Device Operating (device + operating)

Distribution by Scientific Domains

Selected Abstracts

The new V12 ultra-small-angle neutron scattering and tomography instrument at the Hahn,Meitner Institut

M. Strobl
The new V12 instrument at the Hahn,Meitner Institute in Berlin is a multiple setup combining several techniques to investigate the internal structure of bulk samples. It consists of two double-crystal diffractometers (DCDs) and an attenuation tomography device operating with monochromatic neutrons. The three instrument parts can be used independently at the same time. The DCDs are mainly used in the ultra-small-angle neutron scattering (USANS) regime, where they overlap the accessible range of small-angle neutron scattering instruments, while tomographic methods collect real-space information on a macroscopic scale. Together they enable structural investigations over six orders of magnitude (50,nm to 5,cm). Scattering and tomographic methods can even be combined by means of diffraction and scattering-enhanced imaging. The sample environment can be varied over a large range of temperatures and pressures for USANS measurements and a polarized USANS option is available. [source]

Ex vivo histological characterization of a novel ablative fractional resurfacing device,

Basil M. Hantash MD
Abstract Background and Objectives We introduce a novel CO2 laser device that utilizes ablative fractional resurfacing for deep dermal tissue removal and characterize the resultant thermal effects in skin. Study Design/Materials and Methods A prototype 30 W, 10.6 m CO2 laser was focused to a 1/e2 spot size of 120 m and pulse duration up to 0.7 milliseconds to achieve a microarray pattern in ex vivo human skin. Lesion depth and width were assessed histologically using either hematoxylin & eosin (H&E) or lactate dehyrdogenase (LDH) stain. Pulse energies were varied to determine their effect on lesion dimensions. Results Microarrays of ablative and thermal injury were created in fresh ex vivo human skin irradiated with the prototype CO2 laser device. Zones of tissue ablation were surrounded by areas of tissue coagulation spanning the epidermis and part of the dermis. A thin condensed lining on the interior wall of the lesion cavity was observed consistent with eschar formation. At 23.3 mJ, the lesion width was approximately 350 m and depth 1 mm. In this configuration, the cavities were spaced approximately 500 m apart and interlesional epidermis and dermis demonstrated viable tissue by LDH staining. Conclusion A novel prototype ablative CO2 laser device operating in a fractional mode was developed and its resultant thermal effects in human abdominal tissue were characterized. We discovered that controlled microarray patterns could be deposited in skin with variable depths of dermal tissue ablation depending on the treatment pulse energy. This is the first report to characterize the successful use of ablative fractional resurfacing as a potential approach to dermatological treatment. Lasers Surg. Med. 39:87,95, 2007. 2007 Wiley-Liss, Inc. [source]

Effect of Oxygen on Methane Steam Reforming in a Sliding Discharge Reactor

F. Ouni
Abstract Hydrogen-rich gas can be efficiently produced in compact plasma reformers by the conversion of a variety of hydrocarbon fuels, including natural gas and gasoline. This article describes experimental and modeling progress in plasma reforming of methane using a sliding discharge reactor (SDR). Experiments have been carried out in a compact device operating at low consumed power (1,2,kW). Previous studies of methane steam reforming using a SDR at atmospheric pressure show promising results (H2 concentration higher than 55,%). In order to study the effect of oxygen on the methane conversion and thus hydrogen production, a small amount of oxygen in the range of 7,20,% was added to the CH4 -H2O mixture. An unexpected result was that under our experimental conditions in the SDR oxygen did not have any influence on the methane conversion. Almost the totality of added oxygen is recovered intact. Moreover, part of the H2 produced was transformed into water by reaction with O2. A model describing the chemical processes based on classical thermodynamics is also proposed. The results indicate that the reactor design has to be improved in order to increase conversion and hydrogen production. [source]

Transparent Photo-Stable Complementary Inverter with an Organic/Inorganic Nanohybrid Dielectric Layer

Min Suk Oh
Abstract Transparent electronics has been one of the key terminologies forecasting the ubiquitous technology era. Several researchers have thus extensively developed transparent oxide-based thin-film transistors (TFTs) on glass and plastic substrates. However, work in transparent electronics has been limited mostly to high-voltage devices operating at more than a few tens of volts, and has mainly focused on transparent display drivers. Low-voltage logic devices, such as transparent complementary inverters, operating in an electrically stable and photo-stable manner, are now very necessary to practically realize transparent electronics. Electrically stable dielectrics with high strength and high capacitance must also be proposed to support this mission, and simultaneously these dielectrics must be compatible with both n- and p-channel TFTs in device fabrication. Here, a nanohybrid dielectric layer that is composed of multiple units of inorganic oxide and organic self-assembled monolayer is proposel to support a transparent complementary TFT inverter operating at 3,V. [source]

High-frequency ferromagnetic properties of FeCoZr nanocrystalline films

Yung-Wang Peng
Abstract FeCoZr magnetic thin films with high uni-axial anisotropy were fabricated by RF co-sputtering followed by post magnetic annealing. The crystal size of FeCoZr films was less than 15 nm, as calculated by Scherrer equation from X-ray diffraction patterns. By adding Zr element, FeCoZr films exhibited a uni-axial anisotropy after magnetic field annealing at 400 C for 1 hr. Optimal high frequency ferromagnetic properties were achieved in film with 19 at.% Zr, in which strong uni-axial anisotropy field of 300 Oe and high ferromagnetic resonance frequency in excess of 5.2 GHz were obtained. These facts suggest that FeCoZr nano-crystalline film is a potential candidate in high frequency electromagnetic devices operating at GHz bands. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Ultra scale-down approaches for clarification of mammalian cell culture broths in disc-stack centrifuges

Ferhana Zaman
Abstract Ultra-scale down (USD) methodology developed by University College London for cell broth clarification with industrial centrifuges was applied to two common cell lines (NS0 and GS-CHO) expressing various therapeutic monoclonal antibodies. A number of centrifuges at various scales were used with shear devices operating either by high speed rotation or flow-through narrow channels. The USD methodology was found effective in accounting for both gravitational and shear effects on clarification performance with three continuous centrifuges at pilot and manufacturing scales. Different shear responses were observed with the two different cell lines and even with the same cell line expressing different products. Separate particle size analysis of the treated broths seems consistent with the shear results. Filterability of the centrifuged solutions was also evaluated to assess the utility of the USD approach for this part of the clarification operation. 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]