Friday, 11 September 2015

George Simon Ohm


George Simon Ohm (Erlangen, March 16, 1789-Munich, July 6, 1854) was a German physicist and mathematician who contributed to the theory of electricity Ohm's Law, known for his research on electrical currents.

 He studied the relationship between the intensity of an electric current, the electromotive force and resistance, formulated in 1827 the law that bears his name stating that: I = V / R also became interested in acoustics, the polarization of the batteries and light interference.

The unit of electrical resistance, the ohm, is named in his honor.1 finished occupying the position of conservative cabinet of Physics of the Bavarian Academy of Sciences and Humanities.

Tuesday, 8 September 2015

Higher Education in Saudi Arabia

Higher Education in Saudi Arabia

Higher education in Saudi Arabia is consistent with the US higher education system, but modified to accommodate Islamic traditions and customs.

The first college, King Saud University, was founded in Riyadh in 1957. The Ministry of Higher Education oversees all higher education in the country, with a particular focus on scientific research universities government. More than 200,000 students are enrolled in Saudi universities, about half of the students are women.

International students will find a friendly atmosphere in Saudi Arabia, and the government even offers special scholarship programs specifically for students who are not Saudis.

Saudi Arabia is one of the best places in the world to master's programs in Islamic studies in the country also offers a full cultural immersion and Arabic for students not from the Middle East or non-native Arabic speakers. In addition to Islamic studies, modern Saudi institutions offer a wide range of master's programs in art, science, engineering, agriculture, medicine, education, computing and information science.

Many masters curricula are taught in English, especially in technical areas such as engineering.

Saturday, 5 September 2015



Thermodynamics is the discipline inside the mother science, physics, deals with the study of the relationships established between heat and other forms of energy. Among other issues thermodynamics deals with analyzing the effects of changes in variables such as temperature, density, pressure, mass, volume, systems and macroscopic level.
The basis on which all studies of thermodynamics loom is the circulation of energy and how it is able to infuse movement.

Worth noting that this issue was just promoted the development of this science, because its origin was due to the need to increase the efficiency of the first steam engines.
Then, from the kickoff, thermodynamics, has been busy describing how systems respond to changes in their environment, and can be applied to countless situations, both science and engineering, such as motors, chemical reactions, phase transitions, transport phenomena, black holes, among others. And so their results are really appreciated for physical chemistry and chemical engineering.

Meanwhile, Thermodynamics has three fundamental laws ... the first law is popularly known as the principle of conservation of energy and states that if a system exchanges heat with another, its own internal energy change. In this case, the heat energy will be required to exchange a system to compensate for differences between the internal energy and work.

For its part, the second law proposes various restrictions on transfers of energy, which could be realized if one considers the first law; the second principle speaks of regulating direction in which are carried out thermodynamic processes, imposing the possibility that these are developed in the opposite direction. This second law rests against entropy (physical quantity measuring part of the energy may be used to produce work).

And the third and last law holds that it is impossible to reach a temperature equal to absolute zero through a finite number of physical processes.

And the most important processes that take place in thermodynamics are: isothermal (temperature unchanged), isobaric (pressure unchanged), Isochoric (the volume does not change) and adiabatic (no heat transfer occurs).

Wednesday, 2 September 2015

Vector Product

Vector Product

In mathematics, the Gibbs vector product or cross product is a binary operation between two vectors in three dimensional space.

 The result is a vector perpendicular to the vectors are multiplied, and therefore normal to the plane containing them. Because of their ability to get a vector perpendicular to two other vectors, whose meaning varies according to the angle formed between these two vectors, this operation is frequently applied to solve mathematical, physical or engineering problems.

Monday, 17 August 2015

Harvard University

how much is the application fee for harvard

Harvard University

Founded in 1636 by English settlers in New England, Harvard is the oldest US university. With exemplary tradition, Harvard has remained at the forefront of higher education and research in many academic areas. Harvard offers the combination of an outstanding student body, faculty with international recognition and a cozy Residential Houses system for its undergraduate students. They come from 50 states and nearly 80 countries; cities, suburbs, small towns and villages; public and private sectors; of all ethnicities and religions; and from all socioeconomic levels. True to its mission, Harvard remains committed to offering educational opportunities available to all quality. Also, Harvard promotes global activities of all kinds, which is reflected in the various programs, centers, initiatives and special events happening in the world. For more details, visit the website of Harvard in the World.

The Faculty

Harvard students attend classes led by teachers and leading education in their fields of study laboratories. In this intellectual community, all faculty members, including prominent academics, students dictate classroom for both undergraduate and post-graduate. In addition to attending the weekly office hours, students often meet with teachers before and after school, as well as events and dinners in residential houses. Throughout the year, hundreds of students work closely with teachers, assisting in the investigation process or being helped to embark on her own. Opportunities to establish formal and informal relationships with Harvard professors are full and rewarding.

Research Resources

The library system of Harvard University is among the largest in the world, with more than 15 million volumes. Harvard also leads the list of subscribers to electronic portals. Some libraries are considered the "gold standard" in different campuses. For example, the Library of Anthropology Tozzer.

Harvard Campus

Harvard College is located along the Charles River from Boston, and the campus is spread over 220 acres. The residential areas are located in the center of campus, along the river and in the central quadrangle. There are over 400 associated with the University buildings, all connected by an efficient transportation system. Most students walk or ride a bike, and owning a car is not a priority. A site map can be found here.

Other Harvard campus associated with the life sciences (Arnold Arboretum) and medicine (Longwood Campus) and connections with major research centers in the region.

Saturday, 8 August 2015

Induced voltage

The voltage induction (so-called electromotive force: FEM) (represented Ve) is any cause capable of maintaining a potential difference between two points of an open or producing an electric current in a closed circuit. It is a characteristic of each electric generator. Generally it is explained by the existence of an electric field whose circulation Ve, \ int_S \ Ve ds \ ,, defines the induced voltage of the generator.

Units of Measure

The voltage (also called potential difference or voltage) is defined as the generator work done to pass inside the unit negative charge of negative to positive, divided by the value of said charge in coulombs, ie Joules / coulomb. It is usually measured in volts (V) equivalent to joules per coulomb (J / C), but these are SI derived unit. In the international system are the basic units per kilogram per square meter per second party cube amp: m2 · kg · s-3 · A-1

Thursday, 6 August 2015

Ranking Of Worlds Old Universities


University of Bologna (Italy) in 1089, receiving the title of University in 1317;
Oxford University (England) in 1096;
University of Paris (France) in 1150, receiving the title of University in 1256;
University of Modena (Italy) in 1175;
University of Cambridge (England) around 1208;
University of Palencia (Spain) in 1208, the forerunner of the University of Valladolid;
University of Salamanca (Spain) in 1218 (originally it was a cathedral schools whose existence can be traced back to 1130, and is the first in Europe who held the title of University by the edict of 1253 of Alfonso X of Castile and Leon) ;
University of Padua (Italy) in 1223;
Federico II University of Naples (Italy) in 1224 (oldest secular state university in the world);
University of Toulouse (France) in 1229;
University of Valladolid (Spain), XIII century (possible result of the transfer of the University of Palencia around 1240);
University of Murcia (Spain) in 1272;
University of Coimbra (Portugal) in 1290;
University of Lleida (Spain) in 1300;
University of Perugia (Italy) in 1308.1

They are communities of teachers and esiantes. In the European Middle Ages, the word college (Latin universitas) designated a guild corporativo.8 Both could be the university of shoemakers and blacksmiths University. When "University of Salamanca" was said, for example, it was nothing more than a simple short for University Teachers and Students Salamanca.8

The university is a conglomerate formed by the faculty of arts (philosophy), faculty of law (canon and civil), the Faculty of Medicine and the Faculty of Theology. The originality of this trade association, so different from the others, provoked ardent criticism and its inicios.9

Cambridge University, for example, creates its first chair of scientific research in 1794, although the Principle Mathematica Newton were written more than a century earlier, in 1687.10 John Locke, in his book Thoughts on Education (1693) questions the education offered by the University of Oxford and European universities, recommended content such as Latin, useless, and promotes instead as "absolutely necessary" accounts and bookkeeping libros.11 Darcy Ribeiro notes that the European university germinate slow scientific progress and cultural changes of the industrial revolution and technological society XVIII.8 century

Until the nineteenth century, universities were largely elitist centers where only a testimonial percentage of the population had university studies. During the twentieth century they were normalized university studies in Europe reaching 30% of college-educated population by the end of the century. The following table shows the ratio of enrollment in several European countries 12

Friday, 24 July 2015

Development Of Universities In The German-Speaking Countries


The German university system has its origins in the Holy Roman Empire with the creation of universities (ie the awarding of privileges, even to existing schools) by the spiritual and temporal ruler. So especially Bologna (founded 1088-1119) [12] by Barbarossa 1155 (award of a legal privilege) and the Charles University in Prague in 1348 by Charles IV., Both of which did not lie in the German-speaking areas and are, but for German-speaking students, the study places were , That are present in Prague four nationes (students of other origins joined one of these four to) were: Bohemia, Poland, Bavaria and Saxony. What was new was that these universities were founded by a ruler and did not evolve from schools such as Bologna, Paris, Oxford and Salerno.

Some encyclopaedic works like the Brockhaus therefore call Prague as the oldest German university (though the language of instruction - as was customary - Latin was) because the founder Roman-German Emperor was, and the University of Vienna, founded in 1365 by Duke Rudolf IV, the second oldest. . [13] on the territory of the present Federal Republic of Germany claim the University of Erfurt with the first privilege of 1379 [14] and which was founded in 1385 Ruprecht-Karls-Universität Heidelberg [15] the state's oldest university. Difficulties arise in particular from the boundary determination: On the one hand was "Germany" the German language area; on the other hand already studied in Paris, but also within the empire already in Bologna in German nobles (transmontani called from beyond the Alps). Karl founded the University also in his capacity as King of Bohemia, the Emperor, he was only seven years later. The designation of "Germany's oldest universities" so can the complexity of social relations in the medieval period disregarded. What is certain is Vienna (1365), the oldest university of the present state of Austria, Erfurt (1379), the oldest university of the present state of Germany and the University of Basel (1460), the oldest of today's Switzerland (also this city was only since 1501 the Confederation).

It resulted from the Schism [16] more universities. Many sovereigns wanted to upgrade their territory by setting up its own university in their own land. By doubling the papacy this project was more than the financial aspect in the way, because the coveted privilege of the Pope was now to have it easy. Both popes were blackmailed and bestowed upon request, a University of privilege in the knowledge that when a rejection of the respective anti-pope would give the agreement establishing a university. For this reason and because of the higher demand for scholars of canon law more universities were founded: in 1379 in Erfurt (Foundation privilege of the Antipope Clement VII in Avignon, which was awarded in 1389 by Pope Urban VI again, 1392 Commencement of teaching..), In 1386 in Heidelberg , 1388 in Cologne, 1402 in Würzburg, 1409 in Leipzig, in 1419 in Rostock. Until the Reformation was followed by 1456 Greifswald, 1457 Freiburg, Ingolstadt 1472 (moved to Munich), 1473 and 1477 Trier Tübingen and Mainz. Of the universities mentioned but there are only Heidelberg, Leipzig, Rostock, Greifswald and Tübingen since its foundation without interruptions

Thursday, 4 June 2015

Techniques For Group Decision Making


This technique intended to overcome the pressures of conformity in the group interaction that delays the onset of creative alternatives. And this is achieved using a generator of ideas that feed all options without preventing them critical process.

In a typical brainstorming session of ide as, between 6 and 12 people sitting around a table. The group leader makes the problem clearly so that all participants understand. And then they have, with absolute freedom, all the alternatives that are occurring in certain period. No criticism allowed, and all alternatives aimed to discuss and analyze them later. The fact that an idea stimulates another and that the judgment of even the most unlikely of suggestions not until later encourages participants to think about the unusual.

However, brainstorming is but a process for generating ideas.

Nominal group techniques

This technique limits the discussion or interpersonal communication during the process of decision making. Group members are physically present, as in the traditional committee meeting, but operate independently. It is specifically formulated problem and then the following steps occur:

1. Participants meet as a group but before starting the discussion, everyone writes their own ideas about the problem.
2. The period of silence happens presenting an idea by each member. All members take turns going around the table, and expose a single idea until all have been displayed and recorded. The discussion begins when all the ideas have been noted.
3. The group discusses the clarity of ideas and evaluates them.
4. Each member of the group ranks the ideas silently and independently. The final decision is based on the idea that achieves the highest overall rating.

The main advantage of the nominal group technique is that it allows the group formally meet, but not limited to independent thinking much as it does the group interaction.

University of California


The University of California was founded in 1868 and its main campus is located in Berkeley, specifically in the Bay of San Francisco. It is a public university, where currently 35 409 students are enrolled.

The degrees awarded by the university include bachelor, master, doctoral and professional degrees. College programs are organized in schools and colleges, which are: Chemistry, Engineering, Environmental Design, Letters and Sciences, Natural Resources, Education, Journalism, Business, Public Policy, Information, Law, Optometry, Public Health and Social Welfare.

Tuesday, 2 June 2015

Visas For Japan


If you have thought about going to Japan to study, spend some time looking for a job or will need a visa to stay in the country legally.

There are different types of visas will try to summarize the three that matter most.

 To get this visa first have to do the paperwork in the country. The procedures are harder for Asian but for the rest of the world just have to certify that they have hired a school to study and someone in the country has sufficient funds to maintain the student for the period of the visa. Basically it is to show that the family can repay studies, enclosing documents of the bank or paying in advance. This visa allows you to work up to 20 hours a week in a job that is not among the category of hazardous.



In the chain polymerization reaction is triggered by the formation of a chemical species active, call initiator, which can be constituted by a radical, a carbocation or a carbanion. The initiator sum recursively upon himself a monomer molecule, shifting the center of reactivity (the unpaired electron, the electric charge) at the end of the chain As this grows. The production process of a polymer chain is divided into 3 phases: activation, propagation, and termination.

An example of a polymer obtained by chain polymerization is polyethylene.

In the presence of a high temperature or pressure the double bond between the carbon atoms breaks down and is replaced with a covalent single bond. At each carbon atom compete then 7 electrons in the outermost energy level. To meet the demands of bond, the monomer is combined with other monomers of ethylene, thus ensuring that each carbon atom shares four covalent bonds. The polymerization can take place thanks to the presence of a double covalent bond between the carbon atoms in the molecule of the reagent. The double bond (together with the triple bond) is said "unsaturated bond"; it is constituted by two links that have binding forces of different entities: the bond σ (stronger) and the bond π (weaker). The breaking of the bond π generates a chemical species unstable (called radical) that can be counted along additional monomers, lengthening the chain.

The concentration of monomer in the reaction in the case of chain polymerization decreases with constant speed. The yield for this type of polymerization is high, and the polymers that are obtained have a lower degree of polymerization than those obtained in the polymerization in stages.

Wednesday, 27 May 2015

Get Study Visa For Hong Kong

hong kong

Hong Kong is not only a place to be visited by tourists as it is an educational center that brings together people from around the world. Houses some of the best universities in Asia and the world, thanks to international standards that keep these institutions. Each year, the greater the number of foreign students who come for higher education courses, from neighboring nations and not so close. Here, we describe the procedures that must be performed to apply for a student visa in the region:

1. Get a sponsor

Before applying, you must nominate a local sponsor; which may be the school that admitted you as a student, or a person over 18 who is a resident of Hong Kong and economically able to support you throughout the race. In such a scenario, you must complete and fill a "Statement of Financial Sponsor"; and your parents / guardians must authorize sponsorship, especially if you are still a minor.

2. Fill out the necessary forms

The visa applicant must complete the form ID 995A, while the sponsor does the same with the 995B ID. Both can be downloaded online through the website:, or find them at the following locations:
Immigration Department Headquarters
Immigration Division of the Office of Government of the Special Administrative Region of Hong Kong (HKSAR) in Beijing
Immigration Branches
Chinese Diplomatic and Consular Missions Abroad
Economic and Trade Office in Hong Kong in Guangdong

Attach a recent photo on the second page of the return.

3. Attach these documents

Transcripts, awards and certificates
Photocopy of your letter of acceptance issued by a university in Hong Kong, and your letter of acceptance to the specific course
Photocopy of the travel document containing personal data, issue date, expiration date and / or details of previous visas (if applicable)
A passport-sized photograph
Test your financial condition and obtained scholarships, bank statements, passbooks, etc. The minimum amount of money required are $ 120,000 of Hong Kong or the equivalent in any foreign currency

Photocopy of academic results
Photocopy of other qualifications such as IELTS or TOEFL test
Photocopy of identity card or equivalent
Photocopy of passport
Visa Application forms and properly completed Sponsorship Statement
Photocopy of notification of telegraphic transfer / receipt

Ionization Energy


The ionization energy, or EI ionization potential is the energy needed to remove an electron in the ground state of an atom of an element in gas.1 The reaction condition can be expressed as follows:

\ A _ {(g)} + E {I} \ to A ^ + _ {(g)} \ + 1 \ bar e.

Where A _ {(g)} gaseous atoms of a given chemical element; E_i, the ionization energy and \ bar and an electron.

This energy corresponds to the first ionization. The second ionization potential is the energy required to subtract the second electron; this second ionization potential is always greater than the first, because the volume of a positive ion is less than the atom and the attractive electrostatic force that supports the second electron is greater in the positive ion in the atom as it is retained the same nuclear charge.

The ionization potential or energy expressed in electron volts, joules or kilojoules per mole (kJ / mol).

1 eV = 1.6 × 10-19 C × 1 V = 1.6 × 10-19 J

The elements of the same family or group, the ionization potential decreases with increasing atomic number, that is, from top to bottom.

However, the increase is not constant, as in the case of beryllium and nitrogen higher than what could be expected by comparison with the other elements in the same period values ​​are obtained. This increase is due to stability posed by s2 and s2 p3 configurations, respectively.

The higher ionization energy corresponds to the noble gases, since their electron configuration is the most stable, and therefore will have to provide more energy to boot electrons.

Thursday, 21 May 2015

Study At Mexico


Each year, thousands of international students successfully obtain a visa to study in the UK. The British 

Visas and migration in the UK manages to do with Visas for UK and migration. Visit the website of Visas and migration in the UK for more information.

When should I apply for a visa?

It is importatne apply for a visa well in advance of your course comensar. Many students do not realize how long does the process take and do not do it enough. Your request may include the following:

have vaccines or if you come from an area at high risk for tuberculosis, a chest radiograph
documents showing your finances and certifications
attend an interview or a biometric test
take an English test.
You can apply For Visa Of 3 months before the start of your course, but it is good to start your research and you need to plan ahead.

You must have an answer on your visa within a period of three weeks. Check the guide visa processing times Visas and migration in the UK to know how long the process to obtain a visa in your country.

Tuesday, 12 May 2015

Potential Energy


In physics, the potential energy of an object is the energy which it possesses due to its position or its orientation with respect to a field of forces. [1] In the case of a system, the potential energy can depend by the arrangement of the elements that compose it. [2] It can be seen also as the potential energy capacity of an object (or system) to transform its energy into another form of energy, such as the kinetic energy.

The term "potential energy" was coined by Rankine in 1853. In the international system is measured in joules (J).

It is a scalar function of the coordinates of the object in the reference system used. Given a conservative vector field, the potential energy is its capacity to do work: the work relating to a force acting on an object is the line integral of the second kind of force evaluated on the path taken by the object, and if it is conservative value of this integral does not depend on the type of path followed. When it has to do with conservative forces can be defined as a scalar potential, which is sometimes made to coincide with the potential energy, defined in the whole space. In particular, from the mathematical point of view this potential exists only if the force is conservative, and the rest is assumed that for all the conservative forces can always define a potential energy physically.

The lightning Rod


The lightning rod is a device to attract and disperse atmospheric electrical discharges. It was invented by Benjamin Franklin, American physicist, and was applied for the first time successfully in Paris May 10, 1752.

To get to the lightning rod Franklin had made some important considerations on atmospheric electrical discharges, coming to establish that the damage caused by these were not due so much to their power, how much heat they generated on impact with any object. Also he found that when lightning, which is nothing more than an electrical discharge, striking an object, passes through only part: it was necessary then to think of something that would attract the lightning and disperse them through the force of a fixed course.

Discovering the peculiarities of metal spikes, especially those in gold, to attract the electrical discharges, thus acting as a magnet against the lightning, Franklin solved the biggest challenge: to capture him during his discharge.

 The lightning rod then consists in a long, thin metal rod coated with the tip of a noble metal (intrinsically devoid of surface layers of oxides and therefore high electrical conductivity) placed on the top of the building to be protected; from this it is derived a metal wire which is connected to earth: the electrical discharge is drawn from the tip and dispersed to the ground by means of wire. Moreover, the lightning rod, because of its shape, also has a preventive action against lightning. This consequently to the fact that the ground and the lightning conductor (connected to ground) are polarized by induction in response to the charge present on the bottom of the cloud. The lightning conductor so polarized, thanks to the dispersing power of the tips, helps to decrease the potential difference between the cloud and the ground, making it less likely that it reaches the minimum potential capable of beginning the download.

Due to the high currents and voltages that pass through it, the cable for the discharge of lightning can not be shielded. Generally copper, must have an adequate thickness to prevent current leakage into the surrounding space. For the same reasons, the link between the tip of the lightning rod and the grounding should be as short as possible, preferably in a straight line in particular avoiding sudden bends or turns that would increase the electrical impedance.

Sound Propagation


In a compressible fluid medium, usually air, the sound propagates as a pressure change created by the sound source. A speaker, for example, uses this mechanism. Compression spreads, but the air particles oscillate only a few micrometers around a stable position, in the same way that when a stone is thrown into water, the waves travel away from the point fall, but the water remains in the same place, it only move vertically and not follow the waves (a cap placed on the water stays in the same position without moving). In fluids, the sound wave is longitudinal, that is to say that the particles vibrate parallel to the wave traveling direction.

Solid, vibrating, can transmit a sound. The vibration propagates as in fluids, with a low oscillation of the atoms around their equilibrium position, resulting in a stress of the material, equivalent to the pressure in a fluid, but more difficult to measure. The rigidity of the material enables the wave transmission of transverse stresses.

Similarly, although to a lesser extent, the viscosity of a fluid may vary, especially in extreme conditions, the propagation equations derived for an ideal gas.

Propagation or sound célérité1 speed depends on the nature, temperature and pressure of the medium. In a perfect gas the sound propagation velocity is given by the equation:

c = \ frac {1} {\ sqrt {\ rho \ chi_S}} where \ \ rho is the density of gas and \, \ chi_S its isentropic compressibility.

It is seen that the sound propagation speed decreases

when the density of the gas increases (inertia effect)
when its compressibility (the ability to change the volume under the effect of pressure) increases.

In water, the speed of sound is 1482 m / s. In other settings, the vibrations can spread even faster. Thus in the steel, the vibrations they propagate 5,600 m / s to 5900 m / s. The sound does not travel in a vacuum, for lack of material whose vibration could spread into sound waves (sound insulation).

Thursday, 7 May 2015

Visa-for-Studio In Jordan


The study visa allows entry into Italy, for a short stay (90 days. - Type C) or long term (91 to 365 days. - Type D) for foreigners intending to attend university to study or vocational training at institutes recognized or qualified, or the stranger who is expected to perform cultural activities and ricerca.Documenti required for STUDIO Registration to Italian University
Seen to be requested only after confirmation that he was admitted to the entrance exams, according to the provisions issued by the Ministry of Education

1. application form to download an entry visa from the embassy of belonging where the guest arrives;

2. recent passport-size photograph

3. passport valid due over at least three months after visa;

4. demonstration of the availability in Italy of livelihoods, equivalent to not less than € 417.30 per month of academic year. This availability may be demonstrated by:

• exhibition of means personal or family

• financial guarantees provided by institutions and bodies of Italians established credit, by local governments, or by foreign institutions and bodies regarded as reliable by the Italian Embassy

5. statement about the availability of suitable accommodation in Italy.

History Of Electrochemistry

History of electrochemistry

The history of electrochemistry has seen a succession of many milestones in the course of its evolution, often correlated with the development of different branches of chemistry and physics: it takes in fact originated from the discovery of the principles of magnetism at the beginning of the XVI and XVII century and continues up to the theories on the conductivity and transport of electric charge.

The term relates to the study of electrochemical processes in which processing takes place of chemical energy into electrical energy and vice versa.

This term was used during the nineteenth and twentieth centuries, referring to an area mainly theoretical, relegated to the research laboratory; with the passing of time this term has acquired a further meaning application, thanks to the multiple applications of the theories of electrochemistry (also in commercial applications), including: the batteries, accumulators, fuel cells, the development of methods to prevent the corrosion of metals, refining techniques through electrolysis and the development of electroanalytical methods (such as voltammetry, amperometry and the electrophoresis).

Tuesday, 5 May 2015

Chemical Energy

Chemical energy

The chemical energy is an energy that varies due to the formation or breaking of chemical bonds of any type in the chemical elements involved in chemical reactions.

Since the strength of the chemical bonds is associated with the distance between the chemical species (in fact stronger chemical bonds held closer to the chemical species involved in binding), the chemical energy depends on the mutual position of the particles that constitute a substance.

It is then the energy stored in the chemical bonds and is mainly due to the sum of the potential energy of electrostatic interactions of the charges in the ponderable matter, most of the kinetic energy of the electrons.

If you consider as "zero level" of chemical energy that where there are no chemical bonds, chemical energy is negative. Ties have several different binding energy, the more stable have more negative value.

Resonance is a phenomenon chemical structure that greatly influences the chemical energy in a stabilizing way. The reactivity and kinetics of the various compounds suffer from differences of chemical energy.

The chemical energy is produced in the course of the transformations that take place at the molecular level.

The chemical energy introduced into our bodies with food, for example, allows us to live through oxidation and in general cell metabolism (cellular respiration).

Abu Abdullah Mahammad Jabir ibn Al-batani

He, like Qurra Thabit was born in Harran and also his family belonged to the sect of Sabian. But it is believed that the name "Allah Abu Muhammad" indicates that Al-Battani, unlike Thabit Qurra, was of the Islamic faith. So, a younger generation of Thabit. 

It is not inconceivable that the two are popular. He began his career as an astronomical observer (and manufacturer of astronomical instruments) in the Syrian town of Ar-Raqqah and Antioch. Is there a document (Fihrist, "Index"), the century X, certifying the highest level of fame he was gratified in his time both for the quality of his astronomical observations for his works. According to this Fihrist he observed between the years 877 and 918, while his star catalog is the year 880. His works are listed in Fihrist Kitab al-Zij and a commentary on Tetrabiblos Ptolemy.

The Kitab al-Zij is his most important work. It includes 57 chapters and covers topics will happen according to the classical scheme of Zij introduction of mathematical, astronomical theory, tables. Let's see in brief what were the most important results achieved by Al-Battani. He gave a catalog of 489 stars. He perfected the assessment of the duration of the year to 365 days, 5 hours, 48 ​​minutes, 24 seconds. Gave to the precession of the equinoxes the annual value of 54 ".5 and 23; 35 'for the obliquity of the ecliptic.

 Ascertained the progression of solar longitude of the apogee and the possibility of having annular eclipse of the sun. Some But the authority of Ptolemy at the time of Al-Battani was so great that, despite his calculations he had been made to determine the distance of the Sun is deviated greatly from that established by Ptolemy, did not dare to say so publicly. Where instead manifested with clearly their challenge to Ptolemy was the Ptolemaic method of determining the apparent diameter of the Moon: al-Battani states that the Moon can have an apparent diameter smaller than that of the Sun, which explains why they occur annular eclipses. 
He says then that same solar diameter can vary, contrary to what claimed Ptolemy. Commentators agree that the importance of Al-Battani in the development of science manifested itself especially in the influence that his work had on scientists such as Copernicus, Brahe and Galileo .

Using very precise instruments for the time, made a revision of astronomical constants listed in the Almagest, correcting them and discovering the movement solar apogee

Saturday, 2 May 2015

Centripetal Force


Centripetal force in a circular motion.
It is called centripetal force to force, or the component of the force acting on an object moving on a curved path, and is directed toward the center of curvature of the trajectory.

The term "centripetal" comes from the Latin words centrum, "center" and petere, "go to" and can be obtained from Newton's laws. Centripetal force always acts perpendicular to the direction of movement of the body on which it is applied. For an object that moves on a circular path with varying speed, the net force on the body can be decomposed into a perpendicular component that changes the direction of motion and one tangential speed parallel amending module speed.

The centripetal force should not be confused with centrifugal force, as explained in section Common misunderstandings.

Chemical Reaction

Chemical reaction

A chemical reaction is a transformation of the material that occurs without measurable changes of mass, in which one or more chemical species (known as "reagents") modify their structure and original composition to generate other chemical species (called "products"). This occurs through the formation or breaking of the so-called "chemical bonds intramolecular", that is, through a rearrangement of the forces of electrostatic nature which intervene between the individual atoms of which are constituted the molecular entities that are involved in the reaction. These electrostatic forces are in turn related to the effect of the outer electrons of each atom.

Some processes in which chemical reactions are involved:

the corrosion of iron in rust (which is composed of iron oxides);
the combustion of methane or other fuels (methane with oxygen is transformed into carbon dioxide and water vapor);

digestion (food are decomposed by gastric juices into chemicals absorbed by the body);
the solubilization and the formation of mixtures in liquid and solid states generates complexation reactions and dissociation.

A reaction can not take place, or is slowed to a stop or even to regress if not satisfied a number of conditions, such as the presence of the reagents to an appropriate extent and conditions of temperature, pressure and light suitable for the specific reaction.

Tuesday, 21 April 2015

Study At U S A


Since this month Thinkinlaw Law Firm, based in Chicago, will help periodically sending some articles on topics of legal type. The first article provides a general overview of the different categories of visas for the USA.

Recently the charm inherent in the concept of the "American dream" has changed significantly. The economic miracle of emerging markets and the opportunities they offer - even at the cultural level - become, increasingly, a phenomenon that can arouse the interest of young people (and not) emigrants from our own, while the economic and financial crisis that has affected the US has somehow helped to curb the enthusiasm of someone else already 'ready to go. However the United States, for many reasons, are still the country that more than others is the goal and point of landing of immigrants.

What follows is a very broad and general overview of the main categories of visas to USA, cataloged according to the purpose for which you want to enter (and / or live) in the United States. Please note that this is not a complete list of all the options for a visa, but a description of the main categories that aims to be exhaustive anyway.

Structured Cabling


In lateast buildings and offices are made of structured cabling systems, The systems are based on Category 5 or higher and RJ-45 connectors (RJ-11 twisted pairs and for telephone connections). The cables have a maximum length of 90 m, with a further 10 m to the cables commute (side apparatus: EC Equipment Cable, and the terminal side: WAC Work Area Cable). This constraint is dictated by the characteristics of the Ethernet network.

For each location to be served, one or more cables are placed in special ducts in the walls, in ceilings or floors of the building, to reach a distribution cabinet of the plane (in the jargon of the structured cabling, Floor Distributor or FD or wiring horizontal plane), usually it is a standard 19-inch rack, which can accommodate both patch panels that active equipment.

These cables are certified by a party in a patch panel in the closet, the other in a plaque on the wall or the floor near the user station. By connecting a cable from the computer trade-in to a wall outlet, and another from an exchange to a network device (such as a hub or switch), it creates an electrical connection that allows you to connect your computer to the network.

In case the dimensions of the building do not allow to serve all users with a single FD, the various FD are connected to a cabinet in the building (Building Distributor, BD), using copper cables and / or optical fiber (vertical wiring) even these certificates in patch panels. Similarly, the different buildings on a campus are connected to a closet permutation of campus, or Campus Distributor, CD.

The premises that house the cabinets should have adequate characteristics for power supply (preferably protected by a UPS), air conditioning, access control (are privileged places for intruders or to cause network failures).

Sunday, 19 April 2015

Steam Turbine


Turbine is the generic given to most motor turbomachinery. These are fluid machines, by the using of  thah a fluid passes and it continuously delivers its energy through a paddle or impeller blades.

The turbine is a rotary engine that converts energy into mechanical energy of a stream of water, steam or gas. The basic element of the turbine is the wheel or rotor, with paddles, propellers, blades or buckets placed around its circumference, such that the moving fluid produces a tangential force behind the wheel and spins. This mechanical energy is transferred through a shaft to provide movement of a machine, a compressor, an electric generator or a propeller.

The turbines are made of one or two paddle wheels, known rotor and stator, the first being that, driven by the fluid drag the axis on which the rotational movement is obtained.

So far, the turbine is one of the most efficient engines in the world (about 50%) compared to internal combustion engines and even some electrical. Back in the 20s, some inventors, including one named Thyssen, patented a steam turbine which attributed a thermodynamic efficiency of 31%.

The term turbine is also applied, as the main component, the set of several turbines connected to a generator for producing electricity.

Study In Iran

"We can establish a connection between this university (UNI) and technological universities in my country, to transfer experience and information technology issues and her students to work with us," was the theme that shone during the visit of Ambassador of the Islamic Republic Iran in Nicaragua Mr. Saeid Zare, who met with the authorities of this university.

The diplomat spoke with university officials about the importance of universities for the development of peoples, also showed great interest in the admission process running the UNI for students who wish to pursue their career in this Alma Mater. In this regard the ambassador said, you can establish an exchange of students and teachers at the UNI with colleges of engineering in Iran.

For his part, Rector of UNI, Eng. Nestor Zeledon Gallo said he was very pleased by the opening of diplomatic, to invite them to submit all documentation to the Embassy college and that it can be evaluated to realize these plans.

"For UNI it is very important this collaboration, because this exchange can allow us to update the knowledge in the field of engineering and maintaining academic quality so far enjoyed not only in Nicaragua but also at the level of the Central American region," concluded the Rector.

The Islamic Republic of Iran has a student population of 5 million students, distributed in 2,800 universities, including 2 300 public and 500 private.

Saturday, 11 April 2015

Study System in Australia

Study System in Australia

Australia is a federation in which each state is independent and has its own Ministry of Education, so each territory is authorized to operate in a different way. For example, the degree of maturity in NSW is called HSC (High School Certificate), while in Victoria is called VCE (Victoria Certificate of Education) .. We will however try to bring us back to the standards of the system.

Australia has one of the best educational systems in the world and an excellent international reputation for the standards that guarantee. Education is recognized as an essential pillar for the whole of Australia and every year the government invests billions of dollars in the development of the school system and in university research. Today, all the services offered by the schools are designed and organized to meet the needs of the student, so that his training and staff is the best .. And all this at a lower cost than other English-speaking countries! But the most significant is that graduates in Australian universities are easily found work in their area of study, both in Australia and abroad.

Secondary Education:

Includes 7 to 12th school year (usually students from 12/13 to 17/18 years). At the end of Year 12, you get the Senior Secondary Certificate of Education (SSCE), certificate whose name varies depending on the state of Australia. During the Year 11 and 12, are conducted VET courses, known as Certificate I and II.

Tertiary Education in Australia

The qualifications of the school system are classified by the government through the Australian Qualifications Framework (AQF). Australia offers two academic courses: the sector Vocational Education and Training (TAFE and RTO) issuing Vocational Graduate Certificates and Vocational Graduate Diplomas, and Universities that release Diplomas and Advanced Diplomas (Higher Education). The details in the table:

Diploma and Advanced Diploma

The Diploma and Advanced Diploma programs in Australia prepare on complex theories and practical elements in a wide variety of technical roles or management.

Educational institution: TAFE or private educational institutions.
Duration: two to three years.
Prerequisites: typically a Certificate IV in the field of study; Some courses may require work experience also proven expertise in specific subjects.
Es. Diploma in Business and Advanced Diploma in Business: prepare students for positions as "supervisor" in the areas of Human Resources, Marketing, Management and Administration, or for post-secondary professional.

Bachelor's Degree

The Bachelor's degree prepare students for professional careers or courses of postgraduate study in Australia and provide an excellent preparation depth in the academic or professional. Apart from the basic materials, is the student to choose the area (major) who want to delve into his path. In Australia, the offer is extensive and includes among others: Professional Degree, Double Degree, Graduate Entry Degree and Honours Degree.

Master's Degree

The Master in Australia prepare students for advanced knowledge and skills in the area of study chosen. In detail:

Coursework Master: includes course work, project work and research. Prerequisite: Bachelor's degree or Graduate diploma.
Professional Master: includes practical projects based on the professional position. Prerequisites: senior positions in the area and proven professional experience.
Research Master: includes research projects and its thesis. Prerequisite: Bachelor's degree or Master's preliminary year or Graduate Diploma or relevant research experience.
Educational institution: University or other private entities and qualified to deliver Master.
Duration: usually two years.

Doctoral Degree

The Doctoral Degree in Australia are of two types: research and professional; both prepare students to knowledge and skills at the highest levels in the study area chosen. In detail:

Research Doctorate: research supervised by tutors. Prerequisite: Master's degree or Bachelor Honours degree.
Professional Doctorate: professional practice, research and work in the classroom. Prerequisite: Master's degree or Bachelor Honours degree.



The sublimation of a simple substance or a chemical compound is its phase transition from the solid to the gaseous state, without passing through the liquid state. 

In the current language, since it implies the passage through an equilibrium condition (see diagram phase), is also used generically to indicate the opposite process as it would be more correct to icing up or reverse sublimation.

The chemical compounds and simple substances can have three different states of matter: solid, liquid and gaseous. Their status depends on the temperature and pressure and is described by phase diagrams. Usually, in normal environmental conditions, to switch from solid to gaseous need to cross the liquid state. Under certain conditions of pressure, the temperature changes, you can go directly from a solid to a gaseous, this direct transition from ice to gaseous, was observed on the surface of Mars by the probe Phoenix. 

It is noted that the reference pressure is the vapor pressure of the substance and not the pressure of the entire system. An example of sublimation inverse consists of the sulfur vapor, which undergo sublimation for cooling at atmospheric pressure, this is the reason to the base of the deposits of sulfur often present and visible on the ground in so-called solfataras.

An application of this physical property, it is the thermo-sublimation, a technique widely used for textile printing. In chemistry, the sublimation is exploited for the purification of substances by heating under vacuum of the solid in suitable equipment. In these conditions the solid goes into aeriform phase and subsequently will be made to solidify on a cooled surface, with the impurities which will constitute the residue remaining on the bottom of the chamber of sublimation.

The German School System

The German school system

Childhood Education

In Germany, early childhood education (Kindergarten) is voluntary and parents must pay. In some areas of western Germany, there are not enough places to meet demand. According to the long waiting lists, some parents enroll children at birth to ensure a place once the child is age appropriate.

Most children go to nursery school for two or three hours in the morning. If both parents work, you can increase the time until eight or nine hours (including evenings), in which case you will pay more. Children often go to kindergarten Monday through Friday, but some also offer services for children whose parents work shifts and weekends. In some cities, there are some Kinderkrippen for children under three years offering the same services.

Primary education

Primary education (Grundschule) begins between five and half years and six and a half, depending on the month in which the child is born. The first day at primary school is a very important event for German children. It is customary to give children a bag of candy (Schultüte) on your first day of school.

The number of hours in primary school is between 20 and 30, depending on the type and age of the child. Primary education lasts four years, after which parents receive a recommendation from teachers about what kind of school is best for the child to continue their education in high school. This recommendation is based on the assessment that teachers make of the results, level and interests of children. If a child has learning difficulties, the teacher may recommend to give a special school for children with these difficulties (Sonderschule).

Secondary education

After primary school, children often go to one of these three types of secondary schools:

Hauptschule (until age 16) - prepares pupils for vocational education and ends with a Hauptschulabschluss. The Hauptschule is designed for the less academically brilliant students. After graduating usually opt for apprenticeship (Lehre) in a manual occupation, sometimes combined with part-time study on a Berufsschule.
Realschule (until age 16) - offers more options for students in middle and ends with a Realschulabschuss. The Realschule is designed for those who are going to do practical training that require more academic, as nursing knowledge, and put more emphasis on math and language skills in the manual.

Gymnasium (until 18 or 19 years) - prepares students for higher education and ends with the Abitur (a prerequisite for entering college). This is the type of school that's required, with 32-40 hours per week and lots of homework.

In some regions of Germany, there are other schools called Gesamtschule. All children attend the same school, but within it are separated according to their level. At 16 years, depending on the results they have obtained until then, they can leave school for a Lehre, or stay another 3 years to the Abitur.


music dynamics

The dynamic is the branch of mechanics that deals with the study of the motion of bodies and its causes or, in more concrete terms, the circumstances that determine it and modify it. The complete study of the mechanics also includes static and kinematics:

 the dynamic is different from the first that studies the configurations of mechanical equilibrium, the second that studies, in the abstract, all motions conceivable but not about determining which motions can occur in a particular experimental context.

The study of the dynamics is conducted primarily referring to an abstract entity, with mass but with negligible sizeof material point. All related laws of material point can then be extended to the real bodies (with mass and of finite size) interpreted as systems of material points; if we deal with bodies in which the relative distances between the points of the system must not vary over time, it is called "rigid body dynamics"; otherwise it is called "dynamic of deformable bodies."

Chemical Balance

chamical balance

The chemical equilibrium is the condition dependent on the temperature in which the concentrations of the chemical species participating in a chemical reaction does not vary in time in total. This occurs when a chemical reaction proceeds with the same speed as the reverse reaction. This means that the rate of consumption of the reactants is equal to that of the formation of the same reagents and this also applies to the products.

Similarly, one can also say that a reaction is at equilibrium when the concentration of products and reactants remains constant, although the reaction is not stopped, in the sense that it continues to take place but not lead to any increase or decrease in concentration of products and reactants, being equal to the values of the two speeds of the reaction, the direct and inverse. As can be guessed from the definition, it is a dynamic equilibrium (non-static).

Strictly speaking, all the chemical reactions should be considered in balance, but, in common practice, those in which the concentrations of the reactants are low (in comparison to the high equilibrium constant) are easily considered non equilibrium (they are known reactions to completion) because the reaction is strongly shifted towards the formation of products.

There are four characteristics common to each equilibrium reaction.

The first, as already said, is the dynamic nature of equilibrium, in which the reaction reaches a situation defined by the equality of the reactions reactant-product and product-reagent.
The second generalization is in the spontaneity of a chemical equilibrium, that is the assertion that a system spontaneously moves towards a state of equilibrium; happen if a disturbance outside the system, when left to itself, would tend to get back into equilibrium (principle of Le Chatelier).

The third is in the statement that a process can be said to be in balance if this is reversible, ie the nature and properties are the same regardless of the direction of approach to equilibrium itself.
The fourth and final generalization consists in the nature of equilibrium thermodynamics, that is, in the vision of the equilibrium state as a condition of more favorable compromise between the natural tendency of the system to reach the minimum energy and the maximum molecular chaos or entropy.

Friday, 10 April 2015

Chinese Visa For Study


Mode visa application:

Those who plan to study in China can apply for two different types of visa: if the course of study lasts less than or equal to six months must apply for a visa F (which is output even for business reasons), while X must apply for a visa if the course of study lasts more than 6 months. The procedures for requesting two visas, which are different between them, are specified below.

Applications for the Chinese visa to study (both F category, is Category X) should be or one of Chinese Visa Application Service Center (Cvasc) in Rome and Milan, or the Chinese Consulate in Florence. The consulate at the embassy in Rome and the consulate in Milan do not accept applications for ordinary visas, but only for those affixed on diplomatic passports and those of long duration of Hong Kong and Macao.

Those who submit their applications to one of the two Cvacs must complete the online form (click here to complete it) and then print it and present it at the counter when they require a visa. The question must be accompanied by the documents listed below. Contact the Cvasc or consulates if you can not apply for a visa in person and you want to send passport and documents via courier.

Procedure for visa F (courses of study up to six months)

First you need to enroll in a university or in an educational institution that is located in China
the institution requires the issuance of the certificate JW-201 or JW-202 to the Chinese Ministry of Education
the school sends a letter of admission and the certificate of the ministry, by mail or courier, to the student who wants to apply for a visa
the applicant may submit the visa application exhibiting the admission letter and the certificate of the Ministry

Procedure for visa X (courses of study over 6 months):

First you need to enroll in a university or in an educational institution that is located in China
the institution requires the issuance of the certificate JW-201 or JW-202 to the Chinese Ministry of Education
the school sends a letter of admission and the certificate of the ministry, by mail or courier, to the student who wants to apply for a visa
the applicant may submit the visa application exhibiting the admission letter and the certificate of the Ministry
the Cvacs or consulate issuing student visas where X is not specified length of stay (in the box is marked 000); this is because the student can leave for China
Once arrived in China, students must undergo a series of medical examinations (usually are the same university to organize medical examinations for freshmen)
obtained the certificate of good health, the student can go to a police station or an office for immigration, where his visa X will be converted into a temporary residence permit on the duration of the course of study (to avoid sanctions is must convert the visa within 30 days of arrival in China)

Documents required for both visas:

passport valid for at least six months

two passport photos

visa application form (complete it online or download it in pdf)

admission letter all'istuto university or school (the University is to send it to the student)

certificate JW-201 or JW-202 of the Ministry of Education of China (the university is to send it to the student)

Galileo Thermometer


The ampoule having a neutral buoyancy (center) with the 24th sheet shows the temperature.
Galileo thermometer is a thermometer comprising a glass tube containing a liquid with a higher coefficient of expansion than the water.1 and a set of blown glass ampules dipped in it.

With increasing temperature, the density of the blisters is almost constant, but not the liquid, which decreases significantly. This change alters the buoyant density of the blisters. Blister position that indicates this temperature neutral buoyancy.

Its indications are limited to a relatively small temperature range. To indicate a temperature of 18-26 ° C with an accuracy of ± 2 ° C, the device must contain at least five blisters. In addition to the low accuracy, high heat capacity makes it impossible to observe sudden changes in temperature.

Tuesday, 7 April 2015

Study Visa For Egypt


The Egyptian government said that the new procedure does not begin on 15 May, but at a date to be decided in the coming months. Will notify you as soon as possible the new dates.

From May 15 will be more difficult to go to see the pyramids and overwinter on the Red Sea. And 'these days, in fact, the news that the Egyptian government has decided to close the company's policy on visas. If you obtained before arrival at the airport with the payment of $ 25, a few months individual travelers must apply in advance to the diplomatic missions around Italy and the world, even if the bureaucratic details are not yet known.

A decision that could significantly affect the Egyptian tourism sector which today represents 11.3% of the economy of the North African country. Although Reuters spokesman of the Foreign Ministry, Abdelatty Badr, said that "nothing will change for tourist groups, who may continue to obtain a visa on arrival." And organized groups still constitute the majority of arrivals in the country.

A few years ago the same decision had lasted three days, but now the government's choice of Cairo seems destined to last. The region of this change in visa policy lies in the need expressed by the Egyptian government to be able to have more control over who enters the country given the current political situation in the Sinai region, where for months are under constant attacks by Islamist militias .

Egypt in recent years has experienced a swing in the arrival of foreign tourists: if in 2010, the last year of the Mubarak era were 14.7 million, a year later had fallen to 9.8, to go up a little in 2012, 11.5 million, and fall to about 10 million in 2013. The tourism minister, Khaled Ramy, said in recent days to Reuters that the country hopes to reach 20 million arrivals by 2020. But certainly this decision will not help growth.

Electrical Engineering


Originally this branch was called "electrical engineering", and was one of the precursors of the scope of engineering fields. The change of name to "electrical engineering" was necessary with the expansion of the topics discussed and studied, such as the electronic components within the electrical equipment, which made it necessary to adjust the training programs of this specialization.

The electrical engineering separates the early twentieth century from engineering industrial or mechanical, coinciding with the spread of the distribution of electricity. Electrical engineering from engineering was born in the sixties and seventies electronic engineering, the development of telecommunication systems such as radio and television. In the nineties of the twentieth century from the Bachelor of Electronic Engineering born telecommunications engineering. Electrical engineers have contributed decisively in the construction of the Italian telephone network. The courses in electrical engineering and telecommunications have more or less 40 years of separation from the course in electrical engineering. The Decree of the President of the Republic in 2001 328 draws fall in industrial engineering or electrical engineering mechanics from which it was detached 100 years before.

The first course of Electrical Engineering is the 1886 Royal Industrial Museum of Turin, then members will converge in the newborn Politecnico di Torino in 1905.

Currently the term "electrical engineering" is used to indicate specifically that part of electrical engineering that encompasses all the classical theories of electromagnetism applied to studies circuit.

In the US studies of electrical engineering, electronic engineering, computer engineering, telecommunications engineering and automation engineering are included in two unique courses, referred to as electrical engineering and computer engineering, for historical reasons and for reasons actual interdisciplinary.

Saturday, 4 April 2015

Organelles Of Cell


An organelle is a structurally definable area of ​​a cell with a specific role. The definition is inconsistent: some authors call only structures with membrane and organelles, so for example the nucleus, mitochondria, Golgi apparatus and the endoplasmic reticulum. Others take the concept further and also include other structures, such as centrioles. In unicellular "organelle" in this sense is used as a term for complex structures such as scourge and eyespot.

Single-celled living organisms without a nucleus (prokaryotes) usually have no membranes inside the cell and thus not a organelles according to the first definition. However, there are prokaryotic structures that can be seen as organelles in a broader sense.

Limited membrane organelles

Mitochondria, the nucleus and plastids (chloroplasts and their relatives) are surrounded by a double membrane. Other membrane-bounded organelles have a simple membrane. These include the components of the endomembrane system and the plant vacuole. In addition, there are some specific membrane-bounded organelles that only in certain cell types or certain eukaryotic species groups, mostly unicellular occur.

Semi Autonomous organelles

Chloroplasts in the leaf blade of the moss Plagiomnium affine
Occurring in almost all eukaryotes, mitochondria and specific for algae and higher plants plastids have their own genome and its own machinery for protein synthesis. They are therefore referred to as semi-autonomous organelles'.

According to the endosymbiotic theory is seen with them phylogenetically to descendants of bacteria that were taken by early eukaryotic cells. These bacteria were integrated in the course of evolution in the cell. Due to the presence of mitochondrial precursor was the eukaryotic early, before anaerobic cell for the first time possible to use the much more effective oxygen-dependent energy. The inclusion of cyanobacteria, which evolved into the plastids, the use of sunlight for energy was possible: It emerged eukaryotic algae and thus the precursor of all plants.

Semi Autonomous organelles have a double membrane: the outer is made from the host cell is thus eukaryotic origin. It is derived from the constricted in receiving the organelle predecessor plasma membrane. The inner membrane is of prokaryotic origin. This is modified by the plasma membrane of the symbionts. It constitutes a diffusion barrier for the exchange of molecules and electrons.

Redundant structures of the bacterial cells were lost, most of the genes were transferred into the nucleus of the host cell or were also lost. Some genes but were also added to the genome of organelles, eg. As genes for the exchange of proteins and amino acids with the host cell. This left the still existing remains of the one-circular DNA molecule prokaryotic genome and structures that are important for the function of organelles.

Semi Autonomous organelles replicate autonomously by division. In the division of the host cell they are distributed to the daughter cells.

Other common membrane-bounded organelles

In addition to the semiautonomous organelles only the nucleus has a double membrane, the nuclear envelope. The organelles described in this section are found in all cells of an organism in general. These include plants in the vacuole and in all eukaryotes several components of the endomembrane system: the endoplasmic reticulum, the Golgi apparatus, lysosomes and peroxisomes. A brief description of these organelles found in Article cell at this point. Transport vesicles, which provide material exchange between the different components, are also the endomembrane system. Their inclusion in the definition of an organelle is mixed: Sometimes individual vesicles are called organelles, sometimes not.



Industry is all engaged in the production of goods of economic interest with massive criterion (against which differs from crafts), beginning as a transformation of raw materials into semi-finished or finished products. It falls in the secondary sector of the economy.

The term derives from the Latin industry (-a), which can mean hard work, work, ingenuity, diligence, and which in turn comes from endo- (inside) and -struo (build). The term is also used to indicate a process which, starting from a product called the "first" (raw) it produces a "second" (artifact) with added value.

The main aim of the industry is to produce the best and the best cost / benefit of the goods requested. In economics represents all sectors of a system responsible for the production of goods and services on a large scale, using studies and / or contributions mainly produced by scholars of industrial economics and business economics.

According to the traditional economy, the product of the industry is also termed "good secondary" compared to the "primary good" of agriculture and the "tertiary" services, recently developed. The industry is divided into several sectors, each with its own specialization and is constantly changing, adapting each time to the needs of the consumer and new production technologies.

The aim of the industry is to produce the best cost / benefit ratio, which in economic terms means with maximum profit for your money: and this is the vocation of the industry that does not always coincide with that of the territory. In a system of command economy industry, released by the logic of profit, can be addressed to the fullest. The industries in fact bring jobs both directly and in related but need strong infrastructure, and to build an industrial site you must do before a feasibility study.

The added value, in short, is what the production process through technology gives, transforming the raw product into a finished product, ready to be introduced in the chain of distribution. Ultimately, the industry is an organized system to produce wealth, constituted precisely by the added value.

Thursday, 2 April 2015

Study In Italy


Only the entry visa issued in Italy for study purposes is valid for enrollment in courses of study at the Italian institutions of higher education (IS). We do not accept any other type of visa.

If, because of non-EU nationals, still reside abroad and wish to enroll on a course of IS in Italy, you have therefore managed contact the competent Italian diplomatic mission to make you release the passport for a visa for study, said succinctly study visa .

The competent Italian diplomatic missions (embassies, consulates) are the authorities not only to verify whether the candidates meet the requirements necessary to obtain a student visa, but also to receive their applications for pre-registration, and forward them to the individual Italian institutions of IS.


The study visa will be issued only upon demonstration that you:

in Italy you have to adequate housing;
possess sufficient financial resources to keep you (go to means of livelihood);
you are entitled to health care in Italy (go to Health Insurance).
you have the amount of money required to return to your country, or you have already purchased a valid return ticket.


While waiting for appropriate action in the context of specific agreements between Italy and Croatia, the Croatian students commuters may be entered without their obligation to apply for a residence permit, but only on presentation of an entry visa (possibly a visa to multiple inputs) .
The same rule (see point A above) also applies to foreign students who are legally resident in the Republic of San Marino.

Blood Circulation


The circulatory system or cardiovascular is the set of organs responsible for the transport of various fluids - such as blood and, in a more general, the sap - who have the primary task to make the necessary nutrients for the body's cells their livelihood.

In the human being and in all vertebrates, the heart is the body and blood of the engine is the central element of the apparatus, which also includes the blood vessels (arteries and veins) and lymphatic vessels.

Closely related to the circulatory organs are then hematopoietic and lymphoid organs, which are responsible for the continuous production of formed elements in the blood and lymph.

In the different groups of multicellular animals circulation ensures the survival of the organism and the metabolism of every cell of the body, provides chemicals and maintains the physiological properties. The blood carries oxygen from the lungs to the cells and carbon dioxide in the opposite direction (see also breathing).

From the digestive processes that occur in the digestive system, derived nutrients such as lipids, sugars and proteins that are transported in each tissue, there used and, if necessary, can be further modified or conserved. The substances that remain from the metabolism, also referred to as waste products or catabolites (for example, urea and uric acid), are then eliminated from other tissues or organs (such as the kidneys and the colon).

The blood also carries the chemical messengers such as hormones, cells of the immune system and the components of blood clotting in the body.