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Sentjernej, Slovenia

Pohar A.,Slovenian National Institute of Chemistry | Belavic D.,Hipot Rr | Dolanc G.,Jozef Stefan Institute | Hocevar S.,Slovenian National Institute of Chemistry
Journal of Power Sources | Year: 2014

Methanol decomposition on Pt/CeO2/ZrO2 catalyst is studied inside a packed bed microreactor in the temperature range of 300-380 C. The microreactor is fabricated using low-temperature co-fired ceramic (LTCC) technology, which is well suited for the production of relatively complex three-dimensional structures. It is packed with 2 wt% Pt-CeO2 catalyst, which is deposited onto ZrO2 spherical particles. A 1D mathematical model, which incorporates diffusion, convection and mass transfer through the boundary layer to the catalyst particles, as well as a 3D computational fluid dynamics model, are developed to describe the methanol decomposition process inside the packed bed. The microreactor exhibits reliable operation and no catalyst deactivation was observed during three months of experimentation. A comparison between the 1D mathematical model and the 3D model, considering the full 3D geometry of the microreactor is made and the differences between the models are identified and evaluated. © 2014 Elsevier B.V. All rights reserved. Source

Zarnik M.S.,HYB D.o.o. | Belavic D.,Hipot Rr | Novak F.,Jozef Stefan Institute
Sensors (Switzerland) | Year: 2015

An exploratory study of the impact of housing on the characteristics of a low-temperature co-fired ceramic (LTCC) pressure sensor is presented. The ceramic sensor structure is sealed in a plastic housing. This may have non-negligible effect on the final characteristics and should be considered in the early design phase. The manufacturability issue mainly concerning the selection of available housing and the most appropriate materials was considered with respect to different requirements for low and high pressure ranges of operation. Numerical predictions showed the trends and helped reveal the critical design parameters. Proper selection of the adhesive material remains an essential issue. Curing of the epoxy adhesive may introduce non-negligible residual stresses, which considerably influence the sensor’s characteristics. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Source

Marghescu C.,Polytechnic University of Bucharest | Ionescu C.,Polytechnic University of Bucharest | Svasta P.,Polytechnic University of Bucharest | Zarnik M.S.,Hipot Rr | Belavic D.,Hipot Rr
ISSE 2010 - 33rd International Spring Seminar on Electronics Technology: Polymer Electronics and Nanotechnologies: Towards System Integration - Conference Proceedings | Year: 2010

Although the pressure sensor market is dominated by silicon based sensors, in recent years ceramic based sensors have proved interesting and have been increasingly researched due to their material properties which qualify them for use in harsh environments. This paper describes the use of finite element analysis (FEA) to determine the functioning of a diaphragm-type ceramic capacitive pressure sensor starting from mechanical pressure and obtaining the output signal in form of an electrical capacitance. The capability of the software (Ansys/Multiphysics) to realize multi-field analysis will be used here in a very intensive way. Of major concern is the possibility to anticipate the influence of different liquid media on this category of pressure sensors developed using LTCC (Low Temperature Co-fired Ceramic). © 2010 IEEE. Source

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: NMP.2011.1.2-3 | Award Amount: 4.85M | Year: 2012

The main objective of the CERAMPOL project is to achieve a new generation of smart and low-fouling nanostructured membranes based on ceramic and polymeric materials with enhanced affinity to heavy metals and drugs. CERAMPOL will contribute in solving issues related to waste water in metallurgic and pharmaceutical industries/hospital respectively. Moreover, by reducing the concentration of highly toxic contaminants in the water supplies, lakes, rivers, and streams, the new filtration technology developed in the CERAMPOL project will mitigate the risk to humans health and the environment such as bioaccumulation of heavy metals, the emergence of multidrug resistance organisms, chronic toxicity, and metal-related diseases. The new filters will be prepared by innovative processes such as electrospinning, sol-gel, coating processes for obtaining multi-layered membranes possessing several key properties such as: antifouling; self-cleaning; selective filtration of antibiotics and heavy metals. Specifically, the multi-layered membranes will composed of three functional parts CERAMPOL functional parts: an anti-fouling pre-filter based on polymeric nanofibers, a cleaning system based on piezoelectric materials, and a highly selective nanostructured ceramic membrane. The new filters will be scaled up at semi industrial level for in-situ water treatments in foundry, pharmaceutical and hospital effluents. The benefits of such technology will be fully characterized in terms of water filtration efficiency and economic and environmental impacts. Complete technological and economical viability assessments of the CERAMPOL technology will be carried out by the industrial partners. Environmental impact caused by the new filtration technology will be fully assessed in order to highlight benefits in terms of water preservation and recovering.

Zarnik M.S.,HYB D.o.o. | Zarnik M.S.,Hipot Rr | Zarnik M.S.,Jozef Stefan Institute | Belavic D.,Hipot Rr | Belavic D.,Jozef Stefan Institute
Sensors and Actuators, A: Physical | Year: 2014

Glass-containing ceramics can be susceptible to stress corrosion in the presence of humidity. Furthermore, static loading in such conditions may adversely affect their flexural strength. Such degradation can critically affect the reliability of functional ceramic systems operating under mechanical loads. This experimental study examines the operation of pressure sensors made from low temperature cofired ceramics (LTCC). The sensors were subjected to a cyclic pressure loading in deionized water. The effect of this accelerated ageing was evaluated by comparing the changes in the offset voltage and the burst pressure to the characteristics of the sensors aged/loaded under normal ambient conditions. The results showed a satisfactory long-term stability of the sensors after one million full-scale (FS) pressure cycles as well as the sensors subjected to 10,000 overload pressure cycles (5× FS). As expected, the presence of water slightly reduces the burst pressure, but does not critically degrade the performance of the sensors or their reliability. © 2014 Elsevier B.V. All rights reserved. Source

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