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What is E-commerce?

What is E-commerce? E-commerce (Electronic commerce or EC) is the buying and selling of goods and services or transmitting funds or data over an electronic network, primarily the internet. These business transactions occur either business to business, business to consumer, consumer to consumer, or consumer to business. This thesis is concerned with the impact of electronic commerce on international tax laws, specifically source-based taxation. Before looking specifically at the arguments and propositions to be advanced by the thesis, it is both instructive and necessary, to begin with, a discussion of what is meant by ‘electronic commerce’. Discussions relating to electronic commerce normally begin with a pronouncement that it represents a fundamental and revolutionary development in communications that is likely to dramatically change the way business is conducted. This is usually followed by highly variable, speculative, and often mind-numbing estimates of the expected growth of th

Definition of Science

 This section is to give you more information about science so you can know more about doing and understanding those things which make you ethical and prosperous. In the previous section, we saw that science is the word for human activity which produces being ethical and prosperous. This section is a more complete elaboration of the process of science. This section is provided because the more you know of the tool “science,” the better you can use it to accomplish your ends. This systematic elaboration of the process can be accomplished by way of elaborating the definition of science. Science is very much more complex than pat definitions which you can memorize and then put the issue away. The scientific method is what has evolved to help people tell the truth and to understand the world. The following definitions are attempts at applying words to what is done so that you can gain the knowledge through vicarious experience rather than actual experience (the hard way).

Ultrasound Images : about various ultrasound images for diagnostics.

Ultrasound Images: about various ultrasound images for diagnostics. X-rays Modern medicine relies heavily on a variety of imaging techniques. They generate pictures of the interior of the human body for diagnostic purposes. The oldest of these imaging techniques is radiography. It generates pictures by irradiating the body with X-rays and recording the shadows of the internal anatomical structures. X-rays give us sharp and clear shadows of the bones, but they are not very well suited for imaging the soft tissues of the body. X-rays cannot discriminate between tissues of approximately equal densities. For instance, when they pass through the heart, X-rays do not discriminate between the heart muscle and the blood filling the heart cavities - an X-ray picture of the heart is merely a blob, which does not reveal the details of the heart’s anatomy. Ultrasound Imaging Several of the newer imaging techniques generate better pictures of soft tissues. Among these newer techniques is ultrasound

Intensity of Sound

A sound wave is intense and loud if it has a large amplitude. However, the amplitude of a sound wave is hard to measure directly, and it is more convenient to reckon the intensity of a sound wave by the energy it carries.  The intensity of a sound wave is defined as the energy per second transported by this wave per square meter of the wavefront, that is, the power transported by this wave per square meter.  Thus, to measure the intensity, we have to erect an area facing the wave, and we have to check how much energy the wave delivers in this area per second. It can be shown that the intensity of a sound wave is proportional to the square of the pressure disturbance it produces in the air; equivalently, the intensity is proportional to the square of the density disturbance. The unit of intensity is the watt per meter squared (W/m 2 ). At a frequency of 1000 Hz, the minimum intensity audible to the human ear is about 2.5 × 10 -12  W/m 2 . This intensity is called the threshold of hearin

Inner Ear

The inner ear is a complex system of fluid-filled cavities in the temporal bone. Among these cavities are the three semicircular canals, whose function is not hearing, but rather the detection of movements of the head. The organ of the inner ear concerned with hearing is the cochlea, a tube of about 3.5 cm coiled in a tight spiral. The tube is divided lengthwise into three adjoining ducts, separated by two membranes, Reissner’s membrane, and the basilar membrane. The sensory receptor of the inner ear is the organ of Corti, consisting of thousands of hair cells, which sit on the basilar membrane. The vibrations of the oval window excite a wave motion in the fluid of the cochlea, which shakes the basilar membrane. The hair cells detect this motion of the basilar membrane and convert the mechanical energy into electric nerve impulses. The basilar membrane is stiff at the end near the oval window, and soft at the distant end. Because of this, the near part of the membrane responds most rea

Middle Ear

The middle ear is an air-filled cavity in the temporal bone of the skull. The cavity is connected to the nasopharynx by the Eustachian tube; this tube permits equalization of the air pressure in the middle ear with the external atmospheric pressure. The middle ear contains three small bones or oscines: the hammer, the anvil, and the stirrup (malleus, incus, and stapes). These ossicles are arranged in a chain from the eardrum to the oval window of the inner ear. The chain of ossicles to the oval window transmits the vibrations generated by a sound wave striking the eardrum. Since the oval window has a much smaller area than the eardrum (about 1/25), the transmission of sound energy from the eardrum to the oval window results in a significant concentration of the energy, with a consequent increase of the amplitude of vibration. Besides transmitting the vibrations from the eardrum to the oval window, the middle ear plays a crucial role in accommodating the ear to very loud sounds. In resp

How Ear Converts Sounds Into Electric Nerve Pulses

The ear performs the task of converting the mechanical oscillations of a sound wave into electric nerve impulses. Thus, it is similar to a microphone, which also converts the mechanical oscillations of sound into electric signals. However, the ear is unmatched in its ability to accommodate a wide range of intensities of sound. The human ear has three main parts: the outer ear, the middle ear, and the inner ear. The outer ear consists of the auricle and the ear canal. The auricle serves to funnel sound waves into the ear, especially waves arriving from the front of the listener. The ear canal is a tube, about 2.7 cm long, closed off at the inner end by the eardrum, or tympanum. The ear canal guides sound waves toward the eardrum, and also enhances sound waves of a frequency of a few thousand hertz, which are in resonance with the standing-wave modes of the air column in the canal.

What is sound wave?

A sound wave in air consists of alternating zones of low and high density. The vibrating diaphragm of a loudspeaker generates such zones of alternating density. The alternating zones of low density and high-density travel to the right away from the source. However, although these density disturbances travel, the air as a whole does not travel, the air molecules merely oscillate back and forth. The pushes of the loudspeaker or of the tuning fork on the air are longitudinal, and the sound wave itself is also longitudinal. The air molecules oscillate back and forth along the direction of propagation of the sound wave. The restoring force that drives these oscillations is the pressure of air. Wherever the density of molecules is higher than normal, the pressure also is higher than normal and pushes the molecules apart; wherever the density of molecules is lower than normal, the pressure also is lower than normal, and therefore the higher pressure of the adjacent regions pushes these molecu

What is Work?

To introduce the definition of work done by a force, we begin with the simple case of motion along a straight line, with the force along the line of motion, Consider a particle moving along a straight line, say, the x-axis, and suppose that a constant force F, directed along the same straight line, acts on the particle. For example, the particle might be a stalled automobile that you are pushing along a road.  Then the work done by the force F on the particle as it moves some given distance S is defined as the product of the force and the displacement, W = F. S =FSCos α where α is the angle between the force F and the displacement S. Work is a scalar quantity. The unit of work is [W] = [F] [S] In metric system, unit of work is Joule. [W] = 1 Joule = 1 N.m In CGS system, unit of work is erg. Relation between the units of work is 1 Joule = 1 N.m = 10 5 D. 10 2  cm = 10 7  ergs.

What is placenta?

A particular organ built up of material and fetal tissue forms a connection jointly is called the placenta.

What is photophosphorilation?

The process in which green plants prepare carbohydrate food from CO 2  and H 2 O by their chlorophyll pigments remaining in the chloroplast with the help of solar energy is known as photosynthesis. In this process, O 2  is evolved as a by-product and the simplest sugar glucose is formed. 

What do you mean by scientific name?

The scientific name of an animal is binomial which means it contains two parts. This naming is also referred to as binomial nomenclature.

What is classification?

What is classification? Depending on their characteristics, living organisms are grouped into different taxons. This step-wise grouping is known as classification. 

What is Food Web?

In nature, most food chains connect other chains. The complex food chain of more than one is known as a food web. In most cases, it is found that the same consumer can be placed in different trophic levels. This way some food chains collectively may form a net or web like structure. It is called a food web. So, food chains are not distinct. They are interrelated with each other and form a food web.  Read More Why Adulterant food is the barrier to sound health? What are the producers? What are food preservatives? What is food chain? What is tertiary consumer?

What is food chain?

Staring from plant source the transfer of energy by eating and being eaten up by different animals, is known as food chain.  Read More Why Adulterant food is the barrer of sound health? What is producers? What are food preservatives? What is tertiary consumer?


Habit and habitat :  The member of the phylum porifera is commonly known as "Sponge'. Their distribution is worldwide i.e. they are found all over the world. Most of the species are marine. But some live in fresh water. Usually they live in colonies. General characteristics Simplest multicellular animal. Body wall with numerous pores. Through these pores food and oxygen enter into the body. No compact tissue, organ and organ system, Example : Spongilla, Scypha.

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