Engineering of III-nitride semiconductors on low temperature Co-fired ceramics

This work presents results in the field of advanced substrate solutions in order to achieve high crystalline quality group-III nitrides based heterostructures for high frequency and power devices or for sensor applications. With that objective, Low Temperature Co-fired Ceramics has been used, as a non-crystalline substrate. Structures like these have never been developed before, and for economic reasons will represent a groundbreaking material in these fields of Electronic. In this sense, the report presents the characterization through various techniques of three series of specimens where GaN was deposited on this ceramic composite, using different buffer layers, and a singular metal-organic chemical vapor deposition related technique for low temperature deposition. Other single crystalline ceramic-based templates were also utilized as substrate materials, for comparison purposes

Spray deposition of organic electroluminescent coatings for application in flexible light emitting devices

Organic electroluminescent (EL) films of tris(8-hydroxyquinolinato)aluminum (Alq3) mixed with polystyrene (PS) binder were produced by spray deposition. The influence of the substrate temperature on the layer’s morphology and uniformity was investigated. The deposition conditions were optimized and simple flexible light-emitting devices consisting of indium-tin oxide/Alq3:PS/aluminum were fabricated on polyethylene terephthalate (PET) foil to demonstrate the advantages of the sprayed organic coatings. Same structure was produced by thermal evaporation of Alq3 film as a reference. The influence of the deposition method on the film roughness and contact resistance at the electrode interfaces for both types of structures was estimated. The results were related to the devices’ efficiency. It was found that the samples with sprayed films turn on at 4 V, which is 2 V lower in comparison to the device with thermal evaporated Alq3. The current through the sprayed device is six times higher as well (17 mA vs. 2.8 mA at 6.5 V), which can be ascribed to the lower contact resistance at the EL film/electrode interfaces. This is due to the lower surface roughness of the pulverized layers

Heterogeneous IoT Platform for Device Management and Environmental Sensor Data Gathering

In this paper, we propose a new IoT platform which supports the use of different wired and radio connections to manage devices and gather environmental sensor data. We discuss the pilot implementation of our new platform which deals with the smart control of air-conditioning devices in shopping malls. The building blocks of the platform – two types of electronic controllers of our own design – are described in detail. The Internet connectivity of the platform enables the use of an Internetbased control center for storing historical data, performing statistical analyses, making automated corrections in the device control and providing possibilities for remote control by human operators. The end goal of the platform development is to achieve cost savings and increase the level of comfort of customers and employees. ACM Computing Classification System (1998): B.4.0, C.2.0

Conceptual Modeling of IoT Ecosystems: A Business-Oriented Approach

In this paper, a new approach to the conceptual modeling of IoT ecosystems is presented. Taking into consideration the business processes of an organization, this approach allows the creation of models which integrate IoT-devices and IoT-governed activities into the business flow of the company. The main purpose of this research is to help organizations make faster and more efficient choices based on formalized input/output from their IoT-resources and networks. The use of modeling and formal description is necessary in order to include IoT in ERPsystems, so that IoT is considered in the overall strategic planning and decision making on all levels. ACM Computing Classification System (1998): C.2.0, K.6.0

Spray deposition of organic electroluminescent coatings for application in flexible light emitting devices ABOUT THE AUTHORS

Abstract: Organic electroluminescent (EL) films of tris(8-hydroxyquinolinato)aluminum (Alq3) mixed with polystyrene (PS) binder were produced by spray deposition. The influence of the substrate temperature on the layer's morphology and uniformity was investigated. The deposition conditions were optimized and simple flexible light-emitting devices consisting of indium-tin oxide/Alq3:PS/aluminum were fabricated on polyethylene terephthalate (PET) foil to demonstrate the advantages of the sprayed organic coatings. Same structure was produced by thermal evaporation of Alq3 film as a reference. The influence of the deposition method on the film roughness and contact resistance at the electrode interfaces for both types of structures was estimated. The results were related to the devices' efficiency. It was found that the samples with sprayed films turn on at 4 V, which is 2 V lower in comparison to the device with thermal evaporated Alq3. The current through the sprayed device is six times higher as well (17 mA vs. 2.8 mA at 6.5 V), which can be ascribed to the lower contact resistance at the EL film/electrode interfaces. This is due to the lower surface roughness of the pulverized layers

Experimental studies of the structure of biological tissues through mechanical effects with a smart laparoscopic instrument

The article presents investigations in the area of the analysis of heterogeneous biological tissues using tools based on mechanical stimulations. Some known tissue mechanical models are presented along with one approach for specifying the tissue internal structure by measuring mechanical macro parameters of the research tools. The methodology of micro and macro stimulation is described and the construction of an experimental model of a smart laparoscopic tool for its realization is presented