Thermographic phosphors for thermometry: A survey of combustion applications

Temperature is a fundamental thermodynamic parameter used to describe physical, chemical and biological processes. In combustion as in many other applications, knowledge about temperature plays a substantial role in helping to maintain an efficient and clean environment. Being able to measure temperature accurately in combustion and in fire-related applications is important for giving a better understanding of heat transfer phenomena and improving existing models.In the present review paper a method based on the spectroscopy of inorganic luminescent materials is described and exemplified in experiments related to combustion. The method involves the use of thermographic phosphors which enable remote temperature diagnostics to be performed with a high degree of sensitivity and accuracy. The technique is superior to those based on thermocouples and pyrometry, particularly in the vicinity of flames and when the measured surface is subjected to random movements. Several phosphor materials suitable for temperature probing are described. The application of thermographic phosphors to temperature measurements in one-point and in two-dimensions in flame spread scenarios, and in pyrolysis experiments involving different construction materials and polymers are described. Many thermographic phosphors have the property of being insensitive to variations in pressure up to 1 GPa. This property extends the use and development of thermographic thermometry to other domains, such as internal combustion engines. The temperature has been measured in a point and in two-dimensions inside the combustion chamber. The complex procedures required to implement the use of thermocouples on moving objects inside an engine make thermocouples an expensive choice. It also limits the possibilities of altering the measurement locations and thereby also complicating the investigation of different engine geometries and components.Thermographic phosphors have also been employed in gas turbine applications. Temperature probing in the afterburner of a full-size aircraft engine is described with the aim to study the effects of various engine loads on the wall temperature. Furthermore, the application of thermographic phosphors to study the temperature of droplets in relation to sprays is described. In spray dynamics, temperature is a crucial parameter for gaining an understanding of atomisation, evaporation and heat convection from the surrounding gases. Finally the application of thermographic phosphors for gas temperature measurement by seeding the particles into a gas flow is described together with the challenges associated with seeding the particles for in-situ flame measurements.     

Seasonal effects on the physicochemical characteristics of fish sauce made from capelin (Mallotus villosus)

Fresh capelin (Mallotus villosus) was harvested from the North Atlantic during both summer and winter fishing seasons. Reaction conditions for fish sauce processing were optimized with respect to temperature, salt concentration and reaction time, using a response surface methodology (RSM) experimental design. Whole capelin was minced and samples were ground with increasing salt concentrations. RSM optimizations were conducted, ranging from 5% to 30% salt, and incubating at 5° intervals from 0 to 65 °C. Autolytic activity was estimated by extracting the liquid formed by the mixture with trichloroacetic acid and estimating protein content by the Lowry method. Samples for fish sauce production were then prepared under optimized conditions by mixing ground capelin with 10% salt and incubating at 50 °C for up to 270 days for the summer capelin and up to 360 days for the winter capelin. Samples were collected at regular intervals and analyzed for liquid yield, moisture, protein, soluble solids, specific gravity, pH, colour and amino acid content. Kjeldahl protein content in the fish sauce from summer capelin was 2.03% after 250 days of fermentation and twice as high as that in winter capelin fish sauce. Moisture content and pH were lower in the summer capelin fish sauce, but Brix and density were higher than those in fish sauce from winter capelin. Brown colour formation was very rapid in the summer capelin fish sauce but slow in the winter capelin fish sauce. Summer capelin may be successfully utilized for the production of fish sauce without added enzymes.     

White Electroluminescence by Supramolecular Control of Energy Transfer in Blends of Organic‐Soluble Encapsulated Polyfluorenes

Here, it is demonstrated that energy transfer in a blend of semiconducting polymers can be strongly reduced by non‐covalent encapsulation of one constituent, ensured by threading of the conjugated strands into functionalized cyclodextrins. Such macrocycles control the minimum intermolecular distance of chromophores with similar alignment, at the nanoscale, and therefore the relevant energy transfer rates, thus enabling fabrication of white‐light‐emitting diodes (CIE coordinates: x = 0.282, y = 0.336). In particular, white electroluminescence in a binary blend of a blue‐emitting, organic‐soluble rotaxane based on a polyfluorene derivative and the green‐emitting poly(9,9‐dioctylfluorene‐alt‐benzothiadiazole ( F8BT ) is achieved. Morphological and structural analyses by atomic force microscopy, fluorescence mapping, µ‐Raman, and fluorescence lifetime microscopy are used to complement optical and electroluminescence characterization, and to enable a deeper insight into the properties of the novel blend.     

On the Influence of Crosslinker on Template Complexation in Molecularly Imprinted Polymers: A Computational Study of Prepolymerization Mixture Events with Correlations to Template-Polymer Recognition Behavior and NMR Spectroscopic Studies

Aspects of the molecular-level basis for the function of ethylene glycol dimethacrylate and trimethylolproprane trimethacrylate crosslinked methacrylic acid copolymers molecularly imprinted with (S)-propranolol have been studied using a series of all-component and all-atom molecular dynamics studies of the corresponding prepolymerization systems. The crosslinking agents were observed to contribute to template complexation, and the results were contrasted with previously reported template-recognition behavior of the corresponding polymers. Differences in the extent to which the two crosslinkers interacted with the functional monomer were identified, and correlations were made to polymer-ligand recognition behavior and the results of nuclear magnetic resonance spectroscopic studies studies. This study demonstrates the importance of considering the functional monomer–crosslinker interaction when designing molecularly imprinted polymers, and highlights the often neglected general contribution of crosslinker to determining the nature of molecularly imprinted polymer-template selectivity.     

A paradox in the development of computerized materials data systems

In principle, computerization of engineering materials data should be a means of coping with the rapidly increasing amount of information in this field. In practice, however, there is only little common use of the several existing data banks for materials. It appears that something is missing in the construction and operation of the systems. One reason may be the fact that so far computerization has been dealt with principally by materials scientists and engineers, not involving to a sufficient degree the users, designers and manufacturers of industrial products. In order to proceed successfully one has to examine users' attitudes and problem solving processes, using experts on service management and cognitive and social psychology.     

What is a materials data system?

During the last two decades considerable efforts have been made to develop computerized data systems for engineering materials. The results have not come up to the expectations of systems that can be used by designers for selecting of materials. Some factors have been recognized as responsible for the slow progress. It has proved difficult, however, for those involved in this development to make use of such information about the systems in question. Conflicts have occurred between different parties involved. It now seems that too little attention has been paid to the historical background of knowledge and systems related to civiliziation and society. A recently published review of world history from the point of view of the emergence of information technology has provided a basis for some considerations about the nature and roles of data systems. It can be shown that certain activities or features characterize each period of civilization and the development of computers and computerization should be considered as part of this sequence. The same is true for the world history of thinking and knowledge. In the present paper these historical considerations are combined with the observation that in their thinking and perception of ideas people appear to carry with them traditions from the past in varying degrees. Hence differences of opinion about the nature and roles of materials data systems may be explained by differences in the imprint of historical developments on people's ideas. In order to apply this lesson to the development of materials data systems, one has to learn also from the varying interpretations of world history that have been written through the ages. The best approach will probably be incremental and pragmatic rather than holistic and synoptic.     

Combined orchiectomy and external radiotherapy versus radiotherapy alone for nonmetastatic prostate cancer with or without pelvic lymph node involvement: a prospective randomized study

PURPOSE: We compare the combination of orchiectomy and radiotherapy to radiotherapy alone as treatment for pelvic confined prostate cancer, that is T1-4, pN0-3, M0 (TNM classification). MATERIALS AND METHODS: In this prospective study 91 patients with clinically localized prostate cancer were, after surgical lymph node staging, randomized to receive definitive external beam radiotherapy (46) or combined orchiectomy and radiotherapy (45). Patients treated with radiotherapy alone had androgen ablation at clinical disease progression. The effects on progression-free, disease specific and overall survival rates were calculated. RESULTS: After a median followup of 9.3 years (range 6.0 to 11.4) clinical progression was seen in 61% of the radiotherapy only patients (group 1) and in 31% of the combined treatment patients (group 2) (p = 0.005). The mortality was 61 and 38% (p = 0.02), and cause specific mortality was 44 and 27%, respectively (p = 0.06), in groups 1 and 2. The differences in favor of combined treatment were mainly caused by lymph node positive tumors. For node negative tumors there was no significant difference in survival rates. CONCLUSIONS: The progression-free, disease specific and overall survival rates for patients with prostate cancer and pelvic lymph node involvement are significantly better after combined androgen ablation and radiotherapy than after radiotherapy alone. These results strongly suggest that early androgen deprivation is better than deferred endocrine treatment for these patients.     

Use of a resilient bond line to increase strength of long adhesive lap joints

The load capacity of long adhesive lap joints is often governed by stress concentrations at the lap ends. This paper investigates a method to minimize these stress concentrations by using a bond line with low shear stiffness and sufficient strength, here denoted as a resilient bond line. The resilient bond line is intended to increase the load carrying capacity of long lap joints by achieving a more uniform shear stress distribution while maintaining an elastic joint behaviour without damage or plastic deformation. The study comprises analytical, numerical and full-sized experimental work on double lap joints with lengths 200–700 mm comparing conventional stiff bond lines to resilient bond lines. Different resilient bonds lines were obtained by using rubber-like adhesives and by having a rubber mat within the bond line. An analytical definition of a ‘long’ lap joint is suggested and a study of adhesive-rubber bonding is also presented. The numerical analysis clearly indicates that an increase in load carrying capacity is made possible using resilient bond lines. A good agreement is also found between the numerical results and the analytical Volkersen theory, indicating that reasonable strength predictions can be obtained by hand calculations if the joint is designed in order to minimize the influence of peel stress. The experimental results of the resilient bond line verify the numerical findings, although production difficulties decrease the statistical significance of the result. On the contrary, the experimental results of the conventional bond lines significantly exceeded the numerical predictions, showing similar load carrying capacities to the resilient bond line. This is probably due to the specific boundary conditions used in the test setup. Despite some contradictory experimental results, the conclusion of this study is that the efficiency of long lap joints can be increased by the use of a bond line with low shear stiffness and sufficient strength.