Science Zone

How Ship's Floatation on Water Is Possible

<div xmlns='http://www.w3.org/1999/xhtml'>Why is that an iron Rod sink in water? But imagine a ship made by an iron rod does not sink? 
 
This question was asked by one of our readers and I considered it worthy of a blog post. 
 
The ability of an object to float on water depends on factors such as the nature of object, the surface area and so on. 
Let's consider the principle of floatation popularly known as Archimedes's principle, he noted that for an object to float on water, the weight of object must equal the upthrust on the object when immersed in water. 
However it's most important to know that an object only floats on a water if and only if the weight of the body equals the upthrust before it's fully immersed in a liquid. 
Have you witnessed that it's possible for a rubber cup containing water to sink in a bucket of water and a steel cup to float. The both can sink and float based on the condition stated above. 
 
Coming back to your question, you pointed out that iron sinks and so should anything made of it. That's wrong. 
Here we are talking of the surface area, ship has a large surface area and thus before it can sink, it has to displace a large amount of water and its weight on the water leads to increase in upthrust on the ship and thus the weight and the upthrust equals each other. 
The effect of surface area can be seen in this way. 
We know if a stone and a paper are fallen at a height and at the same time in a vacuum, they land the same time. Why that's is not true if done in the atmosphere is that the stone has small surface area unlike the paper. 
 
So the paper has to overcome more resistance from the air i.e displace more air to land compared to the stone.</div>

How Ship's Floatation on Water Is Possible

Why is that an iron Rod sink in water? But imagine a ship made by an iron rod does not sink? This question was asked by one of our readers...

EVER WONDER WHY BIRDS FLY IN V FORMATION

<div xmlns='http://www.w3.org/1999/xhtml'>I stood gazing in wonder when a "V" flew past over me. Not actually a letter "V", rather a flock of birds in V formation. Still watching the beautiful scenery created by those birds in the sky, I noticed the one at the rear fly past others and replaced the leader. 
 
That's awesome I said having realized they possibly continued to change position when the leader is weak as our winged friends continue their migration 
 
Why do birds migrate? 
Why do birds fly in V formation? 
Why do the even prefer V shape? 
 
Away we flock with them to find the answer... 
 
Though not all birds migrate but more than half do. They are referred as migratory birds. 
Reasons why birds migrate to a different habitat vary but shouldn't be far from availability of food or for survival purpose i.e they respond to stimuli such as changes in weather. 
 
Flying in V formation is in fact a characteristic of migratory birds. 
Reason; to save energy during their long journey. 
 
Funny enough! birds migrate several kilometers away from their habitat. Don't be surprised why they mainly feed on grains because the grains provide the energy they burn up during their flight. Flying consumes a lot energy even a pilot can tell you that. 
 
Thanks to nature that has this amazing feature bestowed to our winged friends to enable their aerial adaptation. 
 
In the northern hemisphere, many birds migrate south during the winter months when the weather becomes too cold for them to survive in their northern habitats. Once spring arrives, the birds return to their homes. Equally as varied as the reasons for migrating are the ways in which different migratory birds make their journey. Some birds migrate alone, others travel in pairs and many move in large flocks. Some birds often migrate in swarms, while larger birds, such as geese,migrate in formation. 
 
Many times this migration takes the form of the letter V. 
Why? 
The reason birds prefer to fly in a V shape has puzzled researchers for many years. There are two general theories to explain the V-shaped phenomenon. The most accepted theory is that the formation of a flock influences aerodynamics, making it easier for the birds to fly. As the birds flap their wings, the air flowing off their wing tips gives birds in the back of the V an extra lift. 
 
This reduces the amount of energy the birds need to fly. Over the course of the migration, birds take turns leading the front of the V, the most difficult position. When a bird is tired of leading, it falls to the rear of the V, where there is the least wind resistance. Rotating through various positions in the V maximizes the use of each bird’s energy, allowing flocks to fly for long periods of time without having to stop. 
 
The second theory suggests flying in a V offers each bird an unimpaired line of sight as the flick flies through the air. This makes it easier for the birds to keep track of each member of the flock. Groups of fighter pilots often arrange their planes in V formation for the same reason.</div>

EVER WONDER WHY BIRDS FLY IN V FORMATION

I stood gazing in wonder when a "V" flew past over me. Not actually a letter "V", rather a flock of birds in V formation...

EVER WONDER WHY BIRDS FLY IN V FORMATION

EVER WONDER WHY BIRDS FLY IN V FORMATION

I stood gazing in wonder when a "V" flew past over me. Not actually a letter "V", rather a flock of birds in V formation...

WHY ARE GRASSHOPPERS GREEN DURING RAINY SEASON BUT BROWN DURING DRY SEASON

Ever wondered why grasshoppers are green during the rainy season but brown during the winter. Well it's an adaptive coloration to escape...

SKIN AS BODY TEMPERATURE REGULATOR

<div xmlns='http://www.w3.org/1999/xhtml'>The skin as we all know is the largest organ in the body. Also with exception of the bones and cartilages, it's the toughest tissue in the body. It does live up to its status by carrying out numerous functions such as protection, excretion, storage of food, sensitivity, regulation of the body temperature, production of vitamin D through the early sunshine and so on. 
 
Today we are going to see how the skin regulates the body temperature especially in we homoiothermic animals; animals with constant body temperature. 
 
This is truly amazing as how the skin keeps the body temperature constant regardless of changes in external environment though the liquid tissue cell (blood) also plays a role at body temperature regulation. 
 
On a hot day or weather, there's usually an increase in the temperature of the environment and the skin carry out the following processes to get rid of excess heat and thus to keep the body temperature constant. 
 
VASODILATION: 
There is a dilation of the capillaries near the skin surface and a constriction of those in the deeper layer. The impact of this is a large volume of blood flow close to the surface of the skin such that there's a loss of heat via the three mood of heat transfer namely; conduction, convection and radiation. 
 
DECREASE IN METABOLIC RATE: There is a reduction in metabolic activity by the skin or body and this reduces the heat released by metabolic activity and thus heat production is reduced. 
 
LOWERING OF HAIRS: We usually notice that the hairs especially those on the hands and legs rise and fall. Yes they rise and fall. 
During hot days, the hair erector muscles relax causing the hairs to lie flat on the skin surface. This expose most of the air trapped by the hairs and also heat from the body is lost as the air evaporates. 
 
SWEATING: 
The sweat gland is usually active during hot periods and there's large sweat production. As the sweat evaporate from the skin, latent heat of evaporation is also extracted from the body hence the heat of the body is reduced. 
 
On a cold day or weather, the following processes are done by the skin to regulate the body temperature. 
 
RAISING OF THE HAIRS: 
The hair erector muscle contract to raise the hair and trap more air during a cold weather. Since air is a bad conductor of heat, the layer of air next to the skin acts as an insulator and prevent heat loss from the body and conserves the normal body temperature. 
 
VOSOCONSTRICTION: There's constriction of capillaries close to the skin surface and also a dilation of capillaries in deeper layer of the skin. This brings about small volume of blood flow near the skin surface and hence prevents loss of heat and conserves body heat or temperature. 
 
INCREASE IN METABOLIC ACTIVITY: The skin increases the metabolic activity of the body especially the respiratory activity of the liver that release large amount of energy and heat. This help to generate the heat necessary to keep the body's temperature from dropping during cold weather. 
 
SWEATING: 
THE sweat gland become inactive on a cold day and hence there is very little production of sweat that gets evaporated thereby conserving the latent heat of vaporization and rather use it to keep the body temperature constant by ensuring no drop 'in temperature rate throughout the body.</div>

SKIN AS BODY TEMPERATURE REGULATOR

The skin as we all know is the largest organ in the body. Also with exception of the bones and cartilages, it's the toughest tissue in t...

WHY WE URINATE MUCH AND OFTEN ON A COLD WEATHER OR DAY

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No one can claim that he's oblivious of the fact that we tend to urinate more and often during cold weather. Yes you heard me right! 
 
But why is it so? 
Well let me address the question once and for all. 
 
First! How does the body react during cold and hot weather with regard to even temperature distribution through out the body. 
 
But then when does one feel warm and cold? 
I mean how does the body cope with hemostasis, to sound less complex the regulation of the body's temperature in order to attain and maintain a fairly constant temperature rate. 
 
The blood and the skin see to that. 
The blood cell does its by even distribution of blood around the body to ensure an even body temperature. 
To be precise, the blood disperse the temperature of a particular part of the body to all other parts of the body. <a href="http://sciencezone12.blogspot.in/2015/02/skin-as-body-temperature-regulator.html/">The skin does its as body temperature regulator</a> 
 
The body is usually warm on a hot day as a result of heat from the sun and high metabolic activity in the body. When the body is warm, there's a stimulation for sweat production and this is due to the high metabolic activity of the liver which heats up the body. 
 
For the sweat to be evaporated from the body, latent heat of vaporization is derived from the body and thus the body's temperature is continually reduced as the sweat evaporate. 
This and cold weather bring about the sensation of cold stimuli while hot weather and high metabolic activity within the body lead to warm sensation we feel. 
 
Acknowledging this, it's also important to understand how the body dispose sweat in each atmospheric condition and thus why we urinate much and often during cold weather or atmospheric condition than the warm one. 
 
During hot weather, the skin helps the liver dispose excess salt or sweat produced by the sweat gland through body sweating because the sweat gland is highly active and produces high amount of sweat. 
 
Unlike hot atmospheric condition, the sweat gland is inactive during a cold day and produces very little sweat. The effect of this is a drastic reduction of heat or sweat loss through evaporation. Not only does this result to body heat conservation but also result to the skin not excreting excess salts or sweat and then the sweat become excreted by the liver as urine. 
That's why we urinate much and often on a cold weather or day.</div>

WHY WE URINATE MUCH AND OFTEN ON A COLD WEATHER OR DAY

No one can claim that he's oblivious of the fact that we tend to urinate more and often during cold weather. Yes you heard me right! ...

Functions Of White Blood Cells And Immunization

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People can protect themselves from serious diseases by carrying out immunization i.e artificial immunization. 
 
But then, what's immunization?  
Immunization is the process of ingesting substances that is primed to make ones immune system  resistant to a specific pathogenic organisms or disease. Immunity created in the body is called natural immunization while the ones created by humans are called artificial immunity. 
 
Let's now know how artificial immunization is possible. 
 
We all know that the solid component of the blood known as the white blood cell carries out the important function of defending the body from pathogens or diseases. To make this more efficient,  the white blood cell is further categorized in two which include the phagocytes (that carry out phagocytosis, i.e ingestion of pathogens ) and the lymphocytes that secret substances called antibodies that function as follows in relation with the phagocytes. 
 
-Neutralization: the lymphocytes  neutralize the toxic produced by those pathogens or render them inactive. 
-Flocculation: The lymphocytes secret the disease causing organisms with antibodies that would cause them to clump together and then ingested by the phagocytes. 
 Clotting: during the process of clotting, the lymphocytes got attached to the mesh of fibrin that block the cut and thus prevent the entry of pathogenic organisms. 
 
Let's break down the lymphocytes a bit further. 
 
The lymphocytes are further classified into two principal groups and the null-group. 
B-lymphocytes: produce antibodies in the humoral immune response. 
 
T-lymphocytes: participate in the cell mediated immune response. 
 
The null-group contains the cytotoxic cells (natural killer cells) and  participates in the cell innate immune response. 
 
It's now important to note that a particular type of pathogen stimulates the production of a particular antibody. 
 
How immunization works: 
The artificial immunization is simply aimed at making or creating an awareness of a possible presence a disease and causing the lymphocytes to recognize them. 
This is done by ingesting a small dose of dead or weakened causal micro-organism of such disease into the body. 
This will quickly draw the attention of the lymphocytes and thus effect the production of a specific antibody that would kill the disease. 
 
So when these white blood cells are destroyed,  the body is left defenseless and thus exposed to any possible disease or pathogen. This exactly what AIDS does. 
 
It attacks and destroys the white blood cells. The diseased is left defenseless and different diseases invade the body. This will lead to the actual death of the person. What Aids does is only destroying the body immune,then the different diseases that invade the body lead to the death of such. 
 
Got any suggestion? 
Use the comment space. 
 </div>

Functions Of White Blood Cells And Immunization

People can protect themselves from serious diseases by carrying out immunization i.e artificial immunization. But then, what's immuni...

Science Zone

How Ship's Floatation on Water Is Possible

EVER WONDER WHY BIRDS FLY IN V FORMATION

EVER WONDER WHY BIRDS FLY IN V FORMATION

WHY ARE GRASSHOPPERS GREEN DURING RAINY SEASON BUT BROWN DURING DRY SEASON

SKIN AS BODY TEMPERATURE REGULATOR

WHY WE URINATE MUCH AND OFTEN ON A COLD WEATHER OR DAY

Functions Of White Blood Cells And Immunization

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