Observation of Geometry Induced Doping in Thin Si Nano-grating Layers

AbstractWe fabricate Si nano-grating layers and measure their electrical characteristics to monitor geometry induced doping. SOI device layer was thinned down by thermal oxidizing and subsequent wet etching of the oxide. Grating was fabricated using laser interference lithography (375nm laser) followed by reactive ion etching of Si. Next, large square island (0.5x0.5mm) was shaped in the device layer and four Si\Ti\Ag ohmic contacts were formed to measure electrical characteristics. The I-V characteristics were recorded using both 4 wire and 2 wire methods. Resistance-temperature dependences (T= 4-300K) were recorded as well. For all 12 samples, nano-grating layers show 2-3 order reduction of resistivity. Resistivity anisotropy was in the range 0.2-1 at 300K. Obtained geometry induced doping level corresponds to “effective impurity” concentration of 3x1018 cm-3. The dependence is in agreement with G-doping theory only below T=150K

Monthly average daily global and diffuse solar radiation based on sunshine duration and clearness index for Brasov, Romania

The main objective of this study is to develop single location appropriate models for the estimation of the monthly average daily global and diffuse horizontal solar radiation for Brasov, Romania. The study focuses particularly on models based on the sunshine duration and clearness index. The data used for the calibration of the models were collected during a period of 4 yr, between November 2008 and October 2012, at the Transilvania University of Brasov. The testing and validation of the models was carried out using data from the online SoDa database for Brasov for the year 2005. Different statistical error tests were applied to evaluate the accuracy of the models. The predicted values are also compared with values from three other known models concerning the global and diffuse solar radiation. A new mixed model was developed for the estimation of monthly average daily global horizontal solar radiation. The data processing was performed by means of a real-time interface developed with LabVIEW graphical programming language. The parameters taken into account were the relative sunshine, the clearness index, the extraterrestrial radiation, the latitude and the longitude. The methodology is simple and effective and may be applied for any region. Its effectiveness was proven through comparison with global models

The Remote Experiment in the Light of the Learning Theories

The interference of technology in education requires the development of new theories of learning. The paper analyzes connectivism as the most important representative of the theories related to the “digital age.” From the point of view of the environment, called a remote experiment, learning occurs initially at the individual level, encompassing all three classic theories of learning: behaviorism, cognitivism, and constructivism. It shows that the virtual environment has introduced a powerful lever of imbalance for the real environment. This is how we arrived at the explanation of learning theories in real-virtual environments through the theory of chaos or complex environments. Like any knowledge storage network with nodes between which connections can be made, even the remote experiment is subject to random laws. The addition of knowledge is not simply the sum of the effects produced by each individual node (the system is not linear). A distinction is made between information and knowledge. Even if the information in the nodes can be read, this aspect does not represent learning. The remote experiment not only expanded the realm of knowledge but also emphasized the critical role of time. The time remained constant, while the amount of information increased. The teacher, as a knowledge synthesizer, can help orient the student to this vast amount of information, especially when time is limited. Additionally, the student can also play an active role in organizing and systematizing the information. Two examples of experiments are given, which, being inter- and transdisciplinary, can contribute to the introduction of the elements of non-linearity and unpredictability as a method of designing the educational environment, precisely to be able to transform it into a thinking system suitable for the mixture between real and virtual environments in which we live more and more intensely

Self Growing Remote Controlled Laboratory

In the last few years, focused on the collaboration with a team from Carinthia Tech Institute Villach -Austria, we have tried to develop a remote controlled laboratory in the Electronic Engineering field at the â??Transilvani

Influence of Heat and Thermochemical Treatment Parameters on C75 Steel Fatigue Resistance

The paper presents the results of the fatigue testing of heat-treated and thermochemically treated C75 steel with different process parameters in terms of working medium (gas, salt bath), temperature, and time. The experimental program aims to analyze the changes in microstructure under the influence of heat treatment and fatigue resistance. The relationships between the structural changes, the internal stress, and the heat-treated material’s mechanical and physical properties can determine the first nano cracks leading to rupture propagation. Based on the experimental values of this paper, we highlight the dependence between the nature of the cracks and the stress to which the specimen was subjected. The paper presents a brief introduction to the fatigue test and the experimental tests performed to determine the fatigue resistance characteristics, the macroscopic analysis of the material, and the crystallographic analysis. The results obtained allow a comparison between the fatigue limits of heat-treated and thermochemically treated C75 steel in gas and salt baths

FPGA LabVIEW Programming, Monitoring and Remote Control

NI ELVIS is an educational design and prototyping platform from National Instruments Corp. based on NI LabVIEW graphical system design software. The platform is used for teaching concepts in areas such as instrumentation, circuits, control, communication, and embedded design in a hands-on, interactive manner. NI ELVIS contains an integrated suite of the 12 most commonly used instruments â?? DMM, oscilloscope, function generator, MIO, Counter etc - in a compact, rugged, laboratory-friendly form factor. A new instrument, the Digital Electronics FPGA Board has been added to the NI-ELVIS platform in order to help educators teach concepts of FPGA programming. This paper presents an example of graphical FPGA programming and monitoring using the Digital Electronics FPGA Board and LabVIEW FPGA graphical programming.