The Fundamental Role Of Concrete In Roman Architecture History Essay

The Fundamental Role Of Concrete In Roman Architecture History Essay The development of concrete in Roman style architecture was of great use in producing many world famous, monumental buildings that are representative of the Roman era. Not only did concrete provide a unique scheme in the production of Roman architecture, it was also a convenient and functional tool when other raw materials were unattainable. In this essay, I will discuss the development of concrete, concretes properties, surfacing techniques, concretes ease of use and labour requirements, and the construction of the famous Pantheon as a prominent example of the immense benefits of concrete to the Romans. Concrete was not invented by the Romans, but simply an adaptation of different mortar usages in earlier construction. MacDonald describes a mortar as, materials of mixed composition in a semi-fluid state at the time of construction. Because Romans didnt possess marble quarries like the Greeks, mortar became the practical alternative. Volcanic rock was the most common building material located in the Italian region, and was therefore, the most basic tool to create mortar, which would develop into useful concrete. As early as the 4th and 3rd centuries B.C., the observation of limestone walls with rock debris between each stone was made in Pompey. From this point onward, Roman concrete and mortar use became more and more prominent and by the late 3rd century B.C., Romans had improved the recipe of mortar to include lime and clay. When combined with different types of filling elements, also known as aggregates, as well as different types of facings, Roman mortars were able to create stro ng and dense walls. By the 1st century, the use of concrete is said to have been perfected by the Romans. In order for concrete to become a useful building technology, the properties of concrete must be carefully examined. The Romans used concrete for a wide variety of purposes. Concrete has been used in Roman buildings as strong base foundations, as well as in the highest vaults. In order to give structure and substance to mortar, aggregates, or stones of different sizes mixed into the mortar, were used. Not only did aggregates give mortar structure and substance by increasing the mortars mass, but they also helped to strengthen the building material. Aggregates were an essential part of concrete construction because they work together with mortar to defy crushing that can be caused by immense weights. This is clearly important when concrete was used as a foundation. Different types of stone were used to produce aggregates dependent upon the use of the concrete. For strong solid base foundations, heavier rock materials were used. In these types of foundation, aggregate was often times two thirds of the volume of the entire fabric. For lighter concrete forms, including high vaulting, lighter rock materials (such as pumice) were used. Debris from destroyed structures was also a common form of aggregate, including buildings and sculptures. Concrete is an indefinite, nearly fluid substance from the time that it is mixed to the time that it is set. Composed of lime, clay and aggregate, dry concrete is mixed with water, and this compound (opus caementicum) will harden into a solid mass. With this property in mind, Roman concrete construction was relatively simple. Generally wooden frames were set to pour the concrete mixture into and allow it to harden. Therefore, to produce this type of Roman architecture, both a mortar substance and a frame were necessary. Until Augustan times, the concrete used by Romans was a simple lime mortar. When limestone is burned, quicklime is produced. This quicklime is then slaked to produce calcium hydroxide, which is then mixed with sand. Once evaporated, calcium carbonate crystals are formed. These crystals are the fundamental bonding element of this basic concrete. Mixing more sand with the crystals increases the mortars strength because the crystals bind to coarse surfaces. A great benefit of concrete use was fireproofing buildings. By the late 2nd century B.C., a new kind of mortar came into existence that not only aided in fire proofing the structural design, but also in waterproofing it. Romans came across a type of volcanic ash near the city of Pozzuoli, Italy, which they used to create fine cement that reacts in a different manner than the simple lime mortar. This type of mortar is called pozzolana, and is also known as hydraulic cement. Pozzolana is composed of silicates and aluminates. When combined with lime, pozzolana forms a hydrated silicate of calcium. Comparatively, this combination of chemicals does not need to lose water through an evaporative process; it actually retains water into its structure. In doing so, pozzolana mortars can set in damp areas. This new found type of concrete was of great importance in waterproofing buildings. It helped to prevent decay and corrosion to buildings, allowing them to survive longer. Pozzolana is one of the most standard features of concrete in central Italy. To further aid the waterproofing of concrete, different types of stone facings were developed. Facings were originally used to protect the surfaces of concrete. Typically, facings of stone and other material were set into wet concrete to create a strong casing when the concrete dried. Facings are of valuable importance in dating buildings, and there are several different types that evolved over the centuries. During the late 2nd Century B.C., Opus Incertum, or concrete faced with small irregular shaped stones, was commonly seen. Concrete faced with small four sided stones in a definite pattern, called Opus Reticulatum, is dated shortly after 100 B.C. Opus Testaceum, concrete faced with brick, was found throughout the early empire until the 4th century B.C. Opus Mixtum is concrete facing characterized by a combination of brick and stone in a decorative pattern, and dated from the same period as the former. Principally, concrete facings were both practical and decorative, used for prot ection as well as ornamentation. For the Romans, using concrete in constructing buildings was just as convenient as it was practical. In terms of labour, the majority of workers necessary to complete any type of Roman structure did not need to be skilled or educated. Generally, the only highly skilled workers that were involved in the projects included the architect, the master masons and master carpenters. The tasks of mixing, carrying, hauling and pouring concrete were performed by rather unskilled labourers. This same demographic also fit into the category of creating forms into which the concrete would be poured. The timetables of such workers were scheduled around the drying of the concrete. It was certainly possible for Roman architecture to be built of stone, but this type of work would require labourers to dress the stones to exact dimensions, a more challenging task than that of concrete use. Because of this fact, the ease of using concrete made it a more prevalent type of building technology. Designed by Roman Emperor Hadrian, The Pantheon is a prime example of concrete use by the early Romans. Hadrian was known for advancement in the vaulted style, and The Pantheon exemplifies this style with its impressive concrete work. Work on The Pantheon began sometime between July of 118 A.D. and July of 119 A.D., and was completed between the years of 125 and 128 A.D. During the period of construction, concrete was used vastly. The Pantheon is built on a foundation of concrete, nearly 90 percent of the intermediate block and rotunda is made of concrete, and roughly 5,000 metric tons of concrete make up The Pantheons dome. As in many concrete buildings, The Pantheons construction was completed in levels, where different strengths of aggregate were used in each plane. The Pantheon is said to have five different layers of concrete with five separate types of aggregate. Naturally, the lowest level contains the densest and most cohesive aggregate. As the levels of concrete ascend, a lighter form of aggregate is used than the previous layer. The dome of The Pantheon is made of the lightest aggregate in the entire structure, pumice. The Pantheons major features were methodically configured. Carpenters were required to construct castings used to pour concrete for foundations. The rotunda walls were created by pouring a dense concrete and aggregate mixture into short, wide trenches. Once dried, more concrete was set atop the original trench in layers, until the dome terrace was reached. At this point, the dome had to be poured. The dome is one of the greatest features of The Pantheon. Again, the concrete that was used to create the dome was poured on to a wooden form built in a half sphere shape. The dome form was held in place with wooden struts and timber to allow a light aggregate concrete mixture to dry atop it. Castings of coffers, or sunken panels, were attached to the wooden form to create the domes intricate detail. As the dome was being poured, circular brick dams in the form of step-ring buttraces formed the domes exterior. Step upon step, concrete was poured until it reached the more nearly horizontal region of the dome, where tacky concrete was used. At the top most point, vertically set horizontal tiles finished the dome. As one of the greatest achievements of concrete work, The Pantheon represents the fundamental function of concrete in Roman Architecture. It is obvious that concrete played an essential role in the construction of Roman buildings. The development and adaptation of concrete in the Roman world was the most practical means of construction. Not only was concrete an available source of building material, constructing with concrete was also an uncomplicated and efficient technique. Fire and water proofing of Roman buildings were just a few of the practical functions that concrete provided. Concretes properties allowed for Roman architecture to survive throughout the centuries; because such a useful material was discovered and widely utilized, we are still able to view and study some of the worlds most brilliant structures.

HIV/AIDS in Prisons and Jails :: STD, HIV, AIDS

In addressing the prevention of the spread of the HIV virus in prisons, we have seen a rush to develop and implement prevention measures. Much attention has centered on such controversial issues as compulsory or voluntary blood testing, isolation versus integration of HIV infected inmates into the prison mainstreams, provision of condoms and disposable needles, and effective educational measures for specific groups within the prison.   Ã‚  Ã‚  Ã‚  Ã‚  Unfortunately, this rush to develop and implement preventive measures has resulted in a degree of polarization which has hindered progress towards implementation of effective prevention measures. Prisons and jails offer uniquely important opportunities for improving disease control in the community by providing health care to disease prevention program to a large and concentrated population of individuals at high risk for disease. Inmates often have little interaction with the health care system before and after being incarcerated. (U.S. News & World Report) The bureau of Justice Statistics (BJS) reported that in 1999, HIV/AIDS in prisons and jails was a growing problem in American correctional facilities. The AIDS rate in US prisons was five times the rate of general population. (Society. 2003)   Ã‚  Ã‚  Ã‚  Ã‚  For a variety of reasons, many inmates do not seek diagnosis or treatment for illness before arriving to prison or jail. Because inmates are literally a â€Å"captive† audience, it is vastly more efficient and effective to screen and treat them while incarcerated than to conduct extensive outreach in local communities. (AIDS Weekly. 1998) Uninfected prisoners have sued the authorities for failing to test and segregate. In a recently reported case, Cameron v. Metcuz 705 F. Supp 454 (N.D. Ind 1989), an uninfected plaintiff prisoner sued prison authorities for failing to segregate a known infected prisoner with a violent history who had bitten the plaintiff. In that case, the court found that the authorities’ failure to segregate a known infected prisoner with a violent history did not amount to gross negligence or reckless indifference to the prisoner who was bitten. (Mead. Vol. 15 no. 5, pp. 197-9).   Ã‚  Ã‚  Ã‚  Ã‚  There is a clear case for urgent reform of the law as it relates to prisoners right’s to ensure meaningful HIV/AIDS prevention and care strategies for both the prison and general populations.

Find out the compounds that would get formed when heating copper carbonate

The colour of CuO and Cu2O are black and red respectively. Heating copper carbonate strongly will produce copper (ll) oxide and carbon dioxide that will be given off so basically the equation that results from this is: CuCO3 (s) ? CuO (s) + CO2 (g). By heating for about 3g of the green powder of copper carbonate, I should obtain a new compound with the black colour proving the presence of copper (ll) oxide. The volume of the carbon dioxide that will result from heating copper carbonate depends on the mass of copper carbonate. Actually, it is proportional to it: the bigger the mass of copper carbonate the bigger the volume of gas given off and the bigger the mass of the product formed. The time of heating is very important as well because the copper carbonate isn't completely burnt, it will affect the quantity of gas and the mass of the compound formed. In the preliminary experiment, I just identified which compound that was formed knowing the colours. Using the same apparatus as in the proper experiment, I heated 1.00gram of a green powder of copper carbonate and obtained 0.30gram of copper (ll) oxide. That experiment was limited in the fact that I couldn't measure directly the volume of gas that was given of in the reaction and, considering the accuracy of the chemical balance used, that mass used was small providing an error of ? 1% in the mass of copper carbonate. So, to improve this I used a much bigger mass in the proper experiment for the accuracy of the balance couldn't be improved. * Crucible and lid. * Pipe clay triangle. * Tripod. * Heatproof mat. * Bunsen burner. * Tongs * Chemical balance. * Green powder of copper carbonate. * Bell jar. (Eye protection required: WEAR SAFETY GOGGLES ?TAKE CARE TO AVOID BURNS. WEIGH (to the nearest 0.01g) EVERYTHING TWICE AT LEAST TO AVOID ERRORS. 1. Set the tripod, Bunsen burner (switched off), heatproof mat and pipe clay triangle as above. 2. Weigh the crucible and lid and record the measurement. 3. Letting the crucible on the balance, add the powder of copper carbonate for a little more than 3.00g. 4. Put the lid back and record the measurement. 5. Place the set onto the pipe clay triangle. 6. Switch the Bunsen burner on and heat the crucible strongly. 7. Using the tongs, lift the lid slightly from time to time to check whether the colour of the copper carbonate has completely changed or not. 8. When the colour has changed totally (after about 10 minutes), switch the Bunsen burner off and remove the crucible and lid using tongs form the pipe clay triangle. 9. Allow it to cool into a Bell jar. 10. Re-weigh the crucible and lid and copper (ll) oxide formed in and record the measurement. 11. Range the apparatus back. Mass of crucible + lid = 17.86g Mass of crucible + lid + copper carbonate = 21.58g Mass of copper carbonate = 3.72g Mass of crucible + lid + copper oxide formed = 20.45g CuCO3 (s) ? CuO (s) + CO2 (g). n CuCO3 (s) = n CO2 (g). M CuCO3 (s) = V CO2 (g). Mr Vm Mr = 63.5 + 12 + 3 x 16 = 123.5 gmol-1 M CuCO3 (s) = 3.72 g Vm = 24 dm-3 3.72 g = V CO2 (g). 123.5 gmol-1 24 dm-3 So V CO2 (g) = 0.723 dm-3 M CuO (s) = Mass of (crucible + lid + copper oxide formed) – Mass of (crucible + lid) so M CuO (s) = 2.59g. If my method and my results are right then the volume of CO2 given up was 0.723 dm-3 and the mass of CuO obtain was 2.59g. This method could only enable us to calculate the volume. The total uncertainties in that volume is the same of one of the mass of copper oxide formed for they depend quantitatively to the mass of copper carbonate used. The chemical balance was accurate to 0.01g. That error is [?(0.01/3.72) x 100] ? 0.27% then the order of proportionality of the results are: V CO2 (g) = (0.723 ? 0.0027) dm-3 and M CuO (s) = (2.59 ? 0.0027) g. If I had to repeat this experiment, I would use a gas inch well greased (to enable the pressure of gas to push it) by which I can just measure the volume of gas directly using a similar mass.

William Shakespeare s Othello - The Moor Of Venice

William Shakespeare’s tragic play: â€Å"Othello: the Moor of Venice† starts out in the place of love and water, the beautiful Venice, Italy. In this play Shakespeare brings to life the true definitions of love, betrayal, jealousy, and revenge. Iago and Roderigo, two characters in the play, that are plotting against the general of the Venetian Army because Iago was not chosen to be the lieutenant. Instead Othello chose Cassio. In the quest for vengeance the two tell the very influential Senator Brabanoti, the father of Desdemona, about the secret marriage between her and Othello. The father becomes enraged when he finds the two meddlers’ story to be true. He raced to her room only to find that Desdemona had run away with her soon to be tragic†¦show more content†¦He is the one that Iago is jealous of because of his position as Lieutenant to the General of the Venetian Military. He tells Othello that the Duke of Venice needs to see him because there is m ilitary action taking place in Cyprus. Right as the three men are speaking up walks Senator Brabantio with every intention to if not kill, then hurt Othello very badly for the unethical marrying of his beloved daughter Desdemona. Everyone ends up having to travel to see the Duke of Venice. Upon arrival Othello speaks in his defense stating to the Senator that the marriage of his daughter was not all his idea. He made sure to mention that his daughter Desdemona had lots of influence on the couple eloping. He assured that Senator Brabantio dismantled the notion of his daughter being tricked into marriage. By then Desdemona had also arrived to the Dukes of Venice. There she admitted to her father that her love for Othello was so real that she went behind his back in marriage. The Duke tell Senator Brabantio stop his whining so that the General of the Venetian Military could carry on with his mission. Later the audience finds out that Roderigo, Iago’s partner in crime, is madly in love with Desdemona also. The two begin to plot against Othello in hopes of ending the marriage between Othello and his wife Desdemona. Iago comes up with the craziest rumor, so crazy that he himself would never believe. The rumor involved his own wife