A fire-resistance rating means the duration for which a passive fire protection system can withstand a standard fire resistance test. This can be quantified as a measure of time, or it may entail a host of other criteria, involving other evidence of functionality or fitness for purpose; the following depict the most used international time/temperature curves: There are many international variations for nearly countless types of products and systems, some with multiple test requirements. Canada's Institute for Research in Construction requires a special test regime for firestops for plastic pipe penetrants. Fire endurance tests for this application must be run under 50Pa positive furnace pressure in order to adequately simulate the effect of potential temperature differences between indoor and outdoor temperatures in Canada's winters. Special hoods are applied here to provide suction on the top side of a test assembly in order to reach the 50Pa pressure differential. Afterwards, a 30PSI hose-stream test may be applied.
Outdoor spray fireproofing methods that must be qualified to the hydrocarbon curve may be required to pass a host of environmental tests before any burn takes place, to minimize the likelihood that ordinary operational environments cannot render a vital system component useless before it encounters a fire. If critical environmental conditions are not satisfied, an assembly may not be eligible for a fire-resistance rating. Regardless of the complexity of any given test regime that may lead to a rating, the premise is product certification and, most listing and approval use and compliance. Testing without certification and installations that cannot be matched with an appropriate certification listing, are not recognised by any Authority Having Jurisdiction unless it is in a realm where product certification is optional; the following classifications may be attained when testing in accordance with UL 72. This rating is the requirement in data safes and vault structures for protecting digital information on magnetic media or hard drives.
Temperatures inside the protected chamber must be held below 125 °F for the time period specified, such as Class 125-2 Hour, with temperatures up to 2,000 °F outside the vault. The temperature reading is taken on the inside surfaces of the protective structure. Maintaining the temperature below 125 °F is critical because data is lost above that temperature threshold if the media or hard drives appear to be intact; this is the rating required to protect microfilm and other film-based information storage media. Above 150 °F film is distorted by the heat and information is lost. A Class 150-2 Hour vault must keep the temperature below 150 °F. for at least two hours, with temperatures up to 2,000 °F. outside the vault. This rating is the requirement for protecting paper documents. Above 350 °F paper is distorted by the heat and information is lost. A Class 350-4 Hour vault must keep the temperature below 350 °F. for at least four hours, with temperatures up to 2,000 °F. outside the vault. Most countries use the building elements curvefor residential and commercial spaces, nearly identical in most countries as, what results by burning wood.
The building elements curve is characterized jointly by, but not limited to, DIN4102, BS476, ASTM E119, ULC-S101, etc. For industrial facilities in the hydrocarbon & petrochemical industries, a hydrocarbon curve is used, reflecting a more rapid temperature rise; the only used exposure beyond this, apart from the more recent tunnel curves shown above, would be the jet fire exposure standards such as ISO 22899, which are used where equipment may be subject to the extreme heat and momentum effects of jet fire exposure. Big differences between different countries in terms of the use of the curves include the use of pipes, which shield the furnace thermocouples inside of NAFTA testing laboratories; this slows down the response time and results in a somewhat more conservative test regime in North America. On the other hand, the ISO based. North America selectively uses a hose-stream test between 30 and 45PSI, to simulate real-world impacts and damages that may not be simulated in a laboratory; the US Navy insists on a 90PSI hose-stream test for some of its assemblies, which may simulate the pressure available to firefighters in fighting a fire, but which has little to do with countermeasures against damaging effects of manual fire suppression.
The hose-stream is intended to add a level of toughness to matters because without this, some flimsy systems can pass a test, thus receive a rating and thus be permissible by a building code but be so weak that ordinary building use may damage a thus qualified system before it encounters a fire. Germany's DIN4102 includes a significant impact test for a potential firewall, which is, applied from the wrong side: the cold side. Applying the impact from the cold side is more practical to do in a lab setting, potential impacts should come from the exposed side, not the unexposed side. Still, for the person designing and paying for the test, the fire resistance itself may be rather uneventful unless major problems appear; the burn itself is the long duration, up to 4 hours, but the hose stream test only lasts a few minutes, with large damage potential due to the sudden thermal and kinetic impacts, as the fire was upwards of 1,100 °C, whereas the sudden hose-stream test is as cold as the domestic water fed to the fire hose used in the test, whi
A university is an institution of higher education and research which awards academic degrees in various academic disciplines. Universities provide undergraduate education and postgraduate education; the word university is derived from the Latin universitas magistrorum et scholarium, which means "community of teachers and scholars". While antecedents had existed in Asia and Africa, the modern university system has roots in the European medieval university, created in Italy and evolved from cathedral schools for the clergy during the High Middle Ages; the original Latin word universitas refers in general to "a number of persons associated into one body, a society, community, corporation, etc". At the time of the emergence of urban town life and medieval guilds, specialized "associations of students and teachers with collective legal rights guaranteed by charters issued by princes, prelates, or the towns in which they were located" came to be denominated by this general term. Like other guilds, they were self-regulating and determined the qualifications of their members.
In modern usage the word has come to mean "An institution of higher education offering tuition in non-vocational subjects and having the power to confer degrees," with the earlier emphasis on its corporate organization considered as applying to Medieval universities. The original Latin word referred to degree-awarding institutions of learning in Western and Central Europe, where this form of legal organisation was prevalent, from where the institution spread around the world. An important idea in the definition of a university is the notion of academic freedom; the first documentary evidence of this comes from early in the life of the University of Bologna, which adopted an academic charter, the Constitutio Habita, in 1158 or 1155, which guaranteed the right of a traveling scholar to unhindered passage in the interests of education. Today this is claimed as the origin of "academic freedom"; this is now recognised internationally - on 18 September 1988, 430 university rectors signed the Magna Charta Universitatum, marking the 900th anniversary of Bologna's foundation.
The number of universities signing the Magna Charta Universitatum continues to grow, drawing from all parts of the world. According to Encyclopædia Britannica, the earliest universities were founded in Asia and Africa, predating the first European medieval universities; the University of Al Quaraouiyine, founded in Morocco by Fatima al-Fihri in 859, is considered by some to be the oldest degree-granting university. Their endowment by a prince or monarch and their role in training government officials made early Mediterranean universities similar to Islamic madrasas, although madrasas were smaller, individual teachers, rather than the madrasa itself, granted the license or degree. Scholars like Arnold H. Green and Hossein Nasr have argued that starting in the 10th century, some medieval Islamic madrasas became universities. However, scholars like George Makdisi, Toby Huff and Norman Daniel argue that the European university has no parallel in the medieval Islamic world. Several other scholars consider the university as uniquely European in origin and characteristics.
Darleen Pryds questions this view, pointing out that madaris and European universities in the Mediterranean region shared similar foundations by princely patrons and were intended to provide loyal administrators to further the rulers' agenda. Some scholars, including Makdisi, have argued that early medieval universities were influenced by the madrasas in Al-Andalus, the Emirate of Sicily, the Middle East during the Crusades. Norman Daniel, views this argument as overstated. Roy Lowe and Yoshihito Yasuhara have drawn on the well-documented influences of scholarship from the Islamic world on the universities of Western Europe to call for a reconsideration of the development of higher education, turning away from a concern with local institutional structures to a broader consideration within a global context; the university is regarded as a formal institution that has its origin in the Medieval Christian tradition. European higher education took place for hundreds of years in cathedral schools or monastic schools, in which monks and nuns taught classes.
The earliest universities were developed under the aegis of the Latin Church by papal bull as studia generalia and from cathedral schools. It is possible, that the development of cathedral schools into universities was quite rare, with the University of Paris being an exception, they were founded by Kings or municipal administrations. In the early medieval period, most new universities were founded from pre-existing schools when these schools were deemed to have become sites of higher education. Many historians state that universities and cathedral schools were a continuation of the interest in learning promoted by The residence of a religious community. Pope Gregory VII was critical in promoting and regulating the concept of modern university as his 1079 Papal Decree ordered the regulated establishment of cathedral schools that transformed themselves into the first European universities; the first universities in Europe with a form of corporate/guild structure were the University of Bologna, the University of Paris, the University of Oxford.
The University of Bologna began as a law school teach
University of Hanover
The University of Hanover the Gottfried Wilhelm Leibniz Universität Hannover, short Leibniz University Hannover, is a public university located in Hannover, Germany. Founded on May 2, 1831, it is one of the largest and oldest science and technology universities in Germany. In the 2014/15 school year it enrolled 25,688 students, it has nine faculties. The University is named after Gottfried Wilhelm Leibniz, the 18th century mathematician and philosopher. Leibniz University Hannover is a member of TU9, an association of the nine leading Institutes of Technology in Germany, it is a member of the Conference of European Schools for Advanced Engineering Education and Research, a non-profit association of leading engineering universities in Europe. The university sponsors the German National Library of Science and Technology, the largest science and technology library in the world; the roots of the University of Hanover begin in the Higher Vocational College/Polytechnic Institute, founded on May 2, 1831.
In 1879 the Higher Vocational School moved into the historic Guelph Palace, the Welfenschloss, specially converted for the purpose. On April 1, 1879, the Higher Vocational School became the Royal College of Technology. In 1899 Kaiser Wilhelm II granted the College of Technology a status equal to that of universities and the right to confer doctorates; the College was reconstructed in 1921 with the financial support of the College Patrons’ Association. As of July 1, 1922, there were three faculties: Mathematics and Natural Sciences, Civil Engineering, Mechanical Engineering. In 1968 the Faculty of Humanities and Political Science were founded and the "Technische Hochschule" became the "Technische Universität Hannover". Between 1973 and 1980 the faculties of Law and Economics, the independent Teachers Training College were added to the University and in 1978 the "Technische Universität Hannover" was renamed "Universität Hannover". Student numbers exceeded 30,000 for the first time in 1991. On the 175th anniversary of the institution in 2006, the "University of Hannover" was given the name "Gottfried Wilhelm Leibniz Universität Hannover."
While 64 students first attended the Vocational School, today the university has around 25.700 students, more than 2.900 academics and scientists, 160 departments and institutes. The Senate of the University voted in April 2006 to rename the University of Hannover to "Leibniz Universität Hannover". Following agreement by the Leibniz Academy on the use of the name, the "Gottfried Wilhelm Leibniz Universität Hannover" received its name on the 360th anniversary of Gottfried Wilhelm Leibniz's birth; the brand of the university is "Leibniz Universität Hannover." The old logo of the University was inspired by the Massachusetts Institute of Technology. The current logo is a stylized excerpt from a letter to Duke Rudolf August of Wolfenbüttel, in which Leibniz presented binary numbers for the first time. Nine faculties with more than 190 first-degree full-time and part-time degree courses make the university the second-largest institution of higher education in Lower Saxony; the university staff comprises teaching staff, of whom 321 are professors.
It has 1810 additional employees in administrative functions, 90 apprentices and some 1400 staff funded by third parties. Faculty of Architecture and Landscape Sciences Faculty of Civil Engineering and Geodetic Science Faculty of Economics and Management Faculty of Electrical Engineering and Computer Science Faculty of Humanities Faculty of Law Faculty of Mathematics and Physics Faculty of Mechanical Engineering Faculty of Natural Sciences The campus of the university is spread over 160 buildings occupying 322,700 m2 of floor space; the University's overall budget was 441.8 million euros in 2013, broken down as follows: Income of 222.6 million according to the annual report External funding amounting to 101.8 million euros Special funds from the State of Lower Saxony amounting to 58.3 million euros 42.3 million euros from other income 16.8 million euros from student contributions The Times Higher Education World University Rankings 2018 ranked Leibniz University of Hanover between 201-250 worldwide in the field of engineering and technology.
The library was established on the founding of the Höhere Gewerbeschule/Polytechnische Schule in 1831. It expanded into an important collection as the institution evolved from a vocational/technical college into the full University; the removal of the books into storage during the Second World War secured valuable old stocks that became a unique national collection of scientific and technical literature in postwar Germany. This was the basis on which the library of the Institute of Technology was established in 1959. Today the collection forms the heart of the German National Library of Science and Technology, the largest institution of its kind in the world. GISMA Business School in Hannover, was launched in 1999 as a joint initiative by the state of Lower Saxony and visionary private-sector enterprises; the school was affiliated with the Krannert School of Management at Purdue University until 2011 when the Leibniz University Hannover became its parent. In 2013 the association with Leibniz ended, GISMA became part the for-profit education company Global University Systems.
Friedrich Bergius, Nobel Prize in chemistry Constantin Carathéodory, M
The Physikalisch-Technische Bundesanstalt is the national metrology institute of the Federal Republic of Germany, with scientific and technical service tasks. It is a higher federal authority and a public-law institution directly under federal government control, without legal capacity, under the auspices of the Federal Ministry for Economic Affairs and Energy. Together with NIST in the USA and the NPL in Great Britain, PTB ranks among the leading metrology institutes in the world; as the National Metrology Institute of Germany, PTB is Germany's highest and only authority in terms of correct and reliable measurements. The Units and Time Act Bundesgesetzblatt, part I, No. 28, p. 1185 ff. 11 July 2008] assigns all tasks which are related with the realization and dissemination of the units to PTB. All relevant aspects regarding the units as well as PTB’s responsibilities have been combined in this Act. All questions regarding the units as well as the role of PTB had been distributed among three laws: the Units Act, the Time Act, the Verification Act.
PTB consists of nine technical-scientific divisions. 60 departments. These again are subdivided into more than 200 working groups. PTB's tasks are as follows: the determination of natural constants; this spectrum of tasks is supplemented by services such as the German Calibration Service and by metrology for the area regulated by law, metrology for industry, metrology for technology transfer. As the basis for its tasks, PTB conducts fundamental research and development in the field of metrology in close cooperation with universities, other research institutions, industry. PTB employs 1900 staff members, it has a total budget of approx. 183 million euros at its disposal. 15 million euros were, in addition, canvassed as third-party funds for research projects. The Units and Time Act entrusts PTB especially with the dissemination of legal time in Germany. To have a time basis for this, PTB operates several atomic clocks By order of PTB, the synchronization of clocks via radio is performed via the time signal transmitter DCF77 operated by Media Broadcast.
Computers which are connected with the Internet can obtain the time via the three public NTP time servers of PTB. In Berlin-Adlershof, PTB operates the MLS electron storage ring for calibrations in the field from the infrared to the extreme ultraviolet. Department Q.5 ""Technical Cooperation"" realizes projects of the German and international development cooperation in the field of quality infrastructure. These activities promote competitiveness as well as environmental protection and consumer protection in developing countries and in countries in transition. One of the tasks of PTB’s "Metrological Information Technology" Department – in accordance with the German Gambling Ordinance – is to grant type approvals for gaming machines which offer the possibility to make winnings. According to the Federal Ordinance on Voting Machines, PTB is in charge of the type approval of voting computers; this is, irrelevant as, in a judgment of 3 March 2009, the Federal Constitutional Court has declared the use of such voting machines to be inadmissible.
Weapons which may be carried with the Minor Firearms Certificate, i.e. weapons for shooting blanks or irritants and weapons used as signaling devices, require a PTB test mark for their approval. These weapons are jointly referred to as "PTB weapons" and bear the PTA or PTB proof mark F; the main site of PTB is in Braunschweig. Other sites are in Berlin-Adlershof. Divisions 1 to 6 as well as Division Q are located in Braunschweig. In Berlin-Charlottenburg Divisions 7 and 8 are located, in Berlin-Adlershof the two electron storage rings BESSY II and the Metrology Light Source. PTB is headed by the Presidential Board in Braunschweig, composed of the President, the Vice-President and a further member. Another executive committee is the Directors’ Conference, with the Presidential Board and the Heads of the Divisions as members. PTB is advised by the "Kuratorium", composed of representatives from science, the economy and politics. PTB is composed of the following 9 Divisions.: Division 1: Mechanics and Acoustics with the following departments: Mass, Solid Mechanics, Gas Flow, Liquid Flow, Sound and Dynamics Division 2: Electricity with the following departments: Direct Current and Low Frequency, High Frequency and Electromagnetic Fields, Electrical Energy Measuring Techniques, Quantum Electronics, Semiconductor Physics and Magnetism, Quantum Electrical Metrology Division 3: Chemical Physics and Explosion Protection with the following departments: Metrology in Chemistry and Thermodynamic State Behavior of Gases, Thermophysical Quantities, Physical Chemistry, Explosion Protection in Energy Technology, Explosion Protection in Sensor Technology and Instrumentation, Fundamentals of Explosion Protection Division 4: Optics with the following departments: Photometry and Applied Radiometry and Wave Optics, Quantum Optics and Unit of Length and Frequency Division 5: Precision EngineerinꞋ with the following departments: Surfa
In the field of solid mechanics, torsion is the twisting of an object due to an applied torque. Torsion is expressed in either the Pascal, an SI unit for newtons per square metre, or in pounds per square inch while torque is expressed in newton metres or foot-pound force. In sections perpendicular to the torque axis, the resultant shear stress in this section is perpendicular to the radius. In non-circular cross-sections, twisting is accompanied by a distortion called warping, in which transverse sections do not remain plane. For shafts of uniform cross-section unrestrained against warping, the torsion is: T = J T r τ = J T ℓ G φ where: T is the applied torque or moment of torsion in Nm. Τ is the maximum shear stress at the outer surface. It is equal to the second moment of area about the neutral axis. Jz = Iz for twisting about axis z. For more accuracy, finite element analysis is the best method. Other calculation methods include membrane shear flow approximation. R is the farthest point in the section.
ℓ is the length of the object. Φ is the angle of twist in radians. G is the shear modulus called the modulus of rigidity, is given in gigapascals, lbf/in2, or lbf/ft2 or in ISO units N/mm2; the product JTG is called the torsional rigidity wT. The shear stress at a point within a shaft is: τ φ z = T r J T Note that the highest shear stress occurs on the surface of the shaft, where the radius is maximum. High stresses at the surface may be compounded by stress concentrations such as rough spots. Thus, shafts for use in high torsion are polished to a fine surface finish to reduce the maximum stress in the shaft and increase their service life; the angle of twist can be found by using: φ = T ℓ G J T. Calculation of the steam turbine shaft radius for a turboset: Assumptions: Power carried by the shaft is 1000 MW. Yield stress of the steel used to make the shaft is: 250 × 106 N/m². Electricity has a frequency of 50 Hz. In North America, the frequency is 60 Hz; the angular frequency can be calculated with the following formula: ω = 2 π f The torque carried by the shaft is related to the power by the following equation: P = T ω The angular frequency is therefore 314.16 rad/s and the torque 3.1831 × 106 N·m.
The maximal torque is: T max = τ max J zz r After substitution of the polar moment of inertia, the following expression is obtained: D = 1 / 3 The diameter is 40 cm. If one adds a factor of safety of 5 and re-calculates the radius with the maximum stress equal to the yield stress/5, the result is a diameter of 69 cm, the approximate size of a turboset shaft in a nuclear power plant; the shear stress in the shaft may be resolved into principal stresses via Mohr's circle. If the shaft is loaded only in torsion one of the principal stresses will be in tension and the other in compression; these stresses are oriented at a 45-degree helical angle around the shaft. If the shaft is made of brittle material the shaft will fail by a crack initiating at the surface and propagating through to the core of the shaft, fracturing in a 45-degree angle helical shape; this is demonstrated by twisting a piece of blackboard chalk between one's fingers. In the case of thin hollow shafts, a twisting buckling mode can result from excessive torsional load, with wrinkles forming at 45° to the shaft axis.
Structural rigidity Torsion siege engine Torsion spring or -bar Torsional vibration Torque tester Saint-Venant's theorem Second moment of area List of area moments of inertia
The euro is the official currency of 19 of the 28 member states of the European Union. This group of states is known as the eurozone or euro area, counts about 343 million citizens as of 2019; the euro is the second largest and second most traded currency in the foreign exchange market after the United States dollar. The euro is subdivided into 100 cents; the currency is used by the institutions of the European Union, by four European microstates that are not EU members, as well as unilaterally by Montenegro and Kosovo. Outside Europe, a number of special territories of EU members use the euro as their currency. Additionally, 240 million people worldwide as of 2018 use currencies pegged to the euro; the euro is the second largest reserve currency as well as the second most traded currency in the world after the United States dollar. As of August 2018, with more than €1.2 trillion in circulation, the euro has one of the highest combined values of banknotes and coins in circulation in the world, having surpassed the U.
S. dollar. The name euro was adopted on 16 December 1995 in Madrid; the euro was introduced to world financial markets as an accounting currency on 1 January 1999, replacing the former European Currency Unit at a ratio of 1:1. Physical euro coins and banknotes entered into circulation on 1 January 2002, making it the day-to-day operating currency of its original members, by March 2002 it had replaced the former currencies. While the euro dropped subsequently to US$0.83 within two years, it has traded above the U. S. dollar since the end of 2002, peaking at US$1.60 on 18 July 2008. In late 2009, the euro became immersed in the European sovereign-debt crisis, which led to the creation of the European Financial Stability Facility as well as other reforms aimed at stabilising and strengthening the currency; the euro is managed and administered by the Frankfurt-based European Central Bank and the Eurosystem. As an independent central bank, the ECB has sole authority to set monetary policy; the Eurosystem participates in the printing and distribution of notes and coins in all member states, the operation of the eurozone payment systems.
The 1992 Maastricht Treaty obliges most EU member states to adopt the euro upon meeting certain monetary and budgetary convergence criteria, although not all states have done so. The United Kingdom and Denmark negotiated exemptions, while Sweden turned down the euro in a 2003 referendum, has circumvented the obligation to adopt the euro by not meeting the monetary and budgetary requirements. All nations that have joined the EU since 1993 have pledged to adopt the euro in due course. Since 1 January 2002, the national central banks and the ECB have issued euro banknotes on a joint basis. Euro banknotes do not show. Eurosystem NCBs are required to accept euro banknotes put into circulation by other Eurosystem members and these banknotes are not repatriated; the ECB issues 8% of the total value of banknotes issued by the Eurosystem. In practice, the ECB's banknotes are put into circulation by the NCBs, thereby incurring matching liabilities vis-à-vis the ECB; these liabilities carry interest at the main refinancing rate of the ECB.
The other 92% of euro banknotes are issued by the NCBs in proportion to their respective shares of the ECB capital key, calculated using national share of European Union population and national share of EU GDP weighted. The euro is divided into 100 cents. In Community legislative acts the plural forms of euro and cent are spelled without the s, notwithstanding normal English usage. Otherwise, normal English plurals are sometimes used, with many local variations such as centime in France. All circulating coins have a common side showing the denomination or value, a map in the background. Due to the linguistic plurality in the European Union, the Latin alphabet version of euro is used and Arabic numerals. For the denominations except the 1-, 2- and 5-cent coins, the map only showed the 15 member states which were members when the euro was introduced. Beginning in 2007 or 2008 the old map is being replaced by a map of Europe showing countries outside the Union like Norway, Belarus, Russia or Turkey.
The 1-, 2- and 5-cent coins, keep their old design, showing a geographical map of Europe with the 15 member states of 2002 raised somewhat above the rest of the map. All common sides were designed by Luc Luycx; the coins have a national side showing an image chosen by the country that issued the coin. Euro coins from any member state may be used in any nation that has adopted the euro; the coins are issued in denominations of €2, €1, 50c, 20c, 10c, 5c, 2c, 1c. To avoid the use of the two smallest coins, some cash transactions are rounded to the nearest five cents in the Netherlands and Ireland and in Finland; this practice is discouraged by the Commission, as is the practice of certain shops of refusing to accept high-value euro notes. Commemorative coins with €2 face value have been issued with changes to the design of the national side of the coin; these include both issued coins, such as the €2 commemorative coin for the fiftieth anniversary of the signing of the Treaty of Rome, nationally i