David E.,Romanian Institute of Isotopic And Molecular Technology |
Kopac J.,University of Ljubljana
Journal of Hazardous Materials | Year: 2012
A simple method with high efficiency for generating high pure hydrogen by hydrolysis in tap water of highly activated aluminum dross is established. Aluminum dross is activated by mechanically milling to particles of about 45μm. This leads to removal of surface layer of the aluminum particles and creation of a fresh chemically active metal surface. In contact with water the hydrolysis reaction takes place and hydrogen is released. In this process a Zero Waste concept is achieved because the other product of reaction is aluminum oxide hydroxide (AlOOH), which is nature-friendly and can be used to make high quality refractory or calcium aluminate cement. For comparison we also used pure aluminum powder and alkaline tap water solution (NaOH, KOH) at a ratio similar to that of aluminum dross content. The rates of hydrogen generated in hydrolysis reaction of pure aluminum and aluminum dross have been found to be similar. As a result of the experimental setup, a hydrogen generator was designed and assembled. Hydrogen volume generated by hydrolysis reaction was measured. The experimental results obtained reveal that aluminum dross could be economically recycled by hydrolysis process with achieving zero hazardous aluminum dross waste and hydrogen generation. © 2012 Elsevier B.V.
Pop M.N.,Romanian Institute of Isotopic And Molecular Technology
International Journal of Thermal Sciences | Year: 2016
A stacked three layer monolithic sub-system comprising a pyroelectric (PE) sensor, a thermal coupling layer and an external plate (EP), intended to detain a rigid, corrosion resistant external surface and to be used in front detection configuration for liquid samples' thermal parameters measurement is proposed herein. The thermal waves (TWs) are generated on the irradiated surface of the PE material and after propagating through the sensor and the coupling layer reach the EP. The EP, positioned in contact with the liquid sample is intended to act as a buffer layer (protective against mechanical and corrosion agents) while successfully transmitting the probing TWs to the investigated semi-infinite sample. The normalized signal can be described by means of an analytical model obtained by assuming one-dimensional TWs propagation through the five layered system: air/proposed sub-system and backing liquid sample. The theoretical signal is firstly analyzed by studying the numerical behaviour of the normalized amplitude and phase and the behaviour of the sensitivity coefficients specific to these components when the thermal effusivity of a semi-infinite liquid is aimed to be extracted. The experimental results obtained by performing frequency scanning measurements using a composite sub-system with a brass EP and different backing sample liquids are presented. © 2016 Elsevier Masson SAS. All rights reserved.
Garabagiu S.,Romanian Institute of Isotopic And Molecular Technology |
Mihailescu G.,Romanian Institute of Isotopic And Molecular Technology
Journal of Electroanalytical Chemistry | Year: 2011
In this work we propose the design of an electrochemical setup (hemoglobin-gold-nanoparticles-ITO glass), used for the determination of a hemoglobin adduct (acrylamide). Acrylamide is neurotoxin and potential carcinogen, formed mainly in high temperatures processed food that contains large quantity of starch (French fries, baked bread). Acrylamide forms hemoglobin adducts, and our sensing device is based on this property, by passivating the hemoglobin-modified electrode by the addition of low concentrations of acrylamide. The sensitivity to acrylamide better as 0.1 μM makes this electrochemical cell configuration suitable for the detection of acrylamide in food products. © 2011 Elsevier B.V. All rights reserved.
Turcu I.,Romanian Institute of Isotopic And Molecular Technology |
Bogdan M.,Romanian Institute of Isotopic And Molecular Technology
Journal of Physical Chemistry B | Year: 2012
One of the most important purposes in molecular technologies is the preparation of supramolecular structures by self-assembling processes. The aromatic molecules self-associate mainly in π-π stacked structures with an aggregate size distribution determined by the association equilibrium constants. A general expression for the equilibrium constants Kn,m which govern the self-association of two aggregates with n and m monomers respectively has been obtained. The model predicts also the concentrations of free monomers, the concentrations of n-mers, and the total concentration of aggregates. 1H NMR experiments have been used to illustrate the applicability of the proposed model in a particular case: π-stacking self-association of ciprofloxacin in solution. © 2012 American Chemical Society.
Buimaga-Iarinca L.,Romanian Institute of Isotopic And Molecular Technology |
Morari C.,Romanian Institute of Isotopic And Molecular Technology
RSC Advances | Year: 2013
Cysteine clusters of various sizes are investigated, as free structures and adsorbed on the Au(110)-(1 × 1) surface, by using density-functional theory. We analyse the adsorption of clusters in protonized and deprotonized forms. The presence of a trend for the values of bonding energy per adsorbed cysteine molecule as a function of cluster size is pointed out. To explain these findings we analyse the electronic density of states of the clusters and the charge transfer occurring between the surface and cysteine molecules. We emphasize the broadening of the molecular density of states as a function of cluster size. Details of the geometrical structure of the adsorbed clusters in protonized and deprotonized forms are compared and discussed from the perspective provided by the electronic structure calculation. By investigating the redistribution of the electron density upon the adsorption we point out the significant features of the molecule-surface charge transfer. In particular we show that the charge redistribution occurs only at the thiol end while the electronic density of the carboxylic group is not affected in the adsorbed state. © 2013 The Royal Society of Chemistry.