Day: October 26, 2021

Environment Issues

Earth is the only planet in the solar system with life. It is home to numerous species. It is home to numerous species. but today, our planet is afflicted with environmental issues that are life threatening. Now water, air, and soil is polluted. Because of the increasing population and the irresponsible human behaviour, the environment conditions are becoming worse and perhaps uninhabitable. Some of the major environment problems faced by the world looming large are listed below.

Global Warming & Climate Change

  • “Global warming” refers to the rise in global temperatures due mainly to the increasing concentrations of greenhouse gases in the atmosphere.
  • “Climate change” refers to the increasing changes in the measures of climate over a long period of time – including precipitation, temperature, and wind patterns.
  • Earth’s climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 11,700 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives.
  • The current warming trend is of particular significance because it is unequivocally the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over millennia. It is undeniable that human activities have warmed the atmosphere, ocean, and land and that widespread and rapid changes in the atmosphere, ocean, cryosphere, and biosphere have occurred.
  • The planet’s average surface temperature has risen about 2.12 degrees Fahrenheit (1.18 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide emissions into the atmosphere and other human activities.4 Most of the warming occurred in the past 40 years, with the seven most recent years being the warmest. The years 2016 and 2020 are tied for the warmest year on record.
  • The ocean has absorbed much of this increased heat, with the top 100 meters (about 328 feet) of ocean showing warming of more than 0.6 degrees Fahrenheit (0.33 degrees Celsius) since 1969.6 Earth stores 90% of the extra energy in the ocean.
  • The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA’s Gravity Recovery and Climate Experiment show Greenland lost an average of 279 billion tons of ice per year between 1993 and 2019, while Antarctica lost about 148 billion tons of ice per year.
  • Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska, and Africa.
  • Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and the snow is melting earlier.
  • Global sea level rose about 8 inches (20 centimeters) in the last century. The rate in the last two decades, however, is nearly double that of the last century and accelerating slightly every year.

Deforestation

  • The clearing or thinning of forests by humans is known as Deforestation.
  • Forests cover 31% of the land area on our planet. They help people thrive and survive by, for example, purifying water and air and providing people with jobs; some 13.2 million people across the world have a job in the forest sector and another 41 million have a job that is related to the sector. Many animals also rely on forests. Eighty percent of the world’s land-based species, such as elephants and rhinos, live in forests.
  • Forests also play a critical role in mitigating climate change because they act as a carbon sink soaking up carbon dioxide that would otherwise be free in the atmosphere and contribute to ongoing changes in climate patterns.
  • But forests around the world are under threat, jeopardizing these benefits. The threats manifest themselves in the form of deforestation and forest degradation.
  • The main cause of deforestation is agriculture (poorly planned infrastructure is emerging as a big threat too) and the main cause of forest degradation is illegal logging. In 2019, the tropics lost close to 30 soccer fields’ worth of trees every single minute.
Illegal deforestation found in the indigenous Uru-Eu-Wau-Wau territory. This area of ​​deforestation was discovered on December 15th 2019 during the first surveillance made by the Uru-eu-wau-wau after the drone course funded by WWF’s Amazon Emergency Appeal. Drones are to be used to monitor deforestation, invasion and land grabbing. The Uru-Eu-Wau-Wau people received drone piloting training in a partnership between Kanindé Ethno-Environmental Defense Association and WWF. From the funds raised from WWF’s Amazon Emergency Appeal WWF donated 14 drones and trained 55 people to operate them during a training course in December 2019 held in Rondônia. The Indigenous Uru-Eu-Wau-Wau territory in Rondônia measures 1,867,117 hectares and is home to the springs of the 17 largest rivers, it is known as “the state water tank”. This Indigenous Land is the most important of Rondônia because of its biodiversity and the economic value of the water available. There are also caves with rock scriptures, endangered animals, flora and fauna that have never been studied. In the history of the Indigenous Land there have been successive invasions by loggers, rubber tappers, farmers, and land grabbers but it suffers in particular from land grabbing and illegal livestock. The invasions intensified from the 1980s and persist to this day. A new wave of invasions has intensified threats to the people of the Uru-eu-wau-wau Indigenous Land since the 2018 election campaign.

Energy Crisis

Our energy sources such as petroleum, biofuel, coal, etc. are ,mostly non-renewable resources. The energy crisis due to the excess usage of these energy sources, are not depleting the sources fast, but are also adding the green the greenhouse gases which in turn are adding to the green house gases which in turn are adding to the global warming condition. So, most countries are looking for alternative energy sources such as wind energy, solar energy, nuclear energy etc, which will be helpful in the future.

Ozone Layer Depletion

  • Ozone layer depletion is the gradual thinning of the earth’s ozone layer in the upper atmosphere caused due to the release of chemical compounds containing gaseous bromine or chlorine from industries or other human activities.
  • This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. One chlorine can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created.
  • Some compounds release chlorine and bromine on exposure to high ultraviolet light, which then contributes to the ozone layer depletion. Such compounds are known as Ozone Depleting Substances (ODS).
  • The ozone-depleting substances that contain chlorine include chlorofluorocarbon, carbon tetra-chloride, hydro-chlorofluorocarbons, and methyl chloroform. Whereas, the ozone-depleting substances that contain bromine are halons, methyl bromide, and hydro bromofluorocarbons.
  • Chlorofluorocarbons are the most abundant ozone-depleting substance. It is only when the chlorine atom reacts with some other molecule, it does not react with ozone.
  • Montreal Protocol was proposed in 1987 to stop the use, production and import of ozone-depleting substances and minimise their concentration in the atmosphere to protect the ozone layer of the earth.
  • If the emission of these gases and other harmful gases are not checked, the ozone layer will disappear very soon. This may expose the living beings to harmful radiations which cause life-threatening diseases like skin cancer.
Forming a Ozone-hole

Pollution

Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical substances or energy, such as noise, heat, or light. All these pollution are very harmful and can seriously affect the living being. Air pollution is related to the emission of harmful gases in the earth’s atmosphere causing health problems. Water Pollution on the other hand, is related to the dumping of waste materials in the water which causes harm to the aquatic as well as terrestrial life. Soil pollution is also related to dumping of waste material, fertilizer run-offs, pesticides and in the sol which degrades the soil. Now comes noise pollution, radio waves from mobile towers and mobile phones, smell pollution, which is related to the high frequency sound ways and pungent smell which are harmful for the ears, brains, nose and lungs.

Waste

  • Waste are unwanted or unusable materials. Waste is any substance which is discarded after primary use, or is worthless, defective and of no use.
  • A by-product by contrast is a joint product of relatively minor economic value. A waste product may become a by-product, joint product or resource through an invention that raises a waste product’s value above zero.
  • Examples include municipal solid waste (household trash/refuse), hazardous waste, wastewater (such as sewage, which contains bodily wastes (feces and urine) and surface runoff), radioactive waste, and others.
  • Inappropriately managed waste can attract rodents and insects, which can harbor gastrointestinal parasites, yellow fever, worms, the plague and other conditions for humans, and exposure to hazardous wastes, particularly when they are burned, can cause various other diseases including cancers.
  • Toxic waste materials can contaminate surface water, groundwater, soil, and air which causes more problems for humans, other species, and ecosystems.
  • Waste treatment and disposal produces significant green house gas (GHG) emissions, notably methane, which are contributing significantly to global warming.
  • As global warming and carbon-dioxide emission increase, soil begins to become a larger carbon sink and will become increasingly volatile for our plant life.
  • Education and awareness in the area of waste and waste management is increasingly important from a global perspective of resource management. The Talloires Declaration is a declaration for sustainability concerned about the unprecedented scale and speed of environmental pollution and degradation, and the depletion of natural resources.
  • Local, regional, and global air pollution; accumulation and distribution of toxic wastes; destruction and depletion of forests, soil, and water; depletion of the ozone layer and emission of “green house” gases threaten the survival of humans and thousands of other living species, the integrity of the earth and its biodiversity, the security of nations, and the heritage of future generations.
Recycling

Oil Spills

An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially the marine ecosystem, due to human activity, and is a form of pollution. Oil spills may be due to releases of crude oil from tankers, offshore platforms, drilling rigs and wells, as well as spills of refined petroleum products (such as gasoline, diesel) and their by-products, heavier fuels used by large ships such as bunker fuel, or the spill of any oily refuse or waste oil. It has become a major cause for the extinction of many marine species. The biggest oil spill in the world history was a result of Gulf War and it took place in the Persian Gulf where more than 420 million gallons of oil was spilled by the Iraqi forces just to stop the American soldiers from landing.

Depletion of Resources

  • Resource depletion is the consumption of a resource faster than it can be replenished.
  • Natural resources are commonly divided between renewable resources and non-renewable resources . Use of either of these forms of resources beyond their rate of replacement is considered to be resource depletion.
  • The value of a resource is a direct result of its availability in nature and the cost of extracting the resource, the more a resource is depleted the more the value of the resource increases.
  • There are several types of resource depletion, the most known being – Aquifer depletion, deforestation, mining for fossil fuels and minerals, pollution or contamination of resources, slash-and-burn agricultural practices, soil erosion, and over consumption, excessive or unnecessary use of resources.

The 1760 industrial revolution saw large-scale mineral and oil exploration and the practice has been gradually growing, leading to more and more natural oil and mineral depletion. And together with the advancements in technology, development, and research in the contemporary era; exploitation of minerals has become easier and humans are digging deeper to access different ore. The increased exploitation of different minerals has led to some of them entering into a production decline.

For example, minerals such as Gasoline, Copper, and Zinc production are estimated to decline in the next 20 years. Plus, oil mining continues to rise due to the upsurge in the number of engines that use petroleum thereby magnifying its depletion. The peak oil theory supports this fact by putting forward that it will come a time when the globe will experience uncertainties on alternative means of fuels owing to the over-harvesting of petroleum.

Overpopulation

The total global population is more than seven billion people. Still, there is a consistent increase in the overall earth populace and this has been a critical factor in accelerating the depletion of natural resources. An increase in the populace expands the need for resources and conditions necessary to sustain it. In addition, It contributes to increased ecological contamination. Research further indicates that developing countries are using more and more resources to industrialize and support their ever-increasing population. Hence, the depletion of natural resources will continue as long as the world population increases.

Nuclear Issues

Nations long to have nuclear weapons. But the fact is, nuclear weapons have become one of the most dangerous environmental issues today. The amount of nuclear weapons we have can destroy the entire earth in a few seconds. There are many disadvantages of nuclear of nuclear power. Water is used to cool the reactors which then mixes up with he other water bodies and by this, it ads to the problem of global warming. The waste which is produced is so dangerous that even a a small amount of nuclear waste can harm, a big area and effect the living beings. The misuse of nuclear power has become a threat to the survival of life on earth.

Nuclear Power Plants

Go Green to Save Earth

In order to save the planet, the only way is to go green. We need to save energy to reduce the energy crisis and to save nature. Switch off all electrical appliances when not in use. Try to avoid non-renewable energy resources and concentrate on renewable energy like solar energy. Save water. preserve rainwater and stop water pollution. Use recycled things. Stop using plastic bags and bottles. Use Eco-friendly things. Control over-population. save trees avoid using paper bags. Plant tress.

Advertisement

Can we choose Youtube as a career?

It lets you follow your passion

Unless you are working for National Geographic or Discovery, desk jobs are mundane. Not every graduate or educated professional ends up working for fun lifestyle channels. Not every show producers get the chance of producing interesting shows like Buffy the vampire slayer or Pushing daisies. Some projects never even find success, some scripts go straight to the dustbin.

Whether you are a writer, producer, entertainer, or director, Youtube gives you the choice of following your passion, unleashing your creativity. Got an idea? Just write a script, self-produced, and broadcast.

Youtube career is not just about a steady paycheck. It’s about finding your audience, getting them to resonate with you while you follow your passion. It lets you connect with strangers with shared passions and drives from all over the world.

No degrees needed, no minimum age

Want to make videos for Youtube? Just get your phone out and start shooting. Want them to look a bit more professional? Get a DSLR and some other YouTube Equipment. You don’t need a lifetime of debt and a snobbish college degree to get a Youtube career. Talent alone is enough. If you know what resonates with your audience, you can start creating video content for your Youtube channel, strategize your posts and start connecting with your audience.

The idea is that if you are starting a Youtube Channel, you are your boss.

No need for a physical office

 You can start it anywhere, anytime without any specific capital or partners. You can start it from your bedroom or your kitchen with just some decent video shooting stuff and interesting scripts.

You don’t have to invite your crew to an office every Monday-Friday and work from your home or even when you are on vacation. You may expand later and set up a physical office but if you want to take a slow, no need to go for the big decision. Just work from home!

No Pressure

Youtube is sure competitive and it’s hard to make your mark but all you need is conviction and understanding. You need to understand your audience, learn what they search and what topics are most revered. And, there is no pressure. You don’t have to worry about medical leaves or too much paperwork. You don’t need to write case studies on weekends or study top business blogs every Monday morning. Just get started with your scripts and work them whenever you like. As long as you have powerful content that moves your audience, you won’t face any pressure.

The cost of producing fine content

It’s good to have a million-dollar idea but you need funding to propel it forward. Producing Video content on iPhone or Android phones is great and DIY but if you are aiming for the stars, you need decent gear. Gear alone could cost you a fortune. A studio setup is usually owned by big channels who invest once, upgrade frequently and reap ROI with regular results through consistent series and shows. If you are keen on producing top-quality content, you need costly gear. Hiring talent for your videos may cost you money too.

Consistency

Youtube has millions of makeup tutorials, all of which use high-end, luxury makeup products. Not many video channels have the capital to invest in the materials needed like makeup or phone for phone review channels. Establishing yourself to qualify for free samples initially may give channels a tough time.

It takes time

Viral videos are otherworldly. It’s hard to tell if the viral factor is wholly organic in cases of viral videos. Perhaps forces of SEO and other tactics are at work there. But the idea is that it’s hard to get your Youtube channel some takes with organic content.

Even if your content is focused on trends, it’s hard to find an audience altogether. 300 hours of videos are uploaded to Youtube every minute. Just imagine the choice YouTubers have! So, it’s really hard to be among the 5 billion videos that are watched every day on YouTube. Cultivating an organic audience of hundreds of thousands of viewers may take time.

Ideas get copied

Starting a Youtube Channel is easy. What if your idea gets copied and the copied video finds the momentum that you couldn’t? A lot of brands pursue plagiarism cases aggressively but small-time channel owners aren’t able to keep track of the new content so there’s no way of finding out if the idea got copied unless it blew up.

Conclusion

Youtube is another coin with two sides and the choice depends on you if you are prepared for the hard work or would like a steady paycheck.

It sure takes money to make impressive videos with high quality and there is no shortage of haters and trolls. But you do need conviction and vision. Are you sure you possess the talent that will make viewers stop and stare? How much faith do you have in your content? Will it set a bar, up the standards, and challenge the mainstream and traditional video content? Do you enjoy working late nights, not having a regular paycheck, shooting and editing videos frequently, developing scripts, coordinating with entertainers, broadcasting cutting-edge content? If yes, Youtube is for you.

Optical Instruments

Optical instruments are the devices which process light wave to enhance an image for more clear view.

Use of optical instruments, such as a magnifying lens or any complicated device like microscope or telescope usually makes things bigger and helps us to see in a more detailed manner. The use of converging lenses makes things appear larger and on the other hand, diverging lenses always gets you smaller images. While using a converging lens, it’s important to remember that, if an object is at a larger distance then the image is diminished and will be very nearer to the focal point. While the object keeps on moving in the direction of the lens, the image moves beyond the focal point and enlarges. When object is placed at 2F, which is two times the focal distance from the lens, the image and object becomes of the same size. When the object moves from 2F towards the focal point (F), it’s image keeps moving out of the lens and enlarges till it goes to infinity when the object reaches the focal point, F. As the object moves closer to the lens, the image moves in the direction of the lens from negative infinity and gets smaller when the object gets closer to lens.

Image enhancement

The first optical instruments were telescopes used for magnification of distant images, and microscopes used for magnifying very tiny images. Since the days of Galileo and Van Leeuwenhoek, these instruments have been greatly improved and extended into other portions of the electromagnetic spectrum. he binocular device is a generally compact instrument for both eyes designed for mobile use. A camera could be considered a type of optical instrument, with the pinhole camera and camera obscura being very simple examples of such devices.

Another class of Optical Instrument is used to analyze the properties of light or optical materials. They include:

  • Interferometer for measuring the interference properties of light waves.
  • Photometer for measuring light intensity.
  • Polarimeter for measuring dispersion or rotation of polarized light.
  • Reflectometer for measuring the reflectivity of a surface or object.
  • Refractometer for measuring refractive index of various materials, invented by Ernst Abbe.
  • Spectrometer or monochromator for generating or measuring a portion of the optical spectrum, for the purpose of chemical or material analysis.
  • Autocollimator which is used to measure angular deflections.
  • Vertometer which is used to determine refractive power of lenses such as glasses, contact lenses and magnifier lens.
  • DNA sequencers can be considered optical instruments as they analyse the color and intensity of the light emitted by a fluorochrome attached to a specific nucleotide of a DNA strand.

Applications of Optical Instruments

Multiple Lenses – There are many devices like telescopes and microscopes which uses multiple lenses to create images. Analyzing any system having multiple lenses shows that it works in stages where each lens forms an image of the object. The original object will work as the object for the first lens and creates an image. This new image will be the object for the second lens and so on..

Microscope

A microscope has two converging lens. This is because it is easier to get higher magnification with two lenses rather than just one. Use of one lens can magnify 5 times more and using a second will magnify 7 times, and you will get an overall magnification of 35 which is not possible in one lens. It’s an easy procedure than to get magnification by a factor of 35 with a single lens. A ray diagram of microscope arrangement is given below. Here you can see the image is the object for the second lens and the image formed by the second lens is the image that you would see when you looked through the microscope.

Types of Microscopes

Simple Microscope

A simple microscope is an optical instrument, we use for the magnification of small objects to get a clear image or vision. It is a convex lens having a short focal length. This microscope is at a small distance from the object for the magnification and hence this forms a virtual image. The simple microscope enables us to view very small letters and figures

Compound Microscope

With a compound microscope, we get very large values of magnification. We use this microscope to see microscopic objects like microorganisms. It comprises of two convex lenses and magnification occurs in both of these lenses. the components of a compound microscope are eyepiece, objective lens, fine and rough adjustment screw.

Telescopes

As we use telescope to view a object that is at very distant place, therefore, a telescope needs at least two lenses. The first lens forms a diminished image which is nearer to its focal point. This device is designed in a way so that real and inverted image formed by the first lens is just nearer to the second lens than its focal length. With the help of a magnifying glass, we gets a enlarged image which is virtual. The final image then inverted with respect to the object. This doesn’t really matter with the astronomical telescope. While observing an object which is on earth, we usually prefer a straight image which is obtained using a third lens.

Types of Telescopes

Refracting Telescopes

All refracting telescopes use the same principles. The combination of an objective lens 1 and some type of eyepiece 2 is used to gather more light than the human eye is able to collect on its own, focus it 5, and present the viewer with a brighter, clearer, and magnified virtual image 6. The figure above is a diagram of a refracting telescope. The objective lens (at point 1) and the eyepiece (point 2) gather more light than a human eye can collect by itself. The image is focused at point 5, and the observer is shown a brighter, magnified virtual image at point 6. The objective lens refracts, or bends, light. This causes the parallel rays to converge at a focal point, and those that are not parallel converge on a focal plane.

Reflecting Telescopes

Reflecting telescopes, such as the one shown in, use either one or a combination of curved mirrors that reflect light to form an image. They allow an observer to view objects that have very large diameters and are the primary type of telescope used in astronomy. The object being observed is reflected by a curved primary mirror onto the focal plane. (The distance from the mirror to the focal plane is called the focal length. ) A sensor could be located here to record the image, or a secondary mirror could be added to redirect the light to an eyepiece.

Catadioptric Telescopes

Catadioptric telescopes, such as the one shown in, combine mirrors and lenses to form an image. This system has a greater degree of error correction than other types of telescopes. The combination of reflective and refractive elements allows for each element to correct the errors made by the other.

X-Ray Diffraction

X-ray diffraction was discovered by Max von Laue, who won the Nobel Prize in physics in 1914 for his mathematical evaluation of observed x-ray diffraction patterns. Diffraction is the irregularities caused when waves encounter an object. You have most likely observed the effects of diffraction when looking at the bottom of a CD or DVD. The rainbow pattern that appears is a result of the light being interfered by the pits and lands on the disc that hold the data. Shows this effect. Diffraction can happen to any type of wave, not just visible light waves
.

X-ray Imaging

X-ray radio-graphs are produced by projecting a beam of X-rays toward an object, in medical cases, a part of the human body. Depending on the physical properties of the object (density and composition), some of the X-rays can be partially absorbed.
The portion of the rays that are not absorbed then pass through the object and are recorded by either film or a detector, like in a camera. This provides the observer with a 2 dimensional representation of all the components of that object superimposed on each other.
.

Tomography

  • Tomography refers to imaging by sections, or sectioning. demonstrates this concept.
  • The three-dimensional image is broken down into sections.
  • (S1) shows a section from the left and (S2) shows a section from the right.

CT Scans

  • CT scans, or computed tomography scans use a combination of X-ray radiography and tomography to produce slices of areas of the human body.
  • Doctors can analyze the area, and based on the ability of the material to block the X-ray beam, understand more about the material. shows a CT Scan of a human brain.
  • Doctors can cross reference the images with known properties of the same material and determine if there are any inconsistencies or problems.
  • Although generally these scans are shown as in, the information recorded can be used to create a 3 dimensional image of the area. shows a three dimensional image of a brain that was made by compiling CT Scans.

Lasers

  • A laser is a device that produces a very focused beam of visible light of just one wavelength and color.
  • Waves of laser light are synchronized so the crests and troughs of the waves line up.
  • Electrons in a material such as a ruby crystal are stimulated to radiate photons of light of one wavelength.
  • At each end of the tube is a concave mirror. The photons of light reflect back and forth in the tube off these mirrors.
  • This focuses the light. The mirror at one end of the tube is partly transparent.
  • A constant stream of photons passes through the transparent part, forming the laser beam.

Optical fibres

  • One use is carrying communication signals in optical fibres.
  • Sounds or pictures are encoded in pulses of laser light, which are then sent through an optical fiber.
  • All of the light reflects off the inside of the fiber, so none of it escapes. As a result, the signal remains strong even over long distances.
  • More than one signal can travel through an optical fiber at the same time, Optical fibers are used to carry telephone, cable TV, and Internet signals.

Camera

A camera is an optical instrument that forms and records an image of an object. The image may be recorded on film or it may be detected by an electronic sensor that stores the image digitally. Regardless of how the image is recorded, all cameras form images in the same basic way.

  • Light passes through the lens at the front of the camera and enters the camera through an opening called the aperture.
  • As light passes through the lens, it forms a reduced real image. The image focuses on film (or a sensor) at the back of the camera. The lens may be moved back and forth to bring the image into focus.
  • The shutter controls the amount of light that actually strikes the film (or sensor). It stays open longer in dim light to let more light in.

Human Eye – An Optical Instrument

  • The human eye is an optical instrument that enables us to view all the objects around us is a very complex organ.
  • The white protective membrane seen when looked into the eye directly is a Sclera. It is tuff, opaque and fibrous outer layer of the eyeball.
  • The circular part is the Iris. The color of the eye is determined by the color of the Iris. The iris works like the shutter of the camera. It absorbs most of the light falling on it and allows it to pass through the pupil.
  • The center transparent area of the iris is the Pupil. The amount of light that enters the inner part of the eye depends on the size of the pupil.
  • In bright light, the iris contracts the pupil to restrict the light, whereas in low light it widens the pupil to emit more light into the eye. The eyeball is spherical in shape.
  • The retina of the eye is able to detect the light and its color because of the presence of senses known as rods and cones.
  • Light entering the human eye is first refracted by the cornea. The refracted light is then incident on an iris. The lens is just behind the iris and light after refracted through the pupil falls on it and forms a sharp image. Image formation exactly on the retina enables us to see the object clearly.

Defects Of Human Eye

Myopia – A condition in which close objects appear clearly, but far ones don’t.

Hypermetropia – A vision condition in which nearby objects are blurry.

Presbyopia – It is the gradual loss of your eyes’ ability to focus on nearby objects. It’s a natural, often annoying part of aging. Presbyopia usually becomes noticeable in your early to mid-40s and continues to worsen until around age 65.

Astigmatism – A common imperfection in the eye’s curvature. With astigmatism, the front surface of the eye or the lens inside the eye is curved differently in one direction than the other. A common symptom is blurry vision.

Conclusion

Based on the property of reflection and refraction many optical instruments have been designed to understand the behaviour of light more better. Based on the total internal reflection, the phenomenon like Mirage, Transmission through optical fibre, and property of Diamonds could be well understood. Likewise other optical instruments like microscope, telescope etc has been designed to help in the advancement of technology and research studies.

Chemicals in Medicine

Chemistry plays a very significant role in our everyday life. There is hardly any aspect of life where the chemistry does not play a role. We are indebted to chemists for most of the life saving drugs such as sulpha drugs, penicillin, and streptomycin etc-etc.
Medicinal chemistry is an interdisciplinary field of combining aspects of organic chemistry, physical chemistry, pharmacology, microbiology, biochemistry as well as computational chemistry .It is concerned with the discovery, design, synthesis and interaction of pharmaceutical agent (DRUG) with the body. Medicinal chemistry is mainly concerned with small organic molecules both natural and synthetic. Compounds in clinical use are primarily small organic compounds.

Drugs, Medicines and Chemotherapy

In all systems of treatment of disease viz. Ayurvedic, Unani and Allopathic systems, chemical compounds of natural or synthetic origin are used for the treatment of diseases.
Drugs– They r chemical compounds of low molecular weights which interacts with macro-molecular targets and produce a biological response.
Medicines– When the biological response of a drug is therapeutic (curative) and useful, it is called medicine and is used for the treatment, diagnosis and prevention of diseases.

Distinction between the terms Drugs and Medicines

  • From chemistry point of view, there is no distinction between the two terms, i.e. all drugs are medicines and all medicines are drugs. However, according to our society and law, these two terms have different meaning as follows-
  • Medicines are the chemical compounds used to treat diseases, are safe to use, cause no addiction and have minimum toxicity.
  • On the other hand, drugs are the chemical substances which cure the diseases but are habit forming, cause addiction, and have serious side effects.
  • For Example, both Penicillin and Heroin are used to cure disease. However, only Penicillin is called Medicine since it does have side effects. On the other hand, Heroin is called a drug because of its pronounced habit forming and addictive properties.

Classification of drugs

Drugs can be categorized in a number of ways. In the world of medicine and pharmacology, a drug can be classified by its chemical activity or by the condition that it treats. Anticonvulsant medications, For example, are used to prevent seizures, while Mucolytic drugs break down mucus and relieve congestion. Each of the regulated drugs that act on the central nervous system or alter your feelings and perceptions can be classified according to their physical and psychological effects.

The different drug types include the following–

  • Depressants – Drugs that suppress or slow the activity of the brain and nerves, acting directly on the central nervous system to create a calming or sedating effect. This category includes barbiturates (phenobarbital, thiopental, butalbital), benzodiazepines (alprazolam, diazepam, clonazepam, lorazepam, midazolam), alcohol, and gamma hydrogenate (GHB). Depressants are taken to relieve anxiety, promote sleep and manage seizure activity.
  • Stimulants – Drugs that accelerate the activity of the central nervous system. Stimulants can make you feel energetic, focused, and alert. This class of drugs can also make you feel edgy, angry, or paranoid. Stimulants include drugs such as cocaine, crack cocaine, amphetamine, and methamphetamine. According to the recent World Drug Report published by the United Nations Office on Drugs and Crime, amphetamine-derived stimulants like ecstasy and methamphetamine are the most commonly abused drugs around the world after marijuana.
  • Hallucinogens – Also known as psychedelics, these drugs act on the central nervous system to alter your perception of reality, time, and space. Hallucinogens may cause you to hear or see things that don’t exist or imagine situations that aren’t real. Hallucinogenic drugs include psilocybin (found in magic mushrooms), lysergic acid diethylamide (LSD), peyote, and dimethyltryptamine (DMT).
  • Opioids – These are the drugs that act through the opioid receptors. Opioids are one of the most commonly prescribed medicines worldwide and are commonly used to treat pain and cough. These include drugs such as heroin, codeine, morphine, fentanyl, hydrocodone, oxycodone, buprenorphine, and methadone.
  • Inhalants – These are a broad class of drugs with the shared trait of being primarily consumed through inhalation. Most of the substances in this class can exist in vapor form at room temperature. As many of these substances can be found as household items, inhalants are frequently abused by children and adolescents. These include substances such as paint, glue, paint thinners, gasoline, marker or pen ink, and others. Though ultimately all of these substances cross through the lungs into the bloodstream, their precise method of abuse may vary but can include sniffing, spraying, huffing, bagging, and inhaling, among other delivery routes.
  • Cannabis Cannabis is a plant-derived drug that is the most commonly used illicit drug worldwide. It acts through the cannabinoid receptors in the brain. Cannabis is abused in various forms including bhang, ganja, charas, and hashish oil.

Therapeutic actions of Different Classes of drugs

Neurologically active drugs -They affect the message transfer mechanism from nerve to receptor.

Tranquilizer

  • A tranquilizer refers to a drug which is designed for the treatment of anxiety, fear, tension, agitation, and disturbances of the mind specifically to reduce states of anxiety and tension.  
  • Tranquilizers fall into two main classes, major and minor. Major tranquilizers, which are also known as anti-psychotic agents, or neuroleptics, because they are used to treat major states of mental disturbance in schizophrenics and other psychotic patients.
  • By contrast, minor tranquilizers, which are also known as anti-anxiety agents, or anxiolytics, are used to treat milder states of anxiety and tension in healthy individuals or people with less serious mental disorders.
  • The major and minor tranquilizers bear only a superficial resemblance to each other, and the trend has been to drop the use of the word tranquilizer altogether in reference to such drugs, though the term persists in popular usage.

Analgesic

  • Any drug that relieves pain selectively without blocking the conduction of nerve impulses, markedly altering sensory perception, or affecting consciousness is called an Analgesic.
  • This selectivity is an important distinction between an analgesic and an anesthetic.
  • Analgesics may be classified into two types: anti-inflammatory drugs, which alleviate pain by reducing local inflammatory responses; and the opioids, which act on the brain.
  • The opioid analgesics were once called narcotic drugs because they can induce sleep. The opioid analgesics can be used for either short-term or long-term relief of severe pain. In contrast, the anti-inflammatory compounds are used for short-term pain relief and for modest pain, such as that of headache, muscle strain, bruising, or arthritis.

Aspirin and its medicinal effect-

  • Aspirin, also known as acetylsalicylic acid (ASA), is a medication used to treat pain, fever, or inflammation. Specific inflammatory conditions which aspirin is used to treat include Kawasaki disease, pericarditis, and rheumatic fever.
  • Aspirin given shortly after a heart attack decreases the risk of death. Aspirin is also used long-term to help prevent further heart attacks, ischaemic strokes, and blood clots in people at high risk. It may also decrease the risk of certain types of cancer, particularly colorectal cancer.
  • For pain or fever, effects typically begin within 30 minutes. Aspirin is a non-steroidal anti-inflammatory drug (NSAID) and works similarly to other NSAIDs but also suppresses the normal functioning of platelets.
  • One common adverse effect is an upset stomach.More significant side effects include stomach ulcers, stomach bleeding, and worsening asthma. Bleeding risk is greater among those who are older, drink alcohol, take other NSAIDs, or are on other blood thinners.
  • Aspirin is not recommended in the last part of pregnancy.It is not generally recommended in children with infections because of the risk of Reye syndrome.High doses may result in ringing in the ears.
Structure of Aspirin

Antipyretics

  • Antipyretics are substances that reduce fever.
  • Antipyretics cause the body then works to lower the temperature, which results in a reduction in fever. hypothalamus to override a prostaglandin-induced increase in temperature.

Paracetamol and its medicinal effect-

  • Paracetamol, also known as acetaminophen and APAP, is a medication used to treat pain and fever.
  • It is typically used for mild to moderate pain relief. There is mixed evidence for its use to relieve fever in children. It is often sold in combination with other medications, such as in many cold medications.
  • Paracetamol is also used for severe pain, such as cancer pain and pain after surgery, in combination with opioid pain medication. It is typically used either by mouth or rectally, but is also available by injection into a vein.
  • Effects last between 2 to 4 hours Paracetamol is generally safe at recommended doses. Recommended maximum daily dose for an adult is 3 or 4 grams.
  • Higher doses may lead to toxicity, including liver failure. Serious skin rashes may rarely occur. It appears to be safe during pregnancy and when breastfeeding.
  • In those with liver disease, it may still be used, but in lower doses.It is classified as a mild analgesic. It does not have significant anti-inflammatory activity.
Structure of Paracetamol

Antimicrobials

  • Antimicrobial agent, any of a large variety of chemical compounds and physical agents that are used to destroy microorganisms or to prevent their development.
  • The production and use of the antibiotic penicillin in the early 1940s became the basis for the era of modern antimicrobial therapy.
  • Streptomycin was discovered in 1944, and since then many other antibiotics and other types of antimicrobials have been found and put into use.
  • A major discovery following the introduction of these agents into medicine was the finding that their basic structure could be modified chemically to improve their characteristics.
  • Thus, antimicrobial agents that are used in the treatment of disease include synthetic chemicals as well as chemical substances or metabolic products made by microorganisms and chemical substances derived from plants.

Antibiotics

  • Antibiotics are powerful medicines that fight certain infections and can save lives when used properly.
  • They either stop bacteria from reproducing or destroy them. Before bacteria can multiply and cause symptoms, the immune system can typically kill them.
  • White blood cells (WBCs) attack harmful bacteria and, even if symptoms do occur, the immune system can usually cope and fight off the infection. Sometimes, however, the number of harmful bacteria is excessive, and the immune system cannot fight them all. Antibiotics are useful in this scenario.
  • The first antibiotic was penicillin. Penicillin-based antibiotics, such as ampicillin, amoxicillin, and penicillin G, are still available to treat a variety of infections and have been around for a long time.
  • Several types of modern antibiotics are available, and they are usually only available with a prescription in most countries.
  • Topical antibiotics are available in over-the-counter (OTC) creams and ointments.
Structure of Penicillin

Antiseptics

  • An antiseptic is a substance that inhibits the growth and development of microorganisms.
  • For practical purposes, antiseptics are routinely thought of as topical agents, for application to skin, mucous membranes, and inanimate objects, although a formal definition includes agents that are used internally, such as the urinary tract antiseptics.
  • Antiseptics are a diverse class of drugs that are applied to skin surfaces or mucous membranes for their anti-infective effects.
  • This may be either bactericidal (kills bacteria) or bacteriostatic (stops the growth of bacteria).
  • Their uses include cleansing of skin and wound surfaces after injury, preparation of skin surfaces prior to injections or surgical procedures, and routine disinfection of the oral cavity as part of a program of oral hygiene.
  • Examples such as chlorine, Iodine Dettol, Savlon, Hexachlorophene, Hydrogen peroxide, Boric acid etc-etc.
For Example, Dettol is an Antiseptic Liquid

Disinfectants

  • Disinfectants are antimicrobial agents that are applied to the surface of non-living objects to destroy microorganisms that are living on the objects.
  • Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical and/or chemical process that kills all types of life.
  • Disinfectants are different from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants are also different from biocides — the latter are intended to destroy all forms of life, not just microorganisms.
  • Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism.
  • Sanitizers are substances that simultaneously clean and disinfect.
  • Disinfectants kill more germs than sanitizers. Disinfectants are frequently used in hospitals, dental surgeries, kitchens, and bathrooms to kill infectious organisms.
Foe Example, Lizol is a Disinfectant

Anti-Fertility Drugs

  • Anti-Fertility drugs are chemical substances which suppress the action of hormones that promote pregnancy.
  • These drugs actually reduce the chances of pregnancy and act as a protection.
  • Anti-Fertility drugs are made up of derivatives of synthetic progesterone or a combination of derivatives of oestrogen and progesterone. they drugs are actually synthetic hormones.
  • The synthetic progesterone derivatives are more potent as compared to natural progesterone.
  • Norethindrone is an example of synthetic progesterone which is one of the most commonly used anti-fertility drugs.
  • Ethynylestradiol is a combination of derivatives of oestrogen and progesterone. These drugs should not be taken without the consultation of a doctor.

Antihistamines

  • Antihistamines are drugs which treat allergic rhinitis and other allergies.
  • Typically people take antihistamines as an inexpensive, generic, over-the-counter drug that can provide relief from nasal congestion, sneezing, or hives caused by pollen, dust mites, or animal allergy with few side effects.
    Antihistamines are usually for short-term treatment.Although people typically use the word “antihistamine” to describe drugs for treating allergies, doctors and scientists use the term to describe a class of drug that opposes the activity of histamine receptors in the body.
  • In this sense of the word, antihistamines are sub classified according to the histamine receptor that they act upon.
  • Histamine receptors exhibit constitutive activity, so antihistamines can function as either a neutral receptor antagonist or an inverse agonist at histamine receptors.

The two largest classes of antihistamines are H1-antihistamines and H2-antihistamines.

  • H1-antihistamines work by binding to histamine H1 receptors in mast cells, smooth muscle, and endothelium in the body as well as in the tuber mammillary nucleus in the brain. Antihistamines that target the histamine H1-receptor are used to treat allergic reactions in the nose (e.g., itching, runny nose, and sneezing). In addition, they may be used to treat insomnia, motion sickness, or vertigo caused by problems with the inner ear.
  • H2-antihistamines bind to histamine H2 receptors in the upper gastrointestinal tract, primarily in the stomach. Antihistamines that target the histamine H2-receptor are used to treat gastric acid conditions (e.g., peptic ulcers and acid reflux).Histamine receptors exhibit constitutive activity, so antihistamines can function as either a neutral receptor antagonist or an inverse agonist at histamine receptors. Only a few currently marketed H1-antihistamines are known to function as inverse agonists.
Structure of a Histamine

Antacids

  • An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach.
  • Medical uses:- Antacids are available over the counter and are taken by mouth to quickly relieve occasional heartburn, the major symptom of gastroesophageal reflux disease and also indigestion.
  • Treatment with antacids alone is symptomatic and only justified for minor symptoms.
  • Antacids are distinct from acid-reducing drugs like H2-receptor antagonists or proton pump inhibitors and they do not kill the bacteria Helicobacter pylori, which causes most ulcers.
  • Side effects:- Versions with magnesium may cause diarrhoea, and brands with calcium or aluminium may cause constipation and rarely, long-term use may cause kidney stones.
  • Long-term use of versions with aluminium may increase the risk for getting osteoporosis.
  • Mechanism of action:-When excessive amounts of acids are produced in the stomach the natural mucous barrier that protects the lining of the stomach can damage the oesophagus in people with acid reflux. Antacids contain alkaline ions that chemically neutralize stomach gastric acid, reducing damage and relieving pain.
  • Examples such as magnesium salts (MgC03,Mg0),Aluminium Salts, Baking soda etc.

Conclusion

Medicinal chemistry is the discipline concerned with the determination of the influence of chemical structure on biological activity. As such, it is therefore necessary for the medicinal chemist to understand not only the mechanism by which a drug exerts its effects but also the physico-chemical properties of the molecules.The primary objective of medicinal chemistry is the design and discovery of new compounds that are suitable for use as drugs. This process requires a team effort. It not only involves chemists but also workers from a wide range of disciplines such as Biology, Biochemistry, Pharmacology, Mathematics, Computing and Medicine amongst others. It has and it will continue to play an important role in today’s society as it deals with Development, synthesis and designs of Pharmatical drugs. These results are then use to give us a better understanding of diseases as well as giving us ways of preventing and curing them.

Vijaya Lakshmi Pandit

The Indian freedom struggle helmed by Mahatma Gandhi witnessed many women taking center stage against the colonial power. Vijaya Lakshmi Pandit was one such woman who played a vital role in the nation-building process and became one of the most distinguished figures of the 20th century.

Vijaya Lakshmi Pandit was a prominent freedom fighter, diplomat, and politician. She was the first woman to be elected as the Governor of Maharashtra and the first woman President of the United Nations General Assembly.

Vijaya Lakshmi Pandit was born on August 18th, 1900, as Swarup Kumari Nehru in Allahabad to Motilal Nehru, a prominent lawyer who served twice as the President of the Indian National Congress and Swaruprani Thussu. She was the younger sister of the first Prime Minister of independent India, Pandit Jawaharlal Nehru. Growing up, she never received any formal education but was tutored privately in India and Switzerland. 

Inspired by her brother, Nehru, who was very active in the Indian political front, and Mahatma Gandhi, Pandit joined the freedom struggle and was imprisoned by the British during the Civil Disobedience Movement. She first ventured into politics in the 1930s through the All India Women’s Conference (AIWC), a non-governmental organization founded by the Margaret Sisters. She actively advocated for the rights and freedom of women and led the organization between 1941 to 1943. 

In 1936, Vijaya Lakshmi Pandit was elected as a member of the Legislative Assembly of the United Provinces but resigned from office two years later to protest against the British in World War II. In 1937, she became a minister of local self-government and public health, making her the first woman in pre – independent India to hold a cabinet post.

Pandit soon entered the diplomatic arena and took to the global stage representing India, and in a way, helped in shaping the country in its post-colonial era.  She led the Indian delegation at the United Nations Organization Conference as her first official diplomatic mission. During her tour of the United States, Pandit openly condemned colonial rule and the inherent problems attached to it. She was vocal about countries being responsible for human dignity, equality, and rights. 

Soon after India gained Independence in 1947, Pandit became appointed as the first Indian ambassador to the Soviet Union (1947-49), the United States and Mexico (1949-51), Ireland (1955-61), and Spain (1958-61), and high commissioner to the United Kingdom (1955-61). In 1953, she became the first woman to serve as the President of the 8th session of the United Nations General Assembly and the first woman to become the Governor of Maharashtra from 1962 to 1964.  From 1964 to 1968, Pandit served as a member of the Lok Sabha, representing a constituency that her late brother had won. In 1978, she served as India’s representative to the United Nations Human Rights Commission. 

After a glorious stint as a diplomat and politician, Pandit retired from politics in the 1960s owing to personal reasons. She soon returned and became a relentless critic of Indira Gandhi, her niece and the prime minister of India, confronting her actions during the emergency era. Pandit has written two books, So I Became a Minister (1939) and Prison Days (1946). She died on December 1st, 1990, in Dehra Dun. After her passing, President Ramaswamy Venkataraman described Pandit as a “luminous strand in the tapestry of India’s freedom struggle.”

“Education was not merely a means for earning a living or an instrument for the acquisition of wealth. It was an initiation into the life of spirit, a training of the human soul in the pursuit of truth and the practice of virtue.”

– Vijaya Lakshmi Pandit

Vijaya Lakshmi Pandit was one of India’s greatest assets. Her diplomatic and political career spanning over several decades is remarkable, and her achievements before and after the independence were commendable in the harsh world of politics. She was a firm believer in the freedom of India and broke many barriers for women, and is an inspiration to many.