Average Bond Dissociation Energies of Fullerene

Average carbon-carbon bond dissociation energy of buckminsterfullerene C₆₀ is estimated to be 106.87 kcal/mol by using experimentally determined thermochemical data. With a few assumptions this value was converted to the following bond-specific dissociation energies for fullerenes in general: 112.04 kcal/mol for 6/6 type bond, and 104.88 for 5/6 type. Similarly an average value of 60.34 kcal/mol was assigned to 5/5 type bond.     

A study of kinetic energy harvesting for biomedical application in the head area

This paper is focused on determining a suitability of using a kinetic energy harvester placed in the area of the human head for supplying power to a new generation of cochlear implants. Placement-dependant volumetric and mass constraints of the harvester are discussed, and the requirements for its power output are set based on the power demands on the state-of-the-art cochlear implants. Measured acceleration data for different activities are presented together with a statistics of a random user behaviour during the course of 10 months. Nonlinear simulation model based on CAD geometry and FEM analyses is developed and its parameters are optimized using the sensitivity analysis in order to generate the maximum power. Real life acceleration data are then employed to feed the input of the simulation model of energy harvester to predict the obtainable power output. The feasibility of employing the energy harvesting to power the selected biomedical application is discussed based on simulation results.     

MEASUREMENT AND COMPUTATION OF PHYSICO-CHEMICAL PROPERTIES OF SUGAR SOLUTIONS

At the Department of Chemistry and Technology of Saccharides, Institute of Chemical Technology in Prague, we study technically important physical properties of sugar solutions. This paper deals with some results of measurement and correlation of boiling point elevation and density.

The present system of tables or nomograms of physical properties of sugar solutions is not satisfactory for automated data processing. In a critical analysis of the existing material it appears that physico-chemical data for sugar solutions were often compiled over ranges of variables which were interesting for laboratory control and not for engineering computations. That all calls for purposeful completion of data in the regions where they are lacking. Additionally, it calls for revision of tabulated values from the literature and for transformation of the tabulated data to functional relationships in order to make computation equations both precise and simple     

Difference kernel iterative method for linear and nonlinear partial differential equations

The purpose of this paper was to propose a new method to solve partial differential equations arising in the field of science and engineering. In this new method, we have reduced the multiple integrals into a single integral and expressed it in terms of a difference kernel. To make the calculation easy and convenient, we have used the Laplace transformation to solve the difference kernel. The method is very simple, easy to understand and calculation minimizing as compared to the Adomian decomposition method and the variational iteration method. Some examples are given to verify the reliability and efficiency of the method.     

9Cr–1W steel strengthened by AlN and BN dispersion

Journal of Materials Science - Ferritic-martensitic steels of 9Cr–1W type strengthened by oxide dispersion (ODS) are candidate structural materials of in-vessel components of proposed...     

EXTRACTION OF Am(lll) AND Eu(lll) NITRATES BY 2-6-DI-(5,6-DIPROPYL-1,2,4-TRIAZIN-3-YL)PYRIDINES 1

ABSTRACT

The extraction of Am(lll) and Eu(lll) by 2,6-di(5,6-dipropyl-1,2,4-triazin-3-yl)-pyridines from mostly 1·9 M (HNO₃ + NH₄NO₃) was studied. The compound with n-propyl (DPTP) forms dimers and trimers in mixed branched alkanes modified with 2-ethyl-1-hexanol. The self-association is supported by enhancing the HNO₃ concentration from 0·3 to 0·9 M. In the above modified diluent, DPTP extracts Am(lll) and Eu(lll) nitrates as the complexes Am(NO₃)₃HNO₃-3B and Eu(NO₃)₃HN033B. The Am(lll)/Eu(lll) separation factor is typically 100 -120. The extraction and separation efficiency of DPTP strongly decreases in the order of diluents (each modified with 2-ethyl-1-hexanol) branched alkanes > cyclohexane > 2-methyl-4-pentanone > 2-ethylhexyl acetate > benzene > chlorobenzene > xylene. 1-Octanol and 2-ethyl-1-hexanol modifiers support appropriately the solubility of protonated forms of DPTP in branched alkanes, and moderately enhance the extraction of Am(lll) and Eu(lll). 1-Butanol modifier allows a higher extraction efficiency but supports less the solubility. The optimum extraction and separation efficiency is attained at 10 - 20 vol% modifier. The isopropyl analogue extracts Am(lll) more effectively than DPTP, but the extraction is slow and the separation from Eu(lll) is inefficient.     

1T‐Phase WS2 Protein‐Based Biosensor

Metallic 1T‐phase transition metal dichalcogenides have been recognized for their desirable properties like high surface‐to‐volume ratio, high conductivity, and capacitive behavior, making them outstanding for catalytic and sensing applications. Herein, a hydrogen peroxide (H₂O₂) biosensor is constructed by the immobilization of hemoglobin (Hb) on 1T‐phase WS₂ (1T‐WS₂) sheets, and entrapment by glutaraldehyde. 1T‐WS₂ not only displays electrocatalytic activity toward the reduction of H₂O₂ but also provides a high surface‐to‐volume ratio and conductive platform for the immobilization of Hb and facilitation of its electron transfer to the electrode surface. The advantageous role of 1T‐phase WS₂ is further demonstrated for the construction of a heme‐based H₂O₂ biosensor compared to its 1T‐phase MoS_2, MoSe₂, and WSe₂ counterparts. Synergistic interactions between 1T‐WS₂ and Hb result in a H₂O₂ biosensor with high analytical performance in terms of wide range, sensitivity, selectivity, reproducibility, repeatability, and stability. These findings have profound impact in the research fields of electrochemical sensing and biodiagnostics.     

Sharing engineering design knowledge in a distributed environment

Engineering design is a complex activity, relying heavily on know-how gained from personal experience. Competitive pressures and new technology are making further demands on the skills and experience of designers, as effective knowledge reuse in design is seen as increasingly vital, and the work of design teams is often a collaborative and distributed activity. University students with a thorough knowledge of the engineering domain can be ill prepared for professional practice, with its increasing reliance on skills and know-how as well as knowledge of theory. Our approach aims to better prepare students for professional practice, through hands-on experience of design reuse, participation in distributed collaboration, and the development of presentation and documentation skills. Our case-study in the domain of modelling engineering systems, in which the course materials themselves are evolving and distributed, has ramifications for the publication model of educational materials, and the way students should be prepared for working life.