Smectite clays as solid supports for immobilization of beta-glucosidase:Synthesis, characterization, and biochemical properties

Nanomaterials as solid supports can improve the efficiency of immobilized enzymes by reducing diffusional limitation as well as by increasing the surface area per mass unit and therefore improving enzyme loading. In this work, beta-glucosidase from almonds was immobilized on two smectite nanoclays. The resulting hybrid biocatalysts were characterized by a combination of powder X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric. analysis, differential thermal analysis, and infrared spectroscopy. Biochemical studies showed an improved thermostability of the immobilized enzyme as well as enhanced performance at higher temperatures and in a wider pH range

Particle Generation of CapaciTorr Pumps

Non Evaporable Getter pumps have been used since four decades in various scientific and industrial Ultra High and Extremely Ultra High Vacuum applications. For the majority of applications properties like high pumping speed vs. small size, powerless operation and hydrocarbon cleanliness are main aspects for the usage. In addition to this a growing number of applications nowadays also require particle free systems. In this paper we report on investigations on in-vacuum particle creation during the conditioning and activation process of CapaciTorr pumps

Particle Generation of CapaciTorr Pumps

Non Evaporable Getter pumps have been used since four decades in various scientific and industrial Ultra High and Extremely Ultra High Vacuum applications. For the majority of applications properties like high pumping speed vs. small size, powerless operation and hydrocarbon cleanliness are main aspects for the usage. In addition to this a growing number of applications nowadays also require particle free systems. In this paper we report on investigations on in-vacuum particle creation during the conditioning and activation process of CapaciTorr pumps

X-ray photoemission spectroscopy study on the effects of functionalization in fulleropyrrolidine and pyrrolidine derivatives

Fulleropyrrolidine and pyrrolidine derivatives were studied using X-ray photoemission spectroscopy in order to determine the effects of the C60-cage on the pyrrolidine nitrogen, as well as the influence of further derivatisation. Charge transfer from the carbon pyrrolidine ring to the C60-cages is observed and this charge redistribution influences not only the carbon atoms but also the nitrogen. The major influence of different functionalization groups on the pyrrolidine nitrogen is whether or not they lead to quaternisation while no differences could be detected for different groups (methyl group or alkyl chain) producing one or the other configuration. However, the type of counter ion is important for the stability of the pyrrolidinium nitrogen: demethylated nitrogen, always found to be present in iodide counter balanced compounds, disappears in compounds counter balanced with BF4- anion.

Conceptual design of scalable vacuum pump to validate sintered getter technology for future NBI application

Non-evaporable getter (NEG) technology is a potential candidate as pumping system for future neutral beam injector applications. The strategy to validate the use of getter pump technology is based on the realization of a relatively large pump mock-up that has to be tested in fusion-relevant conditions. The objectives of this mock-up are to demonstrate that a pump of large dimensions and capacity is usable. This paper deals with the design of the mock-up, based on conceptual studies which involve at first 3D gas flow simulations considering different modular mock-up pumps based on NEG sintered disks. In addition transient thermal simulations with FE method have been performed with the aim to analyze the thermal response of the mock-up. The conceptual design has been carried out in order to define the best configuration to obtain high pumping speed with low spatial gradient of gas concentration inside the getter material. The suggested solution will exhibit a modular structure of getter disks, which on one hand simplifies the mechanical assembling, and on the other hand allows interpretative modelling at different scales. It is foreseen to test the pump mockup in the TIMO facility at KIT Karlsruhe