted by these events can temporarily reach harmful levels. Most human inputs of outdoor air pollutants occur in industrialized and urban areas with their higher concentrations of people, cars, and factories. These pollutants are generated mostly by th

  Chernobyl is known around the globe as the site of the world’s most serious nuclear power plant accident. On April 26, 1986, two simultaneous explosions in one of the four operating reactors in this nuclear power plant in Ukraine (then part of the Soviet Union) blew the massive roof off the reactor building. The reactor partially melted down and its graphite components caught fire and burned for 10 days. The initial explosion and the prolonged fires released a radioactive cloud that spread over much of Belarus, Russia, Ukraine, and Europe, and it eventually encircled the planet. According to UN studies, the Chernobyl disaster was caused by a poor reactor design (not the type used in the United States or in most other parts of the world) and by human error, and it had serious consequences. By 2005, some 56 people had died prematurely from exposure to radiation released by the accident. The number of long-term premature deaths from the accident, primarily from exposure to radiation, ra

  Plants need sunlight, carbon dioxide (from the air), and mineral nutrients such as nitrogen and phosphorus. Traditionally, farmers have obtained these nutrients from soil. Hydroponics involves growing plants by exposing their roots to a nutrient-rich water solution instead of soil, usually inside of a greenhouse. Indoor hydroponic farming has a number of advantages over conventional outdoor growing systems: Crops can be grown indoors under controlled conditions almost anywhere. Yields and availability are increased because crops are grown year round, regardless of weather conditions.  In dense urban areas, crops can be grown on rooftops, underground with artificial lighting (as is now done in Tokyo, Japan), and on floating barges, thus requiring much less land. Fertilizer and water use are reduced through the recycling of nutrient and water solutions. There is no runoff of excess fertilizer into streams or other waterways. In the controlled greenhouse environment, there is little or

  At one time, the North American passenger pigeon was one of world’s most abundant bird species. In 1813, bird expert John James Audubon watched a flock of these passenger pigeons that was so huge it darkened the sky and took three days to fly over his location. By 1900, North America’s passenger pigeon had disappeared from the wild because of three factors: habitat loss as forests were cleared to make room for farms and cities, uncontrolled commercial hunting, and the fact that they were easy to kill. These birds were good to eat, their feathers made good pillows, and their bones were widely used for fertilizer. They were easy targets because they flew in gigantic flocks and nested in long, narrow, densely packed colonies. Beginning in 1858, passenger pigeon hunting became a big business. Shotguns, traps, artillery, and even dynamite were used. Hunters burned grass or sulfur below the pigeons’ roosts to suffocate the birds. Shooting galleries used live birds as targets. In 1878, a pr

Human activities are disrupting and degrading some ecological and economic services provided by marine aquatic systems, especially coastal marshes, shorelines, mangrove forests, and coral reefs. In 2008, the U. S. National Center for Ecological Analysis and Synthesis (NCEAS) used computer models to analyze and provide the first-ever comprehensive map of the effects of 17 different types of human activities on the world’s oceans. In this 4-year study, an international team of scientists found that human activity has heavily affected 41% of the world’s ocean area. No area of the oceans has been left completely untouched, according to the report. In their desire to live near a coast, some people are unwittingly destroying or degrading the aquatic biodiversity and the ecological and economic services that make coastal areas so enjoyable and valuable. In 2010, about 45% of the world’s population and more than half of the U.S. population lived along or near coasts and these percentages are i

Loss of Habitat Is the Single  Greatest Threat to Species: Remember HIPPCO shows the underlying and direct causes of the endangerment and extinction of wild species. Biodiversity researchers summarize the most important direct causes of extinction resulting from human activities using the acronym HIPPCO: Habitat destruction, degradation, and fragmentation; Invasive (nonnative) species; Population growth and increasing use of resources; Pollution; Climate change; and Overexploitation. According to biodiversity researchers, the greatest threat to wild species is habitat loss, degradation, and fragmentation. A stunning example of this is the loss of habitat for polar bears. Because the atmosphere above the Arctic has been getting warmer during the past several decades, the floating sea ice that is a vital part of the bears’ habitat is melting away beneath their feet, which is causing a decline in their numbers. Deforestation in tropical areas is the greatest eliminator of species, followe

  Whale Shark More than 400 known species of sharks inhabit the world’s oceans.  They vary widely in size and behavior, from the goldfish-sized dwarf dog shark to the whale shark, which can grow to a length of 18 meters (60 feet) and weigh as much as two full-grown African elephants. Many people, influenced by movies, popular novels, and widespread media coverage of shark attacks, think of sharks as people-eating monsters. In reality, the three largest species—the whale shark, basking shark, and megamouth shark—are gentle giants. These plant-eating sharks swim through the water with their mouths open, filtering out and swallowing huge quantities of phytoplankton. Media coverage of shark attacks greatly exaggerates the danger from sharks. Every year, members of a few species such as the great white, bull, tiger, oceanic white tip, and hammerhead sharks, injure 60–75 people worldwide. Between 1998 and 2008, there were an average of six deaths per year from such attacks. Some of these sha

Nature’s Survival Strategies Follow  Three Principles of Sustainability Nature has been dealing with significant changes in environmental conditions that affect the planet for at least 3.5 billion years. This is why many environmental experts say that when we face an environmental change that becomes a problem for us or other species, we should learn how nature has dealt with such changes and then mimic nature’s solutions.  To learn how to live more sustainably and thus more wisely, we need to find out how life on the earth has sustained itself. Our research leads us to believe that in the face of drastic environmental changes, there are three overarching themes relating to the long-term sustainability of life on this planet: solar energy, biodiversity, and chemical cycling. In other words, rely on the sun, promote multiple options for life, and reduce waste. These powerful and simple ideas make up three principles of sustainability or lessons from nature. Reliance on solar energy: The

  1. TAJ MAHAL The Taj Mahal is a white marble mausoleum located in Agra, India. It was built by Mughal emperor Shah Jahan in memory of his third wife,  Mumtaz Mahal. The Taj Mahal is widely recognized as "the jewel of Muslim art" in India and one of the universally admired masterpieces of the world's heritage. 2. PYRAMID OF GIZA The Great Pyramid of Giza is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now EI Giza, Egypt.  It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact.  There are three  known chambers inside the Great Pyramid. 3. GREAT WALL OF CHINA The Great Wall of China is a series of fortification made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China in part to protect the Chinese Empire or its prototypical states against intrusions by various nomadic groups or military incu

 "True happiness can be accrueded only through our self-gratification" The life history of Sam Berns erudites and evinces the above lines. We can accentuate the authentic significance of the above lines from the prolific talk given by Sam Berns at a TEDx event. Throughout his talk, he abstrained himself from loitering the complications which he faced because of his Progeria(a rapid ageing syndrome). He began his talk with an incident he met with. Once in his school days, he wished to play snare drum in his school marching band. But maliciously it weighed more than what he could balance. Without becoming languished, Sam Berns importuned an engineer to make a snare drum with weight which he could balance and accomplished his wish with his acumen. In this talk, he mentions his philosophy for a happy life. He tells us to adept at what we can do and we must totally abhor and procrastinate the felling of disability to do some tedious things. He also says us to get surrounded with l