Exergy life cycle assessment of Ni-based catalyst synthesis processes

Within the life cycle assessment, exergy analysis is one of the specific approaches to evaluate impacts on the environment through the quality of energy which is degraded during the production process [1]. Exergy can be described as a measure of resources depletion and it can be used to evaluate the process efficiency. Comparative assessment of product and processes through life cycle assessment is often used to identify the differences and environmental hotspots. This research applies exergy life cycle assessment to compare different Ni-based catalysts synthesis processes. In previous research [2,3] the authors compared novel Ni-Pd/Al2O3 catalyst synthesis processes with other ones from environmental and performance point of view. Idea of this research is to calculate the impacts on the environment by the total exergy consumption of Ni-based catalyst processes and to compare these results with the results from previous research. Compared with other Ni-based catalyst synthesis processes, the assessment results confirm the previous findings that the novel NiPd/Al2O3 catalyst synthesis process has the smallest environmental impact. Furthermore, exergy life cycle assessment provided insight into impacts on the non-renewable and renewable resources

Synthesis and sintering of Cu-Al2O3 nanocomposite powders produced by a thermochemical route

By hydrometallurgy and powder metallurgy along with prognosis of physical-chemical properties, a synthesis of new improved materials can be successfully performed with in advance pre-set properties which is conditioned by a quality of starting powders i.e. by improving their structure. In accordance with that, this paper presents synthesis of the nanocomposite Cu-Al2O3 powder by thermochemical method and sintering with a comparative analysis of the mechanical and electrical properties of obtained solid samples. Nanocrystaline Cu-Al2O3 powders were produced by thermochemical method through following stages: spray-drying, oxidation of precursor powder, reduction by hydrogen and homogenisation. Characterization of powders included differential-thermal and thermo-gravimetric analysis (DTA-TGA), X-ray-diffraction (XRD) and analytical electron microscopy (AEM) coupled with energetic dispersive spectroscopy (EDS). Size of produced powders was 20-50nm with noticeable presence of agglomerates. Composite powders are characterized with A12O3 homogenous distribution in copper matrix. Powders were cold pressed with pressure of 500 MPa and sintered. Sintering of the obtained samples was performed in the hydrogen atmosphere in isothermal conditions at temperature range from 800 to 900°C and time up to 120 minutes. Characterization of Cu-Al2O3 sintered system included examination of density, relative volume change, electrical and mechanical properties, examination of microstructure by SEM analysis, as well as by EDS. The obtained nanocomposite, which structure is with certain changes preserved in final structure, has provided sintered material with homogenous distribution of dispersive in copper matrix, with exceptional effects of reinforcing and excellent combination of mechanical and electrical properties

Short history of just mentorship and support

Since its foundation in 1992, the Croatian Medical Journal (CMJ) has followed the strict standards of quality in the scientific publishing. However, the Journal has been aware that its specific position demands more than just following the already established rules. From the very beginning, the Journal declared an “author-helpful policy,” stating that “journal editors should have a major role in training authors in science communication, especially in smaller and developing scientific communities. Journal authors usually send scientifically acceptable but poorly prepared articles and it is a pity to lose valid data because of their poor presentation.” (1,2). In brief, the editors and editorial staff of the CMJ have been well aware that the skills of scientific reporting and publishing in our academic community are not developed and that valuable research results and valid data are being lost because of poor presentation. To be perfectly honest, ten years ago this statement looked like a nice promise, one of the many we in academic medicine learnt not to take too seriously