Results 1 - 10 of 2663
Results 1 - 10 of 2663. Search took: 0.028 seconds
|Sort by: date | relevance|
[en] The importance of wood as a raw material is described and its deficiencies are listed. The history of the development of some impregnatio processes for fibrous materials is outlined and a hopeful prognosis for the future utilization of improved wood is made. (author)
[en] A study has been undertaken to develop a methodology to determine minor and trace elements in geological ceramic raw materials by wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometry. The set up of the methodology has been done either by optimising not only the sample preparation process but also optimising the measurement with the aid of the software Pro-Trace, and also by making an exhaustive compilation of reference materials for calibration and validation. The developed method is precise and accurate and allows the analysis of Ba, Ce, Co, Cr, Cu, Fe, La, Mn, Ni, Pb, Rb, S, Sr, Ta, Th, U, V, Y, Zn and Zr present in the sample as minor or trace elements in geological materials used as raw ceramic material in a relatively short period of time. Besides, the method is more environmentally friendly than other methodologies as it does not require the use of solvents or reagents. (Author)
[en] Estonia is rich in bogs and we have a comparatively well developed peat industry. Unfortunately, the same cannot be said of the level of research about our peat reserves, because during the recent fifty years Estonia was regarded as only a periphery of the former Soviet Union. Peat is a raw material that allows of a number of various uses. Estonia produces fuel, litter, and horticultural peat, and in small quantities also peat used in combating oil damage. Experiments have been made to produce fodder yeast and plant growth stimulators from peat. Also an original technology has been worked out for the production of active carbon from peat. It is necessary to elaborate a proper conception for the improvement of peat research and the development of an effective peat industry in Estonia.(author)
[en] Transitions between technological systems involve evolutionary processes. The past both shapes the current system and influences future options and pathways. Understanding the nature of energy transitions has become particularly important in light of the major changes that the world faces in the next century in the way that energy is sourced, converted and used. Policy-makers and decisiontakers need to understand the extent to which they can, or should, manage the transition. This paper proposes that a detailed study the patterns of change in a specific sector's past can improve our understanding of how it might evolve. A methodology is presented and applied to a case study of the prospective transition towards renewable raw material (RRM) use in the production of liquid fuels and organic chemicals in the UK. A process analysis of the historical transition to petroleum-based fuels and chemicals was used to shape a series of contemporary interviews that explored the perceptions and expectations of key actors in RRM and biorefining. The results show that the innovation system is already experiencing the socio-technical dynamics of regime disruption and competing designs. An empirical basis is offered for the the use of past transitions to inform scenarios for the future. - Highlights: ► Two sectors were studies in detail to learn about the dynamics of energy transitions. ► A methodology for linking historical studies with foresight work is presented. ► Interview results from a UK case study on biofuels and biochemicals are discussed. ► Socio-technical dynamics of transitions provide insight for decisions about the future. ► Socio-technical dynamics can be a basis for constructing scenarios to inform policy.
[en] Iron zircon coral pigments are very interesting from an industrial point of view because of their high colouring power and their stability at high temperatures. However, the pigment's synthesis is particularly troublesome due to its specific reaction mechanism. As an encapsulated pigment it becomes very important how the raw materials are distributed in the reaction mixture. To evaluate the effectiveness of the mixing process, it would be convenient to define a parameter, that is the mixing index, to estimate the degree of homogeneity of the system. In the current investigation, a mixing index is proposed derived from the power spectrum of Fourier transform of scanning electron microscope (SEM) images of the raw material mixture. Concretely, the number of pixels in a certain range of values in the image of the power spectrum, seems to behave relatively well as mixing index. This index allows us to distinguish between samples with different zirconia and iron oxide used as precursors. The proposed mixing index seems to be related to the colouring power of the final pigment when the synthesis generates enough zircon to encapsulate hematite particles.
[es]Los pigmentos coral de hierro-circón son muy interesantes desde el punto de vista industrial ya que n un alto poder colorante y estabilidad a altas temperaturas. Sin embargo, la síntesis del pigmento es particularmente problemática debido a su mecanismo de reacción. Al tratarse de un pigmento encapsulado, resulta fundamental cómo se encuentran distribuidas las materias primas en la mezcla de reacción. Para evaluar la efectividad del proceso de mezclado, es conveniente definir un parámetro, que es el índice de mezclado, para estimar el grado de homogeneidad del sistema. En el presente trabajo de investigación se propone un índice de mezclado basado en el espectro de potencia de la transformada de Fourier de imágenes obtenidas con el microscopio electrónico de barrido de las mezclas de materias primas. Concretamente, el número de píxeles en un cierto rango de valores en la imagen del espectro de potencia parece funcionar relativamente bien como índice de mezcla. Este índice permite distinguir entre muestras con diferentes circonas y óxidos de hierro uitilizados como precursores. El índice de mezcla propuesto se relaciona con el poder colorante del pigmento final cuando durante la síntesis se genera suficiente cantidad de circón para encapsular las partículas de hematites.
[en] The priorities of source of minerals and raw materials are directed. The detailed study of the sphere of social life reveals that even with utterly high potential in some key mineral. Kazakstan has problems both in mining and making up economic and social basis of the society. Instead of promoting solution of the crisis phenomena, mining and partly processing industries induce and increase problems aggravating the solution. Urgent and radical reforms should be taken in those spheres, otherwise the country will not be to solve the problems. (author)
[en] This monograph is devoted to complex application of mineral raw materials of Tajikistan, including danburite, kaolin clays, argillite, zeolites and others. Thus, the purpose of this research is elaboration of methods of boron- and aluminium containing products obtaining for chemical, medical, agricultural, and others economy sectors.
[en] Radiation processing is now a useful production tool in industry. Every year raw material worth several hundred million dollars is irradiated and converted to newer and better products. This review article is based on a paper presented at Nuclex '69 (Basle, Switzerland, October) on behalf of the Agency by H.C. Yuan, F. Antoni and C.K. Beswick, and summarizes industrial aspects in radiosterilization of medical supplies and polymer processing. (author)