Combustion Calorimetry

2008 ◽  
Author(s):  
José A. Martinho Simões ◽  
Manuel Minas da Piedade
Keyword(s):  
Pressure Vessel ◽  
Inorganic Compounds ◽  
Combustion Calorimetry ◽  
Late Nineteenth Century ◽  
Macro Scale ◽  
New Apparatus ◽  
Internal Volume ◽  
Calorimetric Studies ◽  
Static Bomb ◽  
The One

Calorimetric studies of combustion reactions in oxygen and fluorine atmospheres have been a major source of enthalpy of formation data, particularly for organic and inorganic compounds. As referred to in the previous chapter, in bomb combustion calorimetry the reaction proceeds inside a pressure vessel—the bomb—at constant volume, and in this case the derived quantity is ΔcUo. In flame calorimetry the reaction occurs in a combustion chamber, which is in communication with the atmosphere, and the measurements lead to ΔcHo. The methods of combustion calorimetry will be described in the following paragraphs. “Conventional” combustion calorimeters operate on a “macro” scale, that is, they require samples of 0.5–1.0 g per experiment. Unfortunately, many interesting compounds are available only in much smaller amounts. In the case of oxygen combustion calorimetry, however, several combustion microcaloriemeters that only demand 2–50 mg samples have been developed in recent years. The achievements and trends in this area through 1999 have been reviewed, and interested readers are directed to these publications. Since then, a few new apparatus have been reported. Nevertheless, it should be pointed out that the general principles and techniques used to study compounds at the micro scale are not greatly different from those used in macro combustion calorimetry. Static-bomb combustion calorimetry is particularly suited to obtaining enthalpies of combustion and formation of solid and liquid compounds containing only the elements C, H, O, and N. The origins of the method can be traced back to the work of Berthelot in the late nineteenth century. Most static-bomb calorimeters used are of the isoperibol type, such as the one in figure 7.1. Here, the bomb A is a pressure vessel of ∽300 cm3 internal volume. Combustion bombs are usually made of stainless steel and frequently have an internal platinum lining to prevent corrosion. In a typical high-precision experiment, the platinum ignition wire B connects the two electrodes C, which are affixed to the bomb head. A cotton thread fuse D (other materials such as polyethene are also used), of known energy of combustion, is weighed to a precision of±10−5−10−6 g and tied to the platinum wire.

Isoperibol Reaction-Solution Calorimetry

2008 ◽  
Author(s):  
José A. Martinho Simões ◽  
Manuel Minas da Piedade
Keyword(s):  
Accurate Method ◽  
Solution Calorimetry ◽  
Combustion Calorimetry ◽  
Separate Experiment ◽  
Time Curve ◽  
Reaction Solution ◽  
Static Bomb ◽  
The One ◽  
Temperature Time

The determination of enthalpies of reaction in solution, using isoperibol reaction-solution calorimetry, is often the easiest and most accurate method of determining enthalpies of formation of compounds that cannot be studied by combustion calorimetry. The technique was pioneered by Thomsen who, between 1882 and 1886, performed thermochemical measurements involving the solution of various substances in liquids (e.g., diluted acids). Many types of isoperibol reaction-solution calorimeters have been developed since then. The designs vary according to the nature of the reactions of interest. One of the most widely used consists of a vessel, such as the one shown in figure 8.1, immersed in a thermostatic water bath. The sample is sealed inside a thin-walled glass ampule A, fixed to an ampule breaking system B in the calorimeter head C. The calorimeter head also supports the temperature sensor D, the stirrer E, and an electrical resistance F, used for calibration of the apparatus. The Dewar vessel G, containing the solution to be reacted with the sample, is adjusted to C. The assembled calorimetric vessel is transferred to the thermostatic bath, and from then on, the experimental procedure closely follows that already described in section 7.1 for isoperibol static-bomb combustion calorimetry. The reaction is initiated at the end of the fore period by pushing down the plunger H and breaking the ampule against a pin situated at the bottom of the ampule breaking system B. As a result of the calorimetric experiment, a temperature-time curve such as the one in figure 7.2 is obtained. Note that figure 7.2 is typical of an exothermic process. In the case of an endothermic process, a decrease of the temperature of the calorimetric system is observed during the reaction period. The experiments are usually carried out at atmospheric pressure and the initial goal is the determination of the enthalpy change associated with the calorimetric process under isothermal conditions, ΔHICP, usually at the reference temperature of 298.15 K. This involves the determination of the corresponding adiabatic temperature change, ΔTad, from the temperature-time curve just mentioned, by using one of the methods discussed in section 7.1; the determination of the energy equivalent of the calorimeter in a separate experiment.

scholarly journals The Official Social Philosophy of the French Third Republic: Léon Bourgeois and Solidarism

1961 ◽  
Vol 6 (1) ◽  
pp. 19-48 ◽  
Author(s):  
J. E. S. Hayward
Keyword(s):  
Third Republic ◽  
State Intervention ◽  
Social Philosophy ◽  
Turn Of The Century ◽  
Voluntary Association ◽  
Late Nineteenth Century ◽  
The Social ◽  
The One ◽  
Political Scene ◽  
The Welfare State

At the turn of the century, the authoritative political theorist Henri Michel had this to say of the characteristic approach in France to all problems, and in particular to political problems. “We are infatuated withisms, it is part of the national temperament. It is significant that a large number of our fellow-citizens like them so much, that every time they are presented with a new one, they greedily seize upon it, without asking themselves whether it can be accomodated alongside the one with which they were previously enamoured.”; The accuracy of this observation has not substantially diminished over the last half-century, the parties left of centre being particularly addicted to doctrinaire formulations of their political philosophies and programmes and to the consequent verbal fetishism and pompous dogmatism. The rise of Socialism in the late nineteenth century overshadowed the contemporary crystallisation of Radical attitudes and aims into the doctrine of Solidarism. Solidarism, however, played a major part in galvanising and rallying the protagonists of state intervention and voluntary association; uniting them in the task of building, by a series of piecemeal reforms inspired by a simple principle and a multiplicity of imperative needs what has come to be known as the “Welfare State”. Despite the doctrinal fragility of Solidarism, its practical programme was inspired by and was appropriate to the social and political needs of a society in transition from individualist and non-interventionist liberalism to associationist and statist socialism, just as liberal economism had secured the transition from corporativism and mercantilism to private enterprise, laisser faire and laisser passer. To-day it is Gaullism that dominates the political scene, but the tenacious Radical tradition of the Third and Fourth Republics may yet reassert itself, transforming in retrospect the tidal wave of to-day into a ripple, as it has so frequently done during the last eighty years of France's tormented history.

New tenements and the image of the past: the Crown Street development in Glasgow's New Gorbals

2013 ◽  
Vol 17 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Florian Urban
Keyword(s):  
Late Nineteenth Century ◽  
Victorian Era ◽  
High Rise ◽  
Historical Continuity ◽  
New Development ◽  
Historical Image ◽  
The 1960S ◽  
The One ◽  
Design Preferences ◽  
Building Designs

In 2000, the Crown Street redevelopment in Glasgow's New Gorbals area was completed following a masterplan by Piers Gough and building designs by Page and Park, Elder and Cannon, Hypostyle Architects and others. Built on symbolically contested ground previously occupied by the Gorbals tenements (1870s–1960s) and the high-rise Hutchesontown flats (1960s–1990s), the new development is a textbook example of neotraditional design. The project features ornamented facades, bay windows, courtyards and corridor streets along with local references to the heyday of Glasgow tenements during the late nineteenth century.This paper shows that the new tenements on Crown Street contributed to Glasgow's economic revival strategies by reconfiguring the site and supporting a positive view of Glasgow's Victorian era. In this sense, the architects adapted design preferences – which at the time were evident all over Europe and North America – to a local agenda.The new tenements reconcile conflicting perspectives: on the one hand a break almost as comprehensive as the urban renewal of the 1960s, and on the other hand an idea of historical continuity and long-lasting community life, which rested on a revised conception of the city's industrial past. Conveying a historical image cleared of imperfections they communicate a message of permanence that stands in stark contrast to the area's historic upheavals, but nonetheless contributed to the viability of the new neighbourhood.

I Do Not Buy My Freedom Because I Am Not a Fool

2018 ◽  
pp. 51-73
Author(s):  
Oscar de la Torre
Keyword(s):  
Negative Impact ◽  
Community Formation ◽  
Late Nineteenth Century ◽  
Agricultural Work ◽  
Equatorial Africa ◽  
Commercial Networks ◽  
Late Nineteenth ◽  
Rubber Boom ◽  
Slave Quarters ◽  
The One

The first part of the chapter analyzes the different paths by which slaves acquired environmental knowledge: importing skills and strategies from equatorial Africa, acquiring knowledge when doing agricultural work in plantations and farms, and maintaining interethnic contacts with Indians. As they learned the ways of local peasants, the enslaved gradually built entire parallel economies with vigorous ties to the expanding network of commercial houses that existed in late nineteenth-century Amazonia. Instead of using the term “internal economy of slavery,” I conceptualize them as an economy that ran parallel to that of their masters, given the size and complexity of the commercial networks in which the slaves participated. The chapter also describes the process of community formation inside the slave quarters at the time of Amazonia’s rubber boom, which had both a positive and negative impact on the prospects of Amazonia’s black slaves. On the one hand, it made it possible for them to expand their parallel economy. On the other hand, that slaves could carry out such a broad scope of activities meant that the slaveowners could adapt to the changes of the era. In Amazonia slavery was just like rubber: flexible and adaptable to multiple conditions – hence its durability.

scholarly journals Chaikovsky and the Economics of Art Music in Late Nineteenth-Century Russia

2019 ◽  
Vol 36 (2) ◽  
pp. 195-227
Author(s):  
Philip Ross Bullock
Keyword(s):  
Nineteenth Century ◽  
Art Music ◽  
Late Nineteenth Century ◽  
Art World ◽  
Systematic Account ◽  
Institutional Structures ◽  
Musical Institutions ◽  
The One ◽  
Musical Genres ◽  
The Relationship

As Russia’s first professional, conservatory-trained composer, Petr Il'ich Chaikovsky operated in the rapidly evolving social and economic context of post-emancipation Russia, identifying ways to interact with Russia’s musical institutions—its opera houses and theaters, its concert organizations and publishers—to fashion a career that was as successful financially as it was critically. Yet the myth of Chaikovsky’s financial incompetence persists, and the image, whether popular or scholarly, is still one of Chaikovsky as a spendthrift, unable to manage his income or regulate his outgoings. This article challenges such views by drawing on the recently published complete correspondence between Chaikovsky and his publisher, Petr Iurgenson, as well as on financial records preserved in the composer’s archives. In particular, this article analyzes the relationship among Chaikovsky, Iurgenson, and the operation of Russia’s musical “marketplace” at the level of genre, examining the interaction between financial considerations on the one hand and Chaikovsky’s decision to work in particular musical forms on the other. By examining the connections among Russia’s nascent musical institutions, Chaikovsky’s particular collaboration with his publisher, and the relative status of different musical genres, it becomes possible to establish the nature of Russia’s musical “art world” in the second half of the nineteenth century. In proposing a more nuanced and systematic account of Chaikovsky’s economic agency than has been attempted previously, this article thus contributes to a growing body of work on the institutional structures that shaped the Russian arts in the nineteenth century.

Numerical Modeling of Solidification Substitute – Thermal Capacity of Binary Alloy

2014 ◽  
Vol 354 ◽  
pp. 33-40
Author(s):  
Bohdan Mochnacki ◽  
R. Szopa
Keyword(s):  
Numerical Modeling ◽  
Solid State ◽  
Mathematical Description ◽  
Energy Equation ◽  
Analytical Form ◽  
Thermal Capacity ◽  
Thermal Processes ◽  
Volumetric Fraction ◽  
Macro Scale ◽  
The One

Mathematical description of alloys solidification on the macro scale can be formulated using the one domain method (fixed domain approach). The energy equation corresponding to this model contains the parameter called the substitute thermal capacity (STC). The analytical form of STC results from the assumption concerning the course of the functionfS=fS(T) describing the changes of solid state volumetric fraction and the temperature at the point considered. Between border temperaturesTS,TLthe functionfSchanges from 1 to 0. In this paper the volumetric fractionfS(more preciselyfL= 1-fS) is found using the simple models of macrosegregation (the lever arm rule, the Scheil model). In this way one obtains the formulas determining the course of STC resulting from the certain physical considerations and this approach seems to be closer to the real course of thermal processes proceeding in domain of solidifying alloy.

Experiment and Numerical Analysis of Control Method of Natural Circulation by Injection of Helium Gas

2013 ◽  
Author(s):  
Naoto Yanagawa ◽  
Masashi Nomura ◽  
Tetsuaki Takeda ◽  
Shumpei Funatani
Keyword(s):  
Numerical Analysis ◽  
Mole Fraction ◽  
Pressure Vessel ◽  
Control Method ◽  
Natural Circulation ◽  
Circulation Flow ◽  
Helium Gas ◽  
Air Ingress ◽  
The One ◽  
Reactor Pressure

This study is to investigate a control method of the natural circulation of the air by the injection of helium gas. A depressurization is the one of the design-basis accidents of a Very High Temperature Reactor (VHTR). When the primary pipe rupture accident occurs in the VHTR, the air is predicted to enter into the reactor pressure vessel from the breach and oxidize in-core graphite structures. Finally, it seems to be probable that the natural circulation flow of the air in the reactor pressure vessel produce continuously. In order to predict or analyze the air ingress phenomenon during the depressurization accident of the VHTR, it is important to develop the method for prevention of air ingress during the accident. In this study, the air ingress process is discussed by comparing the experimental and analytical results of the reverse U-shaped channel which has parallel channels. The experiment of the natural circulation using a circular tube consisted of the reverse U-shaped type has been carried out. The vertical channel is consisted of the one side heated and the other side cooled pipe. The experimental apparatus is filled with the air and one side vertical tube is heated. A very small amount of helium gas is injected from the top of the channel. The velocity and the mole fraction of each gas are also calculated by using heat and mass transfer numerical analysis of multi-component gas. The result shows that the numerical analysis is considered to be well simulated the experiment. The natural circulation of the air has very weak velocity after the injection of helium gas. About 780 seconds later, the natural circulation suddenly produces. The natural circulation flow of the air can be controlled by the method of helium gas injection. The mechanism of the phenomenon is found that mole fraction is changed by the molecular diffusion and the very weak circulation.

scholarly journals Hybrid Spider Silk with Inorganic Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1853
Author(s):  
Aleksandra P. Kiseleva ◽  
Grigorii O. Kiselev ◽  
Valeria O. Nikolaeva ◽  
Gulaim Seisenbaeva ◽  
Vadim Kessler ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
High Performance ◽  
Spider Silk ◽  
Inorganic Compounds ◽  
Silk Fibers ◽  
Surface Areas ◽  
Macro Scale ◽  
Performance Functional ◽  
Inorganic Nanomaterials ◽  
Functional Components

High-performance functional biomaterials are becoming increasingly requested. Numerous natural and artificial polymers have already demonstrated their ability to serve as a basis for bio-composites. Spider silk offers a unique combination of desirable aspects such as biocompatibility, extraordinary mechanical properties, and tunable biodegradability, which are superior to those of most natural and engineered materials. Modifying spider silk with various inorganic nanomaterials with specific properties has led to the development of the hybrid materials with improved functionality. The purpose of using these inorganic nanomaterials is primarily due to their chemical nature, enhanced by large surface areas and quantum size phenomena. Functional properties of nanoparticles can be implemented to macro-scale components to produce silk-based hybrid materials, while spider silk fibers can serve as a matrix to combine the benefits of the functional components. Therefore, it is not surprising that hybrid materials based on spider silk and inorganic nanomaterials are considered extremely promising for potentially attractive applications in various fields, from optics and photonics to tissue regeneration. This review summarizes and discusses evidence of the use of various kinds of inorganic compounds in spider silk modification intended for a multitude of applications. It also provides an insight into approaches for obtaining hybrid silk-based materials via 3D printing.

Discussion

1965 ◽  
Vol 285 (1400) ◽  
pp. 141-174 ◽  
Keyword(s):  
Pressure Vessel ◽  
Crack Extension ◽  
Initial Crack ◽  
Pressure Vessels ◽  
Full Scale ◽  
Small Specimen ◽  
Starting Point ◽  
Specimen Test ◽  
Valid Test ◽  
The One

It is our purpose to review fracture characteristics of heavy-walled pressure vessels in relation to the plane-strain crack toughness known under the term, K Ic . As a starting point, suppose that direct measurement of the strength of a full-scale pressure vessel containing a specific crack is contemplated. An initial crack of approximately the desired size can be introduced in several ways, for example, by inserting a sharp groove and then vibrating that region until a fatigue crack develops. However, full-scale testing is often impractical either for reasons of expense or because the introduction of in-service damage, say by nuclear irradiation, is not feasible at the full-scale size. Furthermore, valid test results can usually be obtained at much smaller scale. Small specimen fracture tests Crack extension behaviour observed in a small specimen test can be regarded as representative of full-scale fracture behaviour so long as the stresses carried by the surrounding material into the region containing the crack receive adequate representation. Since the specimen size desired for irradiation purposes is quite limited, we consider next whether crack extension of a large part-through crack in a thick-walled pressure vessel can be modelled by testing just the slice of material indicated in figures 108 ( a ) and ( b ). The calibration and use of test specimens similar to the one shown in figure 108( b ) are described by Sullivan (1964).

scholarly journals Definition of Alloy Substitute Thermal Capacity Using the Simple Macrosegregation Models

2012 ◽  
Vol 12 (4) ◽  
pp. 113-116 ◽  
Author(s):  
B. Mochnacki
Keyword(s):  
Solid State ◽  
Mathematical Description ◽  
Energy Equation ◽  
Analytical Form ◽  
Thermal Capacity ◽  
Thermal Processes ◽  
Volumetric Fraction ◽  
Macro Scale ◽  
The One ◽  
Definition Of

Abstract Mathematical description of alloys solidification in a macro scale can be formulated using the one domain method (fixed domain approach). The energy equation corresponding to this model contains the parameter called a substitute thermal capacity (STC). The analytical form of STC results from the assumption concerning the course of the function fS = fS (T) describing the changes of solid state volumetric fraction and the temperature at the point considered. Between border temperatures TS , TL the function fS changes from 1 to 0. In this paper the volumetric fraction fS (more precisely fL = 1- fS ) is found using the simple models of macrosegregation (the lever arm rule, the Scheil model). In this way one obtains the formulas determining the course of STC resulting from the certain physical considerations and this approach seems to be closer to the real course of thermal processes proceeding in domain of solidifying alloy.

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