Effect of particle size on carburization of Fe-Co alloy catalysts

Bimetallic Fe-Co alloy catalysts supported on silica have been studied by use of combined Mössbauer absorption and emisson spectroscopy. Effects of carburization on samples with different particle size are discussed.     

Purification of labelled antibodies by hydrophobic interaction chromatography

In order to improve the sensitivity of immunometric assays, a chromatographic technique was developed that virtually eliminates components causing non-specific background. Labelled antibodies were applied to a phenyl-Sepharose column in physiological buffer. When labelled anitbodies were purified by this technique, the non-specific background of various time-resolved immunofluorometric assays was reduced 3- to 10-fold and was very close to the instrument background. The assay sensitivity was simultaneously increased by a factor of 2 to 16. This purification method might be used to improve the results of immunometric assays in general.     

Über ein funktionentheoretisches Seitenstück eines elementaren,algebraischen Satzes von Gauss

Ohne Zusammenfassung     

Anisotropy of electron structure at InAs(1 1 1) surfaces by laser pump-and-probe photoemission spectroscopy

The electronic structure and the electron dynamics of the clean InAs(1 1 1)A 2 × 2 and the InAs(1 1 1)B 1 × 1 surfaces have been studied by laser pump-and-probe photoemission spectroscopy. Normally unpopulated electron states above the valence band maximum (VBM) are filled on the InAs(1 1 1)A surface due to the conduction band pinning above the Fermi level (E_F). Accompanied by the downward band banding alignment, a charge accumulation layer is confined to the surface region creating a two dimensional electron gas (2DEG). The decay of the photoexcited carriers above the conduction band minimum (CBM) is originated by bulk states affected by the presence of the surface. No occupied states were found on the InAs(1 1 1)B 1 × 1 surface. This fact is suggested to be due to the surface stabilisation by the charge removal from the surface into the bulk. The weak photoemission intensity above the VBM on the (1 1 1)B surface is attributed to electron states trapped by surface defects. The fast decay of the photoexcited electron states on the (1 1 1)A and the (1 1 1)B surfaces was found to be τ_1 1 1 A ? 5 ps and τ_1 1 1 B ?  4 ps, respectively. We suggest the diffusion of the hot electrons into the bulk is the decay mechanism.     

The process of management review

Management review of the quality-management system is an item in many quality standards and a requirement of the ISO 9001:2000 standard and of laboratory standards ISO 15189 and ISO 17125, and others. These reviews are conducted to ensure that the top management is informed and involved in the quality-management system with respect to continuing adequacy and effectiveness, and opportunities for improvement of the system. The management review is a process that should be conducted and audited utilizing the process approach. A process approach is defined as “An activity using resources and managed in order to enable the transformation of inputs into outputs” (ISO 9001:2000). All identified main processes in the quality system should be monitored through data collection by appropriate methods, assuring that data are valid, representative, and adequate. For management review data must be collected and presented in an accessible form so that processes can be evaluated according to objectives, goals, resources, etc. On the basis of this information the laboratory management makes the necessary decisions and ensure that actions are taken that improve the effectiveness of the quality-management system. As output from the management review process, there should be evidence of decisions regarding: change of quality policy and objectives; plans and possible actions for improvements; corrective actions as appropriate; increased customer satisfaction; and planning of resources needs. Identification of the processes involved and using the process approach in the management review ensures the continual improvement of the quality system. Presented at the conference Quality in the Spotlight, March 2006, Antwerp, Belgium.     

Über den absoluten Betrag einer analytischen Funktion für gegebene Werte des Funktionsargumentes

Ohne Zusammenfassung     

Rotational and spin viscosities of water: Application to nanofluidics

In this paper we evaluate the rotational viscosity and the two spin viscosities for liquid water using equilibrium molecular dynamics. Water is modeled via the flexible SPC/Fw model where the Coulomb interactions are calculated via the Wolf method which enables the long simulation times required. We find that the rotational viscosity is independent of the temperature in the range from 284 to 319 K. The two spin viscosities, on the other hand, decrease with increasing temperature and are found to be two orders of magnitude larger than that estimated by Bonthuis et al. [Phys. Rev. Lett. 103, 144503 (2009)] We apply the results from molecular dynamics simulations to the extended Navier-Stokes equations that include the coupling between intrinsic angular momentum and linear momentum. For a flow driven by an external field the coupling will reduce the flow rate significantly for nanoscale geometries. The coupling also enables conversion of rotational electrical energy into fluid linear momentum and we find that in order to obtain measurable flow rates the electrical field strength must be in the order of 0.1?MV?m(-1) and rotate with a frequency of more than 100 MHz.