Jakub Kelar

GAGG:Ce single crystalline films: New perspective scintillators for electron detection in SEM.

Single crystal scintillators are frequently used for electron detection in scanning electron microscopy (SEM). We report gadolinium aluminum gallium garnet (GAGG:Ce) single crystalline films as a new perspective scintillators for the SEM. For the first time, the epitaxial garnet films were used in a practical application: the GAGG:Ce scintillator was incorporated into a SEM scintillation electron detector and it showed improved image quality. In order to prove the GAGG:Ce quality accurately, the scintillation properties were examined using electron beam excitation and compared with frequently used scintillators in the SEM. The results demonstrate excellent emission efficiency of the GAGG:Ce single crystalline films together with their very fast scintillation decay useful for demanding SEM applications.

ENERGY EFFICIENCY OF PLANAR DISCHARGE FOR INDUSTRIAL APPLICATIONS

Diffuse Coplanar Surface Barrier Discharge has proven its capabilities as an industry-ready plasma source for fast, in-line and efficient plasma treatment at atmospheric pressure. One parameter required by industry is energy efficiency of the device. In this paper, we present the energy efficiency of the whole plasma system, and we investigate possible sources of errors.

Cold Plasma: the Way to Improve the Repeatability of SALD ICP-MS Analysis

Abstract This work deals with the preparation of model biological microsamples for Substrate-Assisted Laser Desorption Inductively Coupled Plasma Mass Spectrometry (SALD ICP-MS). This technique provides the direct and fast analysis of liquid samples deposited onto polyethylene terephthalate (PET) plates (substrates) in the form of dried droplets with minimal sample preparation and submicrolitre sample volume requirements. Furthermore, SALD ICP-MS allows for the direct analysis of samples in organic solvents, which cannot be directly nebulised to ICP-MS. These benefits are, however, balanced out by the low degree of repeatability of the assay, which is typically about 30%. One of the approaches to increase the repeatability is a modification of the substrate surface by Diffuse Coplanar Surface Barrier Discharge (DCSBD) with the addition of an internal standard to the sample. Using this approach, a relative standard deviation (RSD) of less than 10% for model biological samples can be achieved. The only limitation of this technique is the occurrence of the so-called “aging effect”, i.e. the gradual return of the modified physicochemical surface properties to their original state

Study on Surface Treatments of Modified Wood Plastic Composite (WPC) to Improve Adhesion

The presented case study is focused on the complications that affect the adhesion properties of wood plastic composites. In an effort to improve the physical properties of the WPC and the adhesive bonding between the selected material and adhesive systems intended for façade bonding, several surface pretreatments were performed. The surface modification consisted of mechanical roughening or physical treatment with diffuse coplanar surface barrier discharge. The shear strength of the adhesive bond was tested following ČSN EN 1465 and the maximum shear stress was calculated for each treatment method. Although, the increase in bond strength due to these treatments was measured only for one tested adhesive system where the strength was increased by 100% with respect to the control, the diffuse plasma treatment improved the adhesive bondability and a change in failure mode was observed in all tested cases.