Working characteristics

Application. The adhesive should be capable of being applied readily to both concrete and treated steel surfaces in layers from 1 to 10 mm thick, to allow for concrete surface irregularities. Proprietory dispensing equipment is available to facilitate correct metering and mixing of the adhesive. 

Usable life. The usable life of the mixed adhesive before application to the substrate should be not less than 40 minutes at 20 C that is, the viscosity should not rise above 150 Pa within this time. 

Open time. The open time starts when the adhesive has been applied to the parts to be joined, and it represents the time iimit during which the joint has to be closed. It should be not less than 20 minutes at a temperature up to 20 °C. 

Storage life. The storage (or sheif) life of both the resin and hardener should be not less than six months in original containers 

4 Mechanical properties of hardened adhesive and steel-to-steel joints 

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Clays composed only of clay minerals may have higher water of plasticity values than desired. Consequendy, the presence of substantial amounts of nonclay minerals or the addition of materials that reduce the water of plasticity may improve the working characteristics of a clay. 

Gold and gold alloys serve the needs of dentistry better than any other metals or alloy systems. Gold alloys have a broad range of working characteristics and physical properties, coupled with excellent resistance to tarnish and corrosion ki the mouth. 

Cerium is one of the most widely used activators, which improve the working characteristics of many scintillators. Determination of the valence state of cerium in single crystals of alkaline and rare-earth borates allows to establish the nature of activator centers for purposeful influence on the scintillation efficiency of the matrix. 

The atoms of any metal adhere together to form a crystal because of the forces of attraction between them to remove an atom from the surface requires a definite amount of work, characteristic of the metal this is called the sublimation energy. ... 

Laswell et al., 1971 Arato, 1974). All were prone to excessive dissolution and only one had adequate strength and film thickness. Their working characteristics were found to be unduly sensitive to changes in temperature and humidity (Simmons, D Anton Hudson, 1968). All were inferior to conventional zinc phosphate cements. No further development of these cements has taken place, nor is it likely that interest in them will be revived. The modem water-activated glass-ionomer cement has filled this niche and has vastly superior properties including adhesion to tooth material. 

The working characteristics of the other glasses mentioned can usually be deduced from their expansion coefficients. A glass of lower expansion than Monax needs an oxygenated flame, and one with higher expansion needs only a gas-air flame. 

The use of optical immune biosensors based on surface plasmon resonance (SPR) for the diagnostics of human and animal diseases as well as for environmental pollution monitoring, is one of prospective directions in biosensorics. The sensitivity of immune biosensors is similar to the ELIS A-method but the simphcity of obtaining results in the real time regime and the speed of the analysis are the main advantages of the biosensor approach. Performance of optical biosensors based on SPR depends on the state of the metallic surface as well as on the density, structure and the space volume of the immobilized molecules. It was demonstrated that the application of intermediate layers between the transducer surface and the sensitive biological molecules can optimize the working characteristics of the immune biosensor [7-14]. 

The comparison of working characteristics (Table 3) of metal-hydrides, hydrocarbons, and fullerenes shows that fullerenes are one of the most promising materials for hydrogen storage. 

This formula takes advantage of the soft-working characteristics of metol. 

The data on the volume properties of PMS liquids (i.e. coefficient of volumetric expansion, relative volume variation, coefficient of isothermal compressibility) are essential for the performance characteristics of oli-godimethylsiloxanes in hydraulic systems, hydraulic shocks and dampers they allow one to determine the working characteristics of these systems with some brands of PMS liquids at different temperatures and pressures. 

The field of employment of a particular fuel cell is determined by its working characteristics, in particular by its operating temperature and fuel utilized. 

In order to indicate the diverse nature of the chemical engineering profession, the typical work characteristics of different types of chemical engineers are examined. 

Complex investigations on electrode materials and electrode kinetics were carried out with the aim to elaborate electrodes with high electrochemical activity. The route and mechanism of the electrode reactions, dependence of polarization on electrode materials and structure, gas atmosphere, and other factors were studied. As a result of this research the electrodes based on Ni, Co, Cu, manganite, and cobaltite having high working characteristics were elaborated. 

Other attempts have been made to utilize dry powder polyvinyl alcohol and polyvinyl acetate as admixtures for the same purpose. The polyvinyl alcohol is readily soluble in water, and it requires significant amounts in addition to achieve any distinct advantages. Significant amounts of any viscosity range of polyvinyl alcohol contribute to an undesirable increase in viscosity in the cement mortar. Polyvinyl acetate in powder form has been used for this purpose with consequent improvements in working characteristics and physical properties. However, dry powder polyvinyl acetate does not form a true polymer emulsion when dissolved in water. It, therefore, may also be dissolved out of a cement mortar. 

Wilson, M. G. et al. (2004). Work characteristics and employee health and well-being Test of a model of healthy work organization. Journal of Occupational and Organizational Psychology 11 565-88. 

A.A. Bejev, Epoxide Oligomers, Polymers and Composite Materials on their Basis with Improved Working Characteristics, Tashkent Technological Institute, 1991. [PhD Thesis]... 

Chmiel, N. (2005). Promoting health work Self-reported minor injuries, work characteristics, and safety behaviour. In C. Krunka, P. Hoffmann, A. Bussing (Eds.), Change and quality in human service work (pp. 277-288). Mering Rainer Hampp Verlag. 

Little is known, however, about the underlying mechanisms that mediate work demands, stress reaelions, and increased health risks. Classical epidemiological studies based on correlations between work characteristics and health indices provide only limited insight into these mechanisms. Most stress theo-... 

There are personality differences between person and person. Different people on the same kind of work have different adaptability, different work requires people with different personality traits. A character is careless person engaged in complex, delicate work, he will feel overwhelmed, making it feel mental fatigue and let a person personality is composed of flexible in a monotonous, simple work, he may tell mood is low, and even produce rebellious attitude. In both cases, are prone to misuse, the lively, active, aggressive, careless of workers is not suitable for high risk work. Characteristics analysis is advantageous to the enterprise to the worker at the time of recruitment hiring employees as reference. 

For the first-named conditions, Table 20.1 gives an appraisal of working characteristics that relate predominantly to steel and cast iron (Whal 1987). 

It is seen from the comparison of Eqs (119) and (122) that the additivity of HLB numbers follows from the additivity of the transfer work, because the group numbers in Eq. (118) are proportional to the partial values of transfer work characteristic to the individual groups which constitute the surfactant molecule ... 

These materials have been chosen due to their economic expediency and the valuable combination of physical and chemical, physical and mechanical and other properties of individual polymers - PHB is a brittle thermoplastic PIB - an elastomer. Preparation of composite materials based on combinations of plastics and elastomers is well known plastics are used as polymeric fillers in elastomers, improving their technological and working characteristics elastomers effectively improve strike viscosity and reduce brittleness in compositions based on plastics. 

The working characteristics of the adhesive relevant to the application conditions must be determined. For instance viscosity is often temperature, shear-rate and time-dependent, and this will influence the choice of dispensing equipment, the method of application, the usable life and the open time. The viscosity should therefore be regulated bearing in mind the adherend rugosity and surface pretreatment, the method and location of application, and the cure temperature and duration of application. A thixotropic material may be required for application to vertical or soffit surfaces. Generally, relatively thick bondlines are encountered so that the adhesive should be able to cure in thick and/or uneven layers. It should also be remembered that for about every 8 C change in... 

It may be useful to monitor the unreacted components of the adhesive system as well as the properties of the freshly mixed adhesive, partly as a check on the adhesive supplier and partly to establish the working characteristics of the adhesive. Techniques for... 

In a later development of glass ionomer cements, glass phosphonate cements were introduced, in which the glass powder is combined with polyviityl phosphonic acid. These cements exhibit very favorable setting and working characteristics, and attain final compressive strengths of up to 200 MPa. 

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