Fossil Fuels – discovery, utilisation and future

As industry developed and increased, as did the need for reliable and efficient fuels to power the new machinery developed. It did not take long before fossil fuels were discovered, with their innate ability to provide high amounts of energy at seemingly low costs.

Fossil fuels are found deposited in rock formations. They were formed between 350 million and 50 million years ago, and so, although are technically renewable, it would take this long to remake them, which does not really help us today, it is due to the fact we need this long to make them that they are considered nonrenewable, and therefore will at some point run out. The processes by which they formed are not totally understood, other than that sediments buried decayed remains of ancient plants and/or animals. This is then effectively baked over millions of years under conditions of very high temperature and pressure, creating coal, oil, and natural gas, which consist of roughly 90% carbon

Fossil fuels are used widely in all forms of industry, in fact, coal, petroleum and gas provides over 90% of the energy used in most industrialized countries, compared with just 9% which hydroelectricity and nuclear power provide together.

You can read also Waves

When looking at the properties of a good fuel, it is easy to see why fossil fuels are used:

* A fuel should react with an oxidiser to release large amounts of energy – carbon based fuels release over 30000 kJ per kilogram

* A fuel must be oxidised fairly easily, ignite quickly and sustain burning without further intervention – gaseous or easily vaporized fuels (such as oil) usually perform well here as the mix easily and continuously with oxygen which speeds up the reaction. Coal is often crushed to form small powders to make it ignite easier, however it is evident from steam the reliability of steam trains that carbon is easily burnt.

* A fuel should be readily available, in large quantities and at a reasonable price – initially this could be said to be true about fossil fuels, but now, as people become more aware of their cons, and of other fuels’ pros, they are becoming more expensive and less available. Still, the price of oil is so heavily depended upon by the economy, that even the slight fluctuation in price can cause a country to go to war or a government to fall.

* A fuel should not burn to give products that are difficult to dispose of, unpleasant or harmful – fossil fuels definitely do not fall under this category, but the only fuel that does fall under this category is hydrogen.

* A fuel should be convenient to store and transport safely and with out loss – fossil fuels are the only type of fuel that people are currently comfortable with storing, hydrogen and methane are so flammable that people get nervous about using them for cars, and until a safe way of storing them is developed, fossil fuels will have to continue to be used

You may then wonder what the problem with fossil fuels is as they are obviously good at their job. What we must consider is the fact that they are non-renewable, and that we are consuming them at an incredible rate. It is predicted that most of the Earth’s oil sources will be depleted over the century. Also, fossil fuels are used in many important chemical industries, such as making plastics, medicines, and solvents, and by burning them, we are decreasing our the feedstock for these vital products.

Fossil fuels such as oil are made into these products through a series of different processes. First the oil is fractionally distilled then the different sections join together to make polymers. These synthetic plastics and solvents are used largely in everyday life, such as polystyrene cups and PVC plastic.

Secondly, the burning of carbon based fuels produces large amounts of carbon dioxide that is one of the main contributors to the “greenhouse effect”. There are such drastically high levels of carbon dioxide in the air that the only real solution would be to ban all use of fossil fuels, but countries have become so dependant upon them that is not feasible.

Thirdly, spillages of fossil fuels cause serious damages to local environments. When an oil tanker crashes, immense amounts of sea life and birds die, and the effects are disastrous.

Fourthly, inefficient burning of fossil fuels results in the production of carbon monoxide, which is a very harmful and poisonous gas. Inhalation of this gas is likely to cause death as it interferes with the transport of oxygen in the blood stream.

Fifthly, combustion of fossil fuels also produces gases such as nitrogen oxides, which cause acid rain.

In particular we can look at oil. Numerous countries’ entire economies now rely on the price of oil, as their entire wealth is in the drilling, extracting, and trading in it. This is cause for great concern as oil is non-renewable, and we are consuming it so quickly, it will inevitably run out, and counties will no longer be able to rely on it.

We have seen in the past that countries’ entire economies’ have collapsed due to minor fluctuations in the oil market, therefore total collapse of the market would be devastating for many of the world’s major and influential countries. Also, there would be immense amounts of job losses that would inevitably affect the society; this can be seen by looking at the destruction caused when the coalmines closed.

There are few ways which can be seen to overcome this imminent problem, however, one, most likely solution would be to investigate alternatives to fossil fuels, but all of the possible alternatives have their advantages and disadvantages which must be taken into account before making any changes.

* Biofuels (plants can be grown specifically for fuel or the production of fuel, such as wood or sugar cane. Biogas and biomass created by the growing and decaying of plants already produce usable fuel so this could easily be exploited to create a fuel source.) Advantages – renewable, reduces waste, simple technology. Disadvantages – not a large enough supply to totally replace fossil fuels

* Methanol CH3OH (this is a simple alcohol which can be made from methane.) Advantages – burns cleanly and completely Disadvantages – more toxic than ethanol, provides less energy per litre than petrol, can cause corrosion of car engines.

* Nuclear fission (energy is released when the nuclei of atoms of isotopes of uranium U-35 are split. The energy created can be used to heat water to turn steam turbines.) Advantages – no carbon, sulphur, or nitrogen oxides produces. Disadvantages – radioactive waste, safety systems needed are very expensive.

* Nuclear fusion (energy is released when deuterium and tritium “fuse” to create helium) Advantages – potentially almost limitless as an energy supply as the reactants come from water. Disadvantages – very costly, cannot currently be produced at economic rates.

* Moving air (wind turns windmills and wind turbines. Lots of research is already being carried out and soon may provide 10% of the UK’s energy) Advantages – renewable, pollution and waste free, can be used in locality to where the energy is needed. Disadvantages – high initial expense, not reliable in calm weather, noise and visual environmental impact

* Moving water (Hydroelectricity – water stored behind dams can be released through turbines to generate electricity. Waves – The motion of waves is used to create oscillating motion. Tides – incoming tides in river estuaries fill up large water stores behind barrages, which is then released through turbines.) Advantages – renewable, predictable, pollution and waste free, large scale. Disadvantages – costly to install, environmental impact.

* Sunlight (Solar panels – collect solar heat and are used to heat water. Photovoltaic cells – convert light into electricity). Advantages – renewable, pollution and waste free. Disadvantages – Not good for places of low sunlight levels, high initial costs, not very practical for large-scale use.

* Geothermal energy (heat from rocks under the Earth’s surface can be used to heat water which can, in turn, be used to heat houses). Advantages – practically unlimited. Disadvantages – not widely available, large initial costs

* Hydrogen (extracted from water by electrolysis, many things are capable of running on hydrogen). Advantages – no pollution. Disadvantages – people are nervous about using such a dangerously explosive gas, difficult to store and transport.

If some of these possibilities were researched further, they could replace fossil fuels and help many of the previously discussed issues.

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The Computer: Humankind’s Greatest Scientific Discovery

Discoveries throughout time have moved mankind forward in many fields, such as medicine, technology, communications and manufacturing. These findings have also contributed to shifting the way humankind operates on a global basis. Defining the greatest discovery should encompass the revelations which have had the most beneficial impact on our societies. For our generation, it is the
founding of the computer.

The computer has affected virtually every aspect of our lives, from the way people do business to the way we communicate. Since its humble beginnings with the inventions of the first binary computer in 1936 by Konrad Zuse, and the mechanical calculator, the use of computer has become more than just widespread: it has developed into a phenomenon that has altered the lives of every human living on Earth today in some shape or form. In 1939, Hewlett Packard was founded and by 1945, John von Neumann had discovered electronic storage for data.

Subsequently, the year 1967 saw the first metal oxide semiconductor built by Fairchild Camera and Seymour Papert, and it created a language on the computer for children that operated a mechanical turtle. Later in 1967, the first storage system for digital photography was invented by IBM, which had the ability to translate a trillion bits of information. In 1994, Windows first browser Netscape 1.0 was released. Additionally, the Internet search engine, Yahoo, was invented. From this point, computer technologies have constantly been improving and have resulted in modern wonders.

Computers have made the technological advances we enjoy today possible. These include online purchasing, business and private communication through social networks, selling to global markets, creating personal websites, or talking to people while seeing them on our computer screens while they are thousands of miles away, and many more advances. All of this is done with little cost, except for a wireless connection fee.

People tend to store information not in the public archives, libraries, or in other ways that require using physical media, but in a digital format with the help of cloud technologies. Many significant scientific discoveries are made with the help of computers, and even if the findings are made by hand, computers are still used to process and calculate data gathered during these researches. Computers are
indispensable for many business and financial operations, exchange trades, freelance jobs, medicine, production quality control and studying – almost all aspects of life today are tied to the use of the computer.

Clement Mok, former creative director of Apple, once said, “Five years ago, we thought of the Web as a new medium, not a new economy.” As
civilization races ahead, technology also speeds up, creating new markets and jobs while helping with advances in medicine and agriculture. Computers have evolved from a simple mechanical calculator, which was still revolutionary for its time, into a sophisticated and complicated helpful tool that has become an essential part of humans’ everyday lives. Nowadays, it is difficult to find a part of modern humanity’s existence which has not been reshaped by the invention of the computer, and there is no way of knowing where this great discovery will end up leading civilization in the future.

References

  • Mok, Clement.  “Technology Quotes.” IT History Society. N.p., n.d. Web. 24 Jan. 2013. .
  • “Computer History Museum.” Timeline of Computer History. N.p., n.d. Web. 24 Jan. 2013..

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Random Walks for P2P Resource Discovery in Grids

Table of contents

Random Walks for P2P Resource Discovery in Grids

Abstraction:

Peer-to-peer ( P2P ) resource locale methods in grid agreements have been soon investigated to achieve scalability, dependability, efficiency, fault-tolerance, protection, and hardiness. Query declaration for detecting resources and advise informations on their ain resource rank in these agreements can be inattentive as the reverse of allowing one equal to achieve a unconditioned think of Earth informations described on all equals of a P2P unstructured web. In this paper, the agreement is embodied as a set of nodes related to organize a P2P web whereas every individual node holds a piece of informations that is needed to be communicated to all the participants. Furthermore, we accept that the informations can vibrantly alter and that every individual equal sporadically needs to admission the benefits of the informations of all auxiliary equals. A fresh manner established on a changeless flow of use packages exchanged amid the nodes using the random amble rule and rateless cryptography is proposed. An advanced rateless decrypting mechanism that is able to get by aboard asynchronous informations updates is to boot proposed. The presentation of the counseled agreement is assessed both analytically and by experimentation by simulation. The analytical wake show that the counseled scheme warrants speedy diffusion of the informations and graduated tables good to colossal webs. Simulations display that the method is competent to boot in attending of web and information kineticss.

Debut

PEER-TO-PEER ( P2P ) resource locale methods in grid agreements have been investigated to achieve scalability, dependability, efficiency, fault-tolerance, protection, and robustness.To this conclude, structured, unstructured, and intercrossed P2P agreements have been believed and the comparative virtues and drawbacks have been highlighted [ 1 ] , [ 2 ] . Countless propositions working unstructured P2P agreements apportion a public feature: Grid nodes inside one official country sporadically query for detecting resources and advise informations on their ain resource rank across one or excess interface equals. The interface equals ( normally those alongside the biggest capacity ) frolic two chief functions: they are related to auxiliary interface peersforming a P2P unstructured web that is utilised to onward ( and reply to ) questions on the behalf of nodes in its official sphere. They amass and uphold informations of all nodes in the innate functionary domain.Query declaration in these agreements can be inattentive as the reverse of allowing one equal to achieve a unconditioned think of Earth informations described on all equals of a P2P unstructured web. In peculiar, we accept that every individual equal holds a piece of informations ( the sum resource ranks of all nodes in its official sphere ) and that each equal needs to admission the benefits of the informations of all auxiliary equals sporadically at rate _ queries=sec. The purposes to be attained are treble: early, one wants to assure that every individual node is likely to accumulate the finished Earth informations in a timely manner. Furthermore, the contact operating expense have to be retained every bit manipulated as likely to besiege cloging the web. Finally, the processing use of every individual node have to be utilised parsimoniously.

Related work:

The reverse of informations meeting in distributed agreements has been confronted aboard infinite disparate instruments and approaches.A early category of methods are those established on probabilistic gossipmongering. Probabilistic gossipmongering has been utilized both to calculate a intent of the Earth informations, e.g. , norms, and to truly range innate informations across a web as in our scenes even though such methods rely on a set of premises that are tough to assure in exercising. Noteworthy enterprises to beat a small of these restrictions in the p of epidemic airing are that effect in close to optimal latency-bandwidth trade-of. In peculiar, utilizations flow use on the maximal rate at that a member can show updates missing crafting a backlog and devises content rapprochement mechanisms to cut memo redundancy. In exploitation/ execution of topological belongingss of the web are counseled to heighten the presentation of the informations airing procedure.

Algebraic Gossip, counseled in, is the early algorithm turn toing informations meeting alongside web cryptography. In this paper a chitchat algorithm established on NC is gave, and it is proved that the spreading period of this algorithm is ; Nis the figure of nodes possessing a small information to distribute. This algorithm is highly comparable to classical North carolina: at every individual transmittal chance, every individual node sends to one more node a additive combination, computed in Galois Earth GF?q? alongside q _ K, of the beforehand consented packages. However, NC exhibits a elevated computational elaborateness , due to the monetary value of the cryptography and decryption processs gave in high-order GF. Furthermore, every individual package demands cushioning of auxiliary Klog2?q? & A ; gt ; Klog2?K? spots. Such embroidering bends to be impossible for colossal webs ; as an illustration, if K ? 1 ; 000 every individual package needs excess than 104 embroidering spots. Finally, the writers advocate that the memo size m ought to scale alongside the size of the web, as it is needed that m _ log?q? . A disparate manner is to hive away and craft packages using rateless codifications. In  distributed fountain codifications are counseled for networked storage. To craft a new encoded package, every individual storage node asks informations to a indiscriminately selected node of the web. The receiving system replies to the company despatching its informations, that will be utilized by the company to encode a new package. A comparable algorithm is counseled in , whereas the coded package formation mechanism is reversed ; in this instance, the nodes that shops the informations despatch random Walkers embracing the information. The storage nodes store this information and trade encoded packages XORing a small of the informations they by now received. At the conclude of the process, every individual storage node shops an encoded package, and it is likely to repossess the early informations questioning each K ? _ indiscriminately selected storage nodes. Development codifications, counseled in [ 15 ] , utilize a comparable method but advocate a peculiar grade allotment for the rateless codifications to maximise the informations continuity in attending of a lone information aggregator node.

In all the beforehand gave documents, the construct of the codifications is node-centric, i.e. , the nodes cope alongside the informations meeting and the encoding operations this duty is allocated to the packages. The mark of this work is to utilize peculiar random Walkers, shouted as rateless packages, for distributed storage of informations in WSN. Every individual node creates a precise figure of ratelesspackets, that are chiefly empty packages that excursion across the web as random Walkers. The purpose in [ 16 ] is to utilize packages encoded in a distributed manner that will be stored at random locations in the web to maximise informations continuity in the WSN. Every individual rateless package is associated alongside a grade selected prosecuting the mean Luby Change ( LT ) grade allotment, and T, the blending period of the graph, is conjectural to be known. Every individual rateless package performs a random amble across the web and a fresh information is joined simply after every individual T hops ; after a new information is added the package grade is decreased by one. After the grade becomes zero, the rateless package performs t auxiliary hops to hit the node that will hive away it. Though, the focal point of the paper is to lift informations continuity ; the period needed for the allotment of the rateless packages is non studied.

Proposed Work

In this paper we ideal the interface equals of a Grid agreement and the connexions amid them as a graph G?V ; E? , whereas V and E are the set of interface equals and boundary lines associating them, severally. Every individual node of the web is exceptionally recognized by an identifier ID. The ID can be allocated by a fixed rendezvous node, e.g. , a tracker, or can be embodied by the IP, haven reference of the node. Every individual node vj 2 V owns an m-bits informations ten tjvj, whereas tj is a time-stamp or an whole number that is incremented every individual period the informations in vj alterations. To clarify the notation in the remainder of the paper we accept that vj coincides alongside the ID of node ; tj is usually denoted to as the creative activity figure. In our scenes a node can advise its informations asynchronously alongside regard to the remainder of the web, lifting the creative activity associated alongside the information. The purpose of nodes is to discourse aboard one one more the corresponding informations, so as to grok a coincident screening of all the informations amassed by all the nodes in the web. This have to be completed indefinitely often at an arbitrary rate _ by every individual node. This observation Torahs out each centralised declaration whereas all nodes study to a public monitoring node, that in spiral have to propagate the amassed informations to all the participants. This manner is clearly impossible because it imposes a immense figure of traffic to and from the monitoring node, non to note the topics connected to the ballot and exposure of a centralised sink

Therefore, in this paper we advocate a to the full distributed declaration established on random walks. Every individual node is allowed to onset a manipulated figure tungsten of packages that are the random Walkers propagating the information in the web. The parametric quantity w clearly permits one to manipulation the figure of traffic inoculated in the web. On every individual response by a node, the package is forwarded to a random familiarity hence groking a easy signifier of probabilistic gossipmongering. It is good recognized that web coding declarations, e.g. , hold oning additive combinations of the amassed information, increases the presentation in words of throughput, hardiness and continuity. On the auxiliary manus, coding ways display two chief defects. The early and most erudite topic is embodied by the added computational complexness. A likely declaration that has by now been counseled in the plants is to clarify the early random web coding manner, that needs one to fall in the information blocks in elevated order Galois Field, alongside agreements established on easy binary combinations, e.g. , XOR. Our work headers alongside the elaborateness capable using a easy category of rateless codifications, recognized as Luby Change codes. The subsequent most relevant defect of NC is embodied the unlikeliness for a node to advise asynchronously the informations it merges missing calamitously impacting on the decryption accomplishment of all the auxiliary nodes. Indeed, the nodes retain roll uping additive combinations of a set of terra incognitas till they prosperously invert the corresponding agreement of equations. Clearly, the agreement of additive equations is meaningful if one keeps fall ining the similar information. On the contrary, in this paper we advocate a fresh decryption manner for LT codifications that is resilient to asynchronous accommodations of the information. In decision, we allow every individual node propagate a fixed figure of packages hold oning coded informations of the nodes that the packages have hit giving a random amble aboard G?V ; E? . All the nodes use the consented packages to decide a agreement of additive equations allowing them to repossess the informations associated alongside all the informations collected by the web in a timely, finished and robust way.In the prosecuting the characteristics of the counseled random amble coding scheme and the design of the fresh LT decryption algorithm are presented.

This estimate might be computed by the nodes spoting the IDs of the nodes encompassed in the beforehand consented equations. To get by alongside the construct of the equation harmonizing to the RSD, every individual package carries in the heading part the indicating of the grade dF that have to be attained by the equation below formation in the package ( that in our scenes is the early equation composed in the package organic structure signifier left to compensate ) . After a node vj at creative activity tj receives a package, it checks if the grade of the early equation stored in the package has grasped the demanded grade. If dF & A ; gt ; d1, and therefore the mark grade has non been grasped yet, the node performs three operations: it XORs its informations to the word.

Next the degree d1 of the equation is incremented and the corresponding Earth in the package updated. Finally, the node vj and the information timestamp tj are appended to the equation. On the auxiliary manus, if dF ? d1, the early equation has by now attained the demanded grade, therefore a new equation is crafted and stored as the new early equation, as the auxiliary equations are advanced, for example, eqi becomes eqi?1 for I ? 1. . . k. To craft a new equation eq1 a node draws a random grade from RSD and shops it in the dF Earth of the package heading. Following d1 ? 1 is set, its vj, its existent timestamp tj and informations c1 ? x tjvj are composed in the proper Fieldss. Every individual package crafted or notified by a node is following forwarded to one more node, indiscriminately selected amid the innate neighbours. The figure of hops globally seized by a package is non manipulated in our system. The merely restriction is embodied by the maximal package size DIM, that is normally imposed by the maximal transportation component allowed by the implicit in contact cognition at the physical bed. After a package ways the maximal dimension DIM, the eldest equation grasped by it is deleted as it is highly likely to keep aged or by now recognized information.

Random Walk LT Coding

In instance of a vivacious web, whereas nodes can randomly nexus and go the graph G?V ; E? and/or in attending of undependable links that coil into package lickings, a mechanism to admit the attending of a given package in the web have to be devised. As an illustration, an acknowledgement timer ( a Time-to-Live field ) and the reference of the conceiver can be added to the message. As usual, The acknowledgement timer Earth is initialized to a steady worth on the package construct, following every individual node decreases it on every individual hop. After the acknowledgement timer reaches 0 the consenting node acknowledges the conceiver that its random Walker is yet alive. The accepting node to boot resets the acknowledgement timer to the early value. The conceiver of the package uses a timer to detect package losingss ; after a timer expires beforehand the response of the corresponding recognition memo the node is allowed to renew the package.

Asynchronous LT Decoding:

The information scope by the random Walkers can be recouped by each node in the web every bit rapidly as the figure of equations needed to show an LT decryption algorithm has been collected. As our purpose is to retrace the information every bit fleetly as likely, all the equations grasped by every individual package, embracing the 1s that are yet in advancement, are buffered by every individual node. If we accept that the figure of nodes jV J in the web is equal to N, the decipherer undertaking can be formulated as the declaration of the agreement of additive equations Gx ? c whereas G is an N _ N binary1 matrix whose lines embody the N likely independent equations amassed by the node, x and degree Celsiuss are N _ 1 column vectors stand foring the N unfamiliar pieces of informations and the corresponding buffered additive combinations grasped by the packages warheads. Both x and hundred encompass m-bit elements. The node can reimburse all the informations x using a progressive signifier of Gaussian Elimination to decide the system. Clearly, this will necessitate all the nodes in the web to retain their informations sweetheart to besiege unhinging the declaration of the system.

Consequences and execution

In this helping we furnish anscutiny of the period needed to run all the innate informations to all the members in the web, that in the pursuing is described as recovery clip. In peculiar, we are interested in patterning the recovery period as a intent of the size of the innate informations m, the figure of random Walkers generated each node tungsten and figure of nodes in the web N, given the restraint on the maximal size of the random amble packages DIM. Furthermore, the counseled analytical ideal licenses to difference the coded manner versus an correspondent agreement missing cryptography, i.e. , after the information is gossiped explicitly. In fact, the counseled manner degenerates into an uncoded agreement if one

Decision:

In this paper we have shown that the present progresss in rateless cryptography and decryption can be lucratively exploited to carry through a robust and timely P2P resource venue method in Grid systems. The chief freshness of the counseled manner lies in the usage of web coding rules in a scenario whereas innate informations can be notified asynchronously. Furthermore, as challenged to a small signifiers of distributed storage counseled in the plants, our proposition realizes a changeless notify of the Earth informations across the finished distributed agreement, as maintaining the figure of traffic below control. From the algorithmic point of think, the chief part is embodied by the design of a fresh decipherer for rateless codifications that is robust to asynchronous updates of the information. One more interesting effect that we attained is the advancement of a easy analytical ideal for the appraisal of the period needed to run the information as a intent of the web and information sizes, given a restraint on the MTU allowed by the gettable transmittal protocol. Such a ideal can be exploited for the appraisal of the presentation and for the choice of a small critical parametric quantities of the system. The analytical wake show that the counseled coded manner reduces the period needed to discourse all the informations aboard respect to an correspondent system missing coding. Furthermore we clarify that such addition additions alongside the size of the informations to be scope, or analogously after the MTU shall be highly limited. One more paramount effect is that the encoded agreement graduated tables larger than the uncoded 1 after the figure of nodes in the distributed agreement additions.

References

  1. P. Trunfio, D. Talia, H. Papadakis, P. Fragopoulou, M. Mordacchini, M. Pennanen, K. Popov, V. Vlassov, and S. Haridi, “Peer-to-Peer Resource Discovery in Grids: Models and Systems, ” Future Generation Computer Systems, vol. 23, no. 7, pp. 864-878, 2007.
  2. V. Vijayakumar, R.S. WahidaBanu, and J.H. Abawajy, “An Efficient Approach Based on Trust and Reputation for Secured Selection of Grid Resources, ” Int’l J. Parallel, Emergent and Distributed Systems, vol. 27, no. 1, pp. 1-17, 2012.
  3. A. Kermarrec, L. Massouli_e, and A. Ganesh, “Probabilistic Reliable Dissemination in Large-scale Systems, ” IEEE Trans. Parallel and Distributed Systems, vol. 14, no. 3, pp. 248-258, Mar. 2003.
  4. M. Jelasity, A. Montresor, and O. Babaoglu, “Gossip-Based Aggregation in Large Dynamic Networks, ” ACM Trans. Computer Systems, vol. 23, no. 3, pp. 219-252, Aug. 2005.
  5. L. Alvisi, et al. , “How Robust are Gossip-Based Communication Protocols? ”Operating Systems Rev. , vol. 41, no. 5, pp. 14-18, Oct. 2007.
  6. R. new wave Renesse, D. Dumitriu, V. Gough, and C. Thomas, “Efficient Reconciliation and Flow Control for Anti-Entropy Protocols, ” Proc. Second Workshop Large-Scale Distributed Systems and Middleware ( LADIS ’08 ) , 2008.
  7. N. Carvalho, J. Pereira, R. Oliveira, and L. Rodrigues, “Emergent Structure in Unstructured Epidemic Multicast, ” Proc. 37th Ann. IEEE/IFIP Int’l Conf. Reliable Systems and Networks ( DSN ’07 ) , pp. 481-490, 2007.
  8. J. Leitao, J. Pereira, and L. Rodrigues, “Hyparview: A Membership Protocol for Reliable Gossip-Based Broadcast, ” Proc. 37th Ann. IEEE/IFIP Int’l Conf. Reliable Systems and Networks ( DSN ’07 ) , pp. 419-429, 2007.

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Discuss the discovery of the structure of Benzene

Benzene is a chemical compound of the hydro-carbon group. It is a colorless liquid with a characteristic odor and burning taste, formula C6H6. The benzene molecule is a closed ring of six carbon atoms connected by bonds that resonate between single and double bonds; each carbon atom is also bound to a single hydrogen atom. It is insoluble in water, but miscible in all proportions with organic solvents. Benzene itself is an excellent solvent for certain elements, such as sulphur, phosphorus, and iodine; for gums, fats, waxes, and resins; and for most simple organic chemicals.

It is one of the most commonly used solvents in the organic chemical laboratory. Benzene melts at 5. 5° C (41. 9° F), boils at 80. 1° C (176. 2° F), and has a relative density of 0. 88 at 20° C (68° F). It is widely regarded as carcinogenic and, if inhaled in large quantities, is poisonous. The vapors are explosive, and the liquid violently flammable. Many compounds, such as nitrobenzene, are obtained from benzene. Benzene is also used in the manufacture of drugs and in the production of important derivatives, such as aniline and phenol (see Hogben, Lancelot.

Science for the Citizen: A Self-Educator Based on the Social Background of Scientific Discovery, 1999). Benzene and its derivatives are included in the important chemical group known as aromatic compounds. II. Discussion Benzene is only slightly soluble in water, but can be mixed in all proportions with acetone, alcohol, ether, or glacial acetic acid. It burns with a smoky flame. The vapor forms an explosive mixture with air, and has been used in parts of the world as a motor fuel.

At one time, most benzene was obtained from tars and gases produced during the making of coke for the iron and steel industry. Now, however, much of the world’s supply of benzene is obtained by the refining of petroleum. Moreover, the benzene molecule is believed to be shaped like a ring, rather than like a cube or a chain as are other hydrocarbon molecules. The theory of the benzene ring is an important principle in organic chemistry. The aromatic series of hydrocarbons are compounds containing benzene ring.

The theory of the structure of the benzene molecule was first stated by the German chemist August Kekuke in 1865. He suggested that the six carbon atoms of benzene were arranged in a hexagonal ring, with each of the six hydrogen atoms attached to one of the carbon atoms. Since each carbon atom has a valence of 4, alternate carbon atoms share two valence bonds in the benzene ring (see Aftalion, Fred and Benfey,Otto Theodor. A History of the International Chemical Industry, 2000).

Pure benzene burns with a smoky flame because of its high carbon content. When mixed with a large proportion of petrol it makes a satisfactory fuel. In Europe benzene mixed with some methylbenzene and other related compounds has long been added to motor fuels. The wisdom of this in the face of benzene’s carcinogenic qualities has only recently been addressed as a concern. Benzene was discovered in 1825 by the English scientist Michael Faraday, and in 1842 it was made available in large quantities after it was found that coal tar contains benzene.

A ton of coal, if coked in a by-product oven, yields about 7. 6 liters (2 gallons) of benzene (see Audrieth, Ludwig Frederick. Salts, Acids, and Bases: Electrolytes Stereochemistry, 2001). Large quantities of benzene are now obtained from petroleum, either by direct extraction from certain types of crude oils or by chemical treatment of petroleum (hydroforming and cyclization). III. Conclusion The structure of the benzene molecule is of the utmost importance to the theory of organic chemistry.

The first to formulate the resonating ring structure described above was the German chemist Friedrich August Kekulé von Stradonitz, in 1865. For various reasons, 20th-century theorists found difficulties with this picture and instead developed a “molecular orbital” picture of electrons orbiting the entire molecule rather than particular carbon atoms. In the 1980s, however, more advanced studies returned to Kekulé’s picture, but with the electrons in deformed orbits around their particular atoms.

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Alice’s Adventure of Self Discovery in Wonderland

The bildungsroman novel Alice’s Adventures in Wonderland, by Lewis Carroll elucidates the idea of humans needing to be faced with a drastic situation, in order to grow and develop their own identity. Alice begins in the novel as a respectful and naive child, one typical of the Victorian Era. She struggles with adjusting to the new situations, as well as the growth and changes of her body. Alice’s escapades in Wonderland allow her to change her views with regard to authority as well as to understand different life situations.

Alice’s time in Wonderland compels her to become more independent as well as to stand up for herself, ergo becoming a mature, self-reliant young woman. Alice’s adventures in Wonderland permit her to understand and accept her body’s baffling changes. As Alice enters Wonderland, a world where nothing is the same, her body changes sizes eleven times, something that is drastic for anyone, not only a young girl. When “she sat down and began to cry again” (Carroll 17), this was in regard to her body’s rapid and confusing changes.

Alice’s body changed, she was completely hopeless as well had no idea on how to deal with the situation, much like a child entering puberty. When a child first enters puberty, they are extremely uncomfortable, but eventually they become more and more comfortable with the changes and in their own skin. Alice proves that she is becoming more comfortable with herself and her identity when she declares, “Oh dear! I’d nearly forgotten that I’ve got to grow up again! Let me see-how is it to be managed” (39).

Alice’s body no longer has control over her, but instead she has control over her own body. Throughout Alice’s Adventures in Wonderland, Alice continues to become more comfortable with her body as well as in foreign and unfamiliar situations. Alice’s adventure allows her not only to become more comfortable with her body, but also more comfortable in regard to understanding the role that authority plays in society. When Alice first enters Wonderland, she is a confused, helpless child, who does not understand how to stand up for herself.

In the beginning of the novel, Alice is thrown into a world where the strict rules she lives by no longer apply, and as a result does not understand how to act, especially in regard to authority. When the Rabbit makes a mistake of calling to Alice saying, “Why Mary Ann, what are you doing here? … Alice was so frightened she ran off at once without saying a word” (10), Alice clearly acknowledges and understands the mistake. Due to her strict, traditional Victorian upbringing, she was taught to obey authority at all costs and never to contradict someone who was in a position of power.

In Wonderland however, all that Alice thought she knew about authority is tossed aside, as those rules no longer apply. Although Alice indubitably knows she is not Mary Ann, the Rabbit’s maid, she is too afraid to disobey authority and point out the error of his ways. However, further on in the novel, as well as further on in Alice’s growth as a human, she becomes more comfortable with speaking up to authority. When Alice contradicts the Queen and her poor decisions when the Queen exclaims, “Off with her head!

Off with her.. ” but Alice barges in and declares that it is “nonsense. ” (72). Alice not only becomes more comfortable as herself, but more comfortable speaking up and against authority, an important aspect of maturing. Alice’s growth and maturing not only depends on her physical size, but it also depends on her ability to adapt to new situations. In Wonderland, all of the new rules that come with these strange games, from the caucus race to the croquet game are metaphors to social situations.

At the beginning of Alice’s adventure, Alice is confused by these new social situations, and does not quite now how to react to them. During the croquet game, Alice is unsure and “rather doubtful whether she ought not to lie down on her face like the three gardeners. ” (35). Alice had never been in a situation like this, and she clearly did not know how to react, something that is learned over time as a person matures. Another example further along in the novel is when Alice is thrown into a new situation, where a baby is in danger, irrefutably a situation she had never been in before.

Although Alice was unfamiliar with the social protocol, or what one would typically do in such a situation, she was mature enough to trust her instincts and stand up for the child by exclaiming at the Duchess, “Oh please mind what you’re doing! You nearly took his nose off! ” (39). As Alice continues to mature and emerge as a young adult, she begins to trust her intuitions as well as defends her thoughts and ideas. Through Alice’s journey, she becomes more mature and as a result, adapts to new situations more easily.

Alice’s Adventures in Wonderland is a fantasy, bildungsroman novel that explores coming of age, in regard to puberty as well as social maturity. Although within the novel, it is Alice’s physical size that changes quite often, she matures throughout the novel while in Wonderland, adapting more easily to new, frightening situations as well as developing her moral courage. Alice begins her adventure as a frightened young girl, one who can barely cope in a situation, and she ends her journey being a strong, fearless and independent young woman.

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E-Discovery Procurement

Table of Contents Assignment #1: e-Discovery Project Procurement Management2 Introduction2 Plan e-Discovery Procurements3 Conduct e-Discovery Procurements5 Administer e-Discovery Procurements6 Close e-Discovery Procurements8 Conclusion9 References10 Assignment #1: e-Discovery Project Procurement Management Introduction Most projects of whichever size or significance cannot be completed using 100% in-sourced resources. But Project managers must still procure their project’s resources that […]

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Constructivism And Discovery Learning Education Essay

Table of contents

In 1960 Bruner publishedA The Procedure of Education. This was a landmark book which led to much experimentation and a wide scope of educational plans in the 1960 ‘s. Howard Gardner and other immature research workers worked under Bruner and were much-influenced by his work. In the early 70 ‘s Bruner left Harvard to learn at University of Oxford for several old ages ( 1972 – 1979 ) . He returned to Harvard in 1979.A

Subsequently he joined the New York University of Law, where he is a senior research chap ( at the age of 93 ).

Theory A

Bruner was one of the establishing male parents of constructivist theory.ConstructivismA is a wide conceptual model with legion positions, and Bruner ‘s is merely one. Bruner ‘s theoretical model is based on the subject that scholars construct new thoughts or constructs based upon bing cognition. Learning is an active procedure. Aspects of the procedure include choice and transmutation of information, determination devising, bring forthing hypotheses, and doing intending from information and experiences.A

Bruner ‘s theories emphasize the significance of classification in acquisition. ” To comprehend is to categorise, to gestate is to categorise, to larn is to organize classs, to do determinations is to categorise. ” Interpreting information and experiences by similarities and differences is a cardinal concept.

Bruner was influenced byA Piaget’sA thoughts about cognitive development in kids. During the 1940 ‘s his early work focused on the impact of demands, motives, & A ; outlooks ( “ mental sets ” ) and their influence on perceptual experience. He besides looked at the function of schemes in the procedure of human classification, and development of human knowledge. He presented the point of position that kids are active problem-solvers and capable of researching “ hard topics ” . This was widely divergent from the dominant positions in instruction at the clip, but found an audience.

Four Key subjects emerged in Bruner ‘s early work:

  1. Bruner emphasized the function of construction in larning and how it may be made cardinal in learning. Structure refers to relationships among factual elements and techniques. See the subdivision on classification, below.
  2. He introduced the thoughts of “preparedness for larning ” andA coiling course of study. Bruner believed that any topic could be taught at any phase of development in a manner that fit the kid ‘s cognitive abilities. Spiral course of study refers to the thought of revisiting basic thoughts over and over, constructing upon them and lucubrating to the degree of full apprehension and mastery.
  3. Bruner believed that intuitive and analytical thought should both be encouraged and rewarded. He believed the intuitive accomplishments were under-emphasized and he reflected on the ability of experts in every field to do intuitive leaps.
  4. He investigated motive for larning. He felt that ideally, involvement in the capable affair is the best stimulation for larning. Bruner did non like external competitory ends such as classs or category ranking.

Finally Bruner was strongly influenced by Vygotsky ‘s Hagiographas and began to turn away from the intrapersonal focal point he had had for acquisition, and began to follow a societal and political position of larning. Bruner argued that facets of cognitive public presentation are facilitated by linguistic communication. He stressed the importance of the societal scene in the acquisition of linguistic communication. His positions are similar to those ofA Piaget, A but he places more accent on the societal influences on development. The earliest societal scene is the mother-child couple, where kids work out the significances of vocalizations to which they are repeatedly exposed. Bruner identified several of import societal devices including joint attending, common regard, and turn-taking.

Bruner besides incorporated Darwinian thought into his basic premises about acquisition. He believed it was necessary to mention to human civilization and archpriest development in order to understand growing and development. He did, nevertheless, believe there were single differences and that no standard sequence could be found for all scholars. He considered direction as an attempt to help or determine growth.In 1996 he published The Culture of Education.. This book reflected his alterations in point of views since the 1960 ‘s. He adopted the point of position that civilization shapes the head and provides the natural stuff with which we constrict our universe and our self-conception.

Four characteristics of Bruner ‘s theory of instruction:

  • Sensitivity to learn.

This characteristic specifically states the experiences which move the scholar toward a love of larning in general, or of larning something in peculiar. Motivational, cultural, and personal factors contribute to this. Bruner emphasized societal factors and early instructors and parents ‘ influence on this. He believed acquisition and job work outing emerged out of geographic expedition. Part of the undertaking of a instructor is to keep and direct a kid ‘s self-generated explorations.

  •  Structure of cognition

It is possible to construction cognition in a manner that enables the scholar to most readily hold on the information. This is a comparative characteristic, as there are many ways to construction a organic structure of cognition and many penchants among scholars. Bruner offered considerable item about structuring knowledge.

Understanding the cardinal construction of a topic makes it more comprehendible. Bruner viewed classification as a cardinal procedure in the structuring of cognition. ( See the subdivision below on classification. )

Detailss are better retained when placed within the competition of an ordered and structured pattern.

To bring forth cognition which is movable to other contexts, cardinal rules or forms are best suited.

The disagreement between get downing and advanced cognition in a capable country is diminished when direction centres on a construction and rules of orientation. This means that a organic structure of cognition must be in a simple adequate signifier for the scholar to understand it and it must be in a signifier recognizable to the pupil ‘s experience.

Manners of representation: ocular, words, symbols.

Effective sequencing- no 1 sequencing will suit every scholar, but in general, increasing trouble. Sequencing, or deficiency of it, can do larning easier or more difficult.

Classification:

Bruner gave much attending to classification of information in the building of internal cognitive maps. He believed that perceptual experience, conceptualisation, acquisition, determination devising, and doing illations all involved categorization.A

Bruner suggested a system of coding in which people form a hierarchal agreement of related classs. Each in turn higher degree of classs becomes more specific, repeating Benjamin Bloom ‘s apprehension of cognition acquisition every bit good as the related thought of instructional staging ( Bloom ‘s Taxonomy ).

Categories are ”regulations ” that stipulate four thing about objects:

  1. Criterial attributes – required features for inclusion of an object in a class. ( Example, for an object to be included in the class “ auto ” it must hold an engine, 4 wheels, and be a possible agency of transit.
  2. The 2nd regulation prescribes how the criteral properties are combined.
  3. The 3rd regulation assignees weight to assorted belongingss. ( Example, it could be a auto even if a tyre was losing, and if it was used for haling lading it would be shifted to a different class of  ”truck ” or possibly ” new wave ”.
  4. The 4th regulation sets acceptance bounds on properties. Some properties can change widely, such as colour. Others are fixed. For illustration a vehicle without an engine is non a auto. Likewise, a vehicle with merely two wheels would non be included in ”auto ” .

There a several sorts of class:

  • Identity categories – class include objects based on their properties or features.A
  • Equivalent classs (supply regulations for uniting classs. Equality can be determined by affectional standards, which render objects tantamount by emotional reactions, functional standards, based on related maps ( for illustration, ”auto ” , ”truck ” , ”new wave ” could all be combined in an inclusive class called ”motor vehicle”), or by formal standards, for illustration by scientific discipline, jurisprudence, or cultural understanding. For illustration, and apple is still an apple whether it is green, mature, dried, etc ( individuality ) . It is nutrient ( functional ) , and it is a member of of a botanical categorization group (formal).

Coding systems are classs serve to acknowledge centripetal input. They are major organisational variables in higher cognitive operation. Traveling beyond immediate centripetal informations involves doing illations on the footing of related classs.

  • Related class form a ” cryptography system ” . These are hierarchal agreements of related categories.

Bruner ‘s theories introduced the thought that people interpret the universe mostly in footings of similarities and differences.

This is a important part to how persons construct their alone theoretical accounts of the world.

Application

Bruner emphasized four features of effectual direction which emerged from his theoretical constructs.

  1. Personalized: direction should associate to scholars ‘ sensitivity, and facilitate involvement toward learning
  2. Contented Structure: content should be structured so it can be most easy grasped by the learner
  3. Sequencing: sequencing is an of import facet for presentation of material
  4. Support: wagess and penalty should be selected and paced appropriately

Intellectual development

Bruner postulated three phases of rational development.

The first phase he termed ” Enactive ” , when a individual learns about the universe through actions on physical objects and the results of these actions.

The 2nd phase was called ”Iconic ” where acquisition can be obtained through utilizing theoretical accounts and pictures.

The concluding phase was ” Symbolic ” in which the scholar develops the capacity to believe in abstract footings. Based on this three-stage impression, Bruner recommended utilizing a combination of concrete, pictural so symbolic activities will take to more effectual learning.

The importance of language

Language is of import for the increased ability to cover with abstract concepts.BrunerA argues thatA languageA can code stimulations and free an person from the restraints of covering merely with visual aspects, to supply a more complex yet flexible knowledge.

The usage of words can help the development of the constructs they represent and can take the restraints of the “ here & amp ; now ” construct. Basically, he sees the baby as an intelligent & A ; active job convergent thinker from birth, with rational abilities fundamentally similar to those of the mature grownup. Harmonizing to Bruner the kid represents the universe to himself in three different ways.

Educational deductions of Bruner ‘s theory

For Bruner ( 1961 ) , the intent of instruction is non to leave cognition, but alternatively to ease a kid ‘s thought and job resolution accomplishments which can so be transferred to a scope of state of affairss. Specifically, instruction should besides develop symbolic thought in kids.

In 1960 Bruner ‘s text, A The Procedure of EducationA was published. The chief premiss of Bruner ‘s text was that pupils are active scholars who construct their ain cognition.

Bruner ( 1960 ) opposedA Piaget’sA impression of preparedness. He argued that schools waste clip seeking to fit the complexness of capable stuff to a kid ‘s cognitive phase of development. This means pupils are held back by instructors as certain subjects are deemed to hard to understand and must be taught when the instructor believes the kid has reached the appropriate province of cognitive adulthood.

Bruner ( 1960 ) adopts a different position and believes a kid ( of any age ) is capable of understanding complex information: A ‘We Begin with the hypothesis that any topic can be taught efficaciously in some intellectually honorable signifier to any kid at any phase of development ‘ .

Bruner ( 1960 ) explained how this was possible through the construct of theA coiling course of study. This involved information being structured so that complex thoughts can be taught at a simplified degree foremost, and so re-visited at more complex degrees subsequently on. Therefore, topics would be taught at degrees of bit by bit increasing difficultly ( hence the coiling analogy ) . Ideally learning his manner should take to kids being able to work out jobs by themselves.

Bruner ( 1961 ) proposes that scholars ‘ construct their ain cognition and make this by forming and categorising information utilizing a cryptography system. Bruner believe that the most consequence manner to develop a cryptography system is to detect it instead than being told it by the instructor. The construct ofA find learningA implies that pupils construct their ain cognition for themselves ( besides known as a constructist attack ) .

The function of the instructor should non be to learn information by rote acquisition, but alternatively to ease the acquisition procedure. This means that a good instructor will plan lessons that help student detect the relationship between spots of information. To make this a instructor must give pupils the information they need, but without forming for them. The usage of the coiling course of study can help the procedure ofA find acquisition.

Bruner and Vygotsky

Both Bruner and Vygotsky emphasise a kid ‘s environment, particularly the societal environment, more than Piaget did. Both agree that grownups should play an active function in helping the kid ‘s acquisition.

Bruner, like Vygotksy, emphasised the societal nature of acquisition, mentioning that other people should assist a kid develop accomplishments through the procedure ofA scaffolding. The term scaffolding foremost appeared in the literature when Wood, Bruner and Ross described how coachs ‘ interacted with pre-schooler to assist them work out a block Reconstruction job ( Wood et al. , 1976 ) .

The construct of staging is really similar toA Vygotsky’sA impression of theA zone of proximal development, and it non uncommon for the footings to be used interchangeably.ScaffoldingA involves helpful, structured interaction between an grownup and a kid with the purpose of assisting the kid achieve a specific end.

Difference between Bruner and Piaget

Obviously there are similarities betweenA PiagetA and Bruner, but an importantdifferenceA is that Bruner ‘s manners are non related in footings of which presuppose the 1 that precedes it. Whilst sometimes one manner may rule in use, they co-exist. Bruner states that what determines the degree of rational development is the extent to which the kid has been given appropriate direction together with pattern or experience. So – the right manner of presentation and the right account will enable a kid to hold on a construct normally merely understood by an grownup. His theory stresses the function of instruction and the grownup.

AlthoughA Bruner proposesA phases of cognitive development, he does n’t see them as stand foring different separate manners of idea at different points of development ( like Piaget ) . Alternatively, he sees a gradual development of cognitive accomplishments and techniques into more incorporate ”grownup ” cognitive techniques.

Bruner viewsA symbolic representationA as important for cognitive development and since linguistic communication is our primary agencies of typifying the universe, he attaches great importance to linguistic communication in finding cognitive development.

Bruner disagrees with Plaget

  1. Childs are pre – adapted to larn.
  2. Development is a continues process  – non a series of phases.
  3. Childs have a natural curiosity .
  4. The development of language is a cause non a effect of cognitive development.
  5. Children ‘s cognitive structures develop over clip.
  6. You can speed- up ognitive development. You do n’t hold to wait for the kid to be ready.
  7. Childs are Active participants in the acquisition procedure.
  8. The engagement of adults and more knowledgeable peers  makes a large difference.
  9. Cognitive development entails the acquisition of symbols.
  10. Symbolic idea does not replace earlier modes of representation.

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