Development of a magnetic capsule as a drug release system for future applications in the human GI tract

A method for active drug delivery inside the human digestive system is proposed. This method allows the localisation of a magnetically marked capsule on its natural way through the digestive system and to open it at a desired position. Thus, the procedure contains two important components: the magnetic monitoring and active drug release.     

A fractional order model for lead-acid battery crankability estimation

With EV and HEV developments, battery monitoring systems have to meet the new requirements of car industry. This paper deals with one of them, the battery ability to start a vehicle, also called battery crankability. A fractional order model obtained by system identification is used to estimate the crankability of lead-acid batteries. Fractional order modelling permits an accurate simulation of the battery electrical behaviour with a low number of parameters. It is demonstrated that battery available power is correlated to the battery crankability and its resistance. Moreover, the high-frequency gain of the fractional model can be used to evaluate the battery resistance. Then, a battery crankability estimator using the battery resistance is proposed. Finally, this technique is validated with various battery experimental data measured on test rigs and vehicles.     

The contribution of space charge in a high non-homogenous electric field to the creation of negative differential conductivity

The paper describes anomaly origination on current or voltage characteristics in time of positive potential on small curvature radius electrode rod against plane electrodes. An anomaly phenomenon occurred in the narrow voltage area in a high non-homogenous electric field close to the electrode (E > 10⁷ V m^?1). A mathematical – physical analysis of the observed processes in close proximity to the electrode with the above mentioned form is made. The differential equations, which analytically and theoretically describe this phenomenon, are compiled and solved. The space charge created by element particles (electrons, ions) which causes negative differential conductivity origination in narrow voltage area by their behaviour in electric field, plays a substantial role in this phenomenon. Current–voltage characteristics at both polarities of corona electrode were continuously measured at the study of static and dynamic processes occurring during discharge in the surrounding of a small curvature radius electrode. It was proved that an anomaly, in the form of negative differential conductivity (dI/dU < 0), appeared on a highly curved electrode at positive polarity in a narrow voltage area. This phenomenon was subjected to detailed experimental research including investigation of the influence of the shape and material of the electrode (output voltage), electrode temperature, influence of photoionization on the profile of the anomaly, the contribution of exoelectrons to particle distribution, and study of electrochemical potential of metal electrode. Oscillation of low ionized plasma at positive and negative polarity of small curvature radius electrodes has been analyzed. At the same time, the influence of the external forced electric field on the change of current–voltage characteristic profile was investigated. Theoretical justification of the anomaly phenomenon resulted from a change of energy conditions in the investigated place (the distance limit from the electrode is 10^?4–10^?6 m).     

Magnetic fluid in ionizing electric field

This article describes influence of strong (ionizing) electric field on sprayability of magnetic fluid containing colloid particles with size in the range from 10 to 20 nm of magnetite Fe₃O₄. Magnetic fluids can be based for example on both transformer oil and physiological solution for application in medical using (in human medical science research), that supports a fluid colloidal system. Further component of magnetic fluid is surfactant. It is acting as surface-active substance that prevents from nanometric dimension particle settlement. Magnetic fluid gets off nozzle with diameter in range 0.3–1.0 mm from container in surroundings of ionizing (i.e. strong) electric field (E > 10⁷ V m^?1). As a consequence of action of electric field it gives out suppression surface tension in fluid what leads onwards to decomposition of magnetic fluid ligament at the end of nozzle. The diameter of nozzle oneself respects basic theoretical calculations in regards of fluid concentration and thereinbefore its selected size. Magnetic fluid in dependency on its used liquid base has weak-polar till polar orientation polarization character. It gives out sprayability in non-homogeneous electric field E in combination with magnetic field of intensity H. Orientation of vectors Ê and ?, resp. induction of magnetic field B is defined by parallel or vertical direction. Results are confronted with measurements realized explicitly only at action of electric field (variable B = 0). In the case of magnetic field applications with permanent magnet together with electric non-homogeneous field it gives out unconventional dynamics of electrical charging particles of macroscopic dimension. Orientation particle track is influenced by orientation of field vector combinations. This phenomenon develops magneto-dielectric anisotropy, which oneself manifests behaviour of electrophysical quantities characterizing examination system. In consideration of technology utilization of this method it is very important to respect applied magnetic fluid concentration. Electrical characteristics were examined for volume concentration of magnetite particles in the range from 0.125% to 18%. Nevertheless efficiency optimization of given media suggests to boundary concentration of magnetic fluid of 4.0%, when it is in the regions of weak polar till polar material. Electrophysical research refers to exploitation of applied magnetic layer technology on dielectric insulating substances with inorganic origin as well as thin layer technology coating plastic foils created from macromolecular organic substance.     

Hydrothermal preparation of CuGaS2 crystallites with different morphologies

The CuGaS₂ crystallites with different morphologies were prepared at 160 °C through hydrothermal process by using CuCl, GaCl₃ solution, and thiourea as source materials. The samples were characterized by means of X-ray powder diffraction, element analysis, transmission electron microscopy, and photoluminescence (PL). In present route, as-prepared CuGaS₂ crystallites displayed spherical and whisker-like nanoparticles and snowflake-like micrometer particles. Room temperature PL spectrum of the snowflake-like crystallites exhibits a weak emission band at 540 nm and a broad strong emission band at 735 nm. The role that the reaction media played in the morphologies of the CuGaS₂ crystallites was investigated, and a possible reaction mechanism was proposed.     

Solubility of carbon dioxide in aqueous solutions of 2-amino-2-ethyl-1,3-propanediol

The solubilities of carbon dioxide in aqueous solutions of 2-amino-2-ethyl-1,3-propanediol (AEPD) were measured at 313.15, 323.15, and 333.15 K over the partial pressure range of carbon dioxide from 1 to 3000 kPa. The concentrations of aqueous AEPD solutions were 10 and 30 mass%. The solubilities of carbon dioxide in aqueous 10 mass% AEPD solutions at 313.15 K and 30 mass% at 333.15 K were compared with those in aqueous solutions of various amines such as monoethanolamine (MEA), 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-methyl-1-propanol (AMP), and N-methyldiethanolamine (MDEA).     

Electronic coupling in covalently-linked MM quadruple bonds: M2δ to ligand π conjugation

Dimetal tetracarboxylates, M₂(O₂CR)₄, where R=alkyl and M=Mo or W, can be linked in a perpendicular or parallel manner through the agency of a variety of ligands to give ‘dimers of dimers’ [M₂(O₂CR)₃]₂(bridge), or extended chains. A ring of formula [M₂(O₂CR)₂(bridge)]₄ is an alternative to a chain [M₂(O₂CR)₃]₂(bridge)₂]_∞ and ‘molecular squares’ of formula [(RNCHNR)₂M₂(bridge)]₄ have recently been reported by Cotton and Murillo, where M=Mo and Rh and R=p-MeOC₆H₄. The electronic coupling between the M₂ units manifests itself in electrochemical data and in the electronic spectra of the compounds. The electronic coupling occurs by M₂δ to ligand π-conjugation and specific examples are illustrated for the bridging ligands oxalate, perfluoroteraphthalate, 1,8-anthracenedicarboxylate and 2,7-dioxynaphthyridine. Correlations of a variety of spectroscopic data and computations employing density functional theory are presented.