Super Critical CO2 For Power generation

Using CO2 to generate power will revolutionize how power is generated, built, and distributed. Using super critical CO2 to run the turbines for electricity generation instead of conventional steam(water). We all know that water boils at 100 degree C ,but the boiling point can be raised by increasing the pressure, a further increase in pressure and temperature leads us to a point at which the latent heat of vapourisation is zero, or there is no boiling. Water directly becomes steam. This is the Critical Pressure and the Critical Temperature. For steam this occurs at 374 deg C and 220.6 bar.

In super critical condition the density of gas and liquid becomes equal .The critical point for carbon dioxide occurs at a pressure of 73.8 bar and a temperature of 31.1°C. These parameters make equipment design and reaction set-up relatively simple. For water this occurs at 374 deg C and 220.6 bar. The great advantage of CO2 over water it reaches SCF state at almost room temperature.

CO2 is not produced in the the SCF process, rather already existing CO2 is used. There is no addition to any greenhouse effect. 

The use of CO2 in power turbines has been an active area of research for a number of years, and now multiple companies are bringing early stage commercial products to market.

https://www.youtube.com/watch?v=-gCTKteN5Y4&t=175s

Holography

Holography is a three dimensional recording of an image using interference pattern and not regular image focused on film also called lensless photography.The term ‘hologram’ can refer to both the encoded material and the resulting image. Holography was invented by Dennis Gabor in 1948 later awarded Nobel prize.

The light used to make a hologram must be coherent, i.e. of a single wavelength or frequency and with all the waves in phase.  Before reaching the object, the beam is split into two parts, one the reference beam is recorded directly on the photographic plate and the other is reflected from the object to be photographed and is then recorded. Since the two parts of the beam arriving at the photographic plate have traveled by different paths they combine to create an interference pattern of the object. 

A hologram exhibits a property called parallax, the image will change its appearance if you look at it from a different angle, just as if you were looking at a real 3D object.

The image can be reconstructed even from a damaged or partially available film because every point of the hologram contains the image of the object.

The images are scalable. They can be made with one wavelength and viewed with another, with the possibility of magnification.

Applications

Bubble chamber holography has been performed at the Enrico Fermi National Laboratory.Three-dimensional tracks in a 15-foot deep bubble chamber were recorded. The creation and annihilation of matter and antimatter can be seen through these holograms.

Biomedical applications of holography is actively pursued in the U.S. and Europe. Holograms are made inside live organs through optical fibers, providing more details than any previous alternate techniques.

Instantaneous growth rate of a live plant can be directly observed through a hologram. Using optical fibers, the rigid body movements can be isolated from the net growth information.

Bi-focal contact lenses are being manufactured. Compact discs players use holograms to handle light. Grocery store scanners use spinning holograms. High resolution spectrometers use holographic gratings. Anti-counterfeiting in credit card is now a common practice.

 

 

 

 

LASERS

The acronym LASER refers to "Light Amplification by Stimulated Emission of Radiation".The two terms that are important here are one Spontaneous emission and the others stimulated absorption, stimulated emission.

When atom in the ground state absorbs a photon then the atom is excited to higher energy level this is called stimulated absorption, the atom has a short duration to remain in the exited state,the lifetimes are typically a few nanoseconds ( 10^-9  s) and it jumps back to the lower energy state releasing a photon in the process is called spontaneous emission.

While in the excited state if the atom absorbs a photon having an energy equivalent to the energy difference between the two states and jumps back to the lower energy state is called stimulated emission.

There are two conditions for producing LASERS 1) Stimulated emission 2) Population Inversion meaning there are more atoms in the excited state than the ground state.

There are several other important conditions that our laser must satisfy.  First of all, the light that it produces must be coherent. That is to say, it must emit photons that are in-phase with one another. Secondly, it should emit monochromatic light, i.e. photons of the same frequency (or wavelength).  Thirdly, it would be desirable if our laser's output were collimated , producing a sharply defined "pencil-like" beam of light  Lastly, it would also be desirable for our laser to be efficient, i.e. the higher the ratio of output energy - to - input energy, the better.

Types of lasers

Solid-state lasers have lasing material distributed in a solid matrix (such as the ruby or neodymium:yttrium-aluminum garnet "Yag" lasers). 

Gas lasers (helium and helium-neon, He Ne, are the most common gas lasers) have a primary output of visible red light. CO2 lasers emit energy in the far-infrared, and are used for cutting hard materials.

Excimer lasers (the name is derived from the terms excited and dimers) use reactive gases, such as chlorine and fluorine, mixed with inert gases such as argon, krypton or xenon. When electrically stimulated, a pseudo molecule (dimer) is produced. When lased, the dimer produces light in the ultraviolet range.

Dye lasers use complex organic dyes, such as rhodamine 6G, in liquid solution or suspension as lasing media. They are tunable over a broad range of wavelenigths.

Semiconductor lasers, sometimes called diode lasers, are not solid-state lasers. These electronic devices are generally very small and use low power. They may be built into larger arrays, such as the writing source in some laser printers or CD players.

LASER APPLICATIONS

Many scientific, military, medical and commercial laser applications have been developed since the invention of the laser in 1958. They extend from Medical, Welding and cutting ,Surveying, Laser nuclear fusion, Communications, laser printing, spectroscopy, laser cooling ..etc.

Database management systems (DBMS)

A database is a collection of interrelated data in an organized and structured way. DBMS means database management systems which is a Software or collection of programs that enables you to store, modify, and extract information from a database.

 

Basically there are three types of DBMS

 

1) Hierarchical DBMS

2) Network DBMS

3) Relational DBMS

 

In a hierarchical DBMS the data is  organized in a tree-like structure also called a parent-child relationship. In hierarchical database a parent can have multiple children, but a child can only have one parent.

 

Network DBMS is similar to Hierarchical except a child can have more than one-parent. While conceptually simple this database structure can quickly become very complicated.

 

In a relational DBMS data is organized in the form of two dimensional tables where rows are called records and the columns are called fields. 

 

In case of Hierarchical and Network DBMS the data is manipulated using macros and these are mostly implemented on main-frame computers.

 

Where as the RDBMS uses SQL (structured query language) for data manipulations. Oracle, Sybase and SQL server examples of RDBMS. Tables are linked together using a field that uniquely identifies each record this makes the database very effective and called Indexing.

 

The data redundancy is very high in case of Relational database which increases the size of the database and decreases the efficiency of the database while its almost absent in the other two database types. Also need to create Index tables to speed up the query process in case of RDBMS which increases the size of the database further and also requires data purging and Index management.