Smoke management in office buildings

Design considerations for smoke control systems have been addressed by numerous researchers and practicing engineers. However, papers discussing the actual observed performance of smoke control systems are less frequently encountered. The following three papers address the testing of smoke control systems from two perspectives. First, suggested procedures for testing smoke control systems are described relative to test methodology, system parameters requiring evaluation, and measurement systems. Second, the performance of actual systems is described as observed in tests.     

FLUIDIZED-BED APPARATUS FOR CRYSTAL GROWTH RATE MEASUREMENTS AND ITS TESTING WITH COPPER SULPHATE

Apparatus for measurement of crystal growth rate in a fluidized bed has been modified. The improvement consists of a new way of introducing and removing seeds, which substantially speeds up the measurement and, due to better stability of the temperature regime, leads to improved reliability of results. Growth rates of CuSO₄ · 5H₂O in aqueous solutions, measured in the original and improved apparatus, are compared and they demonstrate the advantages of the new version of the equipment.     

A study of the thermodynamic properties of the system polystyrene-ethylcyclohexane by the light scattering method

The thermodynamic properties of the system polystyrene-ethylcyclohexane (temperature 70°C) were examined between 57 and 80°C for weight fractions of the polymer 0-0.16. Scholte's light scattering method was used for this purpose. The results are presented in the form of the temperature and concentration dependence of the interaction parameter of the Flory-Huggins equation. The interaction function thus obtained has been tested by comparing calculated and experimental spinodals. The given system has been compared with a pseudoideal solution in order to discuss the pronounced concentration dependence of the interaction parameter and its dependence on molecular weight.     

Reactive polymers XIV. Hydrolysis of the epoxide groups of the copolymer glycidylmethacrylate — ethylenedimethacrylate

Hydrolysis of the epoxide groups of the copolymer glycidylmethacrylate - ethylenedi-methacrylate in variously concentrated sulphuric acid solutions was studied. An approximate activation energy of hydrolysis, 41 kJ mol^?1, was determined from the temperature dependences. For the sake of comparison the effect of pH on the degree of hydrolysis over the whole range of pH values was examined, and the importance of the results with respect to other reactions of the copolymer used was discussed.     

Comparison of the instantaneous and conversion chemical heterogeneity of random copolymers

The calculation of a general distribution function of chemical composition of random copolymers involving the instantaneous and conversion chemical heterogeneity is demonstrated. Typical examples offer a semiquantitative view about the effect of the two types of chemical heterogeneity on the shape and width of the distribution of chemical composition.     

Development of a computer-assisted thermoelectric Peltier cold test procedure with integrated photoplethysmography unit for noninvasive evaluation of acral skin circulation]

Local cold provocation tests are an important, non-invasive diagnostic tool for collecting information about skin perfusion during exposure to cold. In patients suffering from vasospastic circulatory disorders such as Raynaud's phenomenon, it is of particular importance to be able to collect data about acral circulation during the cooling test in the asymptomatic intervals between naturally occurring attacks. By carrying out a series of cold provocation tests, for example, patient response to a newly initiated therapy can be assessed. Here we present a recently developed, computer-aided thermoelectric Peltier device with an integrated finger holder for carrying out local cold provocation tests. The electronic control unit of the Peltier element make it possible to cool or heat to predefined temperatures. At the same time, the temperature of both the finger holder and the skin can be measured. A photoplethysmographic sensor is also integrated within the device, enabling the response of the pulse waves to the controlled temperature changes to be monitored accurately. It is also possible to measure simultaneously laser Doppler flux and capillary pressure in the nailfold and to perform nailfold capillaroscopy to determine red blood cell velocity. The new device provides us with the technical means to study the interrelationship between acral skin perfusion and the thermal regulation of the skin.     

Solution of counter-current separation processes—IV. Application of the GPM method to solution of distillation problems

A new non-iterative method for a parametric study of a particular distillation column is devised. The technique takes use of the similarity between difference and differential equations. For solution of nonlinear boundary value problems for difference equations the GPM technique is used. The method is illustrated by calculated examples.     

Photochromic polymers

Summary Two soluble photochromic polymers containing 1-(ß-hydroxyethyl)-3,3-dimethyl-6-nitrospiro[2H-1-benzopyran-2,2-indoline] bound on a variously long side chain were prepared. It was found that the discolouration process depends on the length of the side chain to which the photochromic centre is bound.     

Rationalized Load and Lifetime of Brittle Materials

The design and testing of structural parts from materials which exhibit subcritical crack growth can be improved by introducing auxiliary quantities into the classical concepts of fracture mechanics. The equivalent static stress, equivalent loading time, standardized loading time, and standardized lifetime, as well as the decrease in lifetime and residual lifetime, are defined, with examples of their application.     

Fast determination of fatty acids in oil-utilizing resins by NMR spectroscopy

This work describes the determination of oil either as such or in oil-utilizing resins such as alkyds and urethanes, by means of NMR techniques. Both the qualitative and quantitative analyses are demonstrated and the accuracy is assessed. Typically, the complete analysis of an alkyd resin takes less than 1 hr.